Microbiology Test II

Sites to be treated: What can't be used on humans? Choose microbial control based on? Example? Immunocompromised means you have to?

1. Harsh chemicals & heat 2. Site of the procedure because it affects potential for infection; finger nail - must use topical cream, not oral medication because minimal blood supply 3. Steralize

An antimicrobial that inhibits cell wall synthesis will result in which of the following? A. Cells become more susceptible to osmotic pressure. B. Cells cannot attach to their hosts. C. Ribosomes lose their function. D. The sterols in the cell wall become nonfunctional. E. The replication of cells, including cancer cells, slows down.

A

Many antimicrobial drugs that affect the cytoplasmic memrane are used only externally because they can be toxic to humans

A

Most drugs that inhibit the synthesis of the cell wall act by A. preventing the cross-linkage of NAM subunits. B. blocking the secretion of cell wall molecules from the cytoplasm. C. preventing the formation of alanine-alanine bridges. D. disrupting the formation of the mycolic acid layer of the cell wall. E. preventing the formation of ?-lactamases.

A

Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes? A. quinolones B. actinomycin C. rifampin D. tetracycline E. 5-fluorocytosin

A

Who discovered the first widely available antibiotic? A. Domagk B. Ehrlich C. Fleming D. Waksman E. Ehrlich and Waksman

A

The mechanism of action of erythromycin is A) inhibition of protein synthesis B) inhibition of cell wall synthesis C) inhibition of nucleic acid synthesis D) inhibition of metabolic pathway E) disruption of cytoplasmic membranes

A - Inhibition of protein synthesis

Which of the following is an example of sanitization

A public toilet is treated with disinfectants.

The mechanism of action of sulfonamides is A) inhibition of metabolic pathways. B) inhibition of cell wall synthesis. C) inhibition of nucleic acid synthesis. D) disruption of cytoplasmic membranes. E) inhibition of protein synthesis.

A- inhibition of metabolic pathways

Antimicrobials that block protein synthesis by binding to the mRNA are A. aminoglycosides. B. antisense nucleic acids. C. macrolides. D. beta-lactams. E. nucleic acid analogs.

B

B-lactamase production is an example of which of the following types of resistance? A. alteration of the target of the drug B. inactivation of the drug C. change in the permeability of the drug D. overproduction of an enzyme in a key metabolic pathway E. removal of the drug via a pump

B

Beta-lactam antibiotics have an effect on which of the following types of cells? A. animal cells B. bacterial cells C. fungal cells D. virus-infected cells E. both animal and fungal cells

B

Most broad-spectrum antibiotics act by A. inhibiting the synthesis of the cell wall. B. inhibiting protein synthesis. C. inhibiting nucleic acid synthesis. D. inhibiting metabolic pathways. E. disrupting the cytoplasmic membrane.

B

Which of the following is NOT a target of drugs that inhibit protein synthesis? A. the shape of the 30S ribosomal subunit B. interference with alanine-alanine bridges C. the enzymatic site of the 50S ribosomal subunit D. movement of the ribosome from one codon to the next E. the tRNA docking site

B

Which of the following is a measurement associated with the broth dilution test? A. the zone of inhibition B. lack of turbidity C. cell lysis D. lack of turbidity and zone of inhibition E. presence of turbidity and cell lysis

B

Which of the following pathways is specifically inhibited by sulfonamides? A. the conversion of tetrahydrofolic acid to PABA B. the conversion of PABA to dihydrofolic acid C. the conversion of dihydrofolic acid to tetrahydrofolic acid D. the conversion of PABA to tetrahydrofolic acid E. the conversion of dihydrofolic acid to PABA

B

Which of the following statements about the zone of inhibition is FALSE? A. It is measured as a diameter. B. The larger the zone, the more resistant the organism is. C. It is a clearing zone with no growth. D. It is a result of diffusion of the drug out of the paper disk. E. It is measured after incubation.

B

Reducing surface tension does what to solvent?

Becomes more effective at dissolving solute molecules

Which of the following is a primary advantage of semisynthetic drugs? A. They are less stable and consequently have fewer side effects. B. They work faster. C. They have a broader spectrum of action. D. They must be administered intravenously. E. They are not readily absorbed, so they persist longer.

C

Which of the following statements concerning development of antibiotic resistance is FALSE? A. It is often mediated by R-plasmids. B. Resistant cells are normally in the minority in a bacterial population. C. Resistant cells grow more efficiently and quickly than susceptible cells. D. New resistance genes can be gained through transformation, transduction, or conjugation. E. Resistance can occur through mutation of existing bacterial genes.

C

The antimicrobials called quinolones act by A) disrupting cytoplasmic membranes B) inhibiting cell wall synthesis C) inhibiting nucleic acid synthesis D) inhibiting a metabolic pathway E) inhibiting protein synthesis

C - inhibiting nucleic acid synthesis

Example of sanitization

Cutlery at restaurant - do not make them get sterilized only sanitized

It is inappropriate to prescribe antibacterial agents to treat colds or flu because A. the microbes involved can develop resistance rapidly. B. these diseases are transmitted by endospores, which are hard to kill. C. these diseases exhibit cross resistance. D. these diseases are caused by viruses. E. these diseases can act synergistically with each other.

