CRCST CRCST Microbiology and Infection Control 5

Question 1

Under the Spaulding classification, a laryngoscope blade that contacts mucous membranes is considered which type of item?

Accepted Answer

Semicritical

Answer

Items that contact mucous membranes or non-intact skin are semicritical and need at least high-level disinfection.

Question 2

Why do gram-positive bacteria appear purple after a Gram stain?

Accepted Answer

Their thick peptidoglycan cell wall retains crystal violet

Answer

The thick peptidoglycan layer holds the crystal violet-iodine complex through decolorization, so the cells stay purple.

Question 3

After caring for a patient with Clostridioides difficile, which hand hygiene method is preferred?

Accepted Answer

Soap and water handwashing

Answer

Alcohol does not kill C. difficile spores, so washing with soap and water is needed to physically remove them.

Question 4

What is the core principle of Standard Precautions?

Accepted Answer

All blood and body fluids are treated as potentially infectious

Answer

Standard Precautions assume every patient's blood and body fluids may carry pathogens, whatever the diagnosis.

Question 5

For instruments used on a patient with suspected Creutzfeldt-Jakob disease, which tissue is considered high-infectivity?

Accepted Answer

Brain

Answer

Brain, spinal cord and posterior eye tissues carry the highest prion infectivity and require special reprocessing protocols.

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