Phylogrouping, Virulence Profile and Antibiogram of Escherichia coli Strains Associated with Canine Pyometra

Background: Multi-drug resistant bacterial strains with biofilm-forming ability are one of the significant reasons contributing to the failure of medical management and recurrence of canine pyometra. The predominant bacterial agent implicated in canine pyometra is Escherichia coli, the different strains of which can be grouped into distinct phylogroups with the same ecological niches, characteristics and tendency to cause disease. The identification of a phylogroup of an unknown strain can facilitate the control, prevention and treatment of infections. Methods: The isolates of E.coli obtained from 25 clinical cases of pyometra were identified based on the cultural, morphological and biochemical characteristics. The antibiogram of the isolates were done employing Kirby-Bauer disk diffusion method. Biofilm forming ability of theisolates were detected by tissue culture plate method and the presence of virulence genes among them were detected using a multiplex PCR. The phylogrouping of E. coli was done employing the novel quadruplex PCR method. Result: In the antibiogram, most isolates were found sensitive to Amoxycillin-clavulanate (90%), Gentamicin (80%),Tetracycline (50%) and Amikacin (50%), while 100% resistance were shown towards ceftazidime-clavulanate, enrofloxacin,ceftriaxone-tazobactam, ciprofloxacin and cefotaxime-clavulanate. Among the E. coli isolates, strong and moderate biofilm producers showed resistance to a wide range of antibiotics compared to non-biofilm producers. Around 80% of the isolates belonged to the phylogroup B2 and all of these had the presence of fimH, sfa, and csgA genes. Among the isolates belonged to the phylogroup B2, 87.5% of the isolates had pap gene while none of them possessed afa gene.