Chapter 9: Physical and Chemical Control of Microbes
You prepare the patient for the sterile procedure. Which of the following statements, by the patient, best demonstrates understanding of the need for sterile equipment and aseptic procedures? A. "Sterile equipment and aseptic procedures are utilized so there are no microorganisms introduced that could cause infection." B. "Sterile equipment and aseptic procedures are utilized to reduce trauma to the urinary tract." C. "Sterile equipment and aseptic procedures are utilized to protect the caregiver from infection." D. "Sterile equipment and aseptic procedures are utilized so that microorganisms on the skin that could cause infection are removed."
A. "Sterile equipment and aseptic procedures are utilized so there are no microorganisms introduced that could cause infection."
The minimum sterilizing conditions in a steam autoclave are A. 121C at 15 psi for 15 minutes. B. 63C for 30 minutes. C. 160C for 2 hours. D. 71.6C for 15 seconds. E. 100C for 30 minutes.
A. 121C at 15 psi for 15 minutes.
If chlorhexidine is unavailable for the procedure, which of the following chemical agents would also be appropriate as a topical antiseptic? A. 2% iodine B. 10% potassium iodide C. formaldehyde D. phenol
A. 2% iodine
HEPA filters are used to remove microbes from A. air. B. liquids. C. human tissues. D. medical instruments. E. All of the choices are correct.
A. air.
The alcohol wipe before an injection is an example of A. antisepsis. B. disinfection. C. sterilization. D. decontamination. E. virilization.
A. antisepsis.
The betadine swab before blood donation in an example of A. antisepsis. B. disinfection. C. sterilization. D. decontamination. E. sanitation.
A. antisepsis.
The method of removing vegetative life forms from living surfaces is termed A. antisepsis. B. disinfection. C. sterilization. D. decontamination. E. fegerming.
A. antisepsis.
Filtration sterilization A. can remove viruses. B. relies on gravity. C. removes toxins. D. uses heat and filtration. E. All of the choices are correct.
A. can remove viruses.
Removal of moisture by dehydration is called A. desiccation. B. flash freeze. C. lyophilization. D. pasteurization. E. sterilization.
A. desiccation.
The use of a physical or chemical process to destroy vegetative pathogens is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. degermation.
A. disinfection.
Dry heat A. is less efficient than moist heat. B. cannot sterilize. C. includes tyndallization. D. is used in devices called autoclaves. E. will sterilize at 121 C for 15 minutes.
A. is less efficient than moist heat.
Which of the following does not affect microbial nucleic acids? A. moist heat B. ultraviolet light C. X rays D. ethylene dioxide E. formaldehyde
A. moist heat
Disinfection of beverages such as apple juice, milk and wine is optimally achieved by A. pasteurization. B. chlorination. C. moist heat autoclave. D. filtration. E. boiling water.
A. pasteurization.
Ethylene oxide is A. sporicidal. B. only effective with high heat. C. the active agent in household bleach. D. used as an antiseptic against anaerobes. E. a halogen.
A. sporicidal.
The lowest temperature needed to kill all microbes in 10 minutes is the A. thermal death point (TDP). B. thermal death time (TDT). C. sporicidal time. D. death phase point. E. None of the choices is correct.
A. thermal death point (TDP).
Which control method would not be a suitable choice for killing Mycobacterium in a capped culture tube? A. ultraviolet (germicidal) light B. gamma rays C. 121C at 15 psi for 15 minutes D. 160C for 2 hours E. All of the choices are correct.
A. ultraviolet (germicidal) light
As the RN, you cleanse the urethral opening with an iodine swab. Which of the following terms most appropriately describes this method of microbial control? A. disinfectant B. antiseptic C. decontaminant D. sterilant
B. antiseptic
What instrument is most effective for pressure-temperature sterilization? A. oven B. autoclave C. water-bath D. Bunsen burner E. incubator
B. autoclave
Placing organisms at 4oC is A. bacteriocidal. B. bacteriostatic. C. decontamination. D. sterilization. E. None of the choices is correct.
