A family outbreak of Escherichia coli O157 haemorrhagic colitis caused by pork meat salami

Abstract

A family outbreak of Escherichia coli O157 infection was microbiologically associated with consumption of dry-fermented salami made with pork meat only and produced in a local plant. E. coli O157 strains isolated from a wife and husband, both hospitalized with bloody diarrhoea, and from the salami carried vt1, vt2 and eae genes and shared the same PFGE pattern. The food vehicle implicated in this outbreak is unusual because of both the animal species from which it originates and the fermentation and drying steps of the manufacturing process. This could be the first report of an outbreak associated with a product containing pork meat only. Even though sources of contamination other than pork meat could not be excluded, pork products should not be neglected in E. coli O157 outbreak investigations.

Diverse Virulence Gene Content of Shiga Toxin-Producing Escherichia coli from Finishing Swine

“…STEC is often acquired by consuming contaminated food or water (8), and cattle are viewed as the most important animal reservoirs (9). Food of bovine origin has been implicated in many STEC infections and outbreaks, though a number of other food products, including pork products, have been confirmed as the source of STEC in a number of outbreaks (10)(11)(12)(13)(14)(15)(16). For example, a recent STEC O157:H7 outbreak was associated with consuming large cuts of pork from a whole roasted pig (16).…”

“…Although the way in which the pork products became contaminated in these outbreaks was uncertain (10)(11)(12)(13)(14)(15)(16), the likelihood that on-farm pigs were the source of STEC contamination cannot be overlooked. Unlike cattle, which do not usually present clinical symptoms due to STEC infection, pigs, specifically postweaning and young finishing pigs, can suffer from edema disease caused by STEC strains carrying the stx 2e variant (17).…”

Characterization of stx2 and its variants in Escherichia coli O157:H7 isolated from patients and animals

“…Recent studies have also demonstrated that, conventional pigs were permissive host for E. coli O157:H7 (Booher et al, 2002;Cornick and Helgerson, 2004), though the prevalence of the organism in these studies was generally low, except for the results from Chile and Chinese Mainland and both suggested that, pig might be an important source of this organism in some countries (Borie et al, 1997;Zheng et al, 2005). Also, one family outbreak had been specifically traced back to pork salami and the E. coli O157 isolates from the couple and the salami carried stx 1 , stx 2 and eae genes and shared the same PFGE pattern (Conedera et al, 2007).…”

Escherichia coli O157:H7 Infections associated with contaminated pork products — Alberta, Canada, July–October 2014

“…The molecular epidemiology of the clinical and pork E. coli O157:H7 outbreak isolates is described elsewhere (3). Pork is a known, although infrequent, source of human E. coli O157 infection (4)(5)(6)(7)(8). Most documented outbreaks have been associated with sausage products containing pork and other meats, and the species-specific source of contamination was not confirmed.…”