Phylogenetic typing and molecular detection of virulence factors of avian pathogenic Escherichia coli isolated from colibacillosis cases in Japanese quail

Abstract

Colibacillosis caused by avian pathogenic <em>Escherichia coli</em> (APEC) is an economic threat to the poultry industry throughout the world. Some of the virulence genes may enhance the ability of <em>E. coli</em> isolates to grow in the tissues of broilers. The APEC strains are assigned to a few distinct phylogenetic groups. The purpose of the present study was to detect the virulence genes and phylogenetic groups of <em>E. coli </em>isolates from colibacillosis cases in Japanese quail in 2014 in Kerman, Iran. In the present study, one hundred and two <em>E. coli</em> isolates were obtained from dead Japanese quails with colibacillosis. <em>E. coli </em>isolates were confirmed by standard biochemical and bacteriological methods. DNA of <em>E. coli </em>isolates was extracted by boiling method. The confirmed <em>E. coli</em> isolates were investigated to detect the phylogenetic groups and virulence genes including <em>sfa/focDE</em>, <em>afaIBC</em>,<em> papEF </em>by PCR methods. <em>E. coli</em> isolates were classified into A (62 isolates), B1 (24 isolates), B2 (12 isolates) and D (four isolates) phylogenetic groups. Among examined isolates nine isolates (8.82%) were positive for <em>papE-F</em>, five isolates (4.90%) for <em>afaIB-C</em> and two isolates (1.96%) for <em>sfa/focD-E</em> genes. Based on our findings, <em>E. coli</em> isolates from colibacillosis of Japanese quail could be assigned to various phylogenetic groups (mostly A and D), and they may contain the adhesion genes in a low prevalence.