Molecular Characterization of Antimicrobial Resistant Escherichia coli Isolated From Clinically Diseased Egyptian Cows and Calves

Antibiotic resistance in E.coli has been reported over the last years leading to therapeutic problems worldwide. The aim of this study was to characterize the antimicrobial resistance of E.coli isolated from clinically diseased Egyptian cows and calves phenotypically and genotypically. Among 232 samples collected from mastitic milk samples, vaginal swabs from cows and nasal swabs from pneumonic calves, a total of 38 resistant E.coli strains were isolate. Recovered isolates were tested for antimicrobial susceptibility by Kirby-bauer's disc diffusion method against penicillin, cefuroxime, cefepime, ampicillin, amikacin, kanamycin, gentamicin, ciprofloxacin, nalidixic acid, doxycycline, trimethoprim-sulphamethazole and chloramphenicol. Resistant isolates were molecularly characterized for presence of integron and other antibiotic resistance genes located outside the integron structure. The integron was detected in 5(13.1%). The B-lactamase encoding genes (bla -TEM and bla -SHV ); aminoglycosides resistance gene, aphA1 ; quinolones resistance gene, qnrA ; sulfonamides resistance genes ( sulI and sulII ) and trimethoprim resistance gene dhfrIa , were also identified in 7(18.4%), 4(80%), 0(0%), 8(40%) and 5(50%) of recovered isolates, respectively.