Chapter 14,10,9 summary review
High numbers of cases spread across multiple continents in a specific time frame is known as what?
A pandemic
What is a reservoir?
A place where microorganisms survive, multiply, and await transfer to a susceptible host
What kind of organism might survive an autoclav?
A thermophil or a hyperthermophil
What is betadine?
A topical microbicide agent used for skin and wound infections. An antiseptic
The microbial death rate is used to measure the effectiveness of . a detergent an antiseptic sanitization techniques all of the above
D: All of the above
What are some advantages and disadvantages of using ionizing radiation to sterilize food?
Advantages - kills microbes, larvae & eggs; also kill cells that spoil or over ripen fruits & vegetables Disadvantages - Can be cancer causing & change taste & nutritional value of fruit & vegtables
Compare airborne and aerosol
Aerosols are clouds of water droplets that travel more than 1 meter in airborne transmission. Airborne simple means that something is able to travel through the air on something such as an aerosol.
Compare and contrast the action of alcohols, halogens, and oxidizing agents in controlling microbial growth.
Alcohol - denatures proteins & disrupts cell membrane (ETOH) Halogens - denatures proteins including enzymes (Cl & iodine )Oxidizing agents - denatures proteins by oxidation (hydrogen peroxide & peracetic acid)
Who discovered penicillin?
Alexander Fleming
one member is harmed while the second is neither harmed nor helped
Amensalism
Invitro vs invivo
An in vitro study occurs in a controlled environment, such as a test tube or petri dish. In vivo is Latin for "within the living." It refers to tests, experiments, and procedures that researchers perform in or on a whole living organism, such as a person, laboratory animal, or plant.
Describe a mechanical vector
An organism that carries a disease without being infected itself.
Describe a vector
An organism that carries a disease.
Describe synthetic drugs
Antimicrobials that are completely synthesized in a laboratory
Antibodies the host forms against exotoxins are called what?
Antitoxins
Describe halogens
Any of the four very reactive, nonmetallic chemical elements: iodine, chlorine, bromine, and fluorine. Halogens are intermediate-level antimicrobial chemicals that are effective against vegetative bacterial and fungal cells, fungal spores, some bacterial endospores and protozoan cysts, and many viruses.
Which of the following goes through pasteurization? Autoclaved agar bleached counter apple juice?
Apple juice
What are "magic bullets" and who coined the phrase?
Arsenic compounds that killed microbes and it was coined by Paul Ehrlich.
Which of the following statements is true concerning the selection of an antimicrobial agent? An ideal antimicrobial agent is stable during storage. An ideal antimicrobial agent is fast acting. Ideal microbial agents do not exist. All of the above are correct.
D: All of the above are correct
Which of the following are most likely to cause disease? opportunistic pathogens in a weakened host pathogens lacking the enzyme kinase pathogens lacking the enzyme collagenase highly virulent organisms
D: Highly virulent organisms
Which of the following statements is the best definition of a pandemic disease? It normally occurs in a given geographic area. It is a disease that occurs more frequently than usual for a geographical area or group of people. It occurs infrequently at no predictable time scattered over a large area or population. It is an epidemic that occurs on more than one continent at the same time.
D: It is an epidemic that occurs on more than one continent at the same time.
Which of the following terms best describes the disinfecting of cafeteria plates? pasteurization antisepsis sterilization sanitization
D: Sanitization
Which of the following adjectives best describes a surgical procedure that is free of microbial contaminants? disinfected sanitized degermed aseptic
D: aseptic
Which antimicrobial chemical has been used to sterilize spacecraft? phenol alcohol heavy metal ethylene oxide
D: ethylene oxide
Which of the following substances would most effectively inhibit anaerobes? phenol silver ethanol hydrogen peroxide
D: hydrogen peroxide
A company that manufactures an antimicrobial cleaner for kitchen counters claims that its product is effective when used in a 50% water solution. By what means might scientists best verify this statement? disk-diffusion test phenol coefficient filter paper test in-use test
D: in-use test
Which of the following items functions most like an autoclave? boiling pan incinerator microwave oven pressure cooker
D: pressure cooker
Which of the following disinfectants contains alcohol? iodophor quat formalin tincture of bromine
D: tincture of bromine
Heavy-metal ions, Irons of arsenic, silver, mercury, copper, and zinc, are low-level disinfectants that do what?
