A clinical lab uses an autoclave to sterilize surgical dressings. The standard recommended parameters are 121°C at 15 psi for 15 minutes. The indicator used to validate sterilization cycle completion is:
- A Bacillus stearothermophilus (now Geobacillus stearothermophilus) spore strips — biological indicator ✓
- B Bacillus subtilis spore strips
- C Bowie-Dick test tape — chemical indicator only
- D Spaulding classification test
Correct answer: A. Bacillus stearothermophilus (now Geobacillus stearothermophilus) spore strips — biological indicator
Explanation
Geobacillus stearothermophilus (formerly B. stearothermophilus) spore strips are the biological indicator for validating autoclaving (moist heat sterilization); these spores are the most heat-resistant biological entity and their non-viability after the cycle confirms adequate sterilization. B. subtilis spore strips are used for dry heat and ethylene oxide sterilization. Bowie-Dick tape is a chemical indicator for steam penetration, not a biological validation. The Spaulding classification categorizes medical devices by infection risk.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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