Bacterial Disease True or False

There are four potential outcomes from encounter with microorganisms. The microorganism may: 1. pass through the body as a harmful transient 2. colonize the body and become part of the normal flora 3. establish a viral infection in the body 4. establish an infection in the body and cause disease

1 False harmless transient 2 True 3 False not always viral 4 True

High levels of antibodies produced against components of the microbiota (sometimes called natural antibodies) can cross react with certain related pathogens, and thereby prevent infection or invasion.

Everything true except LOW levels of natural antibodies

Total cost of treatment for anitbiotic resitant tuberculosis is 1200

FALSE $400,000 for AB reistatnt tuberculosis and 1200 for AB susceptible Tuberculosis

THE LRT has antimicrobial proteins (defensins, LL-37) and peptides (lactoferring, lysozyme)

FALSE (peptides =defensins and ll37, proteins = lectoferring, lysozyme)

a recent study in US suggested that over 2 million pateitns will become infected with an Antibiotic reistant tstrain while hospitalized, and 5 thousand will die beaues they could not be treated with AB

FALSE 90,000 will die not just 5000

The phosorpyralayted regulator pretein then accts o DNA to allow transcpriotn of a specific set of genese

FALSE ALLOW OR PREVENT.

many virulent bacteria have 'local' gregulatory ssystems to regulate virulence factor (i.e., regulatory systems that control the production of multiple diferent virulence factors at once)

FALSE GLOBAL regulatory systems

some gram+ are naturall riessitant to some types of AB due to a combination of poor permeability across teh outer membrane combined with secondary mechanisms such as efflux and antibiotic inactivating enzymes taht takes advantage of the slow uptake of antibotics into the bacterial cell

FALSE GRAM-

unpeeled fruit

FALSE PEELED

envionrmental factors include temperature, nutrients, oxygen, pH outside cell, iron availability, and osmolarity

FALSE PH INSIDE CELL

Tears, and mucus, and saliva, but not blood and lymph all contain antimicrobial substances

FALSE all contain

these antibiotics cannot be used in pateitns becaues the eukaryotic mitochondira are inhibited at the concentrations used in therapy

FALSE are not inhibited @ the therapy concentrations

A 'far-reaching' antibiotic is one that acts on both gram+ and gram- and is more frequently used in medicine.

FALSE broad-spectrum

exposure to antibiotics causes bacteria to become drug resistant

FALSE does not cause drug resitance

Euk ribosome subunit are 50s and 30s while prokaryotic are 60s and 40s

FALSE euk are 60 and 40 while pro are 50 and 30.

Planktonic refers to the single bacterial cells that are growing in liquid (standard labaratory) or to single bacterial cells swimming freely below a biofilm

FALSE freely ABOVE a biofilm

Optimal attributes of chemotherapeutic agent; affectiveness against bacteria at a high concentration,

FALSE low; i.e., low minimal inhibitory concentration

MRSA has now become the most common multiple drug reistant pathogen in hospitals. many MRSA are treatable with many readily available antibiotics

FALSE many MRSA are untreatable

Antibiotic resistance is inheretied ability of microorganisms to resist the effects of an antibiotic to which it is normalyl senstitive

FALSE not inherited but acquired.

Anti Biofilm therapy includes interfering with EPS syntehsis, inhibiting adherence of bifilms to their surface substrate, and targetting persister cells

FALSE not persister cells but targeting autoinducers. If bacteria cant signal to each other, they wont beable to form or maintain a biofilm.

Biofiolm propoerties thought to contribute to antimicrobiral resistance include nutirent and O2 availability as well as the planktonic bacteria that cover the surface of the biofilm

FALSE not the planktonic bacteria but the EPS matrix.

The mucroups sweeps up bacteria and out of the URT while cilia traps the bacteria

FALSE other way around

the pathogenic organism should be isolated from the infectd animal(s) and cultivate in mixed culture

FALSE pure culture

Biofilms are significantly lessresistant to antibiotics and antimicrobiral stressors, including those mounted by natural host responses compared to planktonic bacteria of the same species

FALSE significantly MORE resistant

the GI tract contains the minority of the microbiota

FALSE te majority

Optimal attributes of chemotherapeutic agent; a narrow spectrum of activity., i.e., activity against a narrow range of bateria

FALSE want broad spectrum of activity

In order for the AB to be succesful in elimianting the infection, the bacterial must not be growign and must not be metabolizing

FALSE, must be metabolizinga nd growing

the first is that certai bacterial pathogens cannot be ultivated in vivo

FALSSE cannot be cultivated in vitro

Bacteria deep and closer to surface of biofilm have same physiology

Fale: different due to O2 and nutrient availability

There are microbiota in lymph nodes

False

There are microbiota in the bones

False

There are microbiota in the lower respiratory system

False

Steroid metabolism example is acetic acid and butyric acid

False -> example of organic acid production

The major antimicrobial component of the body fluids is complement. C proteins constitute 5% of the total preotein content of the serum

False 10%

10e12 bacteria in mouth

False 10e10

The average human adult has 3 m^2 of skin surface

False 2m^2

Human intestinal microbiota are responsible for the production of approximately 500-600ml gas per day

False 300-400

These organisms generally lower the pH to around 5-6, which is optimal for lactobacilli but inhibitory for growth of many other bacteria

False 4-5

Within a week, Bifidobacteria account for 50% of the total intestinal bacteria of breast-fed infants

False 90%

Biofilm formation: Dethachment -> Growth -> Attachment

False Attachment -> Growth -. Detach

Germ free offsprin are delivered by vaginal pushing

False C section

The microbiota is obtained from the environment immediately after birth as a result of exposure to pets and animals only

False Humans and pets and other animals

The healthy human body is home to trillions of microorganisms known as Microbiota or Abnormal Flora

False Microbiota or normal Flora

Gas production includes NO3, CO2, CH4, H2

False NO3

An example of an effective antibiotic is one that targets a metabolic process found in the host cell

False NOT found in host cell

public authorities wer able to find S. typhimurium in typhoid mary

False S. typhi

Penicillin is often referred to as the antiobiotic of last resort

False Vancomycin not penicillin

pathogenicity is the ability of an organism to infect a host and is a qualitative concept

False ability to cause disease

Gnotobiotic animals have reduced susceptibility to certain dieases processes which are dependent on the activity of microbes like cavities, and they have normal anatomical and physiologiacl features

False abnormal anamotical and physiological features

Dental plaque formation is initiated by the deposit of a thin organic film of basic glycoproteins from the saliva

False acidic glycoproteins from the saliva.

Bacteria occupy the luman, overlie the epithelial cells, and adhere to the mucosa of the stomach

False adhere to mucosa of intestines

Lactobacillus is a facultative anaerobe

False aeotolerante anaerobe

The microbiota inhibits colonization by pathogens by occupying adherence sites, utilizing nutrients, producing inhibitory by-products, and affects pH and available nitrogen levels

False affects pH and available OXYGEN

THe GI tract consists of stomach, and small intestine

False also large intestine

The large intestine can be viewed as an aerobic bacterial fermentation chamber

False anaerobic

Antioxidants are chemical agents that are applied to living tissues to kill or inhibit growth of microorganisms

False antiseptics

Eukaryotic fungi and some methanogenic Archaea (that colonize the upper intestinal tract) are componants of the microbiota

False archaea that colonize the lower intestinal tract

Bacteria is plural while bacteriae is singular

False bacterium singular

Bacteria in a biofilm behave individually; they sense and respond to stimuli in an uncoordinated manner

False behave as a group -> responde to stimuli in coordinated manner

Biofilms are a single conglomerate of one type of microorganism.

False biofilms are a mixture of microorganisms but one member may predominate the biofilm (e.g., competitive exclusion)

They can iinterefere with Protein syntehsis by binding to the golgi body and inhibiting its function

False by binding to ribosome and inhibiting function.

A pathogen is a bacterium that is capable of harming a compromised host

False capable of harming a normal host

The character of the microbiota stays the same along the length of GI tract

False changes along length

In other cases, symbiosis is beneficial only to the microorganisms, this relationship is called mutualism

False commensalism

They can destabilize the ribosomes

False destabalie cell membrane

Antibiotics were made similar to sulfa drugs

False differenteiated from synthetic compounds because they were the natural produces derived from microbial activity

Either tpe of detachment allows bacteria to attach to a surface or to a biofilm upstream of the original community

False downstream

A local infection is one that begins in a restricted area and then spreads throughout the body

False focal infection

The microorganisms in plaque produce adherent substances (glucose) that encourage further colonization

False glucans

salts stimulates uptake of water and glucose by the mucosal cells

False glucose stimulates uptake of water and salts by the mucosalcells

Gram negative bacteria is more sensitive to antibiotics than gram positive

False gram+ more sens to AB than gram-

bacteria may have acquired the above resistance by vertical gene transfer

False horizontal gene transfrer -> conjgation, ransduction, tranformation) from other microoganism of their own species or different species

Bacteria in the respiratory and circulatory tract are involved in synthesis and excretion of vitamins in excess which can be absorbed by the host

False in the gastrointestinal tract

Prior to the eruption of teeth in the child, the bacterial populations of the microbiota include aerobes as well as a few aerotolerant anaerobes.

False include aerotolerant anaerobes and a few aerobes

Sulfonamides and tripmethoprim interefere with acetic acid metabolism

False interefere with folic acid metabolism

Antibiotic resitance is cheap

False it is costly.

The eps is a dry, film like substance produced by the bacteria of the Biofilm

False it is slimy

The upper region of the hair follicles (just above the epidermis) provides an ideal habitat for microorganisms

False just below the epidermis

Diet: an infant's diet of milk encourages the etablishment of lactose as part of the microbiota

False lactose not a bacterium but lactic acid bacteria is.

Skin bacteria must be able to withstand low moisture and high salt and high pH (from sweat)

False low pH from sweat.

High rate of breakdown or extretion in the body

False low rate

Lactoperoxidase weakens bacteria cell walls by cleaving glycosiic linkages in peptidoglycan

False lysozyme

Few bacteria possess non specific efflux pumps that transport antibiotics out of the organism before the drug can be effective

False many bacteria

Bacteria with low virulence may cause disease in a normal host

False may cause disease in a compromised host

The association between the host and the microbiota is dynamic and mostly a parasitic relationship

False mostly a mutualistic relationship

For an antibiotic to be useful in medicine, it must be able to inhibit bacteria but also affect host cells

False must not effect host cells

In some cases, the body and microbiota both benefit from symbiosis, a type of relationship called commensalism

False mutualism

A broad specturm antibiotic is useful if a narrow spectrum fails to resolve an infection or for special organisms like tuberculosis

False narrow spectrum useful for broad spectrum.

Erythromycin, tetracyclinds, and new oxazolodinones (bactericidal drugs) all interfere with protein sysntehsis by binging to the ribosome

False new oxazolodinones are bacteriostatic not bacctericidal

Vitamin synthesis includes Thiamine, Vitamin A, Riboflavin, Pyridoxine, B12, K

False no Vitamin A

The supporting structures of the teeth are gingiva, cementum, calculus, periodontal membrane, and alveolar ridge

False no calculus and alveolar bone not ridge

Sinuses are always heavily colonized as well

False normally sterile

Saliva itself is a good culture medium because it contains nutrients and substances like lysozyme and lactoperoxidase

False not a good culture medium because it containts few nutrients and antibacterial substances like lys and lac

A secondary infection is a later (or second) infection caused by a pathogen after a primary infection has weakened the host defences

False not a pathogen but opportunistic pathogen

Infection refers to the invasion or colonization of the body by pathogenic (disease causing) microorganisms, and this always results in damage to the body

False not always causes damage or injury to body.

Cell mediated immunity is induced and is completely effective in clearing bacteria

False not completely effective.

There are microbiota in the penis and vagina

False not in penis

Virulence is the measure of the pathogenicity of a virus, and it is a quantitative concept.

False not just a virus, but a microorganism.

The microbiota is obtained from the environment immediately after birth as a result of inhilation of air-borne viruses

False not just viruses but microorganisms

Oral antibiotic therapy: this may result in a decrease in the microbiota of the GI tract leaving the way open for normal pathogens to colonize.

False not normal pathogen but opportunistic bacteria.

