The dairy creamer used in restaurants is usually sterilized by
B) ionizing radiation.
C) UHT sterilization.
An instrument that will come into contact with only the skin of a patient should be disinfected with a(n)
A) degerming agent only.
B) intermediate-level germicide.
C) germistatic agent only.
D) high-level germicide.
E) low-level germicide.
The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?
A) Neisseria gonorrhoeae
B) Bacillus stearothermophilus
C) Mycobacterium bovis
D) Pseudomonas aeruginosa
E) Clostridium botulinum
Which of the following is an example of sanitization?
A) Heat is used to kill potential pathogens in apple juice.
B) An autoclave is used to prepare nutrient agar.
C) A surgeon washes her hands before surgery.
D) A public toilet is treated with disinfectants.
E) A nurse prepares an injection site with an alcohol swab
Seventy percent alcohol is effective against
A) nonenveloped viruses.
C) enveloped viruses.
D) bacterial endospores.
E) protozoan cysts.
A) free of all microbes.
C) free of all pathogens.
Betadine is an example of which of the following groups of antimicrobial agents?
D) heavy metals
Disinfecting agents naturally produced by microorganisms are
Which of the following would NOT be bacteriostatic?
C) refrigeration of mesophiles
D) freezing below 0°C
Boiling water for 10 minutes is effective in ridding it of
A) protozoan cysts.
B) actively growing bacteria.
C) both growing bacteria and enveloped viruses.
D) enveloped viruses.
E) bacterial endospores.
Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?
B) silver nitrate
D) hydrogen peroxide
Standard methods of sterilization are not effective in inactivating
C) bacterial endospores.
D) bacterial cells.
Which of the following antimicrobial agents is the most toxic to humans?
A) ethylene oxide
E) 70% alcohol
Which of the following can be used to disinfect air?
A) ethylene oxide
B) HEPA filters
C) ultraviolet light
D) both HEPA filters and ultraviolet light
E) both ethylene oxide and ultraviolet light
Which of the following is a sterilizing agent?
B) ozone and hydrogen peroxide
C) peracetic acid
D) dish soap
E) hydrogen peroxide
Which of the following would be used to sterilize a mattress?
B) ethylene oxide
C) heavy metals
Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?
A) phenol coefficient
B) in-use test
C) microbial death rate
D) thermal death point
E) use-dilution test
Which of the following describes flash pasteurization?
A) heating at 72°C for 15 seconds
B) heating at 63°C for 30 minutes
C) heating at 72°C for 15 minutes
D) passing liquid through steam at 140°C
E) heating at 134°C for one second
Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?
A) It is harmless to humans.
B) It acts quickly.
C) It is stable during storage.
D) It is inexpensive.
E) It only arrests growth of vegetative cells.
Disinfectants that damage membranes include
A) hydrogen peroxide.
E) both alcohol and phenolics.
Which of the following statements is true of disinfectants?
A) Disinfectants are used for sterilization.
B) Disinfectants are used on inanimate surfaces.
C) Disinfectants are only effective for short periods of time (seconds to minutes).
D) Disinfectants are used on living tissue.
E) Disinfectants are effective in destroying endospores.
Antimicrobial agents that damage nucleic acids also affect
A) the cell wall.
B) protein synthesis.
D) the cell membrane.
E) the viral envelope.
Lysol is an example of which of the following groups of chemical antimicrobial agents?
A) halogens B) phenolics
C) aldehydes D) surfactants
A chemical agent that kills pathogenic microbes in general is a(n)
A) germicide. B) disinfectant.
C) fungicide. D) antiseptic.
Which of the following is NOT an effective means of sterilization?
A) ionizing radiation
B) dry heat
Which of the following statements about quaternary ammonium compounds is FALSE?
A) They are harmless to humans except at high concentrations.
B) Zephiran is an example of a quat.
C) They function by cross-linking proteins.
D) They are a type of detergent.
E) They are not effective against Pseudomonas aeruginosa.
Which of the following types of radiation is nonionizing and has the shortest wavelength?
