Molecular Characterization, Spread and Evolution of Quinolones Resistance in E.Coli of Avian Origin

Resistance to fluoroquinolones encouraged us to study the resistance of E. coli isolates from avian origin in Egypt. A total of 150 poultry samples (liver, lung, heart and bone marrow) collected from chickens, ducks and turkeys, 50 of each, were examined bacteriologically for the presence of E. coli. The obtained results showed that the isolation rate of E. coli was 43.3% (65 from 150 samples). Serotyping of the isolated E. coli revealed 19, 13 and 7 O groups in chickens, ducks and turkeys, respectively. The isolated E. coli was screened against 5 quinolones discs and also for five representing genes (qnrA, qnrB, qnrS, qepA and aac(6′)-Ib-cr). The absolute resistance to three out of five antimicrobial discs appeared in duck isolates; also chicken isolates showed resistance 100% to nalidixic acid and as totally the higher percentage for the examined resistance genes especially that has the role in decreasing the sensitivity to nofloxacin, cibrofloxacin and enrofloxacin.