Phenotypic and Genotypic Characterization of Multi Drug Resistant E.coli Isolated from Chickens

A.A.Abd El-Tawab1, W.M.M. Hassan2, F.R.El-Seedy3 and H.Abdel-Satar2"


This study was performed on 1284 chicken came from 77 poultry farms layers, broilers, grandparents, broiler breeder at Giza and Qalubia governorates for E. coli infection. Samples were taken from these chickens (liver, intestine and yolk sac) after clinical and post mortem examination for morphological changes. The result revealed that, E. coli was isolated from 1204 positive samples (93.7%) represented as 40 (100%) from grandparents, 360 (90%) from broiler breeder,100 (71.4%) from layers and 704 (100%) from broiler. By using polyvalent & monovalent anti sera, these isolates were characterized for 18 different serogroups, most common detected serogroups is O158, O125, O119, O114 and O44 while there is 11 isolates are untypable. Antimicrobial susceptibility test by the disk diffusion method was performed in accordance with NCCLS (2008) for different 7 anti-microbial rugs (sulfamethazole, streptomycin, ciprofloxacin, enrofloxacin, tetracycline, trimethoprime and ampicillin). The results show that isolates were resistant to tetracycline and sensitive to ciprofloxacin. Eighty nine percent of isolates are multi drug resistant E. coli (resistant to 2 or more anti-microbial drug). In this study 20 isolates from total 73 E. coli isolates was examined for presence of resistance genes, the results revealed that: prevalence the gene aac(6′ )-Ib-cr for ciprofloxacin and enrofloxacin resistance in 45% of isolates, the prevalence of the blaTEM gene β- lactem resistance gene was detected in 80% of isolate, the prevalence of the tetA and sul1 genes tetracycline and sulfamethazole resistance genes was detected in 75% of isolates.

Key words

Chickens, E.coli, Genotypic, Multi drug resistant, Phenotypic.