A) X rays
B) ultraviolet light
C) gamma rays
D) infrared radiation
Which of the following is NOT a feature associated with filtration?
A) varying thicknesses of membrane filters used
B) nitrocellulose or plastic membrane filters
C) ability of some filters to trap viruses and proteins
D) sterilization of heat-sensitive materials
E) use of HEPA filters to filter air
Which of the following is used for microbial control in fresh fruits and vegetables?
B) X rays
C) gamma rays
D) ultraviolet light
E) electron beams
Which of the following is a target of pasteurization?
A) Chlamydia trachomatis
B) Clostridium botulinum
C) Brucella melitensis
D) Bacillus stearothermophilus
E) Neisseria gonorrhoeae
A scientist develops a new medication that is a protein compound and that must be administered by injection. Which of the following would be the most effective and safest means of preparing a sterile solution of the new medication?
A) dilution with alcohol
B) ultraviolet irradiation
Which of the following is used to sterilize items that should not, or cannot, be exposed to heat or water?
B) calcium hypochlorite
D) ethylene oxide
E) hydrogen peroxide
Which of the following statements concerning microbial death is FALSE?
A) It can be used to evaluate the efficacy of antimicrobial agents.
B) It is constant over time of exposure to an antimicrobial agent.
C) It is the permanent loss of a microbe's ability to reproduce and can be used to evaluate antimicrobial agents.
D) It is not an effective means of evaluating the efficacy of antimicrobial agents.
E) It is the permanent loss of a microbe's reproductive ability.
Which of the following statements about aldehydes is FALSE?
A) Some aldehydes can sterilize after long periods of exposure.
B) They are used in aqueous solutions.
C) They denature proteins.
D) They are usually hazardous to humans.
E) They are used only to preserve dead tissues.
Which of the following is the most appropriate pairing of microbe and biosafety level?
A) anthrax, BSL-1
B) E. coli, BSL-3
C) Ebola, BSL-2
D) methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
E) tuberculosis, BSL-1
Which of the following is a measurement associated with the broth dilution test?
A) lack of turbidity
B) the zone of inhibition
C) presence of turbidity and cell lysis
D) lack of turbidity and zone of inhibition
E) cell lysis
Which of the following works by inhibiting ergosterol synthesis?
B) amphotericin B
E) both fluconazole and turbinafine
A) involve microbial antagonism.
B) is a term for resistance to antibiotics.
C) are an alternative to the use of chemotherapy.
D) are an alternative to the use of chemotherapy involving microbial antagonism.
E) involve the use of extracts from microorganisms.
The most limited group of antimicrobial agents is the ________ drugs.
An antimicrobial that inhibits cell wall synthesis will result in which of the following?
A) The replication of cells, including cancer cells, slows down.
B) Cells become more susceptible to osmotic pressure.
C) Ribosomes lose their function.
D) The sterols in the cell wall become nonfunctional.
E) Cells cannot attach to their hosts.
It is inappropriate to prescribe antibacterial agents to treat colds or flu because
A) these diseases are transmitted by endospores, which are hard to kill.
B) the microbes involved can develop resistance rapidly.
C) these diseases exhibit cross resistance.
D) these diseases are caused by viruses.
E) these diseases can act synergistically with each other.
Which of the following antibiotics disrupts cytoplasmic membrane function?
A) amphotericin B
Most drugs that inhibit the synthesis of the cell wall act by
A) preventing the formation of β-lactamases.
B) preventing the cross-linkage of NAM subunits.
C) disrupting the formation of the mycolic acid layer of the cell wall.
D) preventing the formation of alanine-alanine bridges.
E) blocking the secretion of cell wall molecules from the cytoplasm
Disruption of the normal microbiota can result in infections caused by which of the following microbes?
A) Clostridium difficile
B) Candida albicans
D) Candida albicans, Mycobacterium, and Clostridium difficile
E) both Mycobacterium and Clostridium difficile
Which of the following pathways is specifically inhibited by sulfonamides?