Denature proteins
Compare and contrast desiccation and lyophilization.
Desiccation - Inhibits growth by removing water that microbes need to metabolize Lyophilization - Uses freezing and drying to preserve microbes for many years, this is long term preservation of microbial culture.
Small numbers of regularly occurring diseases throughout a region is also known as a what?
Endemic (sporadic)
What two things are resistant to disinfectants?
Endospores and prions
High numbers of cases in a concentrated area during a specific time frame is known as what?
Epidemic
The study of where and when diseases occur and how they are transmitted within populations is .
Epidemiology
Compare between biological vector and mechanical vector transmission
Examples of biological vectors would be mosquitos, fleas, ticks. Example of mechanical vectors would be
In terms of microbial control, what does osmotic pressure do?
Exposure to hypertonic solutions it inhibits metabolism which allows for preservation of foods.
How can campers effectively treat stream water to remove pathogenic protozoa, bacteria, and viruses?
Filtering stream Boiling water for at least 1 minute Iodine tablets Adding a couple drops of Cl to 2 liters of water
Corals are colonial marine animals that feed by filtering small microbes from seawater in tropical oceans worldwide. Biologists have discovered that the cells of most corals are hosts to microscopic algae called zooxanthellae. Design an experiment to ascertain whether corals and zooxanthellae coexist in a mutual, commensal, or parasitic relationship.
Find coral that doesn't have those particular microbes present and then compare them to the corals that do. Note any differences and determine if they are positive or negative impacts. If the coral with the zooxanthellae have a benefit the other coral doesn't it would mean that the coral and microbes have a mutualistic relationship. By observing the pros and cons, if any, you can determine which type of relationship the two organisms have.
What do Sulfonomides do?
Folic acid / PABA inhibitor
Nonliving reservoirs of disease, such as a toothbrush, drinking glass, and needle, are called
Fomites
Where do newborns get their normal flora?
From colonization and the environment around them.
Name the 2 sources for most antibiotics
Fungi and bacteria
Why are Gram-negative bacteria more susceptible to heat than Gram-positive bacteria?
Gram (+) bacteria has a thicker peptidoglycan layer than gram (-) & gram (-) has an outer membrane of LPS which contains lipid A
__________infections are those acquired by patients or staff while in health care facilities.
Healthcare-associated;
Explain why Ellen H., a menopausal woman, may have developed gingivitis from her resident microbiome.
Her hormones levels changed which also changed her microbial counts in her mouth.
A prionzyme is denatured by what?
High temps
If a mutation occurred in Escherichia coli that deleted the gene for an adhesin, what effect might it have on the ability of E. coli to cause urinary tract infections?
It would render the E. Coli avirulent
UV light and HEPA filters help what
Keep air clean
3 weakest microbes in order from strongest to weakest
Large enveloped viruses, Most gram + bacteria, enveloped viruses
A disease in which a pathogen remains inactive for a long period of time before becoming active is termed a(n) .
Latent
Who proposed the germ theory of disease
Louis Pasteur
Human tears contain what enzyme and what does it do?
Lysozyme and it digests peptidoglycan cell wall of bacteria
The permanent loss of reproductive capacity in microbes is called what?
Microbial death
Organisms making up the ____ live in and on the body
Microbiome
List 4 virulence factors
Toxins, adhesion factors, extracellular enzymes, antiphagocytic factors
Airborne, waterborne, and foodborne transmissions are all forms of what?
