mona ElEnbaawy

Besides its zoonotic importance, avian pathogenic Escherichia coli (APEC) causes substantial financial losses in the
poultry industry globally. The progress of antimicrobial resistance in APEC is mainly associated with excessive
antimicrobial use and improper sanitation. Since its beginning in the 1970s, the VITEK system has developed into
the VITEK 2 system, which has used an automated system to perform all the steps required for microbial
identification and antibiotic susceptibility rapidly and accurately. The present study aimed to update the available
circulating data about APEC isolates by phenotypic identification, sero-grouping of APEC from broilers chickens
and breeders in five governates of Egypt, investigation of their antibiotic resistance pattern by VITEK 2 system, and
molecular identification of their virulence determinants. The prevalence of APEC isolated from the different internal
organs (liver, lung, heart, heart blood, and spleen) was 67.5%. The most prevalent serotypes were O125, 0114, O44,
O127, O142, and O78. Virulence-associated genes (iutA, fimC, and papC) were detected at rates of 84.4%, 74%, and
54.8%, respectively. The highest resistance was found against ampicillin (100%), trimethoprim-sulfamethoxazole
(80%), and ampicillin-sulbactam (78.5%), which indicates that the poultry farms need a surveillance and
intervention system with proper accuracy and rapidity to prevent the misuse of antibiotics and APEC outbreaks.
Keywords: Escherichia coli, Colibacillosis, PCR, VITEK, Virulence gene