Although benign environmental Biofilm do not generally cause human disease, they are responsble for significant industrial problems such as pollution

False not pollution but corrosion of technologies

Microbiota have pathogenic potential if introduced to other locations in the body. For example: E coli, which is normally in the respiratory tract, my cause urinary tract infections when introduced into the urinary tract

False not respiratory tract but gastrointestinal tract

Colonized with staphylococcus epidermidis and potential pathogen staphylococcus tuberculosis

False not t but aureus.

Some members of the microbiota are able to construct bacterial walls on a surface of a tissue (or implants such as catheters)

False not walls but biofilms

Genetics of host defence systems can affect susceptibility. Some individuals are more resistant or susceptible to infections than others and the molecular differences are fully understood

False not yet understood

Biofilms are disorganized communities of bacteria that are adhered to a surface

False organized

Gnotobiotic literally means germ free but typically means known life

False other way around

Bacteria can grow on tooth surfaces in thick layers called tooth biofilm

False plaque

Gnotobiotic animals have normally developed immune systems

False poorly developed

Quorum sensing uses signaling molecules called autoinducers which are produced by the host

False produced by bacteria

At birth, the oral cavity is sterile but slowly becomes colonized over many weeks of feeding

False rapidly becomes colonized during first feeding.

As the teeth appear, there is a shift towards aerobes that are adapted for growth on the tooth surface and in gingival crevices

False shift towards anaerobes

Lactoperoxidase kills bacteria in a reaction that generates double oxygen

False singlet oxygen

All organisms establish permanent residence within the host

False some are more transient and are present for limited periods of times (days, weeks, months).

At birth the intestinal tract is not sterile because of microbiota from placenta

False sterile

Bacteroides is an aerotolerant anaerobe

False strict anaerobe

The cohabitation of the body and the microbiota is an example of predation

False symbiosis

These organisms normall colonize on one specific tooth

False the contact points between the teeth.

the innermost components of the microorganism

False the outermost: e.g., capsules, outer membrane proteins

microbiota will colonzie areas that do not have secretions of mucous membranes

False they WILL colonize areas that have the secretions

Infection refers to the damage or injury to the body that impairs function

False this is disease

Low virulence = more cells to kill a high percentage of mice

False this is moderate virulence.

toxins

False toxoids (detoxified toxins)

Most disinfectants are able to be used inside the body

False unable because too toxic

A local infection is restricted to a relatively small area of the body. These infections are usually caused by invasive organisms

False usually caused by non-invasive organisms

The skin varies in chemical composition and moisture content but the density and comp. of micriobiota on skin remains the same

False varies with anatomical locale

Virulence of microorganisms is directly attributable to bacterial factors which allow it to enter and colonize host, resist immune defences, and cause damage in host

False virulence factors not bacterial factors

Vancomycin is a glycopeptide that acts by interfering with the synthesis of ribosomes

False with the synthesis of cell wall.

Biofilm communities can develop within seconds

False within hours

Helicobacter pylori is the causative agent of increased bile excretion

False, agent of gastric ulcers and infects over half the world population

all antibiotics have these above optimal attribtues

False, antibiotics tend to be safe effective drugs though

Therapy used in the treatment of certain cancers or maintenance of transplanted organs strengthen immune defences against infection (immunosuppressive therapy)

False, compromise immune defences

Disinfectants are used on live objects to kill microorganisms

False, inanimate objects

The physical association between the microbiota and the host mostlylike involve biochemical interactions between host and bacteria nuclei

False, interactions between bacterial surface components

After antibiotic therapy is completed, micriobiota cannot establish itself alone

False, microbiota can eventually re-establish itself.

the iluem contains no micriobiota

False, moderately mixed microbiota 10e6 to 10e8 per gram of contents

The total numbers of microorganims on the skin is high relative to the digestive tract

False, more in digestive tract.

Young children tend to have less varied microbiota

False, more varied

A highly virulent organism causes disease in a selected population with whom it comes in contact

False, most individuals with whom it comes in contact

Bacteria are the least common and least obvious microbial components of the microbiota.

False, most numerous and most obvious

This is called ciliary beating action

False, mucocilary action

surface tissues such as muscle and mucous membranes are constantly in contact with microorganisms present in the environment

False, not muscles but skin

An avirulent always causes disease in human beings

False, rarely, if ever

case fatality ratio (percentage of infected individuals taht die) has changed because of vaccines to diptheria

False, remain constant. the incidence nad mortality rates have declined but nor fatality ratio.

Bacterial colonizers are acquired quickly. For example Mouth cultures are positive 10-20 hours after birth Fecal cultures are positive 6 hours after birth

False, reverse the hours for both. 6 for mouth and 10-20 for fecal

The second stage of biofilm formation involves the growth and production of EPS which results in reversible attachment

False, stronger and thus often irreversible attachment.

A nosocomial infection is one in which the host has no apparent systems

False, subclinical infection

The lower respiratoyr tract includes trachea, bronchi, and throat

False, trachea, bronchi, and pulmonary tissues

The majority of microorganisms that come into contact with skin are able to multiply and thrive.

False, transient: unable to multiply and die b/c of skin's low moisture or low pH due to organic acid content.

In general, one type of bacteria species can colonize many anatomical sites in all people and are referred to as the microbiota

False, you can find the same species of bacteria in the same anatomical site

There are three factors that affect the composition of the microbiota: diet, infection, and temperature

False: Diet, Infection, and Oral Antibiotic therapy.

Within a single spcies, microbiota in specific body sites are the same across all individuals

False: additional variation of the microbiota that is related to age, sex, diet, and nutrition.

All locations of the host are hospitable for the colonization for bacteria

False: stomach acids, bile salts, and lysozyme.

salmonella c=posses 3 major antigens: H or flagellar antigen; O or somatic antigen, and C or capsular antigen

K not C for capsulr antigen

as the concentration of NaCL increases in the lumen of the intestine, water is lsot from tissues into lumen, resulting in diarrhea

OH okay cool

Evasion of the host defeces

OKAY

Topic 2. Virulence mechanisms of Pathogenic Bacteria

Ok

The____ protein is neccessary for proper assembly and maturation of the pili

PIL C

AB resistance in bacterial ifnections was first observed shorly after the first antibiotic was introduced into clinical use in the 1940s

TRUE

Bacteria may be naturally reistant to an antibiotic because thye lack the structures that the AB inhibit

TRUE

Bacteria stick together because EPS hold them all together

TRUE

Changes in the bacterium that enable it to reist the Ab occur naturally as a result of mutation or genetic recombination

TRUE

EPS matrix: this complex latyer that enmeshes the biofilm can significantly impede the penetration of antimicrobial agents to bacteria buried in the depths of the biofilm

TRUE

Oral biofilms are the primary causative agents of dental caries and gingivitis

TRUE

Smoking, alcohol, and old age affect the functioning of the ciliated epithelium and may increase susceptibility to infections

TRUE

The LR tract is free of microorganisms

TRUE

The URT which includes nose throat and ears is exposed to >10e4 baceteria a day, 7 bacteria a minute

TRUE

The gaseous by-roducts include: CO2, H2, NH3, and H2S. Maethanogens convert the H2 and CO2 produced by other intestinal microorganism to methane (CH4).

TRUE

The mucociliary system includes mucous secreting cells an dciliated cells

TRUE

antibiotics are most effective against metabolically ACTIVE cells tus bacteria in the interior are procted from this type of killing

TRUE

eating only foods that have been thoroughly cooked, still hot

TRUE

thus, the next time that antibotic is used, it will kill the snsitive bacteria (even the bacteria that are beneficial), leaving the resistant bacteria to thrive because thehy face reduced compitition from susceptible organisms

TRUE

Lactoperoxidase generates inglet oxygen to kkill bacteria

Treu

The persistaltic movements of the intestinal contents tends to expel potential pathogens before they can colonize

Tru

10e12 bacteria on skin

True

10e14 bacteria in gastrointestinal tract and 10e13 turnover per day

True

A change in diet can change a person's microbiota.

True

A harmful or unwanted aspect of host microbiota include the production of intestinal gas: Bacteria in the large intestive ferment food ingeted by the host, giving rise to gaseous by products.

True

A large numebr of bacterial spcies colonize the upper respiratory tract (nasopharynx)

True

A normal host means an individual whose defense mechanism are not compromised in any substantial way

True

A primary infection is an initial, acute infection

True

A recent (2004) estimate from the US centers for disease control and prevention estimated that biofilms account for two thirds of bacterial infections that physicians encounter

True

A systemic or generalized infection is one which is spread throughout the body, they are caused by invasive organisms

True

A variety of bacterial species enter the infant but only those bacteria that are capable of colonizing a particular microenvironment will remain

True

ANtimicrobial peptides include beta defensins and LL-37

True

Aminoglycosides like gentamicin (bacteriocidal drugs) interfere with protein synthesis but their mechanism of action is more xomplex

True

An effective antibiotic can target a bacterial protein that is sufficiently different from the homologous protein in the host cell

True

An example of an opportunistic pathogen is Pseudomonas aeruginosa: it causes few infections in healthy individuals, but more than 200,000 infections per year in hospitalized individuals in the states

True

An opportunistic pathogen is a bacterium that harms a compromised host, i.e., a host whose immune system is weakened

True

Antiseptics are used for washing hands or treating surface wounds

True

Any oxygen that may be present is quickly consumed by facultative anaerobes

True

Areas of the body that are not in direct contact with the environment should remain sterile

True

As the child grows, the mouth presents a succession of different ecological situations (e.g., reuption of teeth, formation of supporting structures of teeth - gingival crevice area) and this corresponds with changes in microbiota

True

B-lactams consist of the naturalyl dervied penicillin-like and cephalosporin antibiotics and their many semi-synthetic derivatives.

True

Bacteria benefit by obtaining from the host a supply of nutrients, a stable environment, and a mode of transport

True

Bacteria enter intestinal tract with first feeding

True

Bacteria enter the upper resp tract in air during breathing but are trappedi n the nasal passages and expelled with nasal secretions

True

Bacteria in gastrointestinal tract can produce and excrete vitamin K, and vitamin B12

True

Bacteria in gastrointestinal tract can stimulate the immune system

True

Bacteria survive and multiply inside the macrophage cells, resulting in further spread throughout the lung

True

Benign biofilms can attract, recruit, and concentrate pathogenic bacteria that might not form a biofilm on their own.

True

Benign environmental biofilm example: slippery coating on rockss in streams, coatings on ship hulls.

True

Biofilm is often composed of a single bacterial species

True

Biofilms are surrounded by a matrix oc extracellular polymeric substances (EPS)

True

Biofilms can propagatee through detachment of small or large clumps of cells or by a type of seeding dispersal that releases individual cells

True

Both innate and adaptive immune response contribute to the resistance or susceptibility of the host

True

Cavities are the destruction of the enaml, dentin, or cementum of teeth acused by acid producing bacteria in plaque.

True

Certain species bacteria are located at particular places because at colonization sites, bacteria attach to the host receptors using specific bacterial ligands

True

Certain species of bacteria appear to exhibit a tissue preference for colonization

True

Chemotherapeutic agents can interfere with DNA gyrase activity (DNA unwinding during replication of the chromosome) e.g., nalidixic acid, ciprofloxacin

True

Chemotherapuetic agentss are used to control infectious diseased and can be used internally

True

Cilia sweeps bacteria from lower resp tract upward toward upper resp tract where they are removed by coughing sneezing and swallowing

True

Dental caries and periodontal diseases are very common infectious diseases in the world.

True

Dental caries are also called cavities

True

Developmental changes in humans such as weaning, teeth eruption, and onset/cessation of ovarian functions always affect the composition of the micriobiota in the intestinal, oral, and vaginal areas respectively

True

Dust particles which may carry microorganisms, are fairly large and are trappe in the upper resp tract.

True

E coli is a facultative anaerobe

True

Examples of affected medical devices include: Urinary catheters heart valve implants, Hemodialysis equipment, Dental Implants

True

For birds,, the exterior surface of the egg is sterilized.

True

Gingivitis is an inflammatory condition of the gums

True

Gnotobiotic animald and birds have low antibody, thin itnestinal walls, higher susceptibility to pathogen

True

Helicobacter pylori is a very common infectious diseaseas and the acuse of gastritis, gastric ulcers, most duodenal ulcers and gastric cancers: it causes an inflammatory disease that results in erosion of the stomach lining

True

High virulence = less cells to kill a high percentage of mice

True

Human bodies are exposed to microorganisms in their environment through inhilation, ingestion, or physical introduction

True

If the respiratory tract epithelium becomes damaged, as in bronchities or viral pneumonia, the indviidua lmay become susceptible to infection by pathogens descending from upper resp tract (nasopharynx)

True

In normal hosts, duodenal microbiota is spares (0 to 10e3/gram of contents)

True

In up to 50% of cases, the recommended doses or duration of treatment are incorrect

True

Infection : this results in a emporary increase in pathogen numbers and affects the composition of the microbiota

True

Initial colonizing bacteria will vary with food source of infant

True

Invasiveness is the ability of the organism to invade beyond the original site of entry into the host's body.

