Campylobacter: Changing Analytical Methods
New Technologies Drive Food Safety
By W. Evan Chaney, PhD
The Centers for Disease Control and Prevention (CDC) estimates that the pathogenic Campylobacter species altogether cause about 9% of the estimated 9.4 million annual foodborne illnesses in the U.S. and account for approximately 15% of hospitalizations. By one estimate, the economic cost of Campylobacter illnesses may be as much as $1 billion per year.
The most recent report from the Interagency Food Safety Analytics Collaboration (IFSAC) attributed the bulk of Campylobacter illnesses to chicken products. Not surprisingly, Campylobacter gets both food safety regulatory oversight and public health surveillance and is a focus for research.
Developments in Testing Strategies
While Campylobacter has long been surveilled by the U.S. Department of Agriculture’s Food Safety and Inspection Service (FSIS), last year the agency announced a new method of testing for all raw poultry samples it collects. After changing its sampling media to neutralizing buffered peptone water (nBPW), FSIS learned that Campylobacter contamination was common in product at levels below the limits of their methodology. As a result, the agency changed the regulatory method (MLG 41) from a plate-based quantitative approach to an enrichment-based qualitative approach in combination with rapid detection by commercial PCR (polymerase chain reaction) kits. These observations align with a growing body of research that has further unveiled the complexities that exist within the Campylobacter genus, including diverse genetic markers and the capability of entering viable but not-culturable metabolic states.
As demand for poultry meat continues to grow and consumers exert more influence on production practices and regulatory action, we need technologies that better control Campylobacter risk and the tools to measure progress. The development of new molecular diagnostic assays may aid us in our efforts to reduce risk.
Looking to the future
In non-commercial settings, chicks and young birds of other species hatch in close proximity to their mothers, allowing them access to food soon after hatching. The maternal microbiota also has the opportunity to colonize the gastrointestinal tract of these young birds.
While traditional culture methods have long been the standard for Campylobacter in the industry, PCR methods are increasingly being utilized in multiple formats. Rapid detection methods are fast approaching the capability to allow in-shift test results and decision making with both quantitative and qualitative outcomes. Moreover, next generation sequencing technologies and whole genome analyses are helping us to better understand how to both intervene against the organisms as well as increase the specificity and accuracy of our analytical approaches.
Recently, we co-authored a review article with our collaborators at the University of Arkansas. The article, titled “Developments in Rapid Detection Methods for the Detection of Foodborne Campylobacter in the United States”, was published in Frontiers in Microbiology. It is an open access article, which we hope you will find insightful on where the industry is headed with regards to Campylobacter testing.