CSFA Microbiology and Infection Control 5

Question 1

Gram staining differentiates bacteria based on differences in their:

Accepted Answer

Cell wall peptidoglycan layer thickness

Answer

Gram-positive bacteria retain crystal violet due to their thick peptidoglycan cell wall, while gram-negative bacteria decolorize because of their thin layer and outer lipid membrane.

Question 2

Which of the following describes the CORRECT method for removing a contaminated gown in the OR after a case?

Accepted Answer

Unfasten ties, roll the gown inward (contaminated surface inside), and discard in biohazard container

Answer

Rolling the gown inward contains contaminated surfaces and prevents self-contamination; it is then discarded as regulated medical waste.

Question 3

Which surgical specialty case would most likely be classified as a clean-contaminated (Class II) wound?

Accepted Answer

Elective sigmoid colectomy with bowel entered under controlled conditions

Answer

Elective colon surgery with controlled entry into the GI tract without gross spillage meets the criteria for Class II clean-contaminated wounds.

Question 4

Terminal cleaning of the OR after an infectious case should begin with:

Accepted Answer

Cleaning high-touch surfaces and the surgical field first, then progressing to the floor

Answer

OR terminal cleaning proceeds from the surgical field and high-touch surfaces downward to the floor, following a clean-to-dirty top-down approach.

Question 5

Which antiseptic preparation requires a minimum drying and contact time before incision to achieve maximum antiseptic effect and to prevent surgical fire risk?

Accepted Answer

Chlorhexidine gluconate with alcohol (e.g., ChloraPrep)

Answer

Alcohol-based chlorhexidine preparations must dry completely before draping; the alcohol evaporation eliminates fire risk and the drying time ensures antimicrobial efficacy.

CSFA - Certified Surgical First Assistant Practice Test

CSFA - Certified Surgical First Assistant Practice Test

CSFA Microbiology and Infection Control 5