Which organism is in steam biological indicators

CRCST practice question · Sterilization Process

Which microorganism is used in biological indicators for monitoring steam sterilization?

  • A. Bacillus atrophaeus
  • B. Clostridium difficile
  • C. Geobacillus stearothermophilus
  • D. Mycobacterium tuberculosis

Answer

C. Geobacillus stearothermophilus

Geobacillus stearothermophilus spores are highly resistant to moist heat, making them the standard challenge for steam BIs. Bacillus atrophaeus is used for ethylene oxide and dry heat.

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