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

摘要

Colibacillosis caused by avian pathogenic Escherichia coli (APEC) is an economic threat to the poultry industry throughout the world. Some of the virulence genes may enhance the ability of E. coli 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 E. coli isolates from colibacillosis cases in Japanese quail in 2014 in Kerman, Iran. In the present study, one hundred and two E. coli isolates were obtained from dead Japanese quails with colibacillosis. E. coli isolates were confirmed by standard biochemical and bacteriological methods. DNA of E. coli isolates was extracted by boiling method. The confirmed E. coli isolates were investigated to detect the phylogenetic groups and virulence genes including sfa/focDE, afaIBC, papEF by PCR methods. E. coli 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 papE-F, five isolates (4.90%) for afaIB-C and two isolates (1.96%) for sfa/focD-E genes. Based on our findings, E. coli 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.