B. bacteriostatic.
The compound that is an organic base containing chlorine and two phenolic rings, and is used increasingly for wound degerming, neonatal washes, hand scrubbing, and prepping surgical skin sites is A. carbolic acid. B. chlorhexidine. C. triclosan. D. formalin. E. quarternary ammonium compounds.
B. chlorhexidine.
The method of removing vegetative microbial life forms from inanimate objects is termed A. antisepsis. B. disinfection. C. sterilization. D. decontamination. E. degerming.
B. disinfection.
To reduce the patient's risk of infection, you should assist the physician with applying all of the following prior to the procedure except A. sterile gloves. B. foot covers. C. sterile gown. D. mask.
B. foot covers.
Which of the following forms of radiation is in order from the most penetrating to the least penetrating? A. gamma, cathode, X rays B. gamma, X rays, cathode C. cathode, gamma, X ray D. cathode, X ray, gamma E. X ray, gamma, cathode
B. gamma, X rays, cathode
Heavy metals work by A. rupturing the cell membrane. B. inactivating proteins. C. binding to DNA. D. dissolving the cell wall. E. mutating DNA.
B. inactivating proteins.
Using a HEPA filter in a vacuum or furnace is an example of which microbial control method? A. physical agent B. mechanical method C. chemical agent D. gases E. ionizing agent
B. mechanical method
Microbial death occurs when there is A. no movement. B. no reproduction. C. a change in appearance. D. a decrease in size. E. All of these occur.
B. no reproduction.
Pasteurization A. kills all vegetative forms. B. reduces the number of vegetative forms. C. reduces the number of endospores. D. increases food nutrient value. E. None of the choices is correct.
B. reduces the number of vegetative forms.
Which of the following represents the use of osmotic pressure as a microbial control method? A. bleaching a kitchen counter B. salting of meat C. rinsing of a cut with Betadine D. Both bleaching a kitchen counter and rinsing a cut with Betadine are correct
B. salting of meat
The process that destroys or removes all microorganisms and microbial forms including bacterial endospores on inanimate objects is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. degermation.
B. sterilization.
The shortest time required to kill all the microbes in a sample at a specified temperature is called the A. thermal death point (TDP). B. thermal death time (TDT). C. sporicidal time. D. death phase point. E. None of the choices is correct.
B. thermal death time (TDT).
The easiest microbial forms to kill or inhibit are A. naked viruses. B. vegetative bacteria and fungi. C. endospores. D. protozoan cysts. E. mycobacteria and staphylococci.
B. vegetative bacteria and fungi.
Which concentration of alcohol is deemed most effective in alcohol-based hand cleaners? A. 25% B. 10% C. 70% D. 95%
C. 70%
Which is correct regarding the rate of microbial death? A. Cells die at increasingly greater rates. B. Only older cells die in a culture. C. Cells in a culture die at a constant rate. D. Upon contact with the control agent, all cells die at one time. E. Cells become metabolically inactive, but are never killed.
C. Cells in a culture die at a constant rate.
Which of the following is not a primary target of milk pasteurization? A. Salmonella B. Campylobacter jejuni C. Lactobacilli D. Listeria monocytogenes E. Brucella
C. Lactobacilli
The use of chemical agents directly on exposed body surfaces to destroy or inhibit vegetative pathogens is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. ionization
