What is the biological indicator used for hydrogen peroxide gas plasma sterilization?

The biological indicator used for hydrogen peroxide gas plasma sterilization is Bacillus atrophaeus. This organism is chosen specifically because it has spores that are resistant to the sterilization process. In the context of sterilization, the effectiveness of the process can be assessed by using biological indicators that contain these resistant spores.

When Bacillus atrophaeus is subjected to hydrogen peroxide gas plasma sterilization, if the spores are killed, it indicates that the sterilization process was effective in reaching the necessary parameters (temperature, humidity, and exposure time) to ensure that all microorganisms have been eradicated. The use of this particular indicator is crucial in validating the sterilization process, providing a higher assurance of sterility in medical and surgical settings.

The other organisms listed as options have different uses as biological indicators for varying sterilization methods. For instance, Geobacillus stearothermophilus is typically used for steam sterilization, while Staphylococcus aureus and Escherichia coli are not used as indicators for sterilization processes due to their lack of resistance compared to spores, making them less reliable for validating sterility in this context.