Impact of an oil-based lubricant on the effectiveness of the sterilization processes

Surgical instruments, including hinged instruments, were inoculated with test microorganisms (ie, methicillin-resistant Staphylococcus aureus, approximately colony-forming units [cfu]; Pseudomonas aeruginosa, approximately 3 x 10(6) cfu; Escherichia coli, approximately 2 x 10(5) cfu; vancomycin-resistant enterococci, 1 x 10(5) cfu; Geobacillus stearothermophilus spores, 2 x 10(5) cfu or more; or Bacillus atrophaeus spores, 9 x 10(4) cfu or more), coated with an oil-based lubricant (hydraulic fluid), subjected to a sterilization process, and then samples from the instruments were cultured. We found that the oil-based lubricant did not alter the effectiveness of the sterilization process because high numbers of clinically relevant bacteria and standard test spores (which are relatively resistant to the sterilization process) were inactivated.