True

Lactic acid abcteria produce lactic acid from the fermentation of sugars and other carbohydrates in the diet of the host

True

Lactobacillus sp. predominates in the vagina

True

Loss of protective effect by antibiotic therapy can lead to infection by Candida (yest infection)

True

Low frequency of resistance development

True

Low toxcitity

True

Lysozyme is an anti microbial enzyme

True

Majority of the microbiota in the human body resides in the GI tract

True

Many ppl fail to complete their prescriptions once they start feeling better

True

Methicillin is a semi-synthetic penicillin derivative

True

Most of these microbiota are derived from the mouth and pass through the gut with each meal.

True

Most skin microorganisms are associated directly or indirectly with sweat glands

True

Non allergenic

True

Once the binding of autoinducer molecules has exceeded a certain threshold, a signaling cascade is initiated that modulates gene expressions and in turn modulates bacterial phsyiology to encourage community development

True

One implication of this is bioterrorism:

True

One possible explanation for tissue preference for colonization is that host provides essential growth factor needed by bacterium.

True

Only a few acid tolerant bacteria can be cultured from the stomach like Helicobacter pylori

True

Pathogenic biofilms on implanted medical devices: A variety of bacteria both gram negative and d gram positive, form biofilms on many foreign devices implanted into human bodies: theyse account for significant human infection and disease

True

Pathogenicity represents a genetic component of the pathogen

True

Periodontal diseases are bacterial infections that affect the supporting structures of the teeth

True

Persister cells are those small percentage of population that remians viable despite prolonged exposure to antimicrobial or increased dosage

True

Personal hygiene and diet affect micriobiota on skin

True

Planktonic bacteria can be recreuited to a biofilm or may have sloughed off an exiting biofilm

True

Plaque is a type of complex biofilm

True

Prior to birth, humans are free of microorganisms

True

Resident microbiota on skin outcompete other microorganisms that are able to multiply on the skin

True

Side effects are inherent in all drugs

True

Since the urinary tract is flushed with urine every few hours, microbiota have problems gaining access and becoming established

True

Some Biofilms have been found to contain hundreds of different species of bacteria living together

True

Some bacteria are found regularly at particular body sites, others are present only occasionally, or at certain times during life

True

Some bacteria have an intrinsic (natural) or acquied resistance to antibiotic

True

Some biofilm stuctures include a network of pores that provides a primitive circulatory system

True

Some examples of anaerobic microbiota include E coli and Lactobacillus

True

Sometimes an indvidua ltaking AB will expreicne side effects

True

Steroid metabolism example is bile acids that are convereted to steroids that are reabsorbed by the host

True

Streptococcus mutans has most consitently been associated with the initiation of dental caries.

True

Stress and poor nutrition that leaves out essential vitamins or minerals leave the host more susceptible to infection

True

Sugar fermentation is a nexample of glycosidase reaction

True

Sweat glands give warmth, high moisture and this supports the activity and growth of high densities of bacterial cells.

True

The abcteria also possess receptors for these singaling molecules.

True

The b lactam ring forms the core structure of several antibiotics, such a penicillin

True

The bacteria lcount of the stomach is usually very low

True

The bacteria of of the microbiota can resist innate immune defences and do not elicit strong adaptive immune responses

True

The body's internal tissues such as blood, brain, muscle, are normally sterile

True

The composition of the microbiota in a stable micriobiota remains relatively constant

True

The extent of virulence is usually related with the ability of the pathogen to multiply within the host and bay be affected by factors such as route of entry and general health/susceptibility of the host.

True

The film is several micrometers thick and provides an attachment and colonization site for a few species of streptococcus.

True

The host benefits by microbial antagonism whereby the microbiota inhibits colonization by pathogens AND benefits by certain nutritional synergisms

True

The host receptors that interact with the bacterial ligands are expressed only at certain locations in the host's body.

True

The interaction between the human body and the microorganism is a relationship. That means, both contribute to the final outcome.

True

The intestinal microbiota is a complex ecosystem containing many bacterial species, and the majority of them are anaerobes

True

The key requirement of chemotherapeutic agents is their selective toxicity; they inhibit or kill bacteria without causing serious harm to the host

True

The lower Resp tract is lined with ciliated epithelium

True

The lung contains alveolar macrophages

True

The micriobiota of humans is sufficiently constant

True

The microbiota is obtained from the environment immediately after birth as a result of ingestion of fluids and food

True

The microbiota is obtained from the environment immediately after birth as a result of passage through the birth canal

True

The microbiota of corresponding anatomical sites in different animal species varies widely

True

The microbiota of the large intestine is dense 10e9 to 10e11/g contents and contains a diverse population of bacteria

True

The microorganisms of the microbiota are adapted to their host

True

The mitochoondria of eukaryotic cells have ribosomes of the prokaryotic type; this means that an antibioti used to inhibit protein systhesis in bacteria may also inhibit protein syntehsis in these organelles.

True

The nostrils are always heavily colonized

True

The oral cavity is more complex microbial habitat in the body.

True

The pathogen: Bortadella pertussis is specifically able ot colonzie the tracheal epithelium of humans, allowing it to produce whooping cough

True

The presence of food particles and epithelial debris makes the mouth a favorable habitat for a great number of bacteria

True

The secretions of the sebaceous gland associated with the hair follicle contain microbial nutrients such as urea, amino acids, salts, lactic acid, and lipids

True

The skin is constantly exposed to microorganisms

True

The stomach is very acidic and is a barrier to most microbial growth

True

The susceptibility to infection is increased if the anti-bacterial defences of the host are compromised

True

The tooth consists of enamel (a mineral matrix of calcium phosphate crystals) within which the living tissue of the tooth is present (dentin and pulp)

True

The urethra may contain skin microorganisms

True

The urogenital tract is normally sterile with the exception of the vagina and the distal 1 cm of the urethra

True

The weather: change in temperature and moisture content of skin can affect microbiota

True

There are microbiota in The colon

True

There are microbiota in The small intestine

True

There are microbiota in in the urethra

True

There are microbiota in the appendix

True

There are microbiota in the mouth

True

There are microbiota in the upper respiratory system

True

There are microbiota on the skin

True

These bacterial surface components include ligands and adhesins and the host cell molecules include receptors

True

These pesissters generally confer no hertible resitance to progeny once the selective pressure is removed but this characteristic allows cells in a biofilm to survive for extremely long periods of time, and likely contribetus to long term survival of bacterial species in general

True

These specific bacterial ligands include capsules, cell wall components, and fimbriae

True

They can interefere with DNA-directed RNA pol activity inhibiting tarnscription e.g., rifampin

True

This relationship is influenced by the pathogenicity of the microbe and the resistance or susceptibility of the host

True

Underdeveloped immune defences of newborns and the degeneration of immune responses that comes with age result in the old and young being more vulnerable to infection

True

Underlying disease or infection like AIDS, cancer, inherited immunodeficiencies leave the host more susceptible to infection

True

Urine is normally sterile

True

Virulence is a property that determines the extent of the disease

True

Well tolerated in human body

True

When breast-fed infants are switched to a diet of cows milk or solid food, Bifidoabteria are progressively joined by Enterobacteria, Bacteroides, Enteroccocci, Lactobacilli, and Clostridia

True

When elevated numbers of bacteria are present in close proximity to each other, autoinducer concentration increases

True

With acute inflammation: fibrinogen enters tissues; analogous to the complement pathway, it results in the formation fo a firbin cloth through a pathway, and it forms a wall around the damaged host cell which localizes the infection

True

With bactericidal antibotics, the baceria cannot grow when they concentration falls below the MIC

True

Within the genus and species of S. pyogenes there are many individuals

True

a narrow spectrum AB is one that acts on only a single group of organisms

True

gnotobiotic animals and birds have different characteristics

True

in the 20th century, scientists discovered ways to make or modify antibiotics, thus making the current antibiotic field an array of natural, semi-synthetic, and synthetic antiibotics

True

microbiota can induce an antibody response in the host

True

they can itnerfere with bacterial cell wall biosynthesis by inhibiting transpeptidation reactions during peptidoglycan biosynthesis (e.g., B-lactam antibiotics)

True

when the concentration of bacteriostatic antibotics falls below a certain concentration (the minimal inhibotry concentration or MIC) thebacteria start to grow again

True

10e14 bacteria in GI tract > # of eukaryotic cells in all organs in human host

True because human host eukaryotic = 10e13

M. tuberculosis induces an inflammatory reaction in the lungs, resulting in teh engulfment of the bacteria by phagocytic cells

True.

Biofilm formation occurs as a result of coodinated chemical signaling between cells (quorum sensing) and when the benefits of forming a community outweigh the costs

TrueTrue

Salmonella invade mammalian cells by triggering ______ arearrangements inside teh cell using the SPI1 system

actin

_________ transmisstion -> idisease is transmitted by droplets or dust (respiratory pathogens)

airborne

______________ diasese is transmitted by inanimate objects (fomites), food, water, blood, drugs (e.g., gastrointensitnal pathogens)

common vehicle transmission

________________ disease is transmitted by direct human contact (e.g., skin pathogens)

contact transmission

ther are hree forms of deases caused by antrhax bcalli: ____ . _____, and inhilation

cutaneous, gasttrointestinal.

three main categories of exotoxins _________. ________.- and ___.

cytolictic, neurotoxins, enterotoxins

the a portion of the toxin enters in to the cytosol where it activates host cells adenosine cylic enzyme

dalse adenylate cyclase enzyme (page. 52)

Bacteria in the biofilm interior while alive are often matabolically active beacuse they have less access to nutrients nad O2

fALSE metabolically INactive

Simpel attachment is done by an adhesin on the host cell surfae

fales adhesin (pili/capusule) is on surface of bacterial cell

recurrent infections of cholera are normal

fals rare. probably due to local immune defense mediated by antibodies secreted onto surfaces of intesintal mucosa

Many antibiotics have been mondified by chemical changes in the lab and are described as 'intersynthetic antibiotics'

false 'semi-synthetic antibiotics'

after 5-7 days, there is an abrupt onset of fever and chills, chest pain, difficulty breathing, malaise, weakness and acough yielding sputum

false 1-3 days

in addition there are 30-35 copies of variant enconding pilin genese

false 10-15

data suggests that AB treatment is warented for onl 40% of individuals seen for cicinal infections

false 20%

typhoid mary was responsibel for 10 outbreaks, involving 300 cases and 50 deaths

false 3 deaths. 50 cases

more than 30 million people are currently infectined with TB in the US

false 30k

the role of the clinical microbiologist in medicine is to isolate and identfy the causative agent of an infecteious disease within 1 week of receiving a specimin from patient

false 48 hours

Gonor is hte 2nd most prevalaent bacterial diesease reported to Health canada

false 4th

CT is a multimeric protein complex composed of 4 identical binding B subunits and an A enxymatic subunit

false 5

each variant encoding genes is truncated at the 3' end and lacks a promoter region and the sequences encoding the N terminal portion of the pilin protein

false 5' end

approximately 25% of the antibiotics produced are used in agriculture

false 50%

the overall mortality rate for pneumococcal bacteremia is abot 20%, but as high as 100% for elderly patients

false 60% for elderly

eocli and slamonella are clsoelreay realyed at about 85%

false 60-70%

female sysmptoms appear 1-14 days after

false 7-21

AB are prescribed 40% of the time

false 80%

The antibiotic regime for M tuberculosis requires long term therapy for 4-6 months with single antibiotiocs

false 9-12 months with multiple antibiotics

the suspected pathogenic organisms should be present in all cases of disease and dormant in healthy animals

false ABSENT not dormant in healthy animals

because of this mucos most successfulpathogens have evolved specific mechanisms to penetrate host tissue

false ADHERE

The most commonly used antibiotics in hospitals are the alpha-lactams (a-lactams)

false B-lactams beta*

therefore, antigenic variation occurs predominatelyt in teh N termina lregion of pilin

false C region

an oral, live, attenuated cholera vaccine - DVD 103-HgR (Mutcahol)

false CVD

infection with N. gonorrhoeae stimulats inflammation and local IgM response

false IgA

The vaccine for tubercuolsos is a dead strain of Mycobacterium bovis BCG that is similar (shares antigens) with M tubercuolossi

false LIVE not dead strain

denotoxin is equated with polysaccaride

false LPS which is on outer membrane of gram negative bacteria

invasive oragnisms ause localized infections

false NON invasive organisms cause localized infections

since 1990, pencillin has been recommended for treatment of gonorrhea infections

false NOT recommedned

two serogrops of Vibrio cholerae known as O2 and O140 are respnsible for cholera outbreaks

false O1 O139

some of the PilC proteins seem to be imporrtant in bacterium-neutrophil interactions even in the absence of antibodies

false Opa proteins

at any time, the bacteriuum may express zero, one, or several different opa proteins. This prcess of on or off expression of a gene product is called antigenic variation

false PHASE variation

at the tip of the pili is anotehr protein PilB

false PilC which functions as an adhesin .