Vehicle transmissions
Which of the following phrases describes a contagious disease? a disease arising from fomites a disease that is easily passed from host to host in aerosols a disease that arises from opportunistic members of the resident microbiome both a and b
B: A disease that is easily passed from host to host in aerosols
Which of the following types of epidemiologists is most like a detective? descriptive epidemiologist analytical epidemiologist experimental epidemiologist reservoir epidemiologist
B: Analytical epidemiologist
Which of the following substances or processes kills microorganisms on laboratory surfaces? antiseptics disinfectants degermers pasteurization
B: Disinfectants
Which of the following chemicals is active against bacterial endospores? copper ions ethylene oxide ethanol triclosan
B: ethylene oxide
Match the following diseases with the level lab that would handle them. Ebola (droplet) MRSA E.Coli (nonpathogenic) Covid (airborne)
BSL 1: E. coli BSL 2: MRSA BSL 3: Ebola BSL 4: Covid
Compare bacteriocidal and bacteriostatic
Bacteriocide kills bacteria (think homicide) whereas bacteriostatic just stops bacterial movement.
Hyperthermophilic prokaryotes may remain viable in canned goods after commercial sterilization. Why is this situation not dangerous to consumers?
Because hyperthermophilic microbes grow at 85 degree C and not at 37 degree C where we store our food.
Why is it necessary to use strong disinfectants in areas exposed to tuberculosis patients?
Because tuberculosis cell wall has lots of waxy lipids mycolic acid, which allows bacteria to survive drying & protects it from most water-based chemical.
Why do warm disinfectant chemicals generally work better than cool ones?
Better penetration with heat
An animal that carries a pathogen and also serves as host for the pathogen is a _____________vector.
Biological vector
What do fluoroquinolones do?
Block DNA synthesis
A sample of E. coli has been subjected to heat for a specified time, and 90% of the cells have been destroyed. Which of the following terms best describes this event? thermal death point thermal death time decimal reduction time none of the above
C: Decimal reduction time
Consider the following case. An animal was infected with a virus. A mosquito bit the animal, was contaminated with the virus, and proceeded to bite and infect a person. Which was the vector? animal virus mosquito person
C: Mosquito
The preservation of beef jerky from microbial growth relies on which method of microbial control? filtration lyophilization desiccation radiation
C: dessication
Which of the following substances is least toxic to humans? carbolic acid glutaraldehyde hydrogen peroxide formalin
C: hydrogen peroxide
Pathogenicity is a microorganism's ability to
Cause disease
Describe semi-synthetic antimicrobial agents
Chemically altered antibiotics—that are more effective, longer lasting, or easier to administer than naturally occurring antibiotics.
Kinase breaks up what?
Clots
one member benefits while the other is relatively unaffected.
Commensalism
What are the 3 modes of transmission
Contact, vehicle, vector
Animal reservoirs harbor agents of
Zoonoses
Describe iodine
a well-known antiseptic used as a tincture or an iodophor.
Describe epidemic
a widespread occurrence of an infectious disease in a community at a particular time. (more cases than usual)
Factors affecting the efficacy of antimicrobial methods include
the site to be treated, the relative susceptibility of microorganisms, and environmental conditions.
Describe vehicle transmission
the transmission of pathogens that involves a medium such as water, food, and air
Describe latent disease
those in which a pathogen remains inactive for a long period of time before becoming active. Herpes is an example of a latent disease.
prevalence refers to
total number of cases
Epidemiology is the study of
where and when diseases occur and of how they are transmitted within populations.
Describe pandemic
worldwide epidemic (more than one continent)
Diseases that are naturally spread from their usual animal hosts to humans are called
zoonoses
For Methods for Evaluating Disinfectants and Antiseptics, describe phenol coefficients
▪ Evaluates efficacy of disinfectants and antiseptics ▪ Compares an agent's ability to control microbes to phenol ▪ Greater than 1.0 indicates agent is more effective than phenol ▪ Has been replaced by newer methods
inanimate objects, including soil, water, and food.
