What does “biological indicator” mean in the context of sterilization?

In the context of sterilization, a biological indicator refers to a test system that contains viable microorganisms specifically selected to challenge the sterilization process. These microorganisms are highly resistant to the sterilization method being evaluated, such as steam, ethylene oxide, or other means. The purpose of using a biological indicator is to confirm that the sterilization process was effective in killing these resistant organisms, thereby ensuring that the items sterilized are free from viable microorganisms and safe for use.

When the biological indicator is subjected to the sterilization process, it's subsequently incubated. If growth of the microorganisms occurs, it indicates that the sterilization has failed, confirming that the process was not effective. On the other hand, if there is no growth, it demonstrates that the sterilization parameters were met, and the items are considered sterile.

This method is crucial for routine monitoring of sterilizers in healthcare settings, ensuring patient safety and compliance with health regulations. Other options, such as neutralizing contaminants, measuring temperature, or methods of cleaning instruments, do not accurately reflect the specific role that biological indicators play in verifying the effectiveness of sterilization processes.