title: Prevalence and characterization of verotoxin-producing Escherichia coli (VTEC) in cattle from an Ontario abattoir.
abstract: This study determined the prevalence of verotoxin (VT)-producing Escherichia coli (VTEC) in Ontario beef cattle at slaughter and characterized the isolates by serotype, virulence factors, virulence markers, and antimicrobial resistance. Cultures of rectal feces from 500 animals were screened for VT by an enzyme-linked immunosorbent assay (ELISA) and by polymerase chain reaction (PCR) for genes vt1, vt2, and eae. The VT-ELISA-positive samples were tested by a VT-immunoblot to isolate VTEC colonies. The prevalence rates of VTEC by VT-ELISA and PCR were 10.2% [95% confidence interval (CI), 7.8% to 13.2%] and 6.2% (95% CI, 4.4% to 8.7%), respectively. Colonies of VTEC were isolated from 27 (53%) of the 51 VT-ELISA-positive samples and belonged to 24 serotypes, which did not include O157:H7. Twelve of the serotypes have been implicated in disease in humans. Virulence profiling of the isolates by PCR revealed that 2 (8%) were eae-positive, 5 (21%) had vt1 only, and 19 (79%) had vt2, of which 3 had vt2 only, 7 had vt1 + vt2, 4 had vt2 + vt2c, 2 had vt2 + vt2c + vt2d, 2 had vt1 + vt2 + vt2c, and 1 had vt1 + vt2 + vt2c + vt2d. The distribution of selected plasmid-encoded putative virulence genes was as follows: ehxA, 63%; espP, 46%; saa, 67%; and subA, 54%. Nine of the 24 isolates were resistant to 1 or more antimicrobials. Major conclusions are that the VTEC prevalence of 10.2% was among the lower rates reported for beef cattle, a high proportion of the isolates had vt2 genes, the subA gene was reported for the 1st time in Canadian VTEC, and the absence of O157 VTEC likely reflects the use of a technique that detected all VTEC.
authors.affiliation: Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1.
authors.forename: Musafiri
authors.initials: M
authors.lastname: Karama
authors.forename: Roger P
authors.initials: RP
authors.lastname: Johnson
authors.forename: Robert
authors.initials: R
authors.lastname: Holtslander
authors.forename: Scott A
authors.initials: SA
authors.lastname: McEwen
authors.forename: Carlton L
authors.initials: CL
authors.lastname: Gyles
mesh_terms: D000003:Abattoirs; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000382:microbiology*; D004197:Disease Reservoirs / Q000662:veterinary; D024881:Drug Resistance, Bacterial; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000662:veterinary; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology / Q000662:veterinary*; D005243:Feces / Q000382:microbiology*; D009864:Ontario / Q000453:epidemiology; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods / Q000662:veterinary; D011159:Population Surveillance; D015995:Prevalence; D012703:Serotyping; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification* / Q000302:isolation & purification; D014774:Virulence / Q000235:genetics
references.citation: Appl Environ Microbiol. 1987 Oct;53(10):2394-6
references.pmid: 3322190
references.citation: J Clin Microbiol. 2003 Nov;41(11):4930-40
references.pmid: 14605120
references.citation: J Clin Microbiol. 2002 Jan;40(1):271-4
references.pmid: 11773130
references.citation: Appl Environ Microbiol. 1998 Nov;64(11):4134-41
references.pmid: 9797257
references.citation: Vet Microbiol. 2003 Jul 30;94(4):341-6
references.pmid: 12829388
references.citation: J Infect Dis. 2005 Oct 15;192(8):1422-9
references.pmid: 16170761
references.citation: J Clin Microbiol. 2000 Mar;38(3):1023-31
references.pmid: 10698990
references.citation: Emerg Infect Dis. 1999 Sep-Oct;5(5):607-25
references.pmid: 10511517
references.citation: J Clin Microbiol. 2001 Sep;39(9):3060-5
references.pmid: 11526129
references.citation: J Clin Microbiol. 1993 May;31(5):1167-72
references.pmid: 8501216
references.citation: Appl Environ Microbiol. 2003 Feb;69(2):1059-66
references.pmid: 12571029
references.citation: Vet Rec. 1997 Feb 1;140(5):112-5
references.pmid: 9042694
references.citation: J Clin Microbiol. 1998 Nov;36(11):3317-22
references.pmid: 9774585
references.citation: J Infect Dis. 2002 Jan 1;185(1):74-84
references.pmid: 11756984
references.citation: Can Vet J. 1999 May;40(5):332-8
references.pmid: 10340094
references.citation: Mol Microbiol. 2006 Oct;62(2):480-90
references.pmid: 16965518
references.citation: J Food Prot. 2000 Nov;63(11):1583-6
references.pmid: 11079704
references.citation: Infect Immun. 2007 Jan;75(1):488-96
references.pmid: 17101670
references.citation: Microbiology (Reading). 1996 Nov;142 ( Pt 11):3305-15
references.pmid: 8969527
references.citation: J Exp Med. 2004 Jul 5;200(1):35-46
references.pmid: 15226357
references.citation: Infect Immun. 2001 Nov;69(11):6999-7009
references.pmid: 11598075
references.citation: Clin Microbiol Rev. 1998 Jan;11(1):142-201
references.pmid: 9457432
references.citation: Appl Environ Microbiol. 1998 Sep;64(9):3166-74
references.pmid: 9726855
references.citation: J Clin Microbiol. 2005 Jun;43(6):2944-7
references.pmid: 15956427
references.citation: Appl Environ Microbiol. 1996 Dec;62(12):4314-7
references.pmid: 8953703
references.citation: J Food Prot. 1996 Oct;59(10):1112-1122
references.pmid: 31195470
references.citation: J Food Prot. 2000 Sep;63(9):1167-72
references.pmid: 10983787
references.citation: Vet Microbiol. 2003 May 29;93(3):247-60
references.pmid: 12695048
references.citation: J Food Prot. 2005 Oct;68(10):2224-41
references.pmid: 16245735
references.citation: J Clin Microbiol. 2003 Apr;41(4):1775-8
references.pmid: 12682185
references.citation: Mol Microbiol. 1997 May;24(4):767-78
references.pmid: 9194704
references.citation: J Clin Microbiol. 1999 Mar;37(3):497-503
references.pmid: 9986802
references.citation: J Clin Microbiol. 2004 Feb;42(2):645-51
references.pmid: 14766831
references.citation: FEMS Microbiol Lett. 1997 Mar 15;148(2):265-72
references.pmid: 9084155
references.citation: Emerg Infect Dis. 2002 Dec;8(12):1409-14
references.pmid: 12498656
references.citation: J Clin Microbiol. 1997 Aug;35(8):2051-4
references.pmid: 9230380
references.citation: J Clin Microbiol. 2002 Oct;40(10):3613-9
references.pmid: 12354854
references.citation: Epidemiol Infect. 1996 Oct;117(2):251-7
references.pmid: 8870622
references.citation: Mol Microbiol. 2004 Mar;51(5):1233-49
references.pmid: 14982621