RESISTANCE TO ANTIBIOTIC OF ESCHERICHIA-C OLI STRAINS OF BOVINE AND AVIAN ORIGIN ISOLATED IN ALGERIA

The sensitivity of 101 E.coli strains of bovine and avian origin to 13 antibiotics has been studied. The strains show a resistance to almost all antibiotics. Regardless the origin of the strains, we notice high frequencies of resistance to Tetracyclin, Streptomycin, Strong Sulfam ids and Kanamycin; intermediate to Chloramphenicol, Trimethoprim, fura ne, Trimethoprim-Sulfamids and Ampicillin; low to Nalidixic acid; and none to Gentamycin, Refampicin and Colistin. The bovine strains, in a great majority, are more resistant than the avian strains. Ninety four percentage (94%) and seventy percentage (70%) of bovine and avian str ains respectively present a resistance to more than 2 antibiotics. Bov in strains resistance spectra are more varied. The phenotypes of resis tance are frequently transferable to high frequencies (1,5 10-4 to 9 1 0-2) and are mediated by plasmids having a high molecular weight (> 50 Mda). The incFI group, common to E.coli, is low represented within 17 plasmids typed with probes for the FIA, FIB and FIC replicons.