Using whole-genome sequencing, officials from the US Food and Drug Administration were able to track a recent multi-state outbreak of Listeria monocytogenes, according to the agency.
The outbreak was first uncovered through a routine inspection by the Ohio Department of Agriculture that found Listeria in frozen organic white sweet cut corn and frozen organic petite green peas, as FDA writes at its Consumer Updates page. In concert with the Centers for Disease Control and Prevention and local health and agriculture departments, FDA compared Listeria DNA obtained from these foods to samples obtained from people who'd fallen ill with listeriosis.
Sequencing found that the frozen corn strain was genetically similar to the bacteria isolated from the seven people with listeriosis and subsequently, with an eighth person who became ill.
The frozen food company, CRF Frozen Foods of Pasco, Washington, recalled hundred of products, and after FDA found similar bacteria in another Pasco-based facility belonging to the Oregon Potato Company, it too recalled a number of products.
The agency adds that it has been building a publicly accessible database of foodborne pathogen genomes. GenomeTrakr aims to help catch contaminants more quickly, and it currently houses sequences from more than 50,000 isolates.
"As the size of the database grows, so will its strength as a tool to help focus and speed investigations into the root cause of illnesses," Marc Allard from the microbiology division of FDA says.
FDA adds that it is also using sequencing to determine which ingredients of a multi-ingredient product is responsible for an outbreak, which illnesses are related to an outbreak, and link illnesses spread across large geographic areas.