D

The Etest determines which of the following? A. susceptibility B. MBC C. MIC D. both susceptibility and MIC E. both MBC and MIC

D

The most limited group of antimicrobial agents is the ________ drugs. A. antibacterial B. antifungal C. anthelmintic D. antiviral E. antiprotozoan

D

Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid? A. vancomycin B. penicillin C. methicillin D. isoniazid E. bacitracin

D

Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus? A. beta-lactams B. aminoglycosides C. quinolones D. tetracyclines E. sulfonamides

D

Ribavirin is an antiviral that interferes with A) protein synthesis B) cell wall synthesis C) cell membrane component synthesis D) Nucleic acid synthesis E) viral attachment

D - Nucleic acid synthesis

Trimethoprim is an example of antimicrobials that A) disrupt cytoplasmic membranes B) inhibit cell wall synthesis C) inhibit nucleic acid synthesis D) inhibit metabolic pathways E) inhibit protein synthesis

D - inhibit metabolic pathways

hot air is an effective sterilizing agent because it denatures proteins & fosters oxidation of metabolic & structural chemical, but requires a LOT OF heat...

Dry heat

A large percentage of antibiotics and semisynthetic drugs are produced by members of the genus A. Cephalosporium. B. Penicillium. C. Bacillus. D. Mycobacterium. E. Streptomyces.

E

Antimicrobial agents that interfere with nucleic acids also stop protein synthesis because A) the ribosome contains ribozymes. B) nucleic acids are involved in the production of proteins. C) proteins are involved in the production of nucleic acids. D) Both A and B are correct. E) A, B, and C are correct.

E

Disruption of the normal microbiota can result in infections caused by which of the following microbes? A. Mycobacterium B. Candida albicans C. Clostridium difficile D. both Mycobacterium and Clostridium difficile E. Candida albicans, Mycobacterium, and Clostridium difficile

E

Probiotics A. involve microbial antagonism. B. are an alternative to the use of chemotherapy. C. involve the use of extracts from microorganisms. D. is a term for resistance to antibiotics. E. are an alternative to the use of chemotherapy involving microbial antagonism.

E

Sulfonamides A. are antimetabolic drugs. B. were the first widely used antimicrobial drugs. C. indirectly inhibit the synthesis of nucleic acids. D. are no longer widely used. E. were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.

E

Which of the following antibiotics disrupts cytoplasmic membrane function? A. streptomycin B. erythromycin C. tetracycline D. penicillin E. amphotericin B

E

Which of the following can result when antibiotic therapy disrupts the normal microbiota? A. anaphylactic shock B. black hairy tongue C. pseudomembranous colitis D. thrush E. both pseudomembranous colitis and thrush

E

Which of the following interferes with cell wall synthesis by blocking alanine bridge formation? A. beta-lactams B. cycloserine C. bacitracin D. vancomycin E. both cycloserine and vancomycin

E

Which of the following works by inhibiting ergosterol synthesis? A. fluconazole B. turbinafine C. amphotericin B D. nystatin E. both fluconazole and turbinafine

E

Which scientist coined the term antibiotic? A. Fleming B. Domagk C. Kirby D. Ehrlich E. Waksman

E

Which of the following antifungals works by inhibiting ergosterol synthesis? A) fluconazole B) turbinafine C) amphotericin B D) nystatin E) both fluconazole and turbinafine

E - both fluconazole & turbinafine

Disruption of the normal microbiota can result in infections caused by which of the following microbes? A. Candida albicans B. Clostridium difficile C. Mycobacterium D. Candida albicans, Mycobacterium, and clostridium difficile E. Both mycobacterium and clostridium difficile

E - candida albicans, mycobacterium & clostridium difficile

Energy without mass traveling in waves at speed of light; released from atoms undergone internal changes

Electromagnetic radiation

Which of the following drugs inhibits nucleic acid synthesis specifically in most bacteria?

Fluoroquinolones

What is used to disinfect inanimate surfaces?

Germicide

Antibacterial drugs that alter cytoplasmic membranes

Gramicidin Nisin Polymyxin Pyrazinamide

Presumably denature proteins

Halogens

Denature proteins (4)

Heavy metals, aldehydes, gaseous agents, enzymes

Can kill bacterial endospores (one of the only things that can kill them)

High level germicides

♣ MRSA (disease) ♣ Development of resistance

How to create resistance to antimicrobial drugs

Process of disinfecting places and utensils used by public to reduce # of pathogenic microbes to meet accepted public health standards

Sanitizations

Which of the following statements is true of selective toxicity? A. Selective toxicity takes advantage of structural differences between host and pathogen B. Selective toxicity takes advantage of metabolic differences between host and pathogen C. To be effective an antimicrobial agent must be more toxic to the patient than the pathogen D. Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogens* E. Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.

Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogens

discovered that other mo's are the sources of useful antimicrobials, most notably species of soil dwelling bacteria in the genus Streptomyces; name? coined what term?

Selman Waksman - coined term antibiotics

The removal or destruction of ALL microbes including viruses & bacterial endospores in or on an object (NOT PRIONS)

Sterilization

electron beams

Sterilizing agent

ethylene oxide

Sterilizing agent

glutaraldehyde

Sterilizing agent

Decrease surface tension of water and disrupt cell membranes

Surfactants

Positively charged organic surfactants that are more soluble in water than soaps

Synthetic detergents

Organs that are commonly affected by drug toxicity include the kidneys & the liver. (T/F)

True

The dairy creamer used in restaurants is usually sterilized by

UHT sterilization

denaturation requires what? which is why aqueous preparations are more effective MO's than what?

