Epidemiology and Infection

Original Papers

Gastrointestinal infection and food poisoning

Shiga toxin-producing E. coli (STEC) in swine: prevalence over the finishing period and characteristics of the STEC isolates

M. TSENGa1 c1, P. M. FRATAMICOa2, L. BAGIa2, D. MANZINGERa2 and J. A. FUNKa1

a1 College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA

a2 Eastern Regional Research Centre, Agricultural Research Service, U.S. Department of Agriculture, Wyndmoor, PA, USA


This descriptive longitudinal study was conducted to investigate the faecal shedding of Shiga toxin-producing E. coli (STEC) in finishing swine and to characterize the swine STEC isolates that were recovered. Three cohorts of finishing swine (n = 50/cohort; total 150 pigs) were included in the longitudinal study. Individual faecal samples were collected every 2 weeks (8 collections/pig) from the beginning (pig age 10 weeks) to the end (pig age 24 weeks) of the finishing period. STEC isolates were recovered in at least one sample from 65·3% (98/150) of the pigs, and the frequency distribution of first-time STEC detection during the finishing period resembled a point-source outbreak curve. Nineteen O:H serotypes were identified among the STEC isolates. Most STEC isolates (n = 148) belonged to serotype O59:H21 and carried the stx2e gene. One O49:H21 STEC isolate carried the stx2e and eae genes. High prevalence rates of STEC during the finishing period were observed, and STEC isolates in various non-O157 serogroups were recovered. These data enhance understanding of swine STEC epidemiology, and future research is needed to confirm whether or not swine STEC are of public health concern.

(Received January 20 2014)

(Revised April 02 2014)

(Accepted April 10 2014)

(Online publication May 08 2014)

Key words

  • Epidemiology;
  • longitudinal;
  • serotype;
  • Shiga-like toxin-producing E. coli ;
  • swine


c1 Author for correspondence: Dr M. Tseng, Food Safety and Toxicology Building, 1129 Farm Lane Rm B41, East Lansing, MI 48824, USA. (Email: marionkttseng@gmail.com)