Nonliving reservoirs of infection
Describe sporadic
Occasional
cause disease when the immune system is suppressed, when normal microbial antagonism (microbial competition) is affected by certain changes in the body, or when a member of the normal microbiome is introduced into an area of the body unusual for that microbe.
Opportunistic pathogens
Hydrogen peroxide, ozone, and peracetic acid are high-level disinfectants and antiseptics that release oxygen radicals, which are toxic to many microbes, especially anaerobes are called what?
Oxidizing agents
Host is harmed but other organism benefits?
Paratisism
portals of entry may be bypassed via the
Parenteral route, by which microbes are directly deposited into deeper tissues.
Defend the following statement: "Pasteurization is not sterilization."
Pasteurization allows thermophilic & thermoduric bacteria to survive (not pathogenic) & sterilization kills all microbes
Exotoxins are secreted by
Pathogens
Penicillin is released from...
Penicillium
Compare and contrast four tests that have been developed to measure the effectiveness of disinfectants.
Phenol coefficient - Oldest method/efficiency against phenol; the greater the ratio the better Kelsey-Sykes capacity - Use in Europe/bacterial suspension added to chemical, lack of turbidity is lack of bacterial growth In-use - Checks real life situations/swab from a suspected site to media and check for growth, most realistic to determining efficacy of chemica lUse - Use in US/Dip metal cylinders into broth culture of bacteria & dry 36 degree C
The total number of cases of a disease in a given area is its
Prevelance
Top 3 most resistant microbes in order from strongest to weakest
Prion, bacterial endospores, cysts of cryptosporidium
Living and nonliving continuous sources of infectious disease are called
Reservoirs of infection
Who developed a series of essential conditions to prove the cause of infectious diseases.
Robert Koch
Who discovered antibiotics?
Selman Waksman is known for his studies of the soil microbes that led to the discovery of streptomycin.
List and describe a few surfactants
Soaps and detergents: Soaps have hydrophilic and hydrophobic ends. Good degerming agents but not antimicrobial. Detergents are positively charged organic surfactants. Quatenary ammonium compounds (quats): Low-level disinfectants Disrupt cellular membranes Ideal for many medical and industrial applications
Describe aerosalization
Something such as a pathogen catches a ride on a droplet of some medium such as water or mucous. Typically only goes about a meter.
whereas thermal death time is the time it takes to completely
Sterilize a volume of liquid at a set temperature.
Synergism vs Antagonism
Synergism: Positive interaction; effect becomes more than what we would expect. Antagonism: Negative interaction; effect becomes less than what we would expect.
Name 5 antibiotics
Tetracycline Penicillin Vancomyocin Sulfonamides Fluoroquinolones
Will P. died of E. coli infection after an intestinal puncture. Explain why this microbe, which normally lives in the colon, could kill this patient.
The microbiota left its regular habitat (the colon) and inhabited a new area it's not supposed to be. Change of location
Microbial death rate measures the efficacy of an
antimicrobial agent
Antibacterial drugs constitute largest number and diversityof
antimicrobial agents
Describe an idophor
any of a group of disinfectants containing iodine in combination with a surfactant.
Infections that may go unnoticed because of the absence of symptoms are called infections.
asymptomatic or subclinical;
Some bacteria and viruses lose the ability to make adhesion factors called adhesins and thereby become
avirulent
When an infectious disease comes from another infected host, either directly or indirectly, it is a
communicable disease
An axenic environment is one that
contains only one species
A patient contracted athlete's foot after long-term use of a medication. His physician explained that the malady was directly related to the medication. Such infections are termed .
endogenous infections
Define an aseptic environment
environment or procedure is free of contamination by pathogens.
The study of the cause of a disease is .
etiology
Name two types of toxins
exotoxins and endotoxins
Describe subacute disease
have durations and severities that lie somewhere between acute and chronic.
