Prevalence of resistance and virulence genes in Escherichia coli isolates from diarrheic dogs

Abstract

The current study was designed to determine the prevalence of antimicrobial resistance and virulence genes in Escherichia coli isolated from canine diarrheal cases. Fecal samples were collected from 77 dogs with clinical diarrhea and 10 non-diarrheic dogs. Breed, age and sex, and clinical manifestations were recorded. Samples were plated on MacConkey and EMB agars, followed by standard isolation procedures and identification of E. coli. An antimicrobial susceptibility test using the disc diffusion method was performed against Ampicillin, Tetracycline, Trimethoprim, Gentamicin, and Streptomycin. PCR was used to determine if the isolates carry virulence intimin adherence protein (eaeA) and antimicrobial resistance genes. Body temperature, respiratory, and heart rates in dogs with diarrhea were significantly higher than in non-diarrheic dogs. PCR detected the eaeA virulence gene in 44(69.8%) of 63 isolates from diarrheic dogs. All isolates were resistant to ampicillin, and 55(87.3%), 47(74.6%), 29(46.0%), and 19(30.2%) of these were resistant to tetracycline, trimethoprim, gentamicin, and streptomycin, respectively. The frequency of antimicrobial resistance genes in the 63 isolates was 81.0, 52.4, 41.3, 33.3, 23.8 and 9.5% for CITM, tet (B), dfrA1, aac (3)-IV, aadA1 and tet (A), respectively. Overall, 6(9.4%), 16(25.4%), and 41(65.1%) were positive for one, two, three, or four resistance genes, respectively. In conclusion, the high prevalence of virulence (69.8%) and resistance 9.5-81.0% genes in E. coli isolates could be responsible for the diarrhea episodes, which may have posed therapeutic implications in affected dogs.

Keywords

• e. coli
• resistance genes
• diarrheic dogs
• antimicrobial resistance