Veterinary Archives, Vol. 79 No. 3, 2009.
Original scientific paper
Occurrence of phenotypic virulence markers, enteropathogenic serotypes and verocytotoxin production amongst strains of Escherichia coli isolated from non-diarrhoeic dogs in Trinidad
Nadira Seepersadsingh
; School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago
Abiodun Adewale Adesiyun
; School of Veterinary Medicine, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago
Abstract
The study was conducted to determine the prevalence and selected characteristics of Escherichia coli in non-diarrhoeic dogs from Trinidad. Rectal swabs or faecal samples were collected. Primary isolation of E. coli was done on eosin methylene blue (EMB) agar, haemolysin and mucoid production were detected on blood agar (BA) and sorbitol fermentation was assayed on sorbitol MacConkey agar (SMAC) agar. Agglutination tests, using commercially available antisera, determined O157-positive and enteropathogenic (EPEC) strains of E. coli while the vero cell assay detected verocytotoxigenic E. coli (VTEC) strains. Overall, of a total of 1,391 dogs sampled, E. coli was isolated from 1,266 (91.0%) dogs. Differences were statistically significant amongst E. coli isolated from dog sources (P<0.05; χ2) with the highest (96.0%) and lowest (81.3%) prevalence detected in hunting dogs and pound dogs, respectively. Of the 1,900 E. coli isolates tested, 100 (5.3%), 81 (4.3%) and 133 (7.0%) were mucoid, haemolytic and non-sorbitol fermenting (NSF) respectively. The difference was statistically significant (P<0.05; χ2). For EPEC strains, of the 333 E. coli isolates tested, 189 (56.8%) belonged to ‘enteropathogenic’ serogroups. The difference in prevalence across the various dog sources was statistically significant (P<0.05; χ2). Of the 558 E. coli strains tested, 74 (13.3%) were positive for verocytotoxin production. It was concluded that asymptomatic dogs in Trinidad carry virulent strains of E. coli, posing a threat as reservoirs of infections to human handlers and their owners and therefore are of significance for public health.
Keywords
E. coli; non-diarrhoeic dogs; Trinidad
Hrčak ID:
45255
URI
Publication date:
16.6.2009.
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