Whole-genome sequencing allowed investigators to home in on one farm in their examination of an ongoing E. coli outbreak associated with romaine lettuce, the Atlanta Journal-Constitution reports.
Days before the Thanksgiving holiday in the US in November, the public was warned to avoid eating romaine lettuce due to an E. coli outbreak that sickened dozens. At the time, the AJC notes that federal officials weren't yet sure where the outbreak originated and issued a blanket warning against eating all romaine lettuce. But since then, it adds, officials from the Centers for Disease Control and Prevention and the Food and Drug Administration relied on their sequencing of the E. coli strain to limit that warning and narrow the scope of their investigation.
As the AJC notes, the investigators found that the E. coli strain behind this outbreak was highly similar genetically to one implicated in an outbreak last year centered in California. Officials collected samples from farms in the region to find that a water reservoir at the Adam Brothers Family Farm in Santa Barbara County harbored the E. coli O157 strain. This led the farm to recall other products, including other lettuces and cauliflower, in mid-December, the AJC says.