Molecular characterization of bovine intrauterine Escherichia coli isolates in rat model

The present study was undertaken to characterize the virulence factors of Escherichia coli isolated from bovine clinical endometritis, and comparison of uterine pathology induced by different phylogroups of E. coli in a rat model. Forty E. coli isolates assigned to different phylogroups, that is, A, B1, C, D, E, F, and clad1 were used. Phenotypic detection using Congo red binding, biofilm and haemolysin production observed 77% (n=31), 55% (n=22) and 68% (n=28) positive isolates, respectively. Multiplex PCR detection of 11 VFs genes, viz; Pap, Sfa, Afa, Hly, Cnf1, Cnf2, eaeA, F41, Sta, csgA, and csgD, found only one positive isolate each for pap and csgD while 3 isolates for F41 and 8 isolates for csgA were positive. Endometritis was inducted in diestrus rats using 4 phylogroups of E. coli. Expression for COX-2 and iNOS inflammatory marker genes was observed, but there was no statistical significant difference of expression among the phylogroups. On the basis of the present findings, it may inferred that different phylogroups of E. coli exhibit different virulence characteristics, but do not differ significantly in their ability to cause uterine disease in rats.