Phenotypic and Genotypic Characterization of Antimicrobial Resistance in Escherichia coli Isolates from Dogs and Their Owners

Introduction and Objectives: Today there are growing concerns about the increased prevalence of antibiotic resistance. Excessive and inappropriate use of antibiotics has an influence on the rate of antimicrobial resistance of not just the pathogenic bacteria but also has effect on the normal flora of the exposed individuals (animals and humans) or populations. The objective of this study was the phenotypic and genotypic characterization of antimicrobial resistance in Escherichia coli (E. coli) isolates obtained from feces of the dogs and their owners. Materials and Methods: A total of 112 E. coli strains isolated from feces of 28 healthy dog–owner pairs (two isolates from each individual) and confirmed by standard biochemical tests. Phenotypic characterization of antimicrobial resistance was done by the Kirby-Bauer method using tetracycline and streptomycin disks. Genotypic analysis was done on two streptomycin resistance genes (strA and strB) and four tetracycline resistance genes (tetA, tetB, tetC and tetD) using PCR method. Results: According to phenotypic analysis, the rate of resistance to tetracycline were 46.7% vs. 25%, and for streptomycin were 67.7% vs. 58.9% in dogs’ and owners’ isolates, respectively. Prevalence of 14.3% vs. 8.9% for strA, 12.5% vs. 1.8% for strB, and 58.9% vs. 48.2% for tetA genes were detected in dogs’ and owners’ isolates, respectively. Prevalence of both tetB and tetC genes in dogs’ and owners’ isolates were the same (8.9%). tetD gene was not found in none of the isolates. tetA was the most prevalent gene in dogs’ and owners’ isolates. Conclusion: There were no significant differences between prevalence of tetracycline and streptomycin resistance genes in E. coli isolates from dogs and their owners. This could show the possibility of sharing of E. coli or their resistance genes between dogs and their owners which was due to common environment and close relationship between them.

کلیدواژه ها:

Antibiotic resistance ، Streptomycin ، Tetracycline ، E. coli ، Dogs and their owners