Sterilization is the:
Destruction of all forms of microbial life.
An antiseptic is used when one needs to remove microbes from:
Skin, prior to injection
Foods to be canned need not be sterile. However, all of Clostridium botulinum must be killed.
Enodpores
Some antimicrobial treatments kill microbes; some inhibit growth. Which term refers to an agent that inhibits bacterial growth?
Bacteriostatic.
Which of the following is not a major target for action of antimicrobials?
Flagella
Decimal reduction time is the time in minutes in which of the population at a given temperature will be killed.
90%
Which is not a characteristic of the autoclave?
The requirement for long (hours) exposure times
Milk that you have never opened spoils in the refrigerator. A sample reveals the presence of microorganisms. The most likely explanation is:
The microbes that survived pasteurization were able to grow at 4 °C.
Choose the best method for the sterilization of an enzyme solution.
A) Freezing.
B) Dry heat.
C) Filtration.
D)Treatment with phenol.
E)Autoclave.
Filtration
The bactericidal effect of UV light is attributed to damage to:
DNA
Some microbes are very resistant to antimicrobial chemicals. Which of the following would be the easiest to kill?
A)Pseudomonas aeruginosa
B) Mycobacterium tuberculosis
C) E. coli
D) cysts of Protozoa
E) Clostridium endospores
E. Coli
In the filter paper method used for evaluation of antimicrobial chemicals, the effectiveness of a chemical is indicated by a around a disc immersed with the test chemical.
Clear Zone
The first disinfectant used by Lister was
Phenol
Alcohol is most effective when used as a solution.
70%
Which chemical was once used to treat the eyes of newborn babies to kill N. Gonorrhoeae?
Silver Nitrate
The following may be listed on the ingredients of your favorite snack food. Which of the following is not antimicrobial?
A) Potassium sorbate.
B) Calcium propionate.
C) Sodium benzoate.
D) Xanthan.
E) Sorbic acid.
Xanthan
The more microbes present in a sample, the ____________________ it takes to eliminate the microbial population.
Longer
The ____________________ is the lowest temperature at which all microorganisms in a liquid suspension will be killed in 10 minutes.
Thermal Death Point
Dry heat kills by ____________________ , similar to the slow charring of paper in a heated oven.
Oxidation
____________________ is a common household disinfectant that has been used to disinfectant everything from dairies to drinking water.
Bleach
A zone of growth inhibition around a copper penny on a plate that had been swabbed with bacteria demonstrates the ____________________ of copper
oligodynamic action
____________________ has little value as an antiseptic but is important in the mechanical removal of microbes.
Soap
Oxidizing agents are useful for irrigating deep wounds where released oxygen will inhibit the growth of ____________________ .
anaerobic bacteria
__________________ can grow in solutions of quaternary ammonium compounds
Pseudomonas
____________ are commonly used as food preservatives in spite of their conversion to the carcinogenic products called nitrosamines.
Nitrates
_______ ammonia compounds are less effective against gram-negative bacteria and more effective against gram-positive bacteria.
Quaternary
Microbes vary with respect to sensitivity to an antimicrobial agent.
True
The presence of organic matter, such as blood or saliva, speeds the action of antimicrobial chemicals.
False
Times required for sterilization in an autoclave are shorter than those required in a dry oven because moist heat penetrates biological specimens more effectively than does dry heat.
True
Aldehydes, alcohols, and halogens kill bacteria by the same method of action
False
UV radiation and X ray radiation are similar in that they damage DNA and have a high penetrating power.
False
Soap is ineffective in killing bacteria. Therefore, hand washing is a rather ineffective measure in preventing disease transmission.
False
70% ethyl alcohol is a more effective bactericide than 100% alcohol.
True