Question 1

The laboratory receives a blood soaked gauze pad with some tissue wrapped in it for culture in a sterile container.The proper disposal of the material will include:

Accepted Answer

Although the laboratory microbiologist is responsible for placing the material in the appropriate biohazard container,the laboratory either has an on-site facility that will properly sterilize the contaminated material or will contract with an outside agency to complete the sterilization process.

Question 2

Biosafety Level 4 agents:

Accepted Answer

Biological agents are classified into levels on the basis of their degree of potential harm,from nonhazardous (Level 1)to the most hazardous (Level 4).

Question 3

All laboratory and health care personnel are required to practice safety and utilize specific controls for the management and handling of infectious or potentially infectious materials.This is considered:

Accepted Answer

Standard Precautions include the use of practices and standard personal protective equipment that minimize exposure to infectious material and agents throughout the health care environment for staff,patients,and visitors.

Question 4

Biosafety Level 2 agents:

Accepted Answer

Biological agents are classified into levels on the basis of their degree of potential harm,from nonhazardous (Level 1)to the most hazardous (Level 4).

Question 5

During the process of phlebotomy,drawing a blood specimen from a patient,the action of cleaning the area on the skin prior to the insertion of the needle requires the application of a(n):

Accepted Answer

Although alcohol is considered an antiseptic in many health care settings,the general term for application of an agent to minimize the level of potentially contaminating organisms on the skin is considered an antiseptic.A disinfectant is used on an inanimate surface.

Question 6

Class III biological safety cabinets:

Accepted Answer

Biological safety cabinets are designated by class according to the degree of biological containment they provide,from the lowest level of containment (class I)to the highest level of containment (class III).

Question 7

Applying a chemical to the surface of the laboratory bench to remove the contaminating microorganisms is considered:

Accepted Answer

The removal of contaminating microorganisms on an inanimate stationary surface is considered disinfection.

Question 8

The primary action in hand washing that prevents the distribution or transmission of microorganisms is:

Accepted Answer

Most antibacterial soaps are simply bacteriostatic and slow down the growth of organisms.The temperature of the water has no effect on microbial growth because it much be cool enough to apply to the skin without burning.The actual mechanical rubbing is the primary means for removal of potentially contaminating microorganisms independent of the chemical nature of the soap.

Question 9

The laboratory receives a bloody,tissue contaminated surgical forceps.Upon removal the laboratory should dispose of the instrument by:

Accepted Answer

Surgical forceps should not be placed in any container for disposal in the microbiological laboratory.Care should be taken to properly return to surgery.Due to the nature of many surgical instruments,methods of sterilization that include moisture and heat may corrode or damage instruments.Therefore they are often sterilized by utilization of ultraviolet light or chemical sterilization to maintain the integrity of the instruments.

Question 10

Chemicals used for disinfection that are capable of disrupting cellular membranes and reduce the surface tension through cationic disruption of water molecules are termed:

Accepted Answer

Quaternary ammonium componds utilize cationic detergents to disrupt the cellular membranes of microorganisms and other organic cells.Alcohols are a dehydrating agent that disrupt hydrogen bonds and chlorine-based agents cause oxidative stress on organisms.Iodines or heavy metals interfere with biological processes by interfering with charge interactions and chelating of enzymatic compounds or cofactors required for enzymatic reactions.

Question 11

To be sterilized in an autoclave,media or instruments should be:

Accepted Answer

Proper temperature,pressure,and exposure time varies depending on the type of material being sterilized.Highly contaminated items such as infectious waste are more vigorously treated than items such as media or instruments.

Question 12

Minimal protection of specimen,personnel,and environment is accomplished with which class of biological safety cabinet?

Accepted Answer

Biological safety cabinets are designated by class according to the degree of biological containment they provide,from the lowest level of containment (class I)to the highest level of containment (class III).

Question 13

The classification of Biological Agents and the use of safety precautions is based on all of the criteria listed except:

Accepted Answer

Although the biological structure is important and may have an impact on all of the other factors listed,the statement of biological structure alone is not significant or specific enough to classify an organism into a specific biosafety category.The other items relate to the potential for exposure and management of that exposure in an infection.

Question 14

Decontaminating and disinfecting surfaces may result in a decreased removal of contaminating organisms when used in combination.This is due to the fact that:

Accepted Answer

Agents mixed together may actually decrease their effectiveness or inactive the activity of the other chemical.In addition,based on the chemical constituency,some chemicals can create hazardous fumes or compounds creating a more hazardous interaction for the laboratory staff.

Question 15

When processing biologically contaminated specimens,the microbiologist is susceptible to exposure through all of the following except:

Accepted Answer

A break in the microbiologists glove will not necessarily present a risk to the microbiologist as long as the skin is intact.The other activities can pose risk for transmission of a variety of infectious agents.

Question 16

A new laboratory assistant was asked to disinfectant the laboratory bench where specimens are received and processed.The laboratory assistant used concentrated bleach to wipe down the laboratory bench.The discrepancy in this situation is:

Accepted Answer

A common mistake is that concentrated disinfectants are more effective in the killing and decontamination of potentially contaminated surfaces.On the contrary,the inclusion of water assists in the breaking of hydrogen bonds that are essential in maintaining the structure of organic molecules such as proteins.Failure to dilute concentrated disinfectants results in a decreased effectiveness of the chemical and decontamination of the surface.

Question 17

Alcohols are an effective chemical disinfectant due to their ability to:

Accepted Answer

Alcohol in effect hydrolyzes hydrogen bonds breaking the secondary,tertiary,and quaternary level of protein structure.When protein structure is destablized,proteins become denatures and loose function.Destroying essential proteins in biological organisms in essence results in loss of function and death.

Quiz 4: Laboratory Safety