C. antisepsis.
As an RN, you diligently practice proper hand washing technique when your hands are visibly dirty. Which of the following terms appropriately describes the type of antimicrobial control provided by hand washing with soap and water? A. sterilization B. disinfection C. decontamination D. antisepsis
C. decontamination
While preparing to insert the urinary catheter, the patient moves her leg and touches the sterile field. What is the most appropriate action for you to take as the RN? A. continue the procedure and place the catheter appropriately B. clean the catheter with alcohol, and then continue the procedure C. discard the sterile field and obtain new supplies D. clean the catheter with iodine, and then continue the procedure
C. discard the sterile field and obtain new supplies
Which of the following is not true of chloramines? A. contains chlorine B. can sanitize and disinfect C. form trihalomethanes with organic compounds D. is safer than free chlorine E. treats wounds and skin surfaces
C. form trihalomethanes with organic compounds
All of the following pertain to hypochlorites except A. release hypochlorous acid in solution. B. cause denaturation of enzymes. C. found in iodophors. D. used to disinfect dairy, restaurant, and medical equipment. E. found in common household bleach.
C. found in iodophors.
The chemical agent that produces highly reactive hydroxyl-free radicals and also decomposes to O2 gas is A. cidex. B. cationic detergents. C. hydrogen peroxide. D. chlorhexidine. E. iodophors.
C. hydrogen peroxide.
In lab, inoculating loops are sterilized using A. moist heat. B. chemicals. C. incineration. D. filtration. E. ethylene oxide.
C. incineration.
The removal of all life forms from inanimate objects is termed A. antisepsis. B. disinfection. C. sterilization. D. decontamination. E. degerming.
C. sterilization.
Intermittent sterilization, which uses three days of lower temperature steam for short periods of time, is also called A. pasteurization. B. incubation. C. tyndallization. D. disinfection. E. dessication.
C. tyndallization.
Antimicrobial agents can target the cell wall by A. blocking its synthesis. B. digesting it. C. denaturing proteins. D. All of the choices are correct.
D. All of the choices are correct.
Following successful placement of the central venous line, you are diligent to prevent infection when accessing and administering medications. Which of the following actions should be completed prior to use of the line? A. hand washing B. disinfection of the access port with alcohol or chlorhexidine prior to use C. application of gloves D. Hand washing, application of gloves, and disinfection of the access port should all be completed prior to use of the line.
D. Hand washing, application of gloves, and disinfection of the access port should all be completed prior to use of the line.
As an RN, you utilize an alcohol-based hand cleaner with friction rub when your hands are not visibly dirty. Which of the following terms appropriately describes the type of antimicrobial control provided by alcohol-based hand cleaners? A. sterilization B. disinfection C. decontamination D. antisepsis
D. antisepsis
Prior to placement of the central venous line, the patient's skin is scrubbed with chlorhexidine. Which of the following microorganisms are targeted by this chemical agent? A. bacteria B. viruses C. fungi D. bacteria, viruses, and fungi
D. bacteria, viruses, and fungi
Which of the following microbes are targeted by alcohol-based hand cleaners? A. bacteria B. viruses C. fungi D. bacteria, viruses, and fungi
D. bacteria, viruses, and fungi
Which of the following microbial forms have the highest resistance to physical and chemical controls? A. naked viruses B. protozoan cysts C. fungal spores D. bacterial endospores E. yeast
D. bacterial endospores
Surfactants work by A. coating the organism, preventing interaction with its environment. B. blocking transport into the organism. C. blocking transport out from the organism. D. disrupting membrane integrity. E. All of the choices are correct.
D. disrupting membrane integrity.
Which of the following acids is not used to destroy or inhibit microbial cells in food? A. acetic acid B. benzoic acid C. lactic acid D. phosphoric acid E. propionic acid
D. phosphoric acid
A cleansing method that mechanically removes microbes and other debris to reduce contamination is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. degermation.
D. sanitization.
Scrubbing or immersing the skin in chemicals to reduce the numbers of microbes on the skin is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. ionization.
D. sanitization.
The process of using a cleansing technique to mechanically remove and reduce microorganisms and debris to safe levels is A. disinfection. B. sterilization. C. antisepsis. D. sanitization. E. degermation.
