Which of the following infectious agents is least resistant to destruction by chemical methods?
enveloped viruses
Which of the following statements is TRUE of disinfectants?
They are used on inanimate surfaces
A stationary broth culture contains 10 billion (1010 )cells. the microbial death rate during autoclaving of this spent culture is 1.5 minutes. How long must it be autoclaved to be considered sterile?
16.5 min
Which of the following is an example of sanitization?
A public toilet is treated with disinfectants
Aseptic means?
free of pathogens
Which of the following is bacteriostatic?
freezing below 0*C
Antimicrobial agents that damage nucleic acids also effect
protein synthesis
Seventy percent alcohol is effective against
enveloped viruses.
An instrument that will come into contact with only the skin of a patient should be disinfected with a
low-level germicide
Which of the following is the most difficult to inactivate?
bacterial endospores
Which of the following describes flash pasteurization?
heating at 72*C for 15 seconds
The dairy creamer used in restaurants is usually treated by
ultra-high temperature pasteurization
Boiling water for 10 minutes is effective in ridding it of
both growing bacteria and enveloped viruses
Which of the following is NOT a feature associated with filtration?
varying thickness of membrane filters used
Which of the following is a target of pasteurization?
Brucella melitiensis
Which of the following types of radiation is non ionizing and has the shortest wavelength?
ultraviolet light
Which of the following is used for microbial control in fresh fruits and vegetables?
gamma ray
Which of the following can be used to disinfect air?
both HEPA filters and ultraviolet light
Silvadene, a topical treatment for burns, contains 1% silver. What category of chemical control agent is in Silvadene?
heavy metals
Which of the following is the most appropriate pairing of microbe and biosafety level?
methicillin-resistant Staphylococcus aureus (MRSA), BSL-2
The use of lysozyme during the preparation of cheeses and wines is effective in reducing the numbers of
bacteria
Which of the following statements about quaternary ammonium compounds is FALSE:
they function by cross-linking proteins
Which of the following is a sterilizing agent?
peracetic acid
Which of the following was used in the past to prevent the transmission of gonorrhea from an infected mother to her newborn?
silver nitrate
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 statements about aldehydes is FALSE?
they are used only to preserve dead tissue
Disinfecting agents naturally produced by microorganisms are
antimicrobials
A chemical agent that kills pathogenic microbes in general is a
germicide
Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?
It only arrests growth of vegetative cells
The endospores of which of the following microbes are used to measure the effectiveness of autoclave sterilization?
Bacillus stearothermophilus
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?
filtration
Which of the following procedures is currently the standard test used in the United States for evaluating the efficiency of antiseptics and disinfectants?
use-dilution test
Which of the following would be used to sterilize a mattress?
ethylene oxide
Disinfectants that damage membranes include
both alcohol and phenolics
Which of the following antimicrobial agents is most toxic to humans?
ethylene oxide
The process of filtration is a
sterilizing method
Hydrogen peroxide is a
disinfecting and sterilizing agent
The process of incineration is used for
sterilization
Alcohols are used for
both antisepsis and disinfection
The chemical agents known as "quats" are used for
disinfection
The compound ethylene oxide is used in
sterilization
Gularaldehyde is used for
both disinfection and sterilization
_____ may be achieved using chlorine dioxide.
Disinfection
Gamma irradiation is a process for
sterilization
______ is the physical removal of microbes.
Degerming
The process of freeze-drying microbes to preserve them is (lyophilization/dessication)
lyophilization
Natural antiseptics such as pine or clove oil are examples of antimicrobial compounds called (alcohols/ phenolics/ detergents).
phenolics
An (iodophor/ halogen) is an iodine-containing organic compound found in such antiseptics as Betadine.
iodophor
Disinfectants known as (alcohols/ oxidizers/ aldehydes) have the chemical group-CHO, which reacts with and damages both proteins and nucleic acids.
aldehydes
The lowest temperature that kills all cells in a broth in 10 minutes is known as the (microbial/ thermal) death point.
Thermal
The amount of time needed to sterilize materials using moist heat is (more/less) than the time needed to sterilize using dry heat.
less
Microbial growth in jellies is inhibited by the ( acidic/ hypotonic/ hypertonic) condition of the food.
hypertonic
The deadliest, most contagious microbes are studied under conditions of (BSL-4/ BSL-3/ BSL-2/ BSL-1) containment.
BSL-4
Ultraviolet light penetrates (more/less) effectively than gamma rays.
less
The antimicrobial chemical pictured above is a (phenolic/ surfactant/ enzyme) compound found in many consumer products.
phenolic
Elements such as iodine, chlorine, and bromine are examples of (oxidizers/ halogens/ metals), which are the basis for many effective antimicrobial agents.
halogens
Heavy metal and oxidizing agent disinfectants damage (proteins/ DNA/ membranes), interfering with microbial metabolism.
proteins
The (endospore/ cysts/ prions) are the infectious agents most resistant to antimicrobial agents or processes.
prions
The process of heating milk or fruit juice to levels that kill any pathogenic microbes present is known as (pasteurization/ sanitization/ lyophilization).
pasterurization
The effectiveness of sterilization procedures is evaluated using (prions/ cysts/ endospores) because of their resilience.
endospores