Escherichia coli in different animal feces: phylotypes and virulence genes.

Abstract

In this study, it was aimed to determine the phylogroups of Escherichia coli isolates from horse, cat, dog, sheep, cattle, and chicken feces samples and to investigate some important virulence genes of the isolates. For this purpose, a total of 600 feces samples, 100 from each animal species, were used as material. For the isolation of E.coli, feces samples were directly inoculated on MacConkey agar. The identification of the isolates was performed via phenotypic tests and species-specific multiplex Polymerase Chain Reaction (mPCR) method. PCR methods were used to phylotype E.coli isolates and to investigate virulence genes (bfpA, eaeA, LT, ST, Stx1, and Stx2). Of the total 600 E.coli isolates recovered in this study, 120 (20%), 269 (44.8%), 58 (9.7%), 19 (3.2%), 35 (5.8%), 56 (9.3%), 31 (5.2%), and 12 (2%) were identified as phylogroup A, B1, B2, C, D, E, F, and Escherichia clade I, respectively. While the virulence gene was detected in 149 (24.8%) E.coli isolates, no virulence gene was detected in 451 (75.2%) isolates. According to the analysis results, the most determined virulence gene was Stx1, while the least determined virulence gene was LT. In conclusion, in this study, when both the animal species and the number of E.coli isolates examined are considered, the data obtained are of great importance in epidemiological terms. However, the detection of virulence genes in 13.5% among phylogroup A, B1, and C isolates with commensal characteristics suggest that these isolates may show pathogenic characteristics with the virulence genes they contain.