Pasteurization is a process using
heat to kill germs in food
Aldehydes are
high level disinfectants
What are nosocomial infections? (Also known as Healthcare-associated infections)
hospital acquired infections from either procedures or the environment.
Mechanical vectors are not
hosts to the pathogens they carry.
Experimental epidemiology involves testing a
hypothesis resulting from analytical studies.
The disease process—the stages of infectious diseases—typically consists of the
incubation period, prodromal period, illness, decline, and convalescence.
List the 5 stages of an infectious disease in proper order.
incubation, prodromal, illness, decline, and convalescence
What are iatrogenic infections
induced by treatment or medical procedures
Antisepsis is the
inhibition/killing of microorganisms (particularly pathogens) on skin or tissue by the use of a chemical antiseptic, whereas disinfection refers to the use of agents (called disinfectants) to inhibit microbes on inanimate objects.
What does penicillin do?
inhibits cell wall synthesis
What does vancomycin do?
inhibits cell wall synthesis / ala ala link Vancomycin inhibits bacterial cell wall synthesis by binding to the peptidoglycan peptide terminus d-Ala-d-Ala found in cell wall precursors
What does tetracycline do?
inhibits protein synthesis CAN BE HARMFUL
Describe alcohols
intermediate-level disinfectants that denature proteins and disrupt cell membranes; they are used either as 70% to 90% aqueous solutions or in a tincture, which is a combination of an alcohol and another antimicrobial chemical.
Describe the parenteral route of infection.
involves a puncture through the skin.
whereas the suffixes -cide and -cidal indicate that the agent
kills or permanently inactivates a particular type of microbe.
The toxic portion of LPS is the lipid, called
lipid A
Endotoxin, also known as_____ , is part of the outer (wall) membrane of Gram-negative bacteria.
lipopolysaccharide (LPS) or lipid A
Endotoxins are
lipopolysaccharides (LPS) released from the cell wall of dead and dying Gram-negative bacteria and can have fatal effects.
When boiling water, less pressure =
lower temp needed to boil the water
Thermal death point is the
lowest temperature that kills all cells in broth in 10 minutes
Describe three types of microbes that are extremely resistant to antimicrobial treatment, and explain why they are resistant.
methicillin-resistant Staphylococcus aureus (MRSA) vancomycin-resistant Enterococcus (VRE) multi-drug-resistant tuberculosis (MDR-TB)
Portals of exit, such as the
nose, mouth, and urethra, allow pathogens to leave the body
incidence of disease refers to
number of new cases
What are fomites?
objects or materials which are likely to carry infection, such as clothes, utensils, and furniture.
A microbe that causes disease is called a .
pathogen
Any parasite that causes disease is called a
pathogen
What are exogenous HAIs
pathogen acquired from the health care environment
virulence is a measure of
pathogenicity
Droplet transmission (a third type of contact transmission) occurs when
pathogens travel less than 1 meter in droplets of mucus to a new host
The high osmotic pressure exerted by hypertonic solutions of salt or sugar can
preserve foods such as jerky and jams by removing from microbes the water that they need to carry out their metabolic functions.
What does surfactant do?
reduces surface tension
Degerming refers to the
removal of microbes from a surface by scrubbing.
The most frequent portal of entry for pathogens is
respiratory tract
Successful chemotherapy requires what?
selective toxicity
List two types of surfactants
soaps and detergents
An autoclave uses
steam under pressure to sterilize chemicals and objects that can tolerate moist heat.
Microbes live with their hosts in ____ relationships, including ____.
symbiotic, including mutualism
Define sterilization
the eradication of microorganisms and viruses; the term is not usually applied to the destruction of prions.
What is the index case
the first case of the disease in a given area or population.
Microbial contamination refers to
the mere presence of microbes in or on the body or object.
What was the process used for historical batch pasteurization
63 C for 30 minutes
What was the process used for flash pasteurization
72C for 15 seconds
Decimal reduction time (D) is the time required to destroy 90% of the microbes in a sample.
