Skip to main content

TL;DR

Study the principles of infection prevention including hand hygiene, PPE use, and transmission-based precautions. Infection control is one of the most heavily weighted sections on the CST Certified Surgical Technologist (NBSTSA).

By Valenke Exam Prep Team·Last updated 2026-06-03

Free Microbiology & Infection Control Practice Questions

CST Certified Surgical Technologist (NBSTSA) · Basic Science

This module covers Microbiology & Infection Control as part of the Basic Science section, testing your understanding of core concepts and their practical application.

ExamCST Certified Surgical Technologist (NBSTSA)
Pass Rate72%
Duration240 minutes
ModuleMicrobiology & Infection Control

Why Microbiology & Infection Control matters

Microbiology & Infection Control is heavily weighted on the CST Certified Surgical Technologist (NBSTSA) because lapses in safety protocols directly threaten patient outcomes.

Sample Practice Questions (5)

1. The surgical technologist sustains a needlestick injury from a contaminated needle during a case involving a patient with unknown hepatitis status. What is the FIRST action the surgical technologist should take?

  • Continue the case and report the injury after the procedure is completed
  • Immediately remove gloves, wash the wound with soap and water, report the injury to the charge nurse, and initiate post-exposure protocol
  • Apply alcohol to the puncture site and resume the procedure
  • Squeeze the wound to express blood and then apply a bandage

2. Prion diseases (such as Creutzfeldt-Jakob disease) present a unique challenge for sterilization because:

  • Prions are destroyed by standard steam autoclaving at 270°F (132°C) for 4 minutes
  • Prions are resistant to conventional sterilization methods; instruments require extended steam sterilization (134°C for 18 minutes in a prevacuum sterilizer) or sodium hydroxide soaking, and may require incineration
  • Prions are easily killed by glutaraldehyde high-level disinfection
  • Prion-contaminated instruments can be safely reused after standard ethylene oxide sterilization

3. Clostridioides difficile (C. diff) is a significant concern in healthcare settings. Which characteristic makes this organism particularly difficult to eliminate from the environment?

  • It is a gram-negative rod that forms a protective biofilm
  • It produces endospores that are resistant to alcohol-based hand sanitizers, most disinfectants, and heat, requiring bleach-based solutions or sporicidal agents for environmental decontamination
  • It is a virus that can survive indefinitely on surfaces
  • It is resistant to all known antibiotics

Want more practice like this?

Start practicing free →

4. A herniorrhaphy (inguinal hernia repair) without break in aseptic technique and no entry into the gastrointestinal tract is classified as which type of surgical wound?

  • Clean (Class I)
  • Clean-contaminated (Class II)
  • Contaminated (Class III)
  • Dirty/infected (Class IV)

5. A surgical technologist is setting up for a total joint arthroplasty. The biological indicator (BI) from the previous sterilization cycle shows a positive result (bacterial growth detected) after incubation. What is the MOST appropriate action?

  • Proceed with the case using the items from that load since the chemical indicator changed color appropriately
  • Recall all items from that sterilization load, quarantine them, and re-sterilize or replace with items from a load with a negative BI
  • Use the items but document the positive BI result for quality improvement review
  • Wipe down the instruments with high-level disinfectant and proceed

Ready to practice for the CST Certified Surgical Technologist (NBSTSA)?

Adaptive practice powered by Item Response Theory targets your weak areas. Start with 3 free sessions.

Start free practice →

Frequently Asked Questions

How many Microbiology & Infection Control questions are on the CST Certified Surgical Technologist (NBSTSA)?
The Basic Science section, which includes Microbiology & Infection Control, typically represents a significant portion of the exam. Focus on understanding core concepts rather than memorizing exact question counts, as the exam uses adaptive testing.
What is the best way to study Microbiology & Infection Control?
Use active recall and spaced repetition rather than passive reading. Practice with realistic exam questions, review explanations for both correct and incorrect answers, and focus on understanding the reasoning behind each concept.
What are common mistakes on Microbiology & Infection Control exam questions?
The most common error is choosing an answer that sounds correct in general but violates a specific safety protocol. Always choose the most conservative safety-first option, and remember that hand hygiene is almost always part of the correct answer.