Drug-resistance and conjugative R plasmids in Escherichia coli strains isolated from wild birds (Japanese tree sparrows,green pheasants and bamboo partridges).

Abstract

E. coli strains were isolated from wild birds (Japanese tree sparrows (J.S.), Green pheasants (G.P.) and Bamboo partriges (B.P.)) for examining their drug-resistance and detection of conjugative R plasmids. Total E. coli strains isolated (30 strains were colected from each one) were 1380, 810 and 1530 respectively. And the isolation frequency of resistant strains were 87.5% (J.S.), 12.5% (G.P.) and 15.8% (B.P.). Individuals that excreted resistant strains were 46 out of 63 J.S. (73.0%), 13 out of 41 G.P. (31.7%) and 51 out of 76 B.P. (67.1%). The frequency of R+ strains among representative resistant strains were 13.9%, 13.5% and 9.2%, respectively. These results indicate that wild birds may also become the carriers of resistant strains and may be responsible for the spread of R plasmids in a wide area.