1. Microbiological contaminants are best described as:
unwanted microbes present on or in a substance
2. Physical agents for controlling microbial growth include all of the following, except:
E. hydrogen peroxide.
Which of the following microbial forms have the highest resistance to physical and chemical controls?
D. bacterial endospores
The process that destroys or removes all microorganisms and microbial forms including bacterial endospores is:
The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is:
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is:
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is:
The shortest time required to kill all the microbes in a sample at a specified temperature is called the:
thermal death time (TDT).
Disinfection of beverages, such as apple juice, milk, and wine, is optimally achieved by:
Which of the following items are typically irradiated in order to kill microbes?
all of the choices are correct
Which control method would not be a suitable choice for killing Mycobacteria in a capped culture tube?
ultraviolet (germicidal) light
The compound that is an organic base containing chlorine and two phenolic rings and is used increasingly for handscrubbing, neonatal washes, wound degerming, and prepping surgical skin sites is:
All of the choices are correct. D. at 50% or higher concentrations dissolve cell membrane lipids.
All of the following are correct about iodophors, except:
this formulation allows a quick release of free iodine.
The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is:
All the following are correct about detergents, except:
they are active in the presence of organic matter.
Which of the following is being used to replace hypochlorites in treating water because of the possibility of cancer-causing substances being produced?
Which of the following is officially accepted as a sterilant and high-level disinfectant?
All of the following are correct about food irradiation, except:
the World Health Organization does not endorse this process
All of the following are benefits of food irradiation, except:
E. it makes the food less nutritious.
Historically, which of the following was instilled into the eyes of newborn infants to prevent gonococcal infections?
D. silver nitrate
All of the following are correct about the autoclave, except:
B. it is effective for sterilizing powders, oils, and waxy substances.
Using toilet bowl cleaner and nonionizing radiation to non-animate surfaces only removes or kills vegetative bacteria. The term that best describes this action is:
Commercial products containing which chemicals are more effective at killing microorganisms?
The presence of organic matter such as saliva and pus can interfere with the actions of disinfectants.
When a control agent targets the metabolic processes of microbial cells, active younger cells typically die more rapidly than older cells. True False
A microorganism that is not motile and has stopped metabolizing could be considered dead. True False
Chlorine compounds remain stable and effective in the presence of excess organic matter. True False
Aniline dyes like crystal violet have antimicrobial activity particularly against gram positive bacteria and some fungi. True False