Virulotyping, Antimicrobial Resistance Profiling and DNA Fingerprinting of Escherichia coli Isolates from Neonatal Calves

Escherichia coli harbors various virulence factors responsible for diarrhea and other diseases in neonatal calves. The antimicrobial resistance (AMR) among the diarrheagenic and non-diarrheagenic E. coli may impose a potential health hazard among the calves and make the antibacterial therapy ineffective. The virulence gene expression among AMR strains plays a crucial role in establishing diarrheal disease with therapeutic complications. This study investigates the diversity of E. coli isolates from neonatal calves. E. coli isolated from the fecal samples were subsequently subjected to pathotyping and virulotyping using the PCR technique. AMR profiling was done by phenotypic and genotypic methods. The ERIC pattern of E. coli pathotypes was compared and correlated with the pattern of AMR and virulence traits. 179 isolates were obtained from 158 fecal samples collected from neonatal calves. Forty-two isolates were pathotypable; predominated by shigatoxigenic E. coli. Seventy-four isolates were ESBL producers. Nineteen isolates were carbapenem resistant and 68 isolates exhibited quinolone resistance. blaAmpC, blaVIM and qnrS were the predominant genes detected among ESBL, carbapenem and quinolone resistance genes, respectively. The present study indicated diverse virulence profiles and the presence of significant ESBL, carbapenem and fluoroquinolone resistance among E. coli pathotypes from calves. The analysis of resistance profiling indicates the risks associated with the indiscriminate antibiotic use among farm animals, which may pose a potential health hazard to livestock owners.