D. sanitization.
Which of the following types of control agents would be used to achieve sterility? A. virucide B. bactericide C. germicide D. sporicide E. fungicide
D. sporicide
Sterilization is achieved by A. flash pasteurization. B. hot water. C. boiling water. D. steam autoclave. E. All of the choices are correct.
D. steam autoclave.
Alcohols A. denature proteins when in a 50-95% alcohol-water solution. B. disinfect items soaked in alcohol. C. are skin degerming agents. D. at 50% or higher concentrations dissolve cell membrane lipids. E. All of the choices are correct.
E. All of the choices are correct.
Hydrogen peroxide is A. sporicidal. B. fungicidal. C. bactericidal. D. virucidal. E. All of the choices are correct.
E. All of the choices are correct.
Which of the following items are typically irradiated in order to kill microbes? A. cured meats B. human tissues such as heart valves and skin C. operating room air D. surgical gloves E. All of the choices are correct.
E. All of the choices are correct.
Which of the following is not a factor that affects germicidal activity? A. the material being treated B. the length of exposure C. the strength of the germicide D. the microorganism being treated E. All of these are factors.
E. All of these are factors.
Which of the following factors will influence the action of microbial agents? A. the number of microorganisms B. the kind of microorganisms C. temperature and pH D. mode and dosage of the agent E. All of these will influence the action.
E. All of these will influence the action.
Agents that can denature microbial proteins include all of the following except A. moist heat. B. alcohol. C. acids. D. metallic ions. E. X rays.
E. X rays.
Which of the following is not used as an antiseptic? A. iodophor B. chlorhexidine C. 3% hydrogen peroxide D. betadine E. aqueous glutaraldehyde
E. aqueous glutaraldehyde
Each of the following is the target of antimicrobial agents except A. cell walls. B. cell membranes. C. ribosomes. D. cellular proteins. E. cytoplasm.
E. cytoplasm.
Electrons are ejected from atoms in cells when organisms are exposed to A. desiccation. B. ultraviolet light. C. ethyl alcohol. D. hydrogen peroxide. E. gamma rays and X rays.
E. gamma rays and X rays.
Physical agents for controlling microbial growth include all the following except A. ultraviolet radiation. B. boiling water. C. HEPA filters. D. pasteurization. E. hydrogen peroxide.
E. hydrogen peroxide.
All the following act as surfactants except A. detergents. B. soaps. C. quaternary ammonia. D. alcohols. E. iodine.
E. iodine.
T/F A microorganism that is not motile and has stopped metabolizing could be considered dead.
FALSE
T/F Bacteriostatic agents kill bacterial cells.
FALSE
T/F Chlorine compounds remain stable and effective in the presence of excess organic matter.
FALSE
T/F Isopropyl alcohol wiped across a skin site can sterilize it.
FALSE
T/F Microbicidal agents are sterilants.
FALSE
T/F Most microbial contaminants of food are killed at freezing temperatures.
FALSE
T/F Pasteurization does not kill endospores or thermoduric microbes.
FALSE
T/F Pasteurization will make milk sterile.
FALSE
T/F Soaps and detergents are very effective as sterilants.
FALSE
T/F Alcohols are more effective at inactivating enveloped viruses than naked viruses.
TRUE
T/F Analine dyes, like crystal violet, have antimicrobial activity particularly against gram-positive bacteria and some fungi.
TRUE
T/F Chlorine and ethylene oxide are sterilizing gases.
TRUE
T/F Hydrogen peroxide can be used to sterilize instruments such as endoscopes.
TRUE
T/F Ionizing radiation is more effective than non-ionizing radiation in killing microbes.
TRUE
T/F Prions require more extensive methods of sterilization than are needed for bacterial endospores.
TRUE
T/F Pseudomonas is resistant to soaps.
TRUE
T/F The presence of organic matter such as saliva and pus can interfere with the actions of disinfectants.
TRUE
T/F When a control agent targets the metabolic processes of microbial cells, active younger cells typically die more rapidly than older cells.
TRUE
