MicroVal has just issued the first certificate for Neogen’s Soleris Enterobacteriaceae, based on a semi-quantitative validation for detection of Enterobacteriaceae at a threshold of <10cfu/ml. The study was conducted by Campden BRI.
This novel approach was designed to meet a specific legislative requirement in EU 2073 for the presence of Enterobacteriaceae in dairy products at a level of <10cfu/ml. Historically, ISO 16140-2:2016 validation studies have either been quantitative i.e. based on enumeration of microorganisms in the test samples, or qualitative, i.e. based on detecting the presence or absence of a target microorganism in a test sample. This semi-quantitative study design compared the results from the enrichment of a test sample in the Neogen Soleris system using the S2-EBAC9 Enterobacteriaceae vial with the results from the reference method which uses a plating method. The unique part of this validation was the use of a single plate of the reference agar where the absence of any colonies was equivalent to detection of <10cfu/ml and the presence of one or more colonies was equivalent to detection of >10cfu/ml. Hence the approach used a plate count method as a qualitative result and not a quantitative result.
This semi-quantitative approach could have a wide application to many other microbiological test methods which use a dilute to specification approach to show compliance with a target threshold of, for example, <10cfu/ml or <100cfu/ml.
The certificate for Neogen’s Soleris Enterobacteriaceae can be found by the number 2018LR83.