There is a growing need for multiplexing capability for food pathogen analysis.
Historically, food pathogen analysis has relied on assays that measure one analyte at a time. To date, multiplex assays that can simultaneously measure several analytes in a single test have not been feasible, either technically or in fitting into the plant workflow.
In 2010, 46.2 million pathogen tests were preformed in the U.S. to help food companies produce safe and wholesome products that meet label claims. Salmonella, Listeria, E. coli O157 and Campylobacter assays predominated.
Some companies may need to test for more than one pathogen to maintain product quality and safety. For example, a prepared foods company might test for both Salmonella and Listeria in their finished product. Since food pathogen tests currently run just one analyte at a time, the prepared foods company would take one sample for the Salmonella test and another sample for the Listeria test. Significant differences in media growth requirements and doubling times for each pathogen, along with other limitations, prevented diagnostic companies from offering tests that combine these two pathogens in a single sample preparation and test protocol.
With more than 15 diagnostic companies now competing in the pathogen analysis space, multiplexing could represent a clear point of differentiation for some.
Recent changes in the food industry may now warrant the production of multiplex assays, for example, new STEC regulations targeting multiple pathogenic E. coli strains and the possibility of regulations targeting specific and potentially antibiotic-resistant strains of Salmonella. A multiplex test could identify specific strains of a particular pathogen without the concerns of enrichment media compatibility and/or differing rates of bacterial growth.
It is difficult to forecast exactly how multiplexing will play out in the food sector. What is clear is there are important benefits for food companies through multiplexing of pathogen analysis and work flow optimization. With more than 15 diagnostic companies now competing in the pathogen analysis space, multiplexing could represent a clear point of differentiation for some.
There is a good article by Susan Vaughn Grooters, MPH, in a recent issue of Food Safety Magazine that touches on multiplexing in relation to antibiotic resistance and food safety.