Scientists at Cornell University have developed a way to detect Salmonella bacteria faster, which could help solve food poisoning outbreaks much more quickly. The Cornell Food Safety Lab, led by dr. Martin Wiedmann and research associate Henk den Bakker, worked with the New York State Department of Health on the next-generation DNA sequencing techniques.
The traditional method of identifying outbreak strains of bacteria, pulsed-field gel electrophoresis (PFGE) is not always precise enough to identify specific pathogen strains, including their relationships to each other and if they have a common origin. With Salmonella Enteritidis, for example, 85% of strains can be grouped into five PFGE types.
Instead, rapid whole-genome sequencing gives doctors and public health officials much more detailed information about the bacteria. New York State Department of Health scientist William J. Wolfgang said in a statement, “this kind of detailed information improves our ability to tell whether outbreaks are isolated, sporadic, or part of a cluster, which allows for more thorough epidemiologic investigations.” The process sequences all 4.5 million base pairs of the bacteria’s DNA. The equipment used to conduct this type of identification is small and bench-top.
A paper published July 16, 2014 in the CDC’s journal Emerging Infectious Diseases details a case study of a Salmonella outbreak in a long-term care facility that was solved using this technique and equipment. Researchers found that the outbreak was even larger than suspected, which indicated that the contaminated food was sourced outside the facility. If public health officials had this information at the time, they may have found the source of the contaminated food.
The FDA is sponsoring development of this technique and equipment through the GenomeTrakr initiative. FDA is supplying funds, reagents, equipment, and training to seven State Public health Labs.
