Prevalence and characterization of verotoxin-producing Escherichia coli (VTEC) in cattle from an Ontario abattoir.
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.
Karama
Musafiri
M
Department of Pathobiology, University of Guelph, Guelph, Ontario N1G 2W1.
Johnson
Roger P
RP
Holtslander
Robert
R
McEwen
Scott A
SA
Gyles
Carlton L
CL
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
Appl Environ Microbiol. 1987 Oct;53(10):2394-6
3322190
J Clin Microbiol. 2003 Nov;41(11):4930-40
14605120
J Clin Microbiol. 2002 Jan;40(1):271-4
11773130
Appl Environ Microbiol. 1998 Nov;64(11):4134-41
9797257
Vet Microbiol. 2003 Jul 30;94(4):341-6
12829388
J Infect Dis. 2005 Oct 15;192(8):1422-9
16170761
J Clin Microbiol. 2000 Mar;38(3):1023-31
10698990
Emerg Infect Dis. 1999 Sep-Oct;5(5):607-25
10511517
J Clin Microbiol. 2001 Sep;39(9):3060-5
11526129
J Clin Microbiol. 1993 May;31(5):1167-72
8501216
Appl Environ Microbiol. 2003 Feb;69(2):1059-66
12571029
Vet Rec. 1997 Feb 1;140(5):112-5
9042694
J Clin Microbiol. 1998 Nov;36(11):3317-22
9774585
J Infect Dis. 2002 Jan 1;185(1):74-84
11756984
Can Vet J. 1999 May;40(5):332-8
10340094
Mol Microbiol. 2006 Oct;62(2):480-90
16965518
J Food Prot. 2000 Nov;63(11):1583-6
11079704
Infect Immun. 2007 Jan;75(1):488-96
17101670
Microbiology (Reading). 1996 Nov;142 ( Pt 11):3305-15
8969527
J Exp Med. 2004 Jul 5;200(1):35-46
15226357
Infect Immun. 2001 Nov;69(11):6999-7009
11598075
Clin Microbiol Rev. 1998 Jan;11(1):142-201
9457432
Appl Environ Microbiol. 1998 Sep;64(9):3166-74
9726855
J Clin Microbiol. 2005 Jun;43(6):2944-7
15956427
Appl Environ Microbiol. 1996 Dec;62(12):4314-7
8953703
J Food Prot. 1996 Oct;59(10):1112-1122
31195470
J Food Prot. 2000 Sep;63(9):1167-72
10983787
Vet Microbiol. 2003 May 29;93(3):247-60
12695048
J Food Prot. 2005 Oct;68(10):2224-41
16245735
J Clin Microbiol. 2003 Apr;41(4):1775-8
12682185
Mol Microbiol. 1997 May;24(4):767-78
9194704
J Clin Microbiol. 1999 Mar;37(3):497-503
9986802
J Clin Microbiol. 2004 Feb;42(2):645-51
14766831
FEMS Microbiol Lett. 1997 Mar 15;148(2):265-72
9084155
Emerg Infect Dis. 2002 Dec;8(12):1409-14
12498656
J Clin Microbiol. 1997 Aug;35(8):2051-4
9230380
J Clin Microbiol. 2002 Oct;40(10):3613-9
12354854
Epidemiol Infect. 1996 Oct;117(2):251-7
8870622
Mol Microbiol. 2004 Mar;51(5):1233-49
14982621