90% of the microbes in a sample.90% of the microbes in a sample.
List Koch's four postulates, and describe situations in which not all may be applicable.
(1) Must be found in diseased but not healthy individuals; (2) Must be cultured from the diseased individual; (3) Inoculation of a healthy individual with the cultured microorganism; (4) The microorganism must be re-isolated from the inoculated, diseased individual and matched to the original microorganism.
Describe halogens
(iodine, chlorine, bromine, and fluorine) are used as intermediate-level disinfectants and antiseptics to kill microbes by protein denaturation in water or on medical instruments or skin.
Describe aldehydes as a means of microbial control
- Compounds containing terminal —CHO groups - Cross-link functional groups to denature proteins and inactivate nucleic acids - Glutaraldehyde disinfects and sterilizes - Formalin used in embalming and disinfection of rooms and instruments
Describe Phenol and Phenolics
- Denature proteins and disrupt cell membranes - Effective in presence of organic matter - Remain active for prolonged time - Commonly used in health care settings, labs, and homes - Have disagreeable odor and possible side effects
Describe heavy metals as a means of microbial control
- Heavy-metal ions denature proteins - Low-level bacteriostatic and fungistatic agents - 1% silver nitrate once used to prevent blindness caused by Neisseria gonorrhoe
Describe the use of osmotic pressure for microbial control
- High concentrations of salt or sugar in foods to inhibit growth - Cells in hypertonic solution of salt or sugar lose water - Fungi have greater ability than bacteria to survive hypertonic environments
Describe the use of halogens as a means of microbial control
- Intermediate-level antimicrobial chemicals - Damage enzymes by denaturation - Iodine tablets, iodophors, chlorine treatment, bleach, chloramines, and bromine disinfection
Describe the use of alcohol as a means of microbial control
- Intermediate-level disinfectants - Denature proteins and disrupt cytoplasmic membranes - More effective than soap in removing bacteria from hands - Swabbing of skin with alcohol prior to injection removes most microbes - Not effective against fungal spores or bacterialendospores
Describe gaseous agents as a means of microbial control
- Microbicidal and sporicidal gases used in closed chambers to sterilize items - Denature proteins and DNA by cross-linking functional groups - Disadvantages:▪ Often highly explosive▪ Extremely poisonous▪ Potentially carcinogenic
What temp does lyophilization reach to freeze things?
-196 C for a few minutes while drying which enables microbes to be stored long term.
Antimicrobial drugs affect pathogens by inhibiting
-cell wall synthesis -translation of proteins -general metabolic pathways -replication of DNA -disrupting cytoplasmic membranes -blocking the attachment of viruses to their hosts -blocking a pathogen's recognition of its host
Antimicrobial methods involving drying are
-desiccation (used to preserve food) -lyophilization (freeze drying) used for the long-term preservation of cells or microbes.
What are the levels of BSL?
1,2,3,4
List four types of symbiotic relationships, and give an example of each.
1. Mutualism - bacteria in the the colon 2. Commensalism - Mites in human hair follicles 3. Amensalism - Fungi secreting antibiotic inhibiting bacteria growth. 4. Parasitism - Tape worms
List three conditions that create opportunities for pathogens to become harmful in a human.
1. introduction of a member of the normal microbiota into an unusual site in the body --> leads to organism becoming an opportunistic pathogen 2. immune suppression --> anything that suppresses the body's immune system can enable opportunistic pathogens 3. changes in the normal microbiota --> normally there is an abundance of normal microbiota which cause microbial antagonism, preventing other pathogens from surviving, BUT if there is less normal microbiota, a member may become an opp. pathogen
What temp (in C) does water boil at sea level?
100 C
Why are alcohols more effective in a 70% solution than in a 100% solution?
100% alcohol will dry bacteria and not kill it
What temperature does an autoclave reach?
