Pathogenicity and antibiotic sensitivity of Escherichia coli isolates from non-diarrhoeic dogs.

ABSTRACT

E. coli isolated from dogs in Trinidad were tested for their susceptibility to antimicrobial agents using the disk diffusion method. Antimicrobial agents and concentrations included cephalothin (KF, 30 ug), ampicillin (AMP, 10ug), kanamycin (K, 30 ìg), neomycin (N, 30 ug), gentamicin (CN, 10 ug), sulphamethoxazole/ trimethoprim (SXT, 23.25 ug/1.75 ug), nalidixic acid (NA, 30 ug) and norfloxacin (NOR, 10 ug). The overall prevalence of resistance to one or more antimicrobial agents for E. coli isolated from dogs was 47.9 per cent. The difference in prevalence across the various sources of the isolates from dogs was statistically significant (P<0.001; x2). Overall, resistance was highest to cephalothin (30.1 per cent). A total of 45 resistance patterns were observed from dogs from all sources and the predominant pattern was KF (25.6 per cent). It was concluded that the relatively high prevalence of resistance to antimicrobial agents amongst E. coli isolates from non-diarrhoeic dogs in Trinidad may pose zoonotic and therapeutic problems.