CRCST CRCST Microbiology and Infection Control 1 — Questions and Answers
Question 1: Which type of microorganism is the MOST resistant to standard sterilization methods?
- Gram-positive bacteria
- Gram-negative bacteria
- Bacterial spores (Correct answer)
- Viruses
Correct answer: Bacterial spores
Bacterial spores (e.g., Clostridium and Bacillus species) are the most resistant microorganisms and are used as biological indicators to validate sterilization.
Question 2: What is the Spaulding Classification used for in central service?
- Classifying employee roles
- Categorizing medical devices by the level of disinfection or sterilization required (Correct answer)
- Ranking sterilization chemical costs
- Ordering surgical instruments by size
Correct answer: Categorizing medical devices by the level of disinfection or sterilization required
The Spaulding Classification system categorizes devices as critical, semi-critical, or non-critical to guide the appropriate level of reprocessing required.
Question 3: Which Spaulding category applies to instruments that enter sterile tissue or the vascular system?
- Non-critical
- Semi-critical
- Critical (Correct answer)
- Minimal-risk
Correct answer: Critical
Critical items contact sterile body tissues or the vascular system and must be sterilized, as any microbial contamination poses a high infection risk.
Question 4: What is the correct term for killing all microorganisms including bacterial spores on inanimate objects?
- Disinfection
- Sanitization
- Sterilization (Correct answer)
- Antisepsis
Correct answer: Sterilization
Sterilization is the complete destruction of all forms of microbial life, including bacterial spores, on inanimate objects.
Question 5: Which organism is used as the biological indicator (BI) for steam sterilization?
- Staphylococcus aureus
- Geobacillus stearothermophilus (Correct answer)
- Bacillus atrophaeus
- Mycobacterium tuberculosis
Correct answer: Geobacillus stearothermophilus
Geobacillus stearothermophilus spores are the standard biological indicator for steam (autoclave) sterilization because of their high heat resistance.
Question 6: What is the Chain of Infection, and why is it important in CS?
- A supply ordering process
- The sequence of elements required for an infection to spread, which CS interrupts by reprocessing instruments (Correct answer)
- A type of instrument linkage
- A hospital policy document
Correct answer: The sequence of elements required for an infection to spread, which CS interrupts by reprocessing instruments
The Chain of Infection describes the path an infection follows from reservoir to host; CS technicians interrupt this chain by decontaminating and sterilizing instruments.
CRCST CRCST Microbiology and Infection Control 1
Which type of microorganism is the MOST resistant to standard sterilization methods?