Drug resistance and R plasmids of Escherichia coli strains isolated from six species of wild birds.

Abstract

Drug resistance and R plasmids of Escherichia coli strains isolated from 30 wild birds of six species (jungle crows, bamboo partridges, grey starlings, rufous turtle doves, brown-eared bulbuls and azule-winged magpies) were investigated. Resistant strains were isolated from three species of birds: 34 (28.3%) of 120 strains isolated from jungle crows, 2 (8.0%) of 25 strains from bamboo partridges and 7 (70%) of 10 strains from grey starlings. Totally 43 (18.7%) of 230 strains were resistant. These strains were resistant to one or more drugs of oxytetracycline hydrochloride, dihydrostreptomycin and sulfadimethoxine. R plasmids were detected in 5 (14.7%) of the 34 resistant strains isolated from jungle crows. Quadruple-, quintuple- and sextuple-resistant strains were found among the 34 strains on agar plates containing oxytetracycline hydrochloride, chloramphenicol or dihydrostreptomycin and R plasmids were detected in eight of them. Of those 13 R plasmids, half of them showed Fi+ character, most of them showed restriction of phages λ, T2, T4 or T7, and their incompatibility groups were untypable. From these results, it is considered that these wild birds play a less role in spreading R plasmids than do domestic animals.