CRCST Microbiology and Infection Control Flashcards

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

Answer: Semicritical

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

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

Answer: Their thick peptidoglycan cell wall retains crystal violet

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

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

Answer: Soap and water handwashing

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

What is the core principle of Standard Precautions?

Answer: All blood and body fluids are treated as potentially infectious

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

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

Answer: Brain

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

Which genus includes spore-forming obligate anaerobes, such as the bacterium that causes tetanus?

Answer: Clostridium

Clostridium species, including C. tetani and C. perfringens, are anaerobic spore-forming bacilli.

Following CDC guidance, which PPE item is generally removed FIRST when leaving the decontamination area?

Answer: Gloves

Gloves are the most contaminated item, so the CDC sequence removes them first to limit self-contamination.