Comparative evaluation of the microbicidal activity of low-temperature sterilization technologies to steam
William A Rutala1, Maria F Gergen2, Emily E Sickbert-Bennett1,3
1Division of Infectious Diseases, University of North Carolina School of Medicine, Chapel Hill, North Carolina.
Objective:
To compare the microbicidal activity of low-temperature sterilization technologies (vaporized hydrogen peroxide [VHP], ethylene oxide [ETO], and hydrogen peroxide gas plasma [HPGP]) to steam sterilization in the presence of salt and serum to simulate inadequate precleaning.
Methods:
Test carriers were inoculated with Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, vancomycin-resistant Enterococcus, Mycobacterium terrae, Bacillus atrophaeus spores, Geobacillus stearothermophilus spores, or Clostridiodes difficile spores in the presence of salt and serum and then subjected to 4 sterilization technologies: steam, ETO, VHP and HPGP.
Results:
Steam, ETO, and HPGP sterilization techniques were capable of inactivating the test organisms on stainless steel carriers with a failure rate of 0% (0 of 220), 1.9% (6 of 310), and 1.9% (5 of 270), respectively. The failure rate for VHP was 76.3% (206 of 270).
Conclusion:
Steam sterilization is the most effective and had the largest margin of safety, followed by ETO and HPGP, but VHP showed much less efficacy.
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