in N. gonorrhoeae the chromsome contains a single complete copy of the pil gine called pilL for 'pilin expression locus"

false PilE

The Salmonella sertpotyps Tpyphi and Typhimurium are the most common Salmonella infections in the states

false Typhimurium and Enteritidis are most common

in the DDAST the bacterial isolate is sapread evenly onto the surfaces of an elisa assay

false agar plate so then when the bacteria grow it will for ma confluent lawn

treatment of a bacterial infection with antibiotics can destroy the pathogenic bacteria but not microbiota

false also microbiota

inhalation anthrax: spores inhaledi nto lungs and ingested by alveolar neutrophils

false alveolar macrophages

chemotherapeutic agents that are able to kill bacteria are usually called antibacterial compounds

false antibiotics

treatmen of endotoxin shock invovles supportive therapy like antibiotics

false antiboiotics aggravate LPS /endotoxin release

during an outbreak of typhoid fever, many ppl become infected and symptomatic

false asymptimatic

Mary mallon was a classic example of a chronic and symptomatic carrier of typhoid

false asymptomatic

the majority of compoentn of bacteria are identical, and at any DNA elvel, ther are between 99%

false between 95 and 99%

bacteria are normally found in blood

false blood is sterile site

The diagnosis of Salmonella infectiosn requires the isolation of the organisms from specimens such as blood or spit

false blood or stool

Vibrio cholerae can survive only in brackish water

false both fresh and brakish

penumonia divded into two forms: bronchial pneomonia and lungal pneumonia

false bronchial and lobar.

the phos regulatory protein transcirptionally activates or represses virulence factors such as flagella genes, toxin genes, or adhesin genes by bydinging to RNA polyermarse

false by byinding to DNA sequence in the regulatory regions of the operons for the virulence factors

the N. gonorrhoeae bacteria are ingested by the phagocytes

false by the epithelial cells.

smallpox is viral deases caused by botulism toxin

false by variola virus

capsule interferes with phagocytosis by preventing c5a opsonization of bacteria

false c3b!

vaccines may only be administered prior to exposure to the pathogen

false can be adminsitered after exposure to thepathogen but before the occurrence of disease

These individua ltests measure teh preence or abseence of certain enzymes involved in metabolism

false catabolism

metabolic activities as a result of growth of suspected pathogen on various carbon sources may or may not result in pH change which increases the amount of bacteria in well with bacteria that favors these nutrients

false causes a chagne in color of the indicating dye when pH changes.

an outbreak of smallpox would be fatal to the world

false could be contained by extensive immunization

culture: incubate for 48 hours > sugar femenation /detextion of nitrogase enzyme

false detection of oxidase enzyme

under a microscope, strep pneumoniae can be seen as triples of cocci

false doubles (diplococci)

botulinum toxin cannot easily be detected

false easily detectable in food industry and easily minotired.

condoms are ineffective in preventing the transmission of gonorrhea

false effective

fluids leak otu of blod vessels, blood coagulates, blood pressure drops, organs fail and death may result. This is known as exotoxin chock

false endotoxin shock

enerotoxins inhibit phagocyte killing

false enteroxosins cause diarrhea and O antigens inhibit phagocyte killing

an endemic disease occurs spradically at an elevated level and occurs continuously at a low level between these outbreaks

false epidemic disease

the centerd lesion taht is blacked is called an anthrax scar

false eschar.

intraellular pathogens can be dividing into two groups: Facultative and nonfacultative

false facultative and obligate

antibiotics are used in clinical practice far less often than necessary

false far more often used than necessary

hundreds of people are still infected nad die from bubonic plague in the us (usually hiekrs or hunters)

false few and effectively treated with antibiotics.

Flagellum helps with inhibiing phagociyte killing

false flegellum helps with motility

The b lactam ring is a five memebred lactam (a cyclic amide)

false four membered

N. gonorrhoeae specificalt adheres to respiratory tissues

false genitourinary tissues

the vesicle is tansported to the ER then the Golgi

false golgn then ER

salmonella are gram positive, flagellated, facultatiely anarobic bacilli

false gram negatie

TTSS are multi protin assemblies that are essential to the virulence of many pathogenic gram positive bacteria

false gram negative

the specimen does not need to get a sample from actual infection site, just as long as there is sufficient inoculum

false has to be from infection site but also sufficient inoculum.

in order to infect a human body, bacterium usuall has to proceed by coming ito contact with host, adhere to or invade the host, has to ultiple, and has to evade host's adaptive immune system

false has to evade innate immune system

S. typhimurium was inside typhoid mary's spleen

false her gallbladder and poo

salmonellaa; very closely related bacteria, many cause diases in all living organisms

false humans and animals

if the zone of inhibition is more than the standard, the organism is considered to be resistant.

false if less than standard.

the pili are immunosubmissive proteins and thus hsould not be neutralized (from the point-of-view of the bacterium) by antibodies

false immunodominant proteins

durign wwII japanese scienteist treid to develop flea bomb to start outbreaks of plague in the states

false in china

increased levels of cAMP cause an inhibiation of the uptake of Cl ions and an increase in secretion of Na ions

false inhibition of Na ions and increase in secretion of Cl ions

Vi capsule antigen inhibits neutrophil binding

false inhibits complement binding

when antiobotic administration is discontinued, the micriobiota of the GI tract cannot be reestablished

false is eventaully reestablished

the SPI2 system is non-critical for virulence because mutants in it are virulent as well

false it is critical becaue mutants without it are avirulent.

lysozome is an iron binding protein

false lactoferrin

cutaneous antrhax is most serious form of diease that results when spores enter cuts or wounds and germiante the tissue

false least seirous

with treatment mortality rate is only 5%

false less than 1%

edema: resonsibel for producing necrotic, black centered lesion in cutaneous antrhax. in inhilation antrhex, disseminated edema results in shock and death

false lethal not edema

pneumotoxin also intitiates a systemic response and that is why pneumonia is so dangerous

false localized inflammatory response in lung, attracts more phagocytic cells to the area.

When the lungs (alveoli in the lungs) ciliated membrane stops working, the lungs are protected by alveolar macrophages and antibodies

false lungs lack a ciliated membrane

in populations of poorer health status, the infecous dose is also high

false lwo

PID is a major cause of shortened earlier births and can lead to chronic pelvic pain

false major cause of sterility

microscopy test confirms mostly female patients

false male

antimicrobial therapy is needed as well

false may be helpful but not essential. the bacteria rar elsot in watery stool

Asymptomatic carriers can be a major factor in the spread of Gonorrhea. 10% of women are asymptomatic and 1/3 to 1/2 of men are asymptomatic

false men 10% women 1/3 to 1/2 asympyomatic

pathogens can be transferrred from patient to patient by hospital staff or visitors. ofthen these drug resistant pathogens can be found as the microbiota of the patietns

false microbiota of the hospital staff

each isolated colony consists of thousands of bacterial cells

false millions

strep pneumoniae causes approx 70% of all bacterial pneumonias, about 50% of hospital acquired pneumonias, and accounts for 2nd most deaths than any vaccine preventable bacterial disease (1st is gonorrhea)

false most deaths.

3. the gene must not be expressed at some point during the infectious process in experimentally infected animals

false must be expressed

Salmonella produce differe adhesins including type III secretion system

false n type I fimbriae and plasmid-encoded fimbriae

Tersinia pestis is a gram positive bacterium

false negative

the infected host cell responds by producing chemokines and other inflammatory mediators which attract macrophages to the area

false neutrophils first.

Although people infected with N. gonorrhoeae mount an antibody response to the pili and other surface proteins, memory b and t cells for N. gonorroeae hide in bone marrow

false no acquired immunity.

strep pneumoniae is a transient member of the microbiota, colonizing the nasopharynx of 40% of healthy adults and children with very adverse effects

false no adverse effects

EPS is composed of polysacharides, carbohydrates, and nucleic acids

false no carbs, but prteins

S. typhimurium produces many enterotoxins neecessary for pathogenic bacteria to cause diarrhea

false no enterotoxins

one simple method to determine the antibiotic sensitivity of a clinal isolate is the disk diffusion anitbiotic facilitation test

false no facilitation but susceptibility.

S. Typhyi pathogenic to humans and animals

false no otehr animal host idenfitied

SPI1 contains inv genes thar ar eresponsible for the rapid division of slamonella once inside (p. 57 paragraph 2)

false no repsonsibe lfor membrane ruffling associated with invasion of host cells.

polysacaride is toxic and induces inflammatory response

false non toxic, does not induce.

strep pneumoniae as highly motile, highly sporulating gram positive cocci

false nonmotile nonsporulating

this stimulates release of prostaglanding which acts on the prefrontal cortex to raise the thermoregualtory set poinnt resulting in a headache

false not a headache but a fever.

Early identification of causative agent of infectiosu dieases is important because it can identify all suitable antibiotic treatment of infection

false not all but most

all pathogens display invasiveness (which is not the same as invasion)

false not all pathogens display invasiveness

All pathogens possess each type of virulence factors

false not all pathogens possess each type of virulence factors

poylsaccradides are very immunogenic like proteins and elicits strong antibody repsonse

false not as imunogenic as proteins and does not elicit strong antibody response

passive immunization in humans is the traditional route to immunity to pathogens

false not currently done in humans although hyper immune gamma globoulin is used for some illnesses such as emegency treatment after exposure to botulism toxin

ruffling allows bacteria to exit cell's cytoplasm in an endocytic vacuole

false not exit but enter cell's cytoplasm.

society is helpless to the trheat of biological warfare.

false not helphless

the diversity fo salmnall is due to ablity of bactea to mutate rapidly

false not just that

Salmonella virulencefactors: adhesins, peptidoglyican, capsules, two type II secretion systems, and abilty to invade and replicate inside host

false not peptidoglycan but LPS

S. Typhyi can multiply in stomach and large numbers of bacteria are realsed into blood steram causing systemic infection

false not stomach btu spleen and liver (p. 58)

MD2 then associates with LPS-TLR4 complex and a signal is transmittion which results in ciytokine activation for IL-2 and IL-6

false not these but transcription factor NF-kB first

opa proteins were originally hought to be involved in adherence but they my play a role in bacetriums role to evade host cells

false not to EVade but to INvade

B. antracis spores are very infectious for humans

false not very infectious a preferred agent.

major clinical syndromes associated with S. pneumoniae are pneumonia (inflammation of the lungs), bacteremia (bacteria in the blood)), and whooping cough (excess mucous in lungs)

false not whooping cough but meningitis: inflammation of membranes surrounding the brain and the spinal column).

incidence = number of people who have the diseases per given time period / 100 k ppl at risk

false number of newly reported cases!

S. typhimurium is transmitted by contamined food, mostly pork and fish

false on chicken and eggs.

the virulence factors are coordinately regulate by a three component system that comprises of two sensors and a regulator protein.

false one sensor and one regulator

the emergence of isoniazid-resistant M. tuberculosis seems to be related to he fact that patients must take oral medication for up to one monthand many do not comply with the whoel course of therapy

false one year

cholerae can beconfirmed only by blood test

false only by stool sample of diarrheic patients.

