Characterization of extended spectrum β-lactamase producing Escherichia coli strains isolated from urogenital system of dogs in Van province of Turkey.

Background: Escherichia coli is a bacterial agent that causes urogenital system infection in dogs. Beta-lactam (β-lactam) group antibiotics are frequently used in the treatment of E. coli infections.

Aims: This study aimed to investigate the presence of extended-spectrum β-lactamase (ESBL) and plasmidic AmpC in E. coli strains isolated from the urogenital tracts of 125 dogs.

Methods: Fifty E. coli strains were identified by conventional bacteriological and PCR methods. Disk diffusion method was used for the determination of antimicrobial susceptibility of the isolates as well as productions of plasmidic AmpC and ESBL. The presence of blaTEM, blaSHV, and blaCTX-M group genes was determined in the isolates by PCR. ERIC-PCR was also used for genotyping of the isolates.

Results: Although 22 (44%) of 50 E. coli isolates were found to be ESBL positive, no isolate shows plasmidic AmpC β-lactamase production. Among 22 ESBL positive isolates, blaTEM, blaSHV, and blaCTX-M group 1 genes were found in 11 (50%), 1 (4.54%), and 6 (27.27%) isolates, respectively. The highest resistance was observed against tetracycline (28%), followed by streptomycin (24%), trimethoprim-sulfamethoxazole (24%), and chloramphenicol (22%), respectively. In the isolates, 11 different main profiles were also determined by ERIC-PCR. It was shown that ESBL positive isolates were related to G10 profiles.

Conclusion: The use of extended spectrum β-lactam group antibiotics for the treatment of E. coli infections in dogs is critical; nevertheless, they may not be effective due to the high rate of resistance to this antibiotic group in E. coli.