Question 1

These disinfectants are cationic, surface-activated agents that work by reducing the surface tension of molecules in a liquid, resulting in the disruption of the cellular membrane of microbes.

Accepted Answer

A)  Quaternary ammonium compounds 
B)  Heavy metals 
C)  Chlorines 
D)  Iodophors

Question 2

All of the following organisms can typically cause infection from aerosolization of specimens, except

Accepted Answer

A)  Mycobacterium tuberculosis. 
B)  Brucella spp. 
C)  Staphylococcus aureus. 
D)  Francisella tularensis.

Question 3

Because biosafety level 3 (BSL-3) organisms have the potential for aerosol transmission, and diseases with these agents may have serious lethal consequences, all of the following guidelines apply to BSL-3 laboratories, except:

Accepted Answer

A)  BSL-3 laboratories should be separated from other parts of the building by an anteroom. 
B)  BSL-3 laboratories should have restricted access with documentation of personnel entering and exiting the laboratory. 
C)  BSL-3 laboratories should have solid ceiling and floor seams, and any seams must be sealed. 
D)  BSL-3 laboratories should have positive air pressure.

Question 4

The chemical or physical method that destroys all forms of life is called

Accepted Answer

A)  sterilization. 
B)  disinfection. 
C)  bacteriostatic. 
D)  bactericidal.

Question 5

Alcohols use this mechanism to inactivate microorganisms.

Accepted Answer

A)  Denature proteins 
B)  Destroy DNA 
C)  Denature RNA 
D)  Inhibit cell wall synthesis

Question 6

The purpose of surgical hand scrubs and waterless hand rubs is to

Accepted Answer

A)  eliminate the transient flora and most of the resident flora on the skin. 
B)  remove all physical dirt and some residential flora. 
C)  remove all resident flora. 
D)  remove all transient flora.

Question 7

Chemosterilizers exert their killing effect through all the following mechanisms, except

Accepted Answer

A)  denaturation of cellular proteins. 
B)  damage of RNA and DNA. 
C)  inactivating enzyme substrates. 
D)  reactions with components of the cytoplasmic membrane.

Question 8

This chemical is a saturated 5-carbon dialdehyde that has broad-spectrum activity, rapid killing action, and remains active in the presence of organic matter.

Accepted Answer

A)  Formalin 
B)  Formaldehyde 
C)  Haloaldehyde 
D)  Glutaraldehyde

Question 9

These two alcohols are effective in killing enveloped viruses such as hepatitis B virus (HBV).

Accepted Answer

A)  50% isopropyl and 50% butanol 
B)  95% propanol and 70% ethanol 
C)  70% isopropyl and 95% ethanol 
D)  70% pentanol and 70% isopropyl

Question 10

If a laboratory uses hazardous chemicals, it must

Accepted Answer

A)  keep a chemical inventory and MSDSs on hand. 
B)  keep chemicals in a special corrosive cabinet. 
C)  keep chemicals in a special locking cabinet. 
D)  post chemical names and locations on the door of the laboratory.

Question 11

The laboratory exposure control plan should contain all the following, except

Accepted Answer

A)  engineer and work practice controls. 
B)  review of control plan every 5 years. 
C)  methods of compliance for Standard Precautions. 
D)  guidelines for handling and disposal of regulated waste.

Question 12

Many materials in hospitals that must be sterilized cannot withstand steam sterilization. Gas sterilization is used instead, using this gas.

Accepted Answer

A)  Nitrous oxide 
B)  Oxygen 
C)  Ethylene oxide 
D)  Carbon dioxide

Question 13

Disinfectants are usually used at this temperature.

Accepted Answer

A)  50° C to 100° C 
B)  0° C to 10° C 
C)  25° C to 50° C 
D)  20° C to 22° C

Question 14

For the most effective microbial killing, all iodophors must be properly diluted because

Accepted Answer

A)  they stain the skin if too concentrated. 
B)  this decreases contact time for adequate killing. 
C)  there must be enough free iodine to kill the microorganisms. 
D)  this increases contact time for adequate killing.

Question 15

High-level disinfectants are active against all the following, except

Accepted Answer

A)  parasites. 
B)  spores. 
C)  fungi. 
D)  tubercle bacilli.

Question 16

Engineering controls and work practice controls to ensure Standard Precautions are followed include all the following, except

Accepted Answer

A)  eyewash stations. 
B)  the use of safety needles. 
C)  plastic shield barriers. 
D)  fire blankets.

Question 17

Why is laboratory-acquired infection an obvious hazard for personnel working in a microbiology laboratory?

Accepted Answer

A)  Microbiology personnel do not always adhere to safety practices. 
B)  Safety practices are not applicable for the microbiology laboratory. 
C)  In-service education is not provided for microbiology staff. 
D)  Personnel deal with a variety of infectious agents: viral, fungal, parasitic, and bacterial.

Question 18

The comprehensive safety program for the microbiology laboratory needs to fulfill all the following provision, except:

Accepted Answer

A)  It is specific to the hospital and does not need to conform to state, local, and federal regulations. 
B)  It must address biological hazards. 
C)  It must teach correct techniques for lifting and moving heavy objects and patients (where applicable). 
D)  It must describe the safe handling, storage, and disposal of chemicals.

Question 19

Even though hypochlorites are inexpensive and have a broad range of microbes that they kill, they are not used as sterilants because of

Accepted Answer

A)  the corrosive nature of the compound. 
B)  the activation required by organic matter. 
C)  short exposure time for sporicidal action. 
D)  long exposure time for sporicidal action.

Question 20

Safety program and work practice controls consist of all of the following, except

Accepted Answer

A)  ensuring written procedures are in place for a task. 
B)  altering the manner in which a task is performed to reduce exposure to infectious agents. 
C)  allowing workers to eat at the bench if it gets busy and they do not have time to take a lunch break. 
D)  reviewing the procedure manual annually.

Exam 4: Control of Microorganisms