N. gonorrhoeae does not cause diseae in experimental animals but experimental animals have been used for N. gonorrhoeae

false only human volunteers

to examin a specimin bby microbiological methods, a seterile swab is used to collect sample and swab is streaked over surface of agar plate only

false or placed directly into liquid culture medium

endotoxins are part of inside of bacteria

false part of bacterial cell wall

DNA: a nucleoic acid based detected test can be used to dectect th presence of bacterial genese in poo sample os cervical swabs

false pee samples not poo b/c urethra

phagocytosis of infected cells

false phagocytosis of the adherent oraganism

the variant incoding gense are called pilV for 'variant loci'

false pilS for silent (non funcitonal) loci.'

The strep capsule is made of LPS

false polysaccharide.

vaccines prevent infection but not disaese

false prevent disease but not infection

gonorrhea must be treated with antibiotics

false recover after 6 months (i.e., self limiting infection)

diffeent pathogens have different modes of trasmission wich are usually related to their habitat in the wild

false related to habitat in hosts body

Bacteria rely on specialized pathogenic factors to cause disease

false rely on specialized virulence factors

treatment: S. typhimurium and S. enteritidis need immediate treatment or die

false resolve within week and do not require treatment

transmission of strep pneumoniae requires physical contact (sexual mostly)

false respiratory droplets

there are two main disaees with salmonella infections: salmonella and thyroid fever

false salmonellosis and typhoid fever

glucose are needed for proper osmolarity

false salts for osmolarity

AB treatment can be effective, if the antibiotics are adminstered before third stage of disease

false secondary stage

bacteria lyse and the cell wall components trigger massive cytokine release resulting in fever and anaphylactic shock

false septic shock.

this may take the form of memrane bound proteins, dry polysaccaride capsules, or LPS (gram negative bacteria only)

false slimy not dry

if bacteria can survive gastric secretions and low pH fo stomach then they are well adapted to sruvival in large intestine

false small itnestine

growth medias are either selective or differential only

false some can be both

a pandemic disease occurs occasionally. they are often recoded as individual cases in geographically separated areas, implyin that htey are cases that are noy related

false sporadic disease

A positive culture from blood samples may be the result of contamination from bacteria in the lungs of a colonized patient. (p. 47)

false sputum sample from mouth not lungs

flouresecetly labeled antibodies would recognize intercellular vesicles in the pathogen

false surface antigens

The bacteria tend to survive in lungs in active state

false survive in dormant state

many diasese are transmitted by insects such as fleas, lice, and flies. insects that fly are more easy to control because we can catch them in air before they spread

false t insects that fly have sifnificant epidemiological implications as they have broader home rangers than non flying insects, so control is much more difficult

individuals in human reservoirs may be symptomatic (recovering from disease and still harbor the infectious agent)

false that is called convalescent. symptomatic means currently have the disease. individals can be symptomatic or convalesecent in human reservoirs

the size of the zone of inhibition is dependent on the concentration of the antibiotic, the concentration of the microorganism, and growth rate of bacterium

false the diffusion rate of AB and sensitivity of microorganism

both commensal and pathogenic bacteria may be translcoated across the intestinal epithelium to the lumen of the larger intestine

false the lamina propria

the most important virulence factor V. cholrae is also the same for pneumonia (the poylsccahride capsule)

false the potent exotoxin called cholera toxin (CT)

exotoxins are generally proteins and thus heat labile. a small dose can have a significant effect. They are not immunogenic

false they ARE immunoginic, they stimulate immune system to produce neutralizing antibodies

endotoxins ar eprotein molecules are are generrally heat labile

false they are non protein and heat stabile

Example: mycoplasmas (a causative agent of penumonia) are rissnt to pnicillin because they lack LPS

false they lack peptidoglycan

after the internalization of the bacterium, there is extensive actin rearrangement in te vicinityy of the invading bacterium, however, the surface of the host cell and the actin filaments in the region never return to normal

false they rreturn to normal (page 62)

penicillin and tetratcyline are effective treaments of N. gonorrhoeaee

false they sued to be effective treamteants but the bacteria gained resistance by acquiring plasmids encoding resitance

public health officials are in a sitautoin where there is only one defence aginst pathogen

false they usually have multiple lines of defence

neurotxoins affect cells lining gastrointestinal tract, causing massive fluid secretion

false this is an enterotoxin

the PilC protein is necessary for bacerim to adhere to a variety of host cell types

false this is what the diffferent Opa proteins enable

food infection results from ingesting food that his contamined with preformed biologically active toxins. they do not have to replicate in host or even be alive in contaminated food

false thsi is food poisoning

vaccine is given to everyon

false to high risk person such as elderly, immunosuppressed patients like aids, and patients with pulmonary disase

the infectious dose (ID) is the number of bacteria required to give an infection

false to produce disease. the infectious dosevaries considerabl between organisms

antigenic variation occurs when the genetic info in a pilE gene is transferred to the complete gene pilS gene by homologous recombination

false transferrred from PilS gene to pilE gene.

TTSS (Type I secretion systems) serve to secrete and inject virulence factors into eukaryotic host cells to manipulate host cells during infection

false type III secretion systems.

the exact ID50 for B anthracis is 200 spores

false uknown but at least 2000 spores

to be inhaled into lung, spores must remain airborne, and in a fine suspenstion so that hte spores bypass the defense of lower airway

false upper airway.

the host responds to adherent oragnisms through: downregulation of produciton of antimicrobioal peptides by epithelial cells

false upregulation

The disease is prevalant in poor people and AIDS patients living in rural american cities

false urban large american cities e.g., new york

cholera is an example of a pathogen that uses an endotoxin to damge its host

false uses an exotoxin which si an enterotoxin to damage its host

symptoms are very specific and you can tell who has gastrointestinal anthrax

false vague, neasuea vomiting, fever and abdonminal

chemotherapeutic agents kill or inhibit growth of bacteria in only one way

false variety of mechanisms

floureseceltly laebeld antibodies can be added directly to the sample and if pathogen is present a psositive identification can be made by the naked eye

false visualize flouresecnetly labeleld bacteria under microscope

The largest area of antibiotic misues is within healthcare

false within agricultural industries

antibiotics are often avaiable in developing coutnries by presecription

false without prescription

Salmonella are acid insentive, individuals who produce little or no stomach acidity are at same risk for other normal humans

false, Salmonella very acid sensitive

the oral vaccine is a capsular material of S. typhi

false, a live attenuated but avirulent strain of S. typhi.

microscopic is good because a specimin usually only contains one or two types of microrganism

false, may contain several microorganisms. in these cases, specimins are used to incoulate growth media for further tests

three lab tehcniques can be used to diagnose gonorrhea: ELISA assay, culture, and microscopy

false, microscopy, culture, and DNA

Epidemiology is the study of when and where diseases occur, and how they infect the body

false, not about how they infect the body but about how they are spread.

P islands are found in genomes of non pathogenic members of the same or related species.

false, they are not found. Example> S. bongori lacks SPI2 P island.

nosocomial ifnections can be endogenous (trasnmitted form another individual) or exogenous (caused by the microbiota)

false; endogenous - caused by microbiota exogenous - transmitted from another inividual

Salmonella enterica involved in causing disease of the stomach

falsenot stomach but intestine (enteric means pertaining ot hte intestine)

presence of bacteria in blood is termed septicaemia

falses bacteremia

When an antibiotic is given orally, some memebrs of the respiratory microbiota may be affected and opportunistic athogens may be able to establish themselves in respitaotyr tract

falso gastrointestinal tract

acute carriers are individuals who have recovered from the clinical diesease but still harbor the infectious agent, or they may be individuals that carry the parthogen as part of their microbiota without hte occurrence of disase

faslse chronic carriers

LD is determined in lab animals and is expressed as the number of bacteria required to kill 50% of the population

i.e., LD 50

_____________ (doctor induced) are a result from surgery, invasiv diagnostic procedures, or medical implant devices such as catheters

iatrogenic.

the ____ form of antrax is most serious and lethal

inhalation

the consumption of food or antacid may provide protection for the bacterium during passage through the stomach

kk.. true.

the ________ dse is the numebr of bacteria required to kill.

lethal dose LD

a relativelty large dose of salmonella is required to infect humans with nomral stomach acid, but inocumum size can be reducd 100 fold when introduced with bicarbonate

mhm.. true.

the transmission of disease can be correlated with geographical, seasonal, and age group incidence with possible _____ of transmission

modes

in some cases a small number of S. typhimurium can enter into immunocompromised ppl like aids or elderly hwhich causes a systemic infection: systemic shock may be fatal if not promptly treated with a vaccine

not a vaccine but antibiotics

Intracellular existence starts now

ok

Our discussion will focus mainly on bacteriums ability to invade and replicate inside host cells

ok

The following is the process for the two component regulatory system for signal transduction

ok

The following questions are about virulence factors important in salmonella pathogenesis:

ok

case study for cholera starts now

ok

here they are

ok

koch postulates include the following

ok

pathogensis of bacillus anthracis

ok

toxins topic starts now

ok

because mutant derivates without polysaccaride capsules are not pathogenic, the capsule is not an essential determinant of the virulence of strep pneumoniae

omg false duh it needs the capsule

they may recover btu become chronic carriers because bacteria persist in gall bladder and are shed inthe feces for years

omg true

shigella dysenteriae -> a causative aegent of dysentery has an ID of 1-10 bacteria

omggggg true

in US there are approx 2 million nosocomial ifnections leading to 100k deaths per year

oomg true

the pili are polymers of thousands of protein subinits called PilE proteins or _____

pilin

_____________ of infection are sites in which viable infectious agents remain and from which infection of individuals may occur

reservoirs

a ______ is a strained differentiated by serological means

serovar

a _____ is a subset of a bacterial species different from other bacteria of the same species by some minor BUT identifiable difference

strain

avoid eating undercooked or raw fish or shellfish

tRUE

Such a culture, when inoculated with susceptible animals, should initiate the characteristic disease symptoms (i other words, suspect pathogen must cause disease in a healthy animal)

tre

CAMP mediates many regulatory sytems in cell.

tru

IT is antibiody binding that all serolgical tests ultimately detectt

tru

Mutachol is licenced incanada and is partially effective agisnt cholera, effected against sergroup O1 only

tru

Vibrio cholerae that lack Tcp pili (for toxin co-regulated pili_ are not pathogenic to humans (p. 53)

tru

adequate seqage and water teraments can limit the spread of v. cholerae and prevent epidmics

tru

boil it, cook it, peel it, or forget it

tru

cross raectivity occurs for several of the capsular types: it is where an antibodyagainst one serotype will bind to another serotype bcause of a shared epitope

tru

drink water that has been boiled or terated with chlorine or iodine, tea nand coffee made with boieled watern and carbonated , bottled beverages NO ICe

tru

example of cytolitic: staphylococcus aereus hemolysin - lysis red blood cells

tru

exotoxins are secreted, made by both + - bacteria.

tru

exotoxins enter blood circ and spread to parts of body and cause damage from from site of colonization

tru

for example. respiratory pathogens are generally airbone and gastrointensintal pathogens are often spread by food and water

tru

lobar: younger adults: involves all of a single lobe of the lungs (although more than one lobe may be involved)

tru

one way N. gonorrhoeae evades immune response is antigenic variation

tru

outer membrane proteins which are products of the acf genes (accessory colonization factor) may be required to medaite tigheter binding to host cells

tru

salmonellosis in humans usually takes the form of a self limiting gastroenteritis (diarrhea)

tru

sanitary measures are most important in controlling cholera outbreaks

tru

the vaccine is administered as a single dose and is approved for adults and hcildren over 2

tru

two types: endotoxins and exoxtoxins

tru

tyhpoid feer can last 2 to 3 weeks and is charcterized by persistitnyl high fever and chills, flusehd appearance, anorexia, and convulsions and delirum

tru

u can prevent cholera

tru

water alone does nto work

tru

1 the gene(s) /factor shuld be present in pathogenic strains of the organism and absent from non pathogenic strains.

true

175 k hospitalized cases of penumococcal penumonia in each year in US. fatality rate of 5-7%

true

2athe molecular disruption (knock out of the genes) should reduce teh virulence of the bacterial strain 2

true

2b - introducing the cloned genes into an avirlent strain sohouulder render that strain virulent

true

30% of all deaths are due to infectious diseases worlwide

true

5% admited to ospital get nosocomial infection

true

90 diff capsule types

true

API streips and BBL enterotubes are kids that contain various growth media in separat wells that are incoulated at the same time

true

Anti phagocytic proteins are induced by oxyR

true

Antibiotics can be fatal like allergies to penicillin

true

Aquaculture is another area in which convernes hav ebeen raised regarding antiobitics use in the envrionment

true

Bacillus antracis is a gram positive spore formign rod.

