Plate-Counting Techniques for Average Bioburden Below the Limit of Detection

Area of Science:

• Microbiology
• Medical Device Sterilization
• Regulatory Compliance

Background:

• Current ISO 11737-1:2018 methods struggle with low bioburden estimation on medical devices.
• Inaccurate low bioburden counts can lead to overestimated device bioburden and under-challenged sterilization validation.
• This can necessitate higher sterilization doses, impacting product viability and cost.

Purpose of the Study:

• To present an improved plate-counting technique for accurate low bioburden estimation.
• To address challenges in bioburden assessment for medical device sterilization validation.
• To enable more precise sterilization dose determination.

Main Methods:

• A novel plate-counting technique is described for bioburden estimation.
• The method is designed for low bioburden scenarios, including sample item portions.
• It accommodates high dilution factors relative to average bioburden.

Main Results:

• The described technique provides consistent and accurate low bioburden estimates.
• It overcomes limitations of current methods in detecting low microbial loads.
• Improved accuracy supports more reliable sterilization validation.

Conclusions:

• The developed plate-counting technique enhances the accuracy of low bioburden determination for medical devices.
• This method supports more efficient and effective bioburden-based sterilization validation and dose setting.
• It offers a solution for products with inherently low microbial contamination.