CRCST Chapter 4 Practice Test: Microbiology for Central Service Technicians

Microbiology provides the scientific basis for every decontamination and sterilization decision. This chapter explains the hierarchy of microbial resistance — from easily killed enveloped viruses at the bottom to highly resistant bacterial spores at the top. Understanding that spores are the benchmark for sterilization explains why biological indicators use spore-forming organisms like Geobacillus stearothermophilus. The chapter covers vegetative bacteria, mycobacteria, non-enveloped viruses, fungi, and prions, along with the conditions each requires for inactivation. You will learn how biofilm forms on instruments left to dry and why point-of-use treatment is critical. This knowledge directly informs your daily choices about cleaning chemistry, exposure times, and sterilization method selection.