true

Bacteria can sense several enviromental factors in regulating expression of their virulence factors

true

C. botulinum is a common soil bacterium, and can potentially contaminate a variety of foods

true

CAMP activates protein kinase A (PKA) which then phophorylates the cystic firbrosis transmembrane regulator (CFTR) resulting in Cl- secretion.

true

Capsule: polysaccharide completely envelops pneumococcal cells.

true

Cytotoxins inhibit host cell protein synthesis; calcium efflux from host cell, and adherene

true

EVASION: inside host cell, Salmonella are protected from resposnes of innate and adaptive. also. they prevent fusion of endosomes with the lysosomes and thus resist intracellular killing as well as activation of innate and acquired immune systems

true

Early identification of causative agent of infectiosu dieases is important because it can identify causative agent of a deases outbreak in a hospital setting (i.e.,e contaminated supplies, poor aseptic technique by hospital staff)

true

Early identification of causative agent of infectiosu dieases is important because it can minizime severity and duration of a disease if proper treatment can be initiated immediately

true

Expression of the PilE gene is controlled at the level of transcription by a regulatory system allowing the bacterium to switch between Pil+ and Pil-.

true

Gonorrhea (NOT N. gonorrhoeae) is a sexually transmitted infection (STI)

true

In some cases, the only drugs available to treat a particular infection have been rendered ineffective because of antibiotic resistance

true

Koch's postulates have been used to prove the causative relationship between most bacterial pathogens and their respective diseases

true

M cells are specialized cells of the intestinal tract that have the function of sampling antigens from the lumen of the intestine.

true

M cells are specialized epithelial cells that take up and transcytose luminal antigens for uptake by phagocytic immune cells

true

M tuberculsosis gies the highest number of deaths which can be attribteud to a single infectious agent

true

M. Tuberculosis kills 3 million people each eyar

true

M. tuberculosis is responsiebl for 5% of all deaths in devleoping ocuntries.

true

N gonorrheoae can vary its surface pathogens

true

N. gonorrheoae can vary the amount of pili and Opa preotins expressed at the cell surface

true

N. gonorrhoeae causes disasese by inducing inflammation and avoiding acquired imune response through antigenic variation (evasion of the host defences)

true

N. gonorrhoeae enteres the body through mucous membrane of genitourinary tract

true

N. gonorrhoeae has two copies of the pilC gene (pilc1 and pilC2)

true

N. gonorrhoeae uses pili and other surface proteins to atach to host cells and remain attached despite periodic urine flow

true

NF-kB enters nucleus of macrophage where it binds to the promoters of pro inflammatory cytokine genes resulting in their transcription

true

Neisseria gonorrhoeae is an example of a pathogen taht uses adherence and antigenic variation to avoid the host's immune system.

true

Nosocomial infections result from many factors

true

Optimal attributes of chemotherapeutic agent; solubility in body fluids with good penetartion to the infection site

true

Outer membrane proteins called opacity-associated proteins or Opa proteins were oringally indentified because their expression causes colonis of N. gonorrhoeae grown on agar to appear opaque

true

P islands are large regions of DNA (10-200kb) that encode clusters of genes associated with viruelnce

true

Patients presure doctors for antibitics in the treatment ofviral infections where antibiotics are completely inapproprite

true

PilC fucntions as an adhesin and medaites adhereence to the urethral or cervical epithelial cells, thereby enhancing the bacterims ability to cause disease

true

S. Typhyi also move from liver to gall bladder where htey are shed in the bile and back into the intestine, allowing some people to shed this organisms

true

S. Typhyi causes typhoir fever: seirous, often fatal

true

S. Typhyi common in developing countries

true

S. typhimurium causes a typhoid like disease in mice.

true

S. typhimurium injfects proteins into intestinal cell via type III secretion system (page 61)

true

Salmonella pathogenicity island 1 (SPI1) contains many genese associated with viruelnce as well as genes involved in the regulation of them.

true

Stan falkow developed a molecular version of koch's postulates

true

The phosphoorlyated sensor protein can then act on a regulator protein and trasnfer the phosphate group

true

The side effects of an antibiotic can range from mild )drowsiness, nasuea, cramps) to severe (toxicity to internal organs or hearing loss after prolonged use of certain AB)

true

There is strong evidence that hte us of antibiotics ina griculture results in AB resitance in bacteria that can then be transferred to humans through handling these animals andb y eating them

true

These facetors prevent deposition of antibodies and complement directly on the bacterial surface, which avoids complement mediated kiling and reducing phagocytosis

true

This can result in disruption of normal digestive functions or diarrhea

true

This is a common system for signal transduction

true

To avoid phagocytosis, many pathogens hav evolved surface ocmpoenent that prevent attachment and engulfment of macrophages and other host cellular immune responses (p. 45)

true

Vaccine and prevention: can be prevented by sanitation and proper handlign and cooking of foods likely to carry the bacteria

true

Vaccines can consist of aviruelent mutans of pathogenic bacteria

true

Vaccines can consist of killed virulent bacteria

true

Vaccines have contribetud significantly to reduced infectious disease-induced mortality

true

Vaccines work by induced the pimrary immune response such that more exosure to the pathogen induces fatter and more vigorous imune response that limits gowth of pathogen.

true

Vibrio cholerae : motile, gram negative, curved rod with a single polar flagellum

true

Vibrio cholerae strains are sertptyped based on their LPS O antigens

true

We will now talk about the intracellular lifestyle of salmonella

true

Widespread resistance has already delveoped to one of hte main antibiotics used (isoniazid) and some pareitsn carry multi-resistant strains that are reisstant to all 8 front line AB in use

true

Xigris reduces mortality. It combines antiboagulant and anti-inflammatory propoerties to deal with endotodxins (p. 50 bottom) apragraph_

true

Y. pestis is capable of blocking phagocytosis nad multiples in the lympnhodes.

true

______ are strains that ar differentiated by biochemical or other non serological means

true

____________ infections are those infections that are acquired by patients as a consequence of hospitalization

true

a _____ is an antigenic propoerty of a cell or virus identified by serological methods. As a verb, ____ means to calssify according to serovar, or to assign a particular serovar

true

a conjugate vaccine consisting of poly antigens covalently bonded to proteins (to make vaccine more immunogenic) has recently been introduced. this vacine covers only 7 of the capsular types and is used primarily for the prevent of ear infections

true

a disease outbreak is when the number of disease cases increases in an area which previously had experienced only sporadic cases of the disease.

true

a healthy carrier can be more dangerous than those sick because there is no way to visually identify a healthy carrier in order to avodi them

true

a pandemic idisease is a widely distributed epiddemic

true

a single bacterium can switch to one copy, then to another, and then back to the original copy of the gene, all over the course of one infection

true

a vaccine is a suspsension of microorganisms or parts of them that are used to induce immunity by injetion or exposure by the more typical portal of entry e.g., ingestion

true

abdominal pain due to inflammatory response that results with recogniztion of bacterium's LPS and subsequent release of cytokines as well as that caused by the SPI1 effects

true

active immunization occurs at the level of a whole society or populatoin

true

after binding by the B subunit to th GM1 ganglioside, the entire toxin molecule etners the cell via endocytosis

true

after examination of a patient, a doctor may collect a sample from the infection site for immunological or micriobiological examination (e.g., blood, urine, cerebrospinal fluid, pus)

true

after incubation for 1 to several days, isolated colonies appear on the surface of the agar plate.

true

after natural infection by Vibrio cholerae patietns develop antibodies aginst several cholera antigens, indlucing antibodie taht will neutralize the enterotoxin

true

agglutination assays to detect group A strep infections can be done in the doctors office

true

all ppl are belived to be susceptble to ifnection, but individuals with damaged or undeveloped immunity, redud sotmach pH or malnutrtion may sufffer more severe forms of cholera

true

an endemic disases occurs continually at a relatively low level, the pathogen that cause the disease may not be very virulent, or the majority of the individuals i na gien area ma be immune to the pathogen

true

antibiotic abuse encourages the emergence of antiibotic resistant forms

true

antibiotics such as chlorampenicol and ceftriaxone are the treatment of choice for S. typhi infections

true

antibody mediated response to poylsaccaride can be induced

true

antibody raised against the virulence factor should offer some protecting agasint infection in an exerpimentally infected animal

true

antigenic varation results from gene rearrangements in the DNA that take place at high frequency.

true

antigenic variation can occer frequently

true

antimicrobial agents reduce the duration of illness by reducing the production of the CT, the volume of stool, and the duration of shedding of vibrios in poo

true

approx 90% of antibiotics used in agriculture in North meerica are used as growth promoting agents in livestock and for the prophylactic treatment of livestock, crops and farmed fish

true

as Salmonella divides inside the endosome, the endosome grows in size and sprouts thin filaments that stretch out from the walls of the surface.

true

as a biooterrorist agent, main concveres have been with the ocntamination of the food and water upplies with botulinum toxin.

true

as a result of the cAMP, the cell secretes Cl- ions (and bicrabonate ions) from the intestinal epithelial cells into the lumen of the intestine.

true

as bacteria on the lawn gow, they ar einhibited to varying degrees by the antibiotic diffusing from the disk

true

asymptomatic carriers are main spreaders of typhoid fever

true

bacteria can also be resitant to antibiotics by modifying the target of the antibiotic

true

bacteria can become reisatant to a given antibiotic because of mtuations that change the structure of the target site

true

bacteria produce two toxins: lethal toxins and edema toxin

true

bacteria turn on different components which include virulence factors only when needed

true

bioterrorism is the use biological agents (microbes) to cause damage, death and or fear

true

blood agar supports growth of most aerobic and fulctative anaerobic bacteria

true

botulism toxin is a protein toxin made by Clostridium botulinum, a gram postiive spore forming rod

true

botulism toxin is the most potent toxin known

true

bronchial: most prevalent in infants, young children, aged adutls: alveoli contiguous to larger bronchioles of the bronchial tree

true

cAMP stimulates the active secretion of large amounts of chlorine ions from the cell into the lumen of the intestine

true

carriers may be in the incubation period of the diseaes which precedes the development of symptoms: they are called acute carriers because their carrier state is transient

true

cell mediate responses include t cell effector mehcanisms and activation of macrophages

true

cell mediated immunity plays an important role in defence agaisnt intracellular pathogens.

true

cholera affects only humans; there is no insect vector or animal reservoir host

true

cholera is senstivie to acid pH (p. 53)

true

cholera is spread by fecal contamination of water and food, linked to poor sanitation

true

cholera toxin is an AB toxin.

true

cholera usually occurs in epidemics

true

common processes regulated at the genetic level include metabolism, resposne to enviornmental stressess, and cell division

true

contact tracting helpes ppl in identifying asymtomatic individuals and those who were exposed to index patient and who may have become infected.

true

contamined foods are frequently of anima lorigin like beef chicken, milk , eggs, but all foods, including vegetables may become contamined

true

current vacine for strep pneumoniae cntains purified, capsular polysaccaride antigens of 23 types of s pneoumoniae even wthougth there are 90 capsule types.

true

cutaensous anthrax responds well to early antibiotic treatment

true

cytolitic: enzymatically attack the cell constituents causes cell lysis

true

diagnosis: gastrointestinal sysmptoms and presence of a rice water stool are presumptive for cholera.

true

diarrhea: water, flakes of mucus and epithelial wells: water rice stool: contains a lot of vibrios (10^8 vibrios per ml)

true

different capsular types can be identiify by serological testing using specific monoclonal antibodies

true

differential media is on in which an indicator dye allows identifaction of bacteria by their appearance on the growth media.

true

diversity of salmonella is due to abiltity of bacteria to to undergo antigenic variation, to create variation in their genese for H, O and K antigens through recombination, alterations in lengthn, gene duplication, and point mutations

true

due to the damage ing the lunge, the person becomes cyanotic due to the lack of oxygen because gas exchange mechanisms are impaired.

true

e have antibiotics that can be used to treat bacterial ifnections.