Water, pure alcohol

Antiviral drugs that inhibit viral uncoating

amantadine rimantadine

antimicrobial agent that inhibits protein synthesis by changing shape of 30S ribosomal subunit

aminoglycosides

Waxy cell wall

Mycobacterium - tuberculosis

antimicrobial agent produced naturally by an organism

antibiotics

chemotherapeutic agent used to treat microbial infection

antimicrobial agents

Antimicrobials that block protein synthesis by binding to the mRNA are

antisense nucleic acids

RNA or single-stranded DNA with nucleotide sequence complementary to molecule of mRNA; control translation of polypeptide

antisense nucleic acids

antiviral drugs that inhibit protein synthesis

antisense nucleic acids (fomivirsen)

chemotherapy lead to discovery of

arsenic compounds against syphilis

antiprotozoan drugs that are antimetabolites

artemisinin atovaquone benzimidazole furazolidone heavy metals iodoquinol lumefrantrine lumefantrine nifurtimox nitazoxanide proguanil pyrimethamuine sulfonamides suramin trimethoprim

A------is an instrument that sterilizes by exposing materials to steam under pressure

autoclave

pressure, pipes to introduce steam, valves to remove air & control pressure, pressure/temperature gauges

autoclave

Which of the following would NOT be bacteriostatic? freezing below 0°C lyophilization autoclaving refrigeration of mesophiles desiccation

autoclaving

temp of 121 C for 15 min w/ 15 lbs pressure per square inch

autoclaving parameters to kill everything!

Methicillin is an example of the beta-lactum class of drugs that A) disrupt cytoplasmic membranes. B) inhibit cell wall synthesis. C) inhibit nucleic acid synthesis. D) inhibit metabolic pathways. E) inhibit protein synthesis.

b - inhibit cell wall synthesis

The mechanism of action of the antibiotic vancomycin is A) inhibition of protein synthesis. B) inhibition of cell wall synthesis. C) inhibition of nucleic acid synthesis. D) inhibition of a metabolic pathway. E) disruption of cytoplasmic membranes.

b - inhibition of cell wall synthesis

antimicrobial that blocks NAG & NAM secretion from cytoplasm, prompting cell lysis

bacitracin

Beta-lactam antibiotics have an effect on which of the following types of cells?

bacterial cells

which of the following is the most difficult to inactivate?

bacterial endospores

Put the following in order, from most resistant to antimicrobial agents to least resistant to antimicrobial agents

bacterial endospores, protozoan cysts, protozoa, nonenveloped viruses, enveloped viruses

anthelmintic drugs taht are antimetabolites

benzimidazole derivatives iodoquinol ivermectin metrifonate niclosamide praziquantal pyrantel pamoate diethylcarbamazine

bacterial enzyme that breaks the beta-lactam rings of penicillin & similar molecules, rendering them inactive

beta-lactamases

antimicrobial whose functional portion is composed of beta-lactam rings, which inhibit peptidoglycan formation by irreversibly binding to the enzymes that cross-link NAM subunits

beta-lactams

Electromagnetic radiation with wavelength greater than 1 nm does not have enough energy to force electrons out of orbit (contain enough energy to excite electrons & make new covalent bonds, affect 3D structure)

Nonionizing radiation (UV light, visible light, infrared radiation, radio waves)

drugs that inhibit nucleic acid synthesis

Nucleosides analogs - molecules with structures similar to the normal nucleotide building blocks of nucleic acids. The analogs enable them to be incorporated into the DNA or RNA of pathogens, where they distort the shapes of the nucleic acid and prevent more replication, transcription, or translation.

Concerning alcohol, which of the following statements is false? Dissolving another chemical in alcohol is a good way to make it more effective. One hundred percent alcohol is the most effective form. Alcohols are intermediate-level disinfectants. Isopropanol is a better disinfectant than ethanol. Alcohols have more than one cellular target.

One hundred percent alcohol is the most effective form (70 is)

Denature proteins by oxidation

Oxidizing agents

High level disinfectants and antiseptics that work by releasing oxygen radicals, particularly effective against anaerobic microorganisms

Oxidizing agents like hydrogen peroxide

*Good for eliminating odor and taste *Supplement chlorination of water (more effective than chlorine but unstable in water)

Ozone

2 types of radiation

Particulate & electromagnetic

High speed subatomic particles freed from their atoms

Particulate radiation

heating beer/wine destroy MO's that cause spoilage without ruining taste (NOT STERILIZATION)

Pasteurization

The use of chemicals that would selectively kill pathogens while having little or no effect on the patient

Paul Ehrlic - chemotherapy

Denature proteins & disrupt cell membranes

Phenol + phenolics, alcohols

Lysol is and example of which of the following groups of chemical antimicrobial agents?

Phenolics

chemically modified by addition of halogens or organic functional groups

Phenolics

Works well with organic materials and thus food for blood and body fluid decontamination.

