Designing of molecular tool for detecting virulence factor genes in avian pathogenic Escherichia coli (APEC)

Abstract

vian pathogenic Escherichia coli (APEC) causes colibacillosis in poultry, a leading cause of poultry mortality worldwide. This study aimed to design commercial molecular tool to detect the most important virulence factor genes ( irp2 , tsh , and hly F F) play crucial role in pathogenesis of E. coli . A total of 55 samples with omphalitis symptoms. in Baghdad province. These samples were cultivation, VITEK2 assays, molecular analysis and antimicrobial susceptibility.50 isolates showed blue-black colonies on (EMB) media and 5 isolate showed negative results. VITEK2 Results exhibited 99% of the characteristics of E. coli , confirmation by PCR analysis for detection the 16S rRNA gene. The results of nucleotide sequencing were submitted in GenBank/NCBI database through accession number (OR142657.1). APEC isolates were tested by designing specific primers to detect APEC-associated genes ( fimC and iucD ). All isolates' positives for these gene. The results of these isolates 25% positives ( irp2 , tsh , hly F ), 23% ( tsh , hly F ), 14% ( irp2 , hly F ), 16% and 10% positive for a single gene ( irp2 , hly F ) respectively. antimicrobial susceptibility tested showed that the isolate was resistant to ampicillin, amikacin also showed were isolates harbord numerus virulence genes highly resistant to the antibiotic.