true

early symptoms of inhilatation anthrax are non specific and resemble symptoms of influenza (headaches, mucle aches, malaise)

true

eating vegatables that are cooked avoid sald

true

edema: toxin results in the inflammation and swellign seen in the infected site

true

elderly patient are at risk because their immune systems do not function as effeciently. for eample, they frequently do no develop fevers in response to bacterial ifnections

true

endotoxin elicits a lot of sysmptoms through its induction of inflammatory response

true

endotoxin in LPS layer produces fever

true

endotoxins act through bdinging to a conserved PRR (toll-like receptor r) on macrophages, leading to signal transduction and activation of transcription factor NF-kb

true

endotoxins are released only when the bacteria die or are digested by phagocytic cells

true

endotoxins cause pyrogenic response (fever)

true

enriched media contains specific growth factors which are often required by certain pathogens.

true

enriched media may be required for the culture of metabolically fastidious bacteria

true

etensive use of Ab especilaly in asia has resulted in larger numebrs of antibiotic resistant organisms, with up to 90 of oragnisms being risstant to primary antibiotics

true

example of enterotoxin is cholera toxin and causes diarrhea

true

exposure to the antibiotic selects for strain of the organism that have become reistant through natural processes

true

facutlattive; live within our outside host cells like salmonella

true

farm animals do not look ill and colonized animals are not identified prior to slaughter. during the slaughter process, anima lcarcasses can become contaminated

true

food infection symptoms only arise after pathogen has had time to replciate in intestine. thus smptoms can develop seeral days afer ingestion of contaminated food or water

true

for bacterium to cause DISEASE, it must possess chemical/molecular mechanisms whereby it dmgs the host (e.g., toxins or host damaging enzymes, or it must trigger a chronic inflammatory response)

true

for those microorganisms that do cause disease, the pathogen directed events can culiminate in disease

true

formation of these filaments is driven by the intracellular bacteria and is linked with intracellular multiplication.

true

gastrointestinal anthrax: when raw or poorly cooked contaminated meat contaminted with B. anthracis spores in consumed.

true

genes that encode these virulence factors are located in the many _____________ _______ found in Salmonella genome

true

glycoproteins/glycolipds on host and adhesins on bacteria benefit pathogen by facilitating coloinzation, preventing the removal of the bacterium by non-specific host defence systems and by localizing the bacterium to the appropriate tisssue.

true

hospital treat patients with infectious diasese, and these patients may be reservoirs of pathogenic organisms

true

hospitals are a breending ground for resistant bacteria because large odses of antibiotics are used to prevent infection during anfd following surgery

true

human reservoirs are where huamsn carry and shed the infectious agent.

true

humans can also be carriers: i.e., have no disease symptoms but carry and shed the infectious agent

true

if bacteria manage to evade the mucociliary system and reach the lung, the capsule prevents phagocytosis

true

in about 15-50% of patients with pneomococcal penumonia, bacteria enter the bloodstream (more than 50k cases each year).

true

in anaeorbicconditions, the bacteria switch to beta hemolysis, (complete lysis of red blood cells surrounding the colony)

true

in females, primary infection is present in the endocervix (mucous membrane lining the cervical canal) possibly with urethral infection

true

in higher dosis, there is damage to circulatory system and shock.

true

in human volunteers the infecious dose of V. cholerae is very high >10^6

true

in humans S. typhimurium causes a self limiting gastroeneritis cahractereized by diarrhea, abdominal cramps, vomiting, and nausea

true

in low doses of endotoxin, a person might experience a fever (endotoxin is pyrogenic), malaise, aches and pains

true

in males, N. gonorrhoeae causes urethritis (inflammation of the urethra) and may include sysmptoms such as painful or difficult urination and disrhage of pus through dick

true

in some cases direct deteection of bacteria wihtout culture is possible

true

in some protocols, the assays are used to directly detect presence of pathogen, in other protocols, assays are used to detect presence of antibodies to the pathogen from the patients serum

true

in systemic salmonellosis, such as typhoid fever, selmonella may target specific types of host cells, such as dendritic cells and / or macropahges that favor disseminatition throughout the body

true

in the mouse model bacteria may enter host through M cells.

true

in the secondary stage of disease, there are high levels of the anthrax toxin ciruclating in the patient

true

in the states, cases of botulism has been reported after consumption of imporperly home-canned veggise

true

inanimate or non living reservoirs: some diases are present and are transmitted from water or soil

true

incidence of disease is about the fraction of population (i.e., per 100k) that contracts (newly acquires) thedisease

true

incubation preiod ranges from a week to am onth after the intiital ingestion of S. Typhyi.

true

indivudal strains of salmonella spp. are often distinguished and distinguishable by seroligcal means

true

infants and young children are at an increased risk because their imue systems have not fully developed

true

inhibition of bacterial growth around a disk following incubation indicates sesitivity to hte particular antibiotic impregnated in the disk

true

instead of developign a vaccine, efforts are made in the detection of bacteria in food and on the public education on safe food handling.

true

intracellular env is rich soruce of nutrients asnd energy (amino acids, atp, and other nucleoside triphosphates)

true

intravenous rehaydration therapy is required for paitents who are in profound shock or cannot drink.

true

inv genes, along with other ones that encode a type II secretion system that is used to inejct proteins (also encoded by SPI1) into the cytoplassm ofeukrayoti cells to mediate invasion and inflmmation.

true

invasive organisms may cause systemic infections i.e.,e infection can be spread throughout body, often through the blood

true

invasiveness is the ability of an infecting organism to spread withing the host body from site of infection

true

invasiveness is the ability of the bacteria to spread to other sides in the body

true

ironically it is used in the cosmetic indurstry known a BoTox to eliminate wrinkels in the skin

true

it also ahs 10 or more copies of the opa genes

true

loss of mucosal cell impairs hosts ability to cler bacteria trapped in the mucus and facilitates colonization of bacteria in the lung

true

lps can be chopped off surface of outer membrane, but large quantities are relseaed when bact die from lysis (as with the use of certain antiboitics)

true

main source of infection is from drinking contaminated water or consumption of food that is washed or irrigated with it

true

many female patients will have a positive ulcture result but a negative cervical gram stain result for N. gonorrhoeae

true

many of these dtection methods involve using antibodies that recognize determinants expressd on the surface of the pathogen.

true

medically it has been used as a powerful neurotixin in ocmbination with phyriscal therapy to treat severely spastic muscles

true

methicillin resistant staphylococcus auerus = MRSA

true

microscoopy helps with a preliminary disagnosis of only a few bacterial pathogens.

true

microscopy is important because it might not be possibel to cultiavate the bacterium outside of the host

true

microscopy: look for gram negative diplococci within neturophils because diploccoci are not typically part of the microbiota of the genitouriniary tract

true

more than 95% o the resistant strains produce a penicillinase to detoxify the antibiotic

true

most animals do not show signs of disease when ifnected with S. thyphimurium but in mice S. typhimurium causes a diesease that resembles human typhoid fever

true

most expersts have discounted the delivery of the toxin through the water supply because the toxin woudl be highly diluted and it would likely stick to particulates that are in the water

true

mutants of N. gonorrhoeae that lack opa prteins are not engulfed by neutrophils ad hav ebeen implicated with PID and gonococcal arthritis

true

mutants or stnaturally occuring strains of Vibrio cholerae that do not produce CT do not cause full blown form of diesease but milder due to the presence of other toxins

true

n ifnected surgivcal wound can result in diesease in any part of the body

true

need to give patients large amouns of water: salts and glucase,, like Gatorade

true

neurotoxins specifically interfere with nerve cell function like tetanus p. 49)

true

new infectious diseases are continuously emerging

true

no eating food, bev, or ice cream from street vendors

true

nosocomial infecions most oftn occur as urinary, respiratory, cutaenous, or cardiovascular infections

true

obligate: MUST grow within host cells adn cannot be cultivated utside host (p. 55) like chlamydia

true

often, hospital pathogens carry a plasmid which carries a gene for antibiotic resistance, and this plamid can be quickly spread among the populations of pathogenic bacteria

true

once inside, Salmonella uses SPI2 type III injector system to inject proteins into the membrane of the endocytic vesicle (endosome) to alter the structure so that it can no longer fuse with lysosomes (that would normally lead to the killing and digestion of the bacteria).

true

once of one of the B subunits has bound to a glycolipid receptor in the cytplasmic membrane of the intestinal epithelial cells, the CT endocytoses and travels to the ER.

true

once phagocytosed, the abcteria are killed by oxygen-dependent mechanisms

true

one major antigen of the capsular antigen, Vi, is possesed onlly by afew serovars of salmonella, primarily those that cause typhoid fever.

true

paper disks impregnated with varous antibiotics are placed on the surface of the plate and the antibiotic is allwoed to diffuse into the culture medium.

true

pathogenesisis is usually dependent on thepossession of multiple virulence factors (ie.e., it is multifactorial)

true

pathogenic bacteria can be killed in aptient but the diases may persist due to the continued action of the toxins

true

patient's throat is wabbed and strep antigen is extract directly from the swab (without prior bacterialogical culture).

true

patients are exposed to numerous pathogens in a hospital setting, many of which may be resistant to antibiotics

true

patients iwht gastric abnormalities are also susceptible to low infectious doses

true

patietns often have wekeaned immuen systems (i.e., they are a compromised host) whih make them more susceptible to infection

true

penicillin and tetracycline are no longer recommende for treatment in canada.

true

penumococcal pneumonia often follows an upper respiratory tract infection.

true

people who abuse alcohol are also at increased risk. this is because alcohol acts as a sedative and can diminish the reflexes that trigger coughing and sneezing. alcohol also interferes with the actions of macrophages, the white blood cells that destroy bacteria and other microbes

true

physicisn sometimes succumb to pateints request and write prescriptions whtout ordering costly tests to pinpoint hte patient's illness

true

positive test is indicated by swelling of capsule which can be viewed under a phase contrast microscope. (reaction called quellung reaction : german for swelling)

true

prevalence of disease is fraction of population having symptoms of the disease durin a specific time period. this means being newlyy acquired and established cases

true

primary isolation media is often a general purspoe media such as blood agar.

true

provides protection from many antibiotics that dont penetrate host cells (p. 55)

true

reactivation of the dsease can lead to rapidly progressing and offten fatal infections

true

recovery is fast with antibiotics for N. gonorrhoeae

true

rehydration therapy may be required for pateints with severe diarrhea (page 63)

true

resistance develops in bact through natural process of mutation and genetic recombination

true

s. typhi infection can result in a potentially fatal disease in aras where sanitation is not adequate.

true

salmonella is an example of an intracellular pathogen that hides from hosts immune defence (p.56)

true

salmonella is the genus, a division tha groups similar though not identical bacteria together

true

salmonella is transmitted from feces of infected people or animals to toehr people or animals via contaminated food or drink

true

salmonella on surface of chicken carcasses sold in stores can be rapidly killed by cooking (page 59)

true

salmonella typhiurium -> a causativ agent of food poisoning has an ID of 1 million

true

selective media is on in which compounds are used to inhibit growth of certain bacteria, but not other types of bacteria

true

septicaemia is when bacteria are multiplying in blood

true

serolgoical methods employ use of antibodies and include agglutination tets, ELISAs and WEstern blots

true

severe gluid and electrolyte loss results in dehydration, anuria (loss of urination) acidosis, and shock

true

severe ulceration of intestine may occur, where infection is fatal

true

she refused to have her gall bladder removed and was labeled as a public health hazard

true

shedding/destruction of epithelial cells taht become colonized with bacteria

true

simple attachment can be done through a receptor on host cell surface (glycoproteins, glycolipids)

true

since the pili is the major virulence factor of N. gonorroheae, there have been many attmpts to produce a vaccine on this surface antigen

true

small pox is only human disease to be eradicated worldwide through use of a vaccine

true

small stretches within a pilS gene can be recombined into the pilin expression locus resulting in chimeric pilin types

true

smokers are at risk because cig smoke can nijure airways and dmg the cilia.

true

sodium, potassium, and bicarbonate ions follwo due to osmosis and the electrical gradients caused by the loss of chlorine ions.

true

some bacter possess many vf like salmonella species

true

some bacteria carry getnetic info that makes the mresistant to the AB they produce; for example , they may have a gene that encodes an enzyme that can modify the antibiotic by breaking a bond or by adding a phosphate grup

true

some bacteria possess few vf like vibrio cholerae

true

sometimes interaction between pathogen and host is specific. this is based on host speicficity and tissue type specificity.

true

spores are infective form for humans and animal

true

spores are stable structures that can be stored in the dried form for years

true

stocks of variola virus are kept in secure facilities at the CDC Atlana and in russia but ther has been controversy as to twhether thes stock should be destroyed

true

strep pneumoniae bacteria can be difficult to grow so a negative result oes not rule out pneomonococcal pneumonia.