Phenols-carboxylic acid

Alcohols are used for

both antisepsis & disinfection

Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?

both cycloserine & vancomycin

Formalin (37% formaldehyde) is used for

both disinfection and sterilization

boiling water for 10 minutes is effective in ridding it of...

both growing bacteria & enveloped viruses

Acts against many different kinds of pathogens

broad spectrum drugs

antimicrobial that works against many types of pathogents

broad-spectrum drugs

test for determining the MIC in which a standardized amount of bacteria is added to serial dilutions of antimicrobial agents in tubes or wells containing both

broth dilution test

A chemical agent that dissolves lipids can damage

cells & enveloped viruses

Work to inhibit DNA, alter cell walls; use antiseptics and disinfectants

chemical methods to control MO's

Elderly, young children, organ recipients, CA, AIDS, autoimmune ds., corticosteroid

immunodeficient patients

Determines efficacy of a chemical

in-use test

formaldehydes and gluteraldehyde are antimicrobial through their actions in

inactivating proteins

iodine w/ alcohol

incture of iodine

drugs that BLANK - selectively toxic to certain fungal or bacterial cells which have cell walls, but not to animals because animals lack cell walls

inhibit cell wall synthesis (antimicrobial action)

All of the following are characteristics of iodophors except: they are halogens. they have long-lasting effects. they are used as an antiseptic. they are inorganic molecules. betadine is an example.

inorganic molecules

can be used with certain amino acids to inactivate enzymes and other cellular proteins

iodine

2 halogens

iodine & chlorine

Example of antisepsis

iodine and/or rubbing alcohol on arm before getting blood drawn

Gamma rays and X rays are examples of---------radiation

ionizing

blast the food with radiation, which alters the cell wall

ionizing radiation

Gamma irradiation is effective for sterilization because it

is penetrating and causes extensive molecular damage.

antimicrobial drug that disrupts formation of aribogalactan-mycolic acid by mycobacteria

isoniazid (INH) or ethambutol

♣ It is the SMALLEST amount of the drug that will INHIBIT the growth and reproduction of the pathogen- can be determined via the BORTH DILUTION TEST • A standard amount of bacterial is added to serial dilutions of antimicrobial agents in tubes

minimum inhibitory control

lack of sensitivity to three or more antimicrobials by so-called superbugs

multiple-drug-resistant pathogens

antimicrobial that works against only a few types of antibiotics

narrow-spectrum drugs

anthelmintic drugs that inhibit nucleic acid synthesis

niridazole oltipraz oxamniquine

blast food with UVA light, alters the DNA

non-ionizing radiation

chemical with structure similar to natural nucleoside

nucleoside analogs

compound structurally similar to normal nucleotide that can be incorporated into DNA; may result in mismatched base pairing

nucleotide analogs

Once scientist identify an effective microbial agent they quantitatively express

Potency as the MIC using ug/mL

The term "sterlization" applies to the removal of the following except: bacterial endospores. prions. fungi. viruses. bacterial cells.

Prions

The tetracyclines interfere with

Protein synthesis

extrachromosomal piece of DNA containing genes for resistance to antimicrobial drugs

R plasmids

Clinical indications in prescribing antimicrobial drugs

Readily available, inexpensive, chemical stable, easy to administer, nontoxic and no allergenic, selectively toxic against a wide range of pathogens

The colder the temp, the higher ability to prevent...

the growth/ reproduction of mo's but at these temperatures we do not kill any mo's just halt their growth

Why do heavy metals work?

their action of oligodynamic action. - when heavy metals combine with sulfhydryl (-SH groups of organic compounds) proteins are denatured

estimate safety of an antimicrobial drug by calculating this

therapeutic index (TI)

range of concentrations of the drug that are effective without being excessively toxic

therapeutic range (window)

The lowest temperature that kills all cells in a broth in 10 minutes is known as the

thermal death point

amount of time it takes to completely sterilize an amount of liquid at a given temperature (time remains constant, we alter temperature to see which minimal temperature can completely get rid of certain MO)

thermal death time

all of the following are characteristics of aldehydes except: some can sterilize after long periods of time they are used only to preserve dead tissues. they are used in aqueous solutions. they denature proteins. they are usually hazardous to humans.

they are used only to preserve dead tissues

All of the following are characteristics of quaternary ammonium compounds EXCEPT: Zephiran is an example of a quat. they are a type of detergent. they function by cross-linking proteins. they are used by Pseudomonas aeruginosa as a nutrient. they are harmless to humans except at high concentrations.

they function by cross-linking proteins.

All of the following are characteristics of quaternary ammonium compounds except

they function by cross-linking proteins.

Which of the following is a primary advantage of semisynthetic drugs?

they have a broader spectrum of action

why are aldehydes antimicrobial?

they interfere with cross linking of organic functional groups. They do not work on DNA or the cell wall directly

they enhance the effectiveness of other antimicrobial agents

tinctures (alcohols)

when you get too much a drug it becomes a poison to you

toxicity

-----is an phenolic antimicrobial compound that has been incorporated into consumer items such as garbage bags and diapers

triclosan

Which of the following types of radiation is nonionizing and has the shortest wavelength?

ultraviolet light

Both cultures of bacteria, dry them at 37C - standard test bacteria = P. aeruginosa, Salmonella entercia, S. aureus.

use-dilution test

Method for measuring the efficacy of disinfectants against specific microbes

use-dilution test

which of the following procedures is currently the standard test for evaluating the efficiency of antiseptics and disinfectants

use-dilution test

Antimicrobial drug that disrupts formation of Gram-positive bacterial cell walls by interfering with alanine-alanine crossbridges link- ing N-acetylglucosamine subunits.

