Submitted to: United States Japan Natural Resources Protein Panel
Publication Type: Proceedings
Publication Acceptance Date: 8/17/2001
Publication Date: 12/15/2001
Citation: Fratamico, P.M., Bhaduri, S., Bush, E.J. 2001. Methods for detection and isolation of bacterial pathogens associated with swine. United States Japan Natural Resources Protein Panel. p. 41-47. Interpretive Summary:
Technical Abstract: A total of 823 and 785 swine fecal samples were tested for the presence of Shiga toxin-producing E. coli and pathogenic Yersina enterocolitica, respectively. The feces were collected from finisher pigs from 28 production sites in the eastern and mid-western states over a period of 25 weeks (September 2000 to February 2001). Using the TaqMan STX1 and STX2 E. coli Detection assays, 544 out of 823 fecal samples (66%) were positive for Shiga toxin 1 (stx1), Shiga toxin 2 (stx2), or both toxin genes. Twenty-two out of 37 isolates (59.5%) possessed the stx2e gene, a variant of stx2 that is found in STEC strains that cause pig edema disease. The serogroups of the STEC isolates included 0101 and 091, which have been associated with human illness. Identification of Y. enterocolitica strains harboring the chromosomal ail gene, found in Y. enterocolitica strains that cause human illness, was accomplished using a TaqMan-based fluorogenic 5' nuclease polymerase chain reaction (PCR) assay. Forty-four fecal samples were positive by the PCR out of 785 samples tested (5.6%). Seven sites out of 28 (25%) contained at least one fecal sample positive for pathogenic Y. enterocolitica. Site number 12 contained 21 positive samples out of 45 samples tested (46.7%). Six ail-containing strains were isolated from the PCR positive samples by the Congo red binding and low-calcium response techniques. The results of these studies indicate that swine in the United States harbor pathogenic Y. enterocolitica and are a potential reservoir of STEC strains that may cause human illness.