In vitro And In vivo Molecular Studies On Some Escherichia coli Serovars Isolated From Chicken.

  • Rokaya Elamary Department of Botany and Microbiology, Faculty of Science, South Valley University, 83523 Qena, Egypt
  • Dina Shibat El-hamed Animal health research institute, Qena, Egypt
  • Waeil Sayed Department of Botany and Microbiology, Faculty of Science, South Valley University, 83523 Qena, Egypt
  • Wesam Mohamed Ali Salem Department of Botany and Microbiology, Faculty of Science, South Valley University, 83523 Qena, Egypt http://orcid.org/0000-0003-0212-2143

Abstract

A total number of 16 Escherichia coli serovars were recovered from different colibacillosis diseased chicken organs. Characterization of the isolates was performed by biochemical and serological tests, biofilm formation, antimicrobial susceptibility assays, detection of virulence and antibiotic resistance genes by PCR. The biofilm formation (at OD595) of all E. coli isolates showed a similar trend. eaeA gene was detected in 3 serovars O2:H6, O26:H11 and O44:H18 while, hly gene was detected in 2 serovars O2:H6 and O144:H21. The gene encoding for stx2 was detected in 2 serovars (O55:H7 and O146:H21) while the gene encoding stx1 was not detected in any serovars. Furthermore, all serovars were carrying the encoding blaTEM. blaSHV and blaCTX were detected in 75% and 18.75% of isolates respectively, while blaOXA-1 was not detected in all serovars. Although all isolates were multi-resistant against most of B-lactams antibiotics, they were susceptible to 20 to 80 mg ml-1 of garlic extract. Finally, we demonstrated that a five-oral administration of garlic extract to baby chicks colonized with E. coli reduces the mortalities and significantly increase the body weight. The efficacy of garlic extract as the antibacterial natural product was sufficient as a bactericidal alternative against the multidrug- resistant E. coli isolates.

1.5% Agarose gel electrophoresis of multiplex PCR of: (a) stx1 (614 bp), stx2 (779 bp), eaeA (248 bp) and hlyA (1177 bp) virulence genes for characterization of Enteropathogenic E. coli.
Published
2018-11-04
Section
Original Articles