Virulence genes and antibiotic resistance of Escherichia coli isolates from dead-in shell chicken embryos

الملخص EN

A study on isolated Escherichia coli from dead in shell chicken embryos was aimed to detect the incidence of three virulence genes and the antibiotic resistance pattern of isolated samples.

Eighty dead in shell chicken embryos were obtained from three different Balady hatcheries in Kafr El Sheikh Governorate, Egypt were subjected to microbiological analysis for detection of Escherichia coli infection.

The percentage of positive samples were 7.5%.

According to sensitivity test Gentamycin was the most proper antibiotics with the highest efficiency against the isolated Escherichia coli in vitro.

The isolates of Escherichia coli obtained by detective enriched and plating were screaned for PCR using pho-A gene as a general marker for Escherichia coli and the presence of 3 virulence-associated genes, including iss , tsh and eae A by direct PCR on the enrichment broth lysate, results revealed that all isolates had the pho A, tsh and iss virulence genes , meanwhile, eae A virulence gene was not detected in any isolate .

It is concluded that the presence of iss and tsh genes increase the virulence of E.

coli and the usage of antibacterial agent must be used under control and according to sensitivity test.