BSMIC Domain Overview
Microbiology accounts for approximately 4.0% of the CST exam (6 of 150 scored items). It covers pathogenic microorganisms, the chain of infection, surgical site infection prevention, antimicrobial agents, and standard precautions.
What to Study First
- The chain of infection - all six links (infectious agent, reservoir, portal of exit, mode of transmission, portal of entry, susceptible host) and how breaking any one link prevents infection.
- Spore-forming organisms - why they require sterilization rather than disinfection, connecting directly to EQSM content.
- Resident vs. transient flora - relevant to surgical scrub effectiveness.
- Standard precautions and PPE - applied to every patient regardless of known infection status.
Read the full BSMIC study guide
Question Strategy
- Chain of infection questions often ask which link is broken by a specific practice (e.g., hand hygiene breaks the mode of transmission link) - study the chain as an actionable framework, not just a memorized list.
- This domain overlaps heavily with EQSM (sterilization) and INTRA (sterile technique) - study these three domains together for reinforced retention.
- Because this is a small domain, prioritize breadth of understanding over exhaustive microbiology detail beyond what is clinically relevant to surgery.
Common Traps to Avoid
- Confusing antisepsis (living tissue) with disinfection (inanimate objects) - these terms are not interchangeable.
- Forgetting that spores are the reason critical items require true sterilization rather than high-level disinfection.
- Underestimating standard precautions content - it applies to every patient, not just those with a known infection.
Study Resources
- BSMIC Glossary - key terms and definitions
- BSMIC Common Mistakes - avoid the most frequent errors
- BSMIC Exam Day Walkthrough
- Infection Prevention in the OR Deep Dive
- Sterilization and Disinfection Deep Dive
Sign up free to access flashcards and practice exams for Microbiology.