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