Which of the following is not a method of microbial control used in ancient times?
|A)||Salting, smoking, pickling, and drying foods|
|B)||Exposing food, clothing, and bedding to sunlight|
|C)||Boiling drinking water|
|D)||Consuming molds to derive antibiotic benefits|
|E)||Burying human wastes|
Which of the following terms is defined as the destruction of vegetative pathogens but not bacterial endospores?
Of the microbial forms listed below, which exhibits the highest level of resistance to physical and chemical methods of growth control?
|B)||Most vegetative bacterial cells|
What is the goal of sterilization?
|A)||The destruction to protozoan trophozoites|
|B)||The destruction of bacterial endospores|
|C)||The destruction or inhibition of vegetative pathogens through chemicals applied to body surfaces|
|D)||To temporarily inhibit the reproduction of microbes but not inflict irreversible damage|
|E)||The destruction of fungal sexual spores (zygospores)|
What term is defined as a chemical agent that is applied directly to body surfaces, wounds, and surgical incisions to destroy or inhibit vegetative pathogens?
Microbial death is defined as which of the following?
|A)||The permanent termination of an organism's vital processes|
|B)||The permanent loss of reproductive capability, even under optimum growth conditions|
|C)||The loss of movement in a motile microbe|
|D)||Exposure to a chemical or physical agent for a period of time until a cell structure becomes dysfunctional|
|E)||Irreversible damage to a cell|
Which of the following does not affect the action of antimicrobial agents?
|B)||Temperature and pH of the environment|
|C)||Presence of water|
|D)||Number of microorganisms present|
|E)||Mode of action of the agent|
Physical and chemical antimicrobial agents can target all but which of the following?
|B)||Cell membrane integrity|
|E)||Cell wall synthesis|
Surfactants function as microbicidal agents because they do what to microorganisms?
|A)||Inhibit peptide bond formation during translation|
|B)||Interfere with the synthesis of peptidoglycan|
|C)||Prevent mRNA transcription|
|E)||Disrupt the integrity and lower the surface tension of cell membranes|
Agents that alter protein function may do all but which of the following?
|A)||Prevent peptide bond formation|
|D)||Alter an enzyme's active site|
|E)||Prevent an enzyme from interacting with its substrate|
Which of the following is not a concern that must be taken into consideration when selecting a method of microbial control?
|A)||The method must be suitable for the application.|
|B)||The method should not leave an undesirable residue behind.|
|C)||The method should be effective regardless of cost and labor effectiveness.|
|D)||The method should destroy only the microbial forms present.|
|E)||If the disinfected item is to be reused, it should be able to withstand the antimicrobial treatment.|
What is the most widely used of the physical methods of microbial control?
Common methods of using moist heat to control microbial growth include all but which of the following?
|B)||Steam under pressure|
|C)||Live, nonpressurized steam|
Pasteurization rids liquids of what microbial form?
|D)||Most viruses and vegetative stages of 97-99% of bacteria and fungi|
Exposure to cold temperatures has what effect on microorganisms?
|A)||It removes moisture from the environment and thus prevents growth.|
|B)||It oxidizes and coagulates proteins.|
|C)||It retards the activities of most microbes.|
|D)||It denatures proteins.|
|E)||It kills endospores and thermophilic organisms.|
Both ionizing and nonionizing radiation tend to effect what?
Which of the following is not an effect of food irradiation?
|A)||It leads to a small decrease in the amount of vitamin B1 in food.|
|B)||It can kill bacterial pathogens that may exist in the food.|
|C)||It can kill insects and worms that live in or on the food.|
|D)||It can inhibit white potatoes from sprouting.|
|E)||It causes the formation of free-radical oxidants that remain in the food indefinitely.|
For what method of microbial growth control is the application of UV light useful?
What organisms are the most susceptible to sonication?
|A)||Gram positive cocci|
|B)||Gram negative rods|
Desirable qualities in a microbicidal chemical include all but which of the following?
|C)||Inactivated by organic matter|
|E)||Soluble in water or alcohol|
Overuse of germicides is leading to all but which of the following problems?
|A)||Survival and growth advantages of resistant strains|
|B)||Obsessive fear of "germs" among the general public|
|C)||The selection of "supermicrobes"|
|D)||Increased sensitivity of microbes to the phenolic triclosan|
|E)||A reduction in natural contact with microbes required for maintenance of normal flora and for stimulation of immunity|
Which of the following chemical agents does not approach the ideal germicidal chemical?
|B)||Hydrogen peroxide, stabilized|
|D)||Ethylene oxide gas|
What germicidal chemical is used to prepare skin and mucous membranes for surgery and injections, is included in surgical handscrubs, is used to treat burns, and is used to disinfect equipment and surfaces?
|A)||Ethylene oxide gas|
Phenolics used for disinfection include all but which of the following?
What microbes were used in the senate's Hart office building to ensure that the fumigation and cleanup of Bacillus anthracis endospores was successful?