121 C
What was the process used for Ultra-High-Temp-Pasteurization
135 C for 1 second
What was the process used for Ultra-High-Temp sterilization
140 C for 1 to 3 seconds
The endospores of which organism can be used as a biological indicator of sterilization? Bacillus stearothermophilus Salmonella enterica Mycobacterium tuberculosis Staphylococcus aureus
A: Bacillus stearothemophilus
In practical terms in everyday use, which of the following statements provides the definition of sterilization? Sterilization eliminates all organisms and viruses. Sterilization eliminates harmful microorganisms and viruses. Sterilization eliminates prions. Sterilization eliminates hyperthermophiles.
A: Sterilization eliminates all organisms and viruses.
Biosafety Level 3 includes . double sets of entry doors pressurized suits showers in entryways all of the above
A: double sets of entry doors
Which of the following types of radiation is more widely used as an antimicrobial technique? electron beams visible light waves radio waves microwaves
A: electron beams
Which of the following is the correct sequence of events in infectious diseases? incubation, prodromal period, illness, decline, convalescence incubation, decline, prodromal period, illness, convalescence prodromal period, incubation, illness, decline, convalescence convalescence, prodromal period, incubation, illness, decline
A: incubation, prodromal period, illness, decline, convalescence
Which of the following disinfectants acts against cell membranes? phenol peracetic acid silver nitrate glutaraldehyde
A: phenol
Which class of surfactant is most soluble in water? quaternary ammonium compounds alcohols soaps peracetic acids
A: quaternary ammonium compounds
Where on a cell does covid invade?
Ace 2
Over 30 children younger than three years of age developed gastroenteritis after visiting a local water park. These cases represented 44% of the park visitors in this age group on the day in question. No older individuals were affected. The causative agent was determined to be a member of the bacterial genus Shigella. The disease resulted from oral transmission to the children. Based only on the information given, can you classify this outbreak as an epidemic? Why or why not? If you were an epidemiologist, how would you go about determining which pools in the water park were contaminated? What factors might account for the fact that no older children or adults developed disease? What steps could the park operators take to reduce the chance of future outbreaks of gastroenteritis?
I wouldn't classify it as an epidemic, mainly because there is too much missing information such as what the normal occurrence of gastroenteritis is in that area. I would collect samples of water from each poop to test for the pathogen. Younger children are known for having weaker immune systems which could account for older kids and the adults not getting sick. Young children are also more likely to swallow the pool water. The operators should check the levels of chlorine in their pools to ensure they're maintaining a toxic environment for pathogenic organisms yet safe for people.
Contrast iatrogenic and healthcare-associated diseases.
Iatrogenic refers to a disease resulting from a medical procedure whereas healthcare-associated diseases refers to a disease that comes from a health care setting. (the environment in the facility)
Why are BSL-4 suits pressurized? Why not just weartough regular suits?
If there is a hole the positive pressure of the air rushing out of the suit will lessen the chances of contamination. The air will push the contaminates away from the hole instead of allowing them to float inside as they would in a non pressurized suit.
What are fomites?
Inanimate objects that harbor infectious agents
Transmission of pathogens via inanimate objects (called fomites) is called
Indirect contact transmission
Contrast the terms infection and morbidity.
Infection: Invasion of a bacteria that will possibly cause symptoms or disease. morbidity is another way of saying disease
List the 7 mechanisms of antimicrobial drugs
Inhibit cell wall synthesis Inhibit protein synthesis Inhibit pathogens attachment to host cell Inhibit RNA synthesis Inhibit DNA replication Inhibit general metabolic pathways Disruption of cytoplasmic membrane
Describe five physical methods of microbial control.
