The selection of a biological indicator organism for use with a new or existing sterilization method is an important endeavor because it will serve as a benchmark for validation, safety, and quality assessments across a range of current and future sterilization systems and machines. By convention, the process for bioindicator selection is to choose an organism demonstrating high relative resistance for the sterilization agent and method under examination and, therefore, includes the evaluation and comparison of the resistance of multiple candidate organisms and spores. This report reviews the basic tenants and principles of modern sterilization science as they relate to the determination and comparison of microbial resistance, uses the pulsed light treatment of Bacillus pumilus spore preparations, and spore stocks prepared via different methods to illustrate how different preparation procedures can affect the results seen with resistance testing, particularly survival/end point testing, and provides insights and experiences into microbial spore resistance testing and examines relevant cases in point.
Author(s): Joseph Dunn