vancomycin

All of the following are associated with filtration except: a. sterilization of heat-sensitive materials b. varying thicknesses of membrane filters used c. use HEPA filters to filter air d. nitrocellulose or plastic membrane filters e. ability of some filters to trap viruses & proteins

varying thicknesses of membrane filters used

drugs that block a pathogen's recognition of or attachment to it's host

virus; arildone is a synthetic antiviral that prevents removal of poliovirus capsids (coating) thereby interrupting viral replication cycle

Desiccation, a time-honored method of preserving food is effective because the

water content is too low to support metabolic function

1) through new mutations of chromosomal genes 2) acquiring resistance genes on extrachromosomal pieces of DNA called R PLASMIDS (R factors) via the process of horizontal gene transfer - transformation, transduction, or conjugation

ways to acquire resistance

Actions of antimicrobial agents

work to either kill or inhibit bacteria

Ultraviolet light penetrates materials----(better/worse than) gamma rays.

worse then

use in antidandruff shampoo

zinc (pyrithione)

used in some mouthwash

zinc chloride

in a diffusion susceptibility test, clear area surrounding drug-soaked disk where microbe doesn't grow

zone of inhibition

Silver is used as 1% silver nitrate solution to prevent...

opthalmia neonatorum (when the mom has chlamydia and gives vaginal birth it can cause the baby to become blind)

what is "simplest" but the concentrations in the body are less that then other routes of admin

oral

the use of high levels of salt or sugar in the preservation of foods relies on the concept of

osmotic pressure

antibacterial drug that inhibits initiation of polypeptide synthesis in gram-positive bacteria

oxazolidinones

what kills by oxidizing the enzyme (pick up free radicals)

ozidizing agents

highly reactive, forms when O2 is passed through an electrical field

ozone

sulfonamides are analogs of (chemically similar to)

para-aminobenzoic acid (PABA)

the process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as

pasteurization

use of HEAT to kill/eliminate bacteria that cause SPOILAGE to foods (wine, juice, milk)

pasteurization

*very good liquid disinfectant, highly sporocidial, leaves no toxic byproducts behind *Is for sterilizing food processing and medical equipment and is approved for washing fruit and veggies

peracetic acid

Which of the following is a sterilizing agent?

peracetic acid ONLY

Natural antiseptics such as pine or clove oil are examples of antimicrobial compound called

phenolics

group of antimicrobial drugs such as amphotericin B that disrupt cytoplasmic membrane of targeted cells by becoming incorporated into membrane & damaging its integrity

polyenes

must heat to 428 to denature it (alter structure & cannot function/reproduce) *proteins need DNA/RNA to function/reproduce

prion (denatured / abnormal protein)

*Help to preserve the normal microbiome during the use of drugs- especially antibiotics.

probiotics (disruption of normal microbiota)

antiviral drugs that inhibit viral proteins

protease inhibiotrs (-avir)

Antimicrobial agents that interfere with nucleic acids also affect

protein synthesis

drugs that inhibit BLANK by targeting the differences between prokaryotes and eukaryotes ribosomes

protein synthesis (translation)

what acts similar to bacterial endospore; heat stable & harder to kill

protozoa can lay a cyst

Boiling water rapidly kills all of the following EXCEPT: protozoan trophozoites. fungal cells. most viruses. bacterial cells. protozoan cysts

protozoan cysts

High level disinfectants and antiseptics that work by?

releasing oxygen radicals, which are particularly effective against anaerobic mo's

Topical, local, oral, intramuscular, intravenous

routes of administration

Which of the following is an example of degerming? cleaning a public toilet using heat to make milk safe to drink scrubbing your hands preparing your lab benchtop for work canning fruits or vegetables

scrubbing your hands

an effective antimicrobial agent must be more toxic to a pathogen than to the pathogen's host.

selective toxicity

principle by which an effective antimicrobial agent must be more toxic to a pathogen than to pathogen's host

selective toxicity

antimicrobial that has been chemically altered

semisynthetics

Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?

silver nitrate

antimicrobial agent that inhibits protein synthesis by blocking tRNA docking site

tetracyclines

Over 90% of Staphylococcus aureus isolates are penicillin- resistant why?

They produce beta lactamase

smallest amount of drug that will inhibit a pathogen

minimum inhibitory concentration (MIC)

* Aqueous ethanol (60-90% pure alcohol); isopropanol (62-65%)= disinfectants *70% is considered the best ethanol concentration

Tincture forms

UV light

disinfectant

alcohols

disinfectant

hydrogen peroxide

disinfectant

quats

disinfectant

What is the relationship of disinfectants and antiseptics

disinfectants are usually more concentrated than antiseptics, and antiseptics are used on living tissue, while disinfectant are used on inanimate objects

Quaternary ammonium compounds ("Quats") are used for...

