What bacterial spore is commonly used for validating hydrogen peroxide gas plasma sterilization cycles?

The use of Geobacillus stearothermophilus as a biological indicator for validating hydrogen peroxide gas plasma sterilization cycles is based on its characteristics and resistance to various sterilization processes. This specific species of bacteria forms spores that are more resistant to the effects of sterilization methods, making it an effective challenge organism in testing the efficacy of these cycles.

Hydrogen peroxide gas plasma sterilization operates at relatively low temperatures compared to steam sterilization, and Geobacillus stearothermophilus spores are particularly suited for this type of validation due to their high resistance to hydrogen peroxide. The successful inactivation of these spores in a sterilization cycle indicates that the process is effective in achieving the desired sterility assurance level.

Other options listed do not serve the same purpose effectively. Bacillus subtilis, while also a spore-forming bacterium, is typically utilized for validating steam sterilization rather than hydrogen peroxide gas plasma. Clostridium difficile is not commonly used for sterilization validation processes as it has different clinical implications, and Staphylococcus aureus is not a spore-former, which inherently limits its utility as a biological indicator in sterilization validation. Thus, Geobacillus stearothermophilus is the most