Moist Heat - use to disinfect, sanitize, sterilize & pasteurize, kills cells by denaturing protein & destroying cytoplasmic membrane (disinfecting baby bottles) Dry heat - Used w/ powders, oils & metals. Hot air is used to denature protein & foster oxidation of metabolic & structural chemical .Refrigeration & Freezing - Used in food preparation & storage. Halts growth of most pathogens, because chemical reactions occur slower at lower temperatures.I onizing radiation - denatures molecules DNA, which causes cell death & mutations Osmotic pressure - high concentration of salt & sugar. Used to preserve food like salted fish. Desiccation & Lyophilzations - technique combining freezing & drying
Which of the following is false concerning microbial contaminants? Contaminants may become opportunistic pathogens. Most microbial contaminants will eventually cause harm. Contaminants may be a part of the transient microbiota. Contaminants may be introduced by a mosquito bite.
Most microbial contaminants will eventually cause harm.
A lichen is an intimate relationship between fungi and a photosynthetic microbe in which the fungi deliver water and minerals to the photosynthetic partner, which delivers sugar to the fungi. What type of symbiosis is involved?
Mutualism
In which type of symbiosis do both members benefit from their interaction?
Mutualism
What's it called when both members benefit?
Mutualism
Contrast between narrow and broad spectrum
Narrow spectrum - Drugs that work against only a few kinds of pathogens. Broad spectrum - effective against many different kinds of pathogens
Why would one disease result in a very high number of incidences (new cases) in the first 3 days but fade away quickly thereafter while the other disease would have low numbers of incidences in the first 3 days but would result in far more cases over and longer period of time?
The red epidemic affected more people during the first 3 days. The red epidemic has a short incubation time and is much more contagious; as a result, the susceptible population was infected in a short time. The blue epidemic has a longer incubation time than the red, resulting in a longer time until cases show up and a longer time over which new infections are occurring.
What is the difference between thermal death point and thermal death time?
Thermal death point is the lowest temperature that kills all cells in broth in 10 min. Thermal death time is the time that it takes to sterilize volume of liquid at a set temperature.
Contrast the structures and actions of soaps and quats.
They are both detergents. SOAPS do not kill organism, they are washed off surfaces & QUATS disrupt cellular membrane where the affected cell lose internal ions
Where does lipid A come from
a component of the lipopolysaccharides, also known as endotoxins, found on the outer membrane of Gram-negative bacteria.
Describe endemic
a disease that normally occurs CONTINUALLY
What is pasteurization?
a method of heating foods to kill pathogens and control spoilage organisms without altering the quality of the food
Sanitization is the reduction of
a prescribed number of pathogens from surfaces and utensils in public settings.
When grouped by time course and severity, disease may be described as any one of the following
acute disease, subacute disease, chronic disease, or latent disease.
Pathogens attach to cells—a process called
adhesion
The process by which microorganisms attach themselves to cells is
adhesion
via a variety of structures or attachment proteins called
adhesion factors
The nature of bacterial capsules
affects the virulence of these bacteria
Antimicrobial agents destroy microbes either by
altering their cell walls and membranes or by interrupting their metabolism and reproduction via interference with proteins and nucleic acids.
The suffixes -stasis and -static indicate that
an antimicrobial agent inhibits microbes
Biological vectors are
animals, usually biting arthropods, that serve as both host and vector of pathogens.
Why are Bacillus endospores used as sterilityindicators?
because bacterial spores exhibit elevated resistance to chemical and physical methods of sterilization
When pathogenic bacterial cells lose the ability to make adhesins, they typically
become avirulent
Some bacteria interact to produce a sticky web of cells and polysaccharides called a
biofilm
What does bacitracin do?
blocks secretion of NAG and NAM from cytoplasm thereby inhibiting cell wall synthesis
Descriptive epidemiology is the
careful recording of data concerning a disease; it often includes detection of the index case
Etiology is the study of the
cause of disease
Analytical epidemiology seeks to determine the
cause of the disease
Describe phenolics
chemically modified phenol molecules, are intermediate- to low-level disinfectants that denature proteins and disrupt cell membranes.
Aerosols are
clouds of water droplets that travel more than 1 meter in airborne transmission.
What are endogenous HAIs
derived from the normal microbiota that become opportunistic while in the hospital setting