disinfection

use for items in contact with skin or mucous membranes

disinfection

Amphotericin B is an antifungal drug that

disrupts cytoplasmic membranes

The antimicrobial polymyxin

disrupts cytoplasmic membranes

♣ Beta- lactams (penicillin's/ cephalosporin's/ carbapenems) ♣ Bacitracin blocks the transport of NAG and NAM across the cytoplasmic membrane ♣ Isoniazid disrupt the formation of mycolic acid

drugs that inhibit cell wall synthesis

antifungal drug that inhibits cell wall synthesis

echinocandins

transmembrane pump that removes antimicrobial drugs from a cell or from the periplasm

efflux pumps

antiprotozoan drugs that inhibit DNA synthesis

eflorinthine nitroimidazoles pentamidine quinolones

Sterilization procedures generally focus on the inactivation or elimination of bacterial

endospores

Which of the following is the least resistant to antimicrobial agents? protozoan cysts bacterial endospores enveloped viruses protozoa Gram-positive bacteria

enveloped viruses

Either speed up chemical reactions or can act to denature proteins/ DNA - speeding up rctn nothing is altered

enzyme

A "zone of inhibition" is associated with which of the following tests used to determine efficacy of antibiotics

etest & diffusion suscepitibility test

Kill enveloped viruses but not naked viruses, 70%- must make surfaces really WET in order to achieve optimum killing

ethyl & isopropyl alcohols

Work via their ability to denature proteins and dissolve lipids

ethyl & isopropyl alcohols

what is NOT good for wound disinfection because proteins coagulate and form a protective coat around bacteria

ethyl & isopropyl alcohols

Penetrates most materials and kills all mo's (and destroys endospores) by cross linking proteins and nucleic acids

ethylene oxide

Which of the following antimicrobial agents is the most toxic to humans? 70% alcohol chloramines ethylene oxide quats iodophors

ethylene oxide

Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water

ethylene oxide

which of the following would be used to sterilize a mattress?

ethylene oxide

Peroxides, ozone, Peracetic acid

examples of oxidizing agents

Can do disinfection and sterilization - commonly used with pharmaceutical drugs because they cannot be heated because that would denature the active chemicals

filtration

Determines the amount of drug required to kill the microbe rather than just the amount to inhibit it

minimum bacterial concentration test

Antimicrobial sugar analogs are effective for A. preventing bacterial protein synthesis. B. preventing cell membrane synthesis. C. preventing virus attachment. D. preventing nucleic acid synthesis. E. blocking a metabolic pathway.

C

The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid, A. cross resistance. B. antimetabolism. C. synergism. D. selective toxicity. E. chemotherapy.

C

Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated? A. their spectrum of action B. their efficacy C. their activity against cell walls D. their route of administration E. their safety

C

boiling water

Disinfectant

chlorine dioxide

Disinfectant

Use of physical or chemical agents to destroy or inhibit MO's (pathogens)? Examples?

Disinfection UV, heat, alcohol, bleach

Refer to agents that destroy or permanently inactivate a particular type of microbe

-cidal / -cide

Suffix to indicate a chemical or physical agent inhibits microbial growth, but doesn't necessarily kill

-static (stasis)

Alteration of cell walls & membranes (via osmosis)

1. Cell wall disrupted by physical of chemical agents; no longer prevents cell from bursting as water moves into cell by osmosis 2. Alter integrity of cell well, cell more susceptible to destruction

Agents used for control of microbes should be

1. Inexpensive 2. Fast acting 3. Stable during storage

All chemical methods to control MO's

1. Phenols 2. Alcohols 3. Halogens 4. Oxidizing agents 5. Surfactants 6. Heavy metals 7. Aldehydes 8. Gaseous agents 9. Enzymes

4 levels capable of handling different levels of pathogens

1. can handle MO's not known to cause ds. in health humans (E. Coli) 2. moderate dangerous = influenza virus MRSA 3. manipulations done within safety cabinets, filters, and air must undergo HEPA, double set doors, lower air pressure in lab that allows air to move into not out of room 4. Most secure = "oh shit" = Zika; lab in separate building, entry/exit controlled airlocks; all air/water filtered; space suits (BSL-4 suits)

3 things impacting efficacy of antimicrobial methods

1. site to be treated 2. relative susceptibility of MO 3. Environmental conditions (temperature / pH)

1. kinda high heat, long time 2. little higher heat, shorter time 3. highest heat, really short time "flash"

3 methods of pasteurization

Bactericides, fungicidal, virucidal against enveloped viruses, not effective against fungal or bacterial spores

Alcohols

Considered to be some of the MOST EFFECTIVE chemical disinfectants

Aldehydes

Antibacterial drugs that inhibit protein synthesis

Aminoglycosides (Neomycin, -mycin) Chloramphenicol Lincosamides Macrolides Mupirocin Oxazolidinones (linezolid) Streptogramin (-pristin) Tetracyclines (-cycline)

Which of the following antibiotics disrupts cytoplasmic membrane function in fungi?

Amphotericin B

Act against cell walls + cell membranes, protein synthesis, & DNA transcription/replication

Antimicrobials

Chemical used on skin or other LIVING tissue; reduction of number of pathogens in living tissue

Antiseptisis

Attachment Antagonists

Arildone Neuraminidase inhibitors

Environment free of contamination by pathogens

Aseptic

Drugs that disrupt unique components of a cytoplasmic membrane

Azoles and alanine's

Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs? A. plasmids B. porins C. mitochondria D. cytoplasmic membrane E. ribosomes

B porins

The spores of which of the following microbes are the most resistant to every known sterilization technique

Bacillus stearothermophilus

Antibacterial drugs that inhibit cell wall synthesis

Bacitracin Beta-lactams (penicillin, imipenem, ampicillin, etc.) Cycloserine Ethambutol Isoniazid Vancomycin

When environment is not good for bacteria to growth they form a hard layer around themselves so that it can persevere the RNA allowing bacterium to re-open, reproduce, and continue growing in more favorable conditions; what is this situation talking about?

