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45 terms

Chapter 7

The Control of Microbial Growth
STUDY
PLAY
Which of the following is the best method to sterilize heat-labile solutions?
Membrane filtration
Which of the following best describes the pattern of microbial death?
The cells in a population die at a constant rate
Which of the following substances can sterilize?
Ethylene oxide
Which of the following substances is used for surgical hand scrubs?
Chlorhexidine
Place the following surfactants in order from the most effective to the least effective antimicrobial activity?
1-Soap, 2-Acid-anionic detergent, 3-Quats
3-2-1
The antimicrobial activity of chlorine is due to which of the following?
The formation of hypochlorous acid
Iodophors differ from iodine in that iodophors
Don't stain
Are less irritating
Are longer lasting
Are combined with a nonionic detergent
ALL OF THE ABOVE
Which of the following does NOT achieve sterilization?
Pasteurization
Which of the following is a limitation of the autoclave?
Cannot be used with heat-labile materials
Which of the following affects the elimination of bacteria from an object?
Number of bacteria present
Temperature
pH
Presence of organic matter
ALL OF THE ABOVE
Which of the following does NOT directly result from application of heat?
Cell lysis
Which of these disinfectants acts by denaturing proteins
Bisphenols
Which of the following substances is NOT an oxidizing agent?
Glutaraldehyde
Which of the following is NOT used to disinfect water?
Heat
Which of the following substances is NOT effective against nonenveloped viruses?
Alcohol
Glutaraldehyde is considered one of the most effective disinfectants for hospital use. Which of the following statements about glutaraldehyde is false?
Stains and corrodes
Which concentration of ethanol is the most effective bactericide?
70%
Which of the following is NOT a factor contributing to hospital acquired infections?
All of the above may contribute to hospital acquired infections
Which of the following treatments is the most effective for controlling microbial growth?
They are equivalent treatments
Which of the following could be used to sterilize plastic Petri plates in a plastic wrapper?
Gamma radiation
In Figure 7.1, what is the thermal death time for a culture (a)?
60 minutes
Assume that one culture is a freshly opened package of dried yeast with 0.1% moisture, another culture is the same yeast with 7.5% moisture, and the third culture is a package of yeast mixed with water. Each culture was exposed to 130C in a hot-air oven. Which graph in Figure 7.1 most likely shows the yeast with 0.1% moisture
____
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In Figure 7.2, the thermal death point for this culture is
Can't tell from the data provided
In Figure 7.2, the decimal reduction time (D value) for the culture is approximately
15 minutes
In Figure 7.2, the thermal death time for this culture is
60 minutes
Which of the following pairs is mismatched?
A. Ag/burns
B. Alcohols/open wounds
C. CuSO4/algicide
D. H2O2/open wounds
E. Organic acids/food preservation
Alcohols/open wounds
Which graph in Figure 7.3 best depicts the effect of placing the culture in an autoclave for 15 minutes at time x?
___
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Which graph in Figure 7.3 best depicts the effect of placing the culture at 7 C at time x?
___________
In Table 7.1, which compound was the most effective against Staphylococcus?
C - 10
In Table 7.1, which compund was the most effective against E. coli?
Can't tell
In Table 7.1, which compound was bactericidal?
Can't tell
The fate of E. coli 0157:H7 in apple cider held at 8 C for 2 weeks, with and without preservatives
In Table 7.2 which preservative is most effective?
Benzoate
Which one of the following does NOT belong with the others?
A. Acid-anionic detergents
B. Benzoic acid
C. Supercritical CO2
D. Pasteurization
E. Peracetic acid
Acid-anionic detergents
Which one of the following does NOT belong with the others?
A. Beta-propiolactone
B. Glutaraldehyde
C. Ethylene oxide
D. Hydrogen Peroxide
E. Propylene oxide
Hydrogen peroxide
Which of the following substances is NOT used to preserve foods?
Biguanides
In Table 7.3, which disinfectant is the most effective at stopping bacterial growth?
Doom
In Table 7.3, which disinfectant was bactericidal?
Mortum
In Table 7.3 which disinfectant was most effective against Salmonella?
Can't tell
Which of the following will not destroy prions?
Boiling
Which one of the following pairs is mismatched?
A. Ionizing radiation/hydroxyl radicals
B. Ozone/takes electrons from substances
C. Plasma sterilization/free radicals
D. Supercritical fluids/CO2
E. Ultraviolet radiation/desiccation
Ultraviolet radiation/desiccation
Which of the following will NOT preserve foods?
Microwaves
Which of the following will NOT inactivate endospores?
High pressure
If you were preparing nutrient agar at home and didn't have an autoclave, what could you use to sterilize the nutrient agar?
Pressure cooker at 121 C for 15 minutes
Bone and tendons for transplant are decontaminated by
Supercritical fluids
Which one of the following is most resistant to chemical biocides?
Mycobacteria