A) the conversion of PABA to tetrahydrofolic acid
B) the conversion of tetrahydrofolic acid to PABA
C) the conversion of PABA to dihydrofolic acid
D) the conversion of dihydrofolic acid to tetrahydrofolic acid
E) the conversion of dihydrofolic acid to PABA
Which of the following is NOT a criterion by which all antimicrobial agents can be evaluated?
A) their route of administration
B) their efficacy
C) their spectrum of action
D) their activity against cell walls
E) their safety
The cooperative activity of drugs such as beta-lactam antibiotics and clavulanic acid,
a β-lactamase inhibitor, is known as
B) cross resistance.
C) selective toxicity.
Which of the following drugs specifically targets cell walls that contain arabinogalactan-mycolic acid?
A) bacitracin B) vancomycin
C) methicillin D) penicillin
Which of the following drugs inhibits nucleic acid synthesis specifically in prokaryotes?
Which of the following statements about the zone of inhibition is FALSE?
A) It is a result of diffusion of the drug out of the paper disk.
B) It is measured as a diameter.
C) The larger the zone, the more resistant the organism is.
D) It is a clearing zone with no growth.
E) It is measured after incubation.
Which of the following is NOT a target of drugs that inhibit protein synthesis?
A) the tRNA docking site
B) interference with alanine-alanine bridges
C) the shape of the 30S ribosomal subunit
D) movement of the ribosome from one codon to the next
E) the enzymatic site of the 50S ribosomal subunit
) Beta-lactam antibiotics have an effect on which of the following types of cells?
A) bacterial cells
B) fungal cells
C) virus-infected cells
D) animal cells
E) both animal and fungal cells
The Etest determines which of the following?
D) both susceptibility and MIC
E) both MBC and MIC
Which of the following statements is true of selective toxicity?
A) Selective toxicity takes advantage of structural and/or metabolic differences between host and pathogen.
B) Selective toxicity takes advantage of metabolic differences between host and pathogen.
C) Selective toxicity takes advantage of structural differences between host and pathogen.
D) Antimicrobial agents must target structural differences between host and pathogen and be more toxic to the patient than the pathogen.
E) To be effective, an antimicrobial agent must be more toxic to the patient than the pathogen
Which of the following interferes with cell wall synthesis by blocking alanine bridge formation?
E) both cycloserine and vancomycin
Antimicrobial sugar analogs are effective for
A) preventing bacterial protein synthesis.
B) blocking a metabolic pathway.
C) preventing cell membrane synthesis.
D) preventing virus attachment.
E) preventing nucleic acid synthesis.
Another term for the Kirby-Bauer test is the
A) diffusion susceptibility test.
B) broth dilution test.
C) minimum bactericidal concentration test.
D) E test.
E) minimum inhibitory concentration test
Which of the following can result when antibiotic therapy disrupts the normal microbiota?
B) black hairy tongue
C) anaphylactic shock
D) pseudomembranous colitis
E) both pseudomembranous colitis and thrush
Alterations in the structure of which of the following are an important aspect of Gram-negative bacterial resistance to antimicrobial drugs?
B) cytoplasmic membrane
Which of the following is a primary advantage of semisynthetic drugs?
A) They have a broader spectrum of action.
B) They must be administered intravenously.
C) They work faster.
D) They are not readily absorbed, so they persist longer.
E) They are less stable and consequently have fewer side effects
Which of the following statements concerning development of antibiotic resistance is FALSE?
A) New resistance genes can be gained through transformation, transduction, or conjugation.
B) It is often mediated by R-plasmids.
C) Resistant cells grow more efficiently and quickly than susceptible cells.
D) Resistance can occur through mutation of existing bacterial genes.
E) Resistant cells are normally in the minority in a bacterial population.
Infection of the ________ would be the hardest to treat with antimicrobial drugs.
A) brain B) liver C) kidneys D) heart E) colon
Antimicrobials that block protein synthesis by binding to the mRNA are
A) antisense nucleic acids.
B) nucleic acid analogs.
A) were the first widely used antimetabolic antimicrobial and indirectly inhibit nucleic acid synthesis.
B) are antimetabolic drugs.