Bacterial endospore

Bacillus & clostridium are resilient species; examples of?

Bacterial endospore (heat STABLE)

Why is mycobacterium not susceptible to normal antibiotics?

Because it doesn't have classic cell wall (waxy)

OTC acne medicine

Benzoyl peroxide

kills vegetative cells of bacteria & fungia, trophozoites of ptrotozoa, and most viruses within 10 min at sea level

Boiling (type of moist heat)

Which of the following can be used to disinfect air? ultraviolet light ethylene oxide HEPA filters Both A and C are correct. Both A and B are correct.

Both A and C are correct

Which of the following is a true statement concerning microbial death? A) It is the permanent loss of a microbe's reproductive ability. B) It speeds up over time of exposure to an antimicrobial agent. C) It can be used to evaluate the efficacy of antimicrobial agents. D) Both A and C are correct. E) A, B, and C are correct.

Both A and C are correct

Alcohols are effective against all of the following except

Both C and D are correct

Infection of the BLANK would be the hardest to treat w/ anti-MO drugs.

Brain

Which of the following is a target of pasteurization?

Brucella melitensis

An antimicrobial that inhibits cell wall synthesis will result in which of the following?

Cells become more susceptible to osmotic pressure

Central endospore vs. terminal endospore?

Central = bacillus Terminal = clostridium

o Good oxidizing agent o Disinfectant in the gas form - used to disinfect drinking water and swimming pools

Chlorine

has germicidal actions based on the formation of hypochlorus acid (HOIC) when it is added to water - excellent disinfectant, sporocidial but easily inactivated by organic material

Chlorine (halogen)

Antibacterial Drugs that inhibit Nucleic Acid Synthesis

Clofazimine Fluoroquinolones Nitroimidazoles Rifamycin

Antibacterial drugs that are antimetabolites

Dapsone Sulfonamides Trimethoprim

Use scrubbing to remove microbes from a surface

Degerming

Damage to proteins & nucleic acids

Denature proteins - pathogen no longer can reproduce

inoculates petri dishes with a standard amount of pathogen, puts small disks of paper with certain amounts of drugs and determines which one is the best

Diffusion susceptibility test

test for determining MIC; plastic strip containing a gradient of the antimicrobial agent being tested is placed on a plate inoculated with the pathogen of interest

Etest

• Place plastic strips containing a gradient of the antimicrobial agent being tested on a plate inoculated with organism • Used in labs (petri dishes) to determine the minimum inhibitory concentration and weather or not a specific strain of a bacteria/ fungus is susceptible to the action of a specific antimicrobial

Etest test

gas commonly used for sterilization

Ethylene oxide

When do you have to use most secure level of pathogens?

Exotic microbes that cause severe or fatal ds. in humans (Ebola, small pox)

Drug-resistant populations of microbes arise when

Exposure to drugs selectively kills sensitive cells, allowing overgrowth of resistant cells*

Because all cells engage in protein synthesis, there are few antimicrobial drugs that selectively inhibit this process

False

Beta-lactam drugs act by inhibiting formation of the cytoplasmic membrane (T/F)

False

If a subculture of an MIC test grows in an MBC test, the concentration of the drug was bactericidal.

False

Paul Erlich coined the term antibiotics for the "magic bullet" antimicrobials he pursued (T/F).

False

The outer membrane of Gram (-) bacteria enables many antimicrobial drugs to enter the cell more easily.

False

o Swabs are taken from actual objects (operating room equipment), both before and after the application of a disinfectant. The swabs are then inoculated into appropriate growth media after that, after incubation, are examined for microbial growth o It allows for a more accurate determination of proper strength and applications o "the phenyl alanine coefficient, this is more realistic—the prior 2 test are used for initial screening"

In-use test

Will not kill bacterial endospores

Intermediate level germicide

is an iodine-containing organic compound found in such antiseptics as Betadine

Iodopher

Wavelengths shorter than 1 nm - when they strike molecules they have sufficient energy to eject electrons from atoms, creating ions

Ionizing radiation (electron beams, gamma rays, some X rays)

All of the following are characterisics of an ideal antimicrobial agent except:

It denatures proteins

What makes BSL-4 Suit during most secure level of handling pathogens so special?

It ensures that any possible pathogens are forced out, where as a regular suit does not ensure that if pathogen enters suit that is forcefully pushed out of suit

The STANDARD alternative assessment approved by the EU to determine the capacity of a given chemical to inhibit bacterial growth bottom

Kelsey Sykes capacity test

Kill vegetative bacteria (living/reproducing), fungi, protozoa

Low level germicide

Permanent loss of reproduction, calculated by BLANK rate

Microbial death

What is the best method for microbial control; commonly used to disinfect, sanitize, sterilize, and pasteurize; kills cells by denaturing proteins and destroying cytoplasmic membranes!

Moist heat

*A ratio comparing the dose of the drug that a patient can tolerate to the drugs effective dose *The higher THIS, the safer the drug!!

Therapeutic Index

Range of concentration of the drug that are effective without being excessively toxic = the IDEAL concentration of a drug

Therapeutic range aka therapeutic window

lowest temp that kills all cells in broth culture

Thermal death point

All of the following statements concerning radiation as a method of microbial control are true EXCEPT: UV light effectively kills cells but does not penetrate surfaces well. X rays are the most practical form of ionizing radiation for microbial control. microwaves are valuable in microbial control only when they are used to heat food. gamma rays penetrate substances well but require hours to kill microbes. electron beams have a lot of energy but do not penetrate substances very well.