true

strep pneumoniae causes 3k-6k meningitis in US each year, with fatality of 30%, but 60% in older. meningtitis occurs when bacteria from bloodstream attach to the membranes that cover the brain and spinal column.

true

strep pneumoniae causes 6 million cases of otitis media (ear infection) each year in the states

true

strep pneumoniae causes alpha hemolysis (greening hemolysis form a reduction in the red blod cell hemoglobin) while growing on blood agar plates in aerobic conditions.

true

strep pneumoniae causes pneumococcal pneumonia, the most common clinical presentation of disease among adults.

true

strep pneumoniae is an example of an opportunistic pathogen

true

strep pneumoniae is very sensitive to heat, cold, and drying

true

strep pneumoniae major virulence factors: anti-phagocytic polysaccaride capsule (p. 46), several adhesisns, pneumolysin (a txoin that binds to cholesterol in host cell membrane nad risrupts them by forming pores), and lipotecihoic acid (LTA)

true

successful isolated can be slow and in or impossible because certain human pathogens cannot be isolated in the laboratory ofr grow extremely poor in culture

true

symptoms for inhalazation anthra are non specific and disease is difficult for doctors to diagnose

true

symptoms may appear 1-14 days after infection but many many my be asymptomatic

true

symptoms may include difficuly peeing, vaginal discharge, absnormal or intermenstrual bleeding, abnormal or pelvic pain

true

symptoms of meningitis include headache, lethargy, vomiting, irritability, fever, seizures and coma

true

tVibrio cholerae withstand propulsive gut motility by their own swimming ability and chemotaxis directed aginst the gut mucosa

true

taxominist suggest there woudl only be two species of salmonela: salmonella enterica and salmonella bongori, and that preivousl designated disase causing species be designated as serovars.

true

teratment with antibiotics (ampicillin, gentamicin, trimehoprim, or ciprofloxacin would be used to treat infections that have spread from the intestine

true

the A subunit actiavtes adenylate cycalse, and enzyme that converts ATP to cAMP.

true

the A subunit is retrotranslocated to the cytoplasm

true

the DDAST test is performed under standardized conditions and standard zones of inhibition have been established for each antibiotic

true

the LPS is then transferrd to TLR4 protein on macrophage.

true

the N terminal region of pilin is highly conserved.

true

the antibody that is induced results in effective opsonization of bacteria and contribteus to the hosts recovery.

true

the bacteria are picked up by the underlying macrophages that are associated with the Peyer's patches (the lymph tissue of the intestine)

true

the basic preimase behind all thees tests mentioened is that antibodies are highly selctive in terms of the proteins (or other structure) to which they bind, to the point that they are able to distniugihs proteins expressed form one strain among many others

true

the capsule can hide compoentnts like petidoglycan which can induce alternet complement pathway and prevent formation of c3b complex.

true

the clinical specimen is first plated onto selective and differential media and idenfication of suspicious colonies is done by biochemical tests

true

the conditions can produce muscle cramping, nausea, vomiting, fever.

true

the cytokine binds to certain receptors on the hypothalamus endothelium

true

the death rate in cutaenous anthrax is less than 20%

true

the diagnosis can be confirmed by observing the agglutination of latex beads coated with antibodies that recognize the bacterial antigen of group A strep

true

the emergence and spread of multi drug resitant pathogens has inrease substantially over the past 20 years

true

the first host barrier for many invading pathogens is usualy a mucosal surface such as gut or respiratory tract

true

the food suppply is the greater concrern since the large number of bacteria can be ingested

true

the full blown form of sieases is caused by an enterotoxin produced by the baccterium and is manifested as a massive diarrhea (fluid loss of up to 20 litres a day WOW)

true

the genes may have been acquired during evolution by horizontal gene transfer and are often associate with abcteriophage or prophage genes

true

the host responds to adherent oragnisms through: producing of antibodies against bacterial surface

true

the hosts body moutns and inflammatory resposne which si respnosibel for most of the symptoms of gonorrhea

true

the injected proteins disrupt normal host cell function and promote internalization of the bacteria

true

the intracellular environment shields them from host's immune system (complement, antibodies, phagochtosis)

true

the loss of poatassium ions may result in cardiac complicatons and ciruclatory failrue

true

the lps is picked up a serium protein called LPS binding protein and transferred to cd 14 of a macrophage

true

the lsot water and electrolytes in mucosal cells are replced from the blood.

true

the macrophage produces prostaglanding which acts on the intestinal epithelial cell to increase the itnernal concentration of cAMP

true

the macrophages carry the spores to the lymph nodes.

true

the major virulence factors for Vibrio cholerae include cholera toxin, Tcp pili and it flagellum for motility. our discussion will focus on the cholera toxin (p. 51)

true

the membrane 'ruffling' and the formation pseudopods engluf the bacterium and internalize it inside an endocytic vesicle.

true

the mortality may exceed 50% even with treatment

true

the mrNA is translated and cytokine is secreted.

true

the nomenclauture was originally based on the one sertype-one species concept, based on serologic identifiaction of the O and H antigens

true

the onset is generally sudden after an incubation period of 6 horus to 5 days.

true

the pathogen should be reisolatd from the experimentalyl infected animals and shown to be the same as the original pathogen islated in step 2

true

the patients sysmptoms typically beign to improve after ceiving antibiotic treatment for 24-48 hours.

true

the presence of microorganisms on the host does not always lead to disease

true

the proportion of samples resistant to ciprofloxacin has risen more than two hudnred fold in the alst decade

true

the reduced uptake of Na+ results in a charge iimbalance, and Cl- from the ell are secreted into the lumen of the intestine. this creates an osmotic balance and water is then secreted into the lumen of the intestine, resulting in diarrhea

true

the route of entry of the pathogen into the body affects the dose -> S typhimurium injected intravenously into mice has LD50 of 10. while orally LD50 of 5 million

true

the ruffles (ruffling) of an itnestinal cell memrbane induced by Salmonella is the result of rearrangement of the filamentous actin cytokeleton caused by the injection of effectors by the bacteria using one of its type III secretion systems

true

the second is that there are no animal models for a specific diesease

true

the secondary stage of desiease results in difficulty breathing, neurological problems and can progress to death

true

the sensor trasmitter (sensor kinase) is activated by a signal, resulting in a conformational chang and subsequent autophosphorylation by ATP

true

the serotype is identified by antigenic analysis of O (cell call anteigen) and H (flagella antigen) antigens using polyvelanet and specific antisera

true

the spores germianted into actively dividing bacteria in the lungs and the lympnodes, and begin to produce two toxins

true

the spread of nosocomial infections can be minimized by isolating highly infectious patients and by good housekeeping measures (diseinfection of all surfaces like floors, door handles, and beds) barrier protection (wearing gloves,caps,gowns) and good hand washing practicess

true

the success of these efforts have been twarted by the extensive antigenic variation of pilin

true

the top four bioterrorist pathogens: bacillus antracis, variola virus, persinia pestis, botulism toxin

true

the ttime it takes for bacteria to translocate across tehse cells may allow time required for a response by activated macrophages

true

the two injected ones are whole dead bacteria and one of capsula material with Vi antigen

true

theTersinia pestis is a causative agent of the bubonic plague

true

ther are efforts to develop chicken vaccines as a preventative measure

true

there are three commercial vaccines available, two are injected and one oral vaccine

true

there are two major impediments that can prevent defienitive proof of causation using koch's postulates

true

there arent suficient stocks of vaccine to vaccinate everybody

true

there is a vaccine for anthrax but limited supplly and several immunizaitons are required to develop immunity to B. anthracis.

true

there is increaseing resistance to new drugs such as erythromycin and teratracycline. penicillin and penicilin derivatives used to work

true

these are impotant determinants of the colonization of V. cholerae in the small intestine: Tcp pili, and outer membrane proteins required for tighter bindign ot host cells

true

these colonies are observed for size, texture, color, and hemolytic reactions (if grown on blood agar) and are an important first step in bacterial identification.

true

they acuse buboes, huge blisters then premature death of cell

true

they may also occur single and in short chains

true

they replicate inside the unactivated macrophages.

true

they trancnscytose through the cell and enter into the subepithelial space

true

this change in ion concentration results in secrtetion of large amounts of water into the intestinal lumen

true

this convers ATP into cyclic AMP (cAMP)

true

this course focuses on LPS of gram negative bacteria

true

this i followed by inflammation and phagocytosis of bacteria by neutrophils and macrophages and recruitment of T and B cells

true

this is beause anthrax is a toxin mediated disease, and killing the bacteria doe not eliminate the toxins.

true

this plague was devasting to europe in the middle ages killing 1/3 of the population

true

this provides the bacteruim with a mechanism to produce approx one million different antigenic varients

true

three main serovars of Salmonella enterica are Typhi, Typhimurium, and Enteritidis

true

thus the toxin damageed cell become pumps for water and electrolytes causesing the diarrhea, losso f eelctronlytes, and dehydration

true

toins are microbial products that can damge the host

true

toxins can cause diasese indepdentnt of bacterium. (p. 49)

true

treatment: rapid replacement of fluids and electrolyte through oral rehydration

true

tuberculosis causes the disease tuberculosis, which often is an infection of the lungs

true

tuberculosis is spread from perso nto person

true

tuberculosis is still amajor public health concern

true

two toxins: edema and lethal

true

type I fimbriae and H antigen are helpful with adherence.

true

untreated cholera results in high mortality rate

true

untreated gonnoreha in women (14-30%) of infections is dessemination into the uterus and fallopian tubes causing pelvic iinflammatory disease (PID)

true

variants that have changes in the strcture of a surface molecule can then evade teh hosts antibody response

true

vertical gene transfer (where mutations are passed to progeny of the cell) can create a larger pool of antibiotic resitant bacteria

true

virulence factors allows pathogenic bacteria to infect normal people and cause disease

true

we can administer antibodies from human donors or animal donors to bolster tha immune system of victims

true

we have vaccines for many of the agents

true

we identifify strep pneumoniae with grampositive statining, hemolytic activity and bile sensitivity

true

we understand how dssease is spread. we know how to prevent hte spread ofdisease

true

weaponized antrhax: spores have been dried, mixed with some powder, ground to produce smaller spore coated particles

true

when ppl fail to complete prescipritons, virulent pathogen are subjected to sublethal doses of antibotic and remian alive to revolve into resitant organisms

true

whether or not the organism requried oxygen for growth is another important differentiating characteristic

true

whif each serotype was considerd a differnt species, salmonella would have over 2400 speice

true

symptoms of ifnection appear 6-24 hours after ingestion and last up to 7 days

true (page 58)

A vaccine cannot be used for endotoxins

true because non protein and not immunogenic.

N. gonorrhoeae is strictly a human pathogen and is the causative agent of Gonorrhea

true.

the most obvious consequnce of antibiotic use has been the inreased rates of mortality when physicains are not able ot terat patients effectively and in a timely manner

true.

toxoids are toxins that hav ebeen treated with heat or chemicals to make them non toxic to the patient. but sitll capable of stimulating the production of neutralizing antibodies for future toxins

true@

when bacteria lyse (some), they release pneumotoxin and damage mucosal host cells

truq

in many cases, the identification of a abcterial pathogen involves the initial isolation and identification using growth-dependent methods, with confirmation ussing serological assays(growth independent methods)

ttrue

antibiotics are smal lchemical molcules that kill bacteria (are bactericidal) or inhibit their growth wihout directly killing them (bacteriostatic)

ture

for example, under the new nomenclature system, salmonella typhi is now known as salmonella enterica serova typhi, and salmonella typhiurium is now called salmonella enterica serovar typhimurium (abbreviated S. typhimurium)

ture omg so compliated

strep pneumoniae invade and grow primarily due ot their resitance to the host phagocytic response (p. 48)

uh durr true

__________ transmission is where diases is transmitted by living agents such as insects, ticks, mites, fleas, rodents, and other animals

vector

________ is ther relative ability of a pathogen to acuse disease and can be estimated by experimental studies to etermine the infectious and lethal doses

virulence

vaccination against toxin mediated diseases can be done with antibodies

what not u use TOXOIDS

some diasese occur in both humans and animals (animal reservoirs) diseaes that occur primarily in wild or domestic animals can be transmitted to humans are called ________

zoonoses