CSSD - Central Sterile Services Department Microbiology and Infection Control Questions and Answers

Question 1

Which of the following microorganisms is considered the most resistant to sterilization processes, making it the benchmark for testing the efficacy of sterilizers?

Accepted Answer

Bacterial spores

Answer

Bacterial spores, such as Geobacillus stearothermophilus, have a highly resistant protective outer coat that makes them the most difficult form of microbial life to kill. For this reason, they are used in biological indicators to provide a direct measure of a sterilizer's lethality and confirm that conditions for sterilization were met.

Question 2

A flexible colonoscope, which will contact intact mucous membranes during a procedure, arrives in the decontamination area. According to Spaulding's Classification, how should this device be categorized, and what is the minimum required level of processing?

Accepted Answer

Semi-critical; requires high-level disinfection.

Answer

Spaulding's Classification categorizes devices based on infection risk. A flexible colonoscope contacts intact mucous membranes and is therefore classified as a semi-critical device. The minimum required reprocessing for semi-critical items is high-level disinfection (HLD), which destroys all vegetative microorganisms, mycobacteria, fungi, and viruses, but not necessarily large numbers of bacterial spores.

Question 3

Which of the following statements is MOST accurate regarding the challenges posed by biofilm on surgical instruments?

Accepted Answer

Biofilm creates a protective layer that can shield microorganisms from detergents and sterilants.

Answer

Biofilm is a complex community of microorganisms encased in a slimy, protective matrix that adheres tightly to surfaces. This matrix acts as a barrier, protecting the embedded microbes from being removed by ordinary cleaning and preventing sterilants and disinfectants from reaching and killing them. Meticulous manual cleaning is essential to physically remove biofilm before disinfection or sterilization.

Question 4

An instrument set used on a patient with suspected Creutzfeldt-Jakob Disease (CJD) is sent to the CSSD. What is a critical processing step that must be taken for these instruments according to AAMI and CDC guidelines?

Accepted Answer

The instruments should be kept moist after use and processed using an extended steam sterilization cycle.

Answer

Prions, the agents that cause CJD, are extremely resistant to conventional sterilization. Guidelines from AAMI and the CDC state that instruments should be kept moist to prevent bioburden from drying. They must then be processed using specific extended steam sterilization cycles, such as 134°C for 18 minutes in a prevacuum sterilizer. Standard cycles are not effective, and while discarding is an option for hard-to-clean items, it is not the only required step.

Question 5

The primary function of the CSSD is to break the chain of infection. Which link in the chain is most directly impacted by the process of cleaning and sterilizing medical devices?

Accepted Answer

Mode of Transmission

Answer

The chain of infection requires several links for a disease to spread. By properly cleaning, disinfecting, and sterilizing instruments, the CSSD eliminates pathogens. This prevents the instruments from acting as fomites (inanimate objects) that can carry pathogens from a source to a patient. This action directly interrupts the 'Mode of Transmission' link in the chain.

CSSD - Central Sterile Services Department Practice Test

CSSD - Central Sterile Services Department Practice Test

CSSD - Central Sterile Services Department Microbiology and Infection Control Questions and Answers