X rays are the most practical form of ionizing radiation for microbial control.

antiviral drugs that inhibit nucleic acid synthesis

acyclovir adenosine arabinoside nucleotide analogs Ribavirin

The contents of a bottle labeled "tincture of iodine" is...

alcohol solution of iodine

who discovered penicillin mole causes a zone where bacteria can't grow around it

alexander flemming 1928

class of antifungal drugs that disrupt cytoplasmic membranes

allylamines and azoles

antimicrobial drug that blocks enzymatic site of 50S subunit, inhibiting polypeptide synthesis

chloramphenicol

gas used for water treatment to prevent or reduce the formation of carcinogens during chlorination - also used to fumigate enclosed building areas contaminated with anthrax endospores

chlorine dioxide

The perfect agent?

control growth + reproduction of every type of microbe while being harmless to humans / objects (DOES NOT EXIST)

used to control green algae growth in ponds, and sometimes used to prevent mildew

copper sulfate

phenomenon in which resistance to one antimicrobial drug confers resistance to similar drugs

cross resistance

semisynthetic antibiotic used to treat infections with gram-positive bacteria

cycloserine

time it takes to destroy 90% microbes

decimal reaction time

------is the process of drying foods such as fruits in order to preserve them from microbial growth

desiccation

drying that inhibits microbial growth because metabolism requires liquid & water

desiccation

Another term for the Kirby Bauer test is the

diffusion susceptibility test

Aseptic means

free of all pathogens

Which of the following is bacteriostatic?

freezing below 0 C

Which of the following is used for microbial control in fresh fruits and vegetables?

gamma rays

A chemical agent that kills pathogenic microbes in general is a

germicide

Betadine is an example of which of the following?

halogens

Betadine is an example of which of the following? phenolics halogens alcohols surfactants heavy metals

halogens

Elements such as iodine, chlorine, and bromine are examples of -------which are the basis for many eddective antimicrobial agents.

halogens

lung machines, sutures, pillows, artificial heart valves, catheters, electronics cannot use heat or water

heart - gaseous agents

which of the following is an example of pasteurization?

heat is used to kill potential pathogens in apple juice

Which of the following describes the batch method of pasteurization?

heating at 63°C for 30 minutes

Which of the following describes flash pasteurization?

heating at 72 C for 15 seconds

Silver, mercury, copper, zinc= germicides

heavy metals

An instrument that will be used in an invasive medical procedure should be disinfected with a(n) low-level germicide. high-level germicide. intermediate-level germicide. Both A and C are correct. A, B, and C are correct.

high-level germicide

not a good antiseptic because is rapidly detoxified by catalase released by injured cells in a wound, but does make good disinfectant on non-living surfaces (important)

hydrogen peroxide (H2O2)

salt and sugar can alter the cellular membrane and therefore change the pressure- example of?

i.e. osmotic pressure

extension of MIC test in which samples are taken from clear MIC tubes are transferred to plates containing a drug-free growth medium and monitored for bacterial replication

minimum bactericidal concentration (MBC) test

Why is disinfection not sterilization?

it only get's rid of MO's that are considered to be pathogens

the amount of time needed to sterilize materials using moist heat is ------(greater/less than) the time needed to sterilize using dry heat.

less than

antimicrobial drug that bind to 50S subunit of bacterial ribosomes, preventing ribosomal movement

lincosamides

Antiprozoan drugs that inhibit protein synthesis

lincosamides (clindamycin) paramomycin

father of ASEPTIC TECHNIQUE

louis pasteur

An instrument that will come into contact with only the skin of a patient should be disinfected with a

low-level germicide

All of the following achieve sterilization except

lyophilization

the process of freeze-drying microbes to preserve them.

lyophilization

combines freezing and drying to preserve microbes and other cells for many years (i.e. liquid nitrogen)

lypilization

antimicrobial agent that inhibits protein synthesis by inhibiting ribosomal 50S subunits

macrolides

What does waxy cell wall of mycobacterium do?

makes it so organism can only be killed via strong disinfectants & heat

Drugs that inhibit multiple things is example of:

mechanisms of antimicrobial action

All of the following are components of an autoclave except: valves. temperature gauges. a pressure chamber. pressure gauges. membrane filters.

membrane filters

bacteriostatic - linked to toxicity and autism

mercury

you notice a sign in a public restroom that states "sanitized for your safety" this means...

methods of disinfection that meet minimum standards of microbial removal have been used

# of different kinds of pathogens a drug acts against

spectrum of action

incineration

sterlizing agent

antimicrobial drug that bind the 50S ribosomal subunit and prevent ribosome movement along messenger RNA

streptogramins

antimetabolic drug that is structural analog of para-aminobenzoic acid (PABA)

sulfonamides

drugs that inhibit general metabolic pathways not use by humans

sulfonamides

All of the following have denaturing proteins included in their mechanism of action except: surfactants. oxidizing agents. gaseous agents. heavy metals. aldehydes.

surfactants

Soap & detergents - decrease surface tension among molecules of liquid

surfactants

interplay between drugs that results in efficacy that exceeds efficacy of either drug alone

synergism

antimicrobial that has been completely synthesized in a laboratory

synthetics