C) were the first widely used antimicrobial drugs.
D) are no longer widely used.
E) indirectly inhibit the synthesis of nucleic acids.
Who discovered the first widely available antibiotic?
C) Ehrlich and Waksman
Most broad-spectrum antibiotics act by
A) inhibiting protein synthesis.
B) disrupting the cytoplasmic membrane.
C) inhibiting nucleic acid synthesis.
D) inhibiting metabolic pathways.
E) inhibiting the synthesis of the cell wall
A large percentage of antibiotics and semisynthetic drugs are produced by members of the genus
β-lactamase production is an example of which of the following types of resistance?
A) inactivation of the drug
B) removal of the drug via a pump
C) change in the permeability of the drug
D) alteration of the target of the drug
E) overproduction of an enzyme in a key metabolic pathway
Which of the following groups of drugs can become incorporated into the bones and teeth of a fetus?
Disinfectants known as ________ have the chemical group CHO, which reacts with and damages both proteins and nucleic acids.
Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called ________.
) ________ is a phenolic antimicrobial compound that has been incorporated into consumer items such as garbage bags and diapers.
The amount of time needed to sterilize materials using moist heat is ________ (greater than/less than) the time needed to sterilize using dry heat.
Elements such as iodine, chlorine, and bromine are examples of ________, which are the basis for many effective antimicrobial agents.
Ultraviolet light penetrates materials ________ (more effectively/less effectively) than gamma rays
Sterilization procedures generally focus on inactivating or eliminating bacterial ________.
process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as ________.
passage of liquid of through sieve to trap particles
Filtration mode of action is _________________.
denature proteins, penetrate paper and plastic wraps and diffuse into every crack
Ethylene oxide mode of action is _________________.
A(n) ________ is an instrument that sterilizes by exposing materials to steam under pressure
The use of high levels of salt or sugar in the preservation of foods relies on the phenomenon of ________.
A(n) ________ is an iodine-containing organic compound found in such antiseptics as Betadine
Heavy metal and oxidizing agent disinfectants damage ________, interfering with microbial metabolism
thermal death point
The lowest temperature that kills all cells in a broth in 10 minutes is known as the ________.
External infections can be treated by ________ administration, in which a drug is applied directly to the site of infection.
Competition between beneficial microbes and potential pathogens is called ________.
Extrachromosomal pieces of DNA called ________ promote horizontal transfer of genes among bacteria and contribute to the spread of antimicrobial resistance.
A(n) ________ concentration of a drug is one at which microbes survive but are not able to grow and reproduce.
Antiviral medications frequently block unique ________ to prevent production of new virus
________ are serious secondary infections that result from the killing of the normal microbiota
________ means that a given antimicrobial agent is more toxic to a pathogen than to the host being treated
directly interferes with formation of alanine-alanine bridges between NAM
Vancomycin mode of action is _________________.
deactivates enzyme that cross links the NAM subunits of peptidogycan
Methicillin mode of action is _________________.
Antimicrobial agents that mimic the chemical structure of DNA building blocks are called ______________.
________ drugs are semisynthetic drugs developed to combat resistance against an existing drug
Some bacteria develop resistance to groups of drugs because the drugs are all structurally similar to each other; this is a phenomenon known as ________.
The abbreviation ________ stands for the smallest amount of a drug that will inhibit the growth and reproduction of a pathogen.
Some viruses are inactivated by the same chemical or physical agents that damage cytoplasmic membranes.
phenol coefficient is one of the most widely used measurements of an antimicrobial agent's effectiveness.
Because all cells engage in protein synthesis, there are few antimicrobial drugs that selectively inhibit this process.
Many antimicrobial drugs that affect the cytoplasmic membrane are used only externally because they can be toxic to humans.
Brain and spinal cord infections are difficult to treat because most antimicrobial drugs cannot diffuse out of the blood into these organs.
Some bacterial cells are resistant to a variety of antimicrobials because they actively pump the drugs out of the cell
If a subculture of an MIC test grows in an MBC test, the concentration of the drug was bactericidal