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Sterility Testing: The Detection of Stressed Microorganisms in 7 Days

Posted by Rapid Micro Biosystems on May 8, 2015

At the 2015 PDA Annual Meeting in Las Vegas, the main tracks of the event included “Improving Manufacturing Performance”, “Changing Regulatory Landscape” and “Technology, Advances and Expectations”  In the poster area of the event, Rapid Micro Biosystems presented a study entitled, “Sterility Testing: The Detection of Stressed Organisms in Seven Days” The poster is available here.

The poster identifies the results of a study using the Growth DirectTM Sterility Test in conjunction with a novel microbiological media, modified Schaedler Chocolate Broth (mSCB), to show detection of stressed microorganisms within seven days, reducing the length of traditional sterility tests by 50 percent.

As microbiologists know, cellular damage can greatly extend the lag time of a cell. For example, a heat-stressed cell may stop replicating in order to repair itself or a nutrient-stressed cell may stop replicating in order to produce the enzymes necessary to adapt physiologically to its new growth conditions. These longer lag times become the limiting factors for any growth based sterility assay; no matter what  technology is used, these cells cannot be detected until they begin growing and thus it is imperative that any rapid growth-based sterility test is able to support the recovery of stressed organisms and still detect them within the timeframe of the assay.

The poster outlines the steps used to prepare the samples, as well as the methods performed to stress both the spores and vegetative cells that we part of the study.  The prepared cassettes containing the stressed organisms were loaded into the Growth DirectTM System where incubation and detection of the stressed organisms were performed.


One hundred percent of the stressed microorganisms chosen for the study were detected in under seven days. In many cases, study organisms were detected in under five days. These results show a superior media that allows for the rapid recovery and growth of stressed organisms, and that the Growth DirectTM System is capable of detecting these colonies in seven days or fewer. This represents a 50 percent timesavings over the compendial sterility test, which allows for faster product release, improving manufacturing performance and more rapid response to sterility failures through advances in technology.

To learn more about this study, download the poster here.


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