E. coli: The big six strains are here

USDA and CDC start to test beef for more enterohemorrhagic strains of E. coli

Most strains of Escherichia coli, or E. coli, are harmless. But some produce toxins that can sicken or kill people. The USDA banned the most commonly enterohemorrhagic strain identified — E. coli O157:H7 — from raw ground beef, a pathogen that can attach to vegetables and survive. It’s scheduled to ban another six enterohemorrhagic strains in past June. Birds and flies are usual vectors of these enteric pathogens.

Here are some outbreaks associated with those six enterohemorrhagic strains:

E. coli O26: A multi-state outbreak linked to raw clover sprouts at Jimmy John’s sandwich shops sickened more than two dozen people and hospitalized seven this year. In 2010, Cargill recalled about 8,500 pounds of ground beef because it may have been contaminated with this strain and led to three illnesses in New York and Maine. A more recent outbreak due to O26 was reported recently in Germany.

E. coli O45: Through 2008, CDC had identified three outbreaks linked to this strain. Two were suspected to involve infections from contact with animals at a petting zoo and a family farm.

E. coli O103: In 2000, two people were hospitalized in an outbreak possibly linked to water-based punch at a banquet hall in Washington State.

E. coli O111: The first community outbreak linked to this strain in the United States sickened five dozen girls attending a Texas cheerleading camp in 1999. More recently, one person was killed in a 2008 outbreak traced to an Oklahoma restaurant; hundreds were sickened. In both cases, the exact source of contamination is unknown.

E. coli O121: As of 2008, the largest outbreak tied to this strain involved contaminated lettuce that sickened 42 people at a catered event in Utah.

E. coli O145: Shredded romaine lettuce from an Ohio processing plant was contaminated with this strain and sickened more than two dozen people in 2010. Three developed kidney failure. No deaths have been reported.

Sources: CDC and USDA