養殖ウナギより分離されたEdwardsiella tarda由来多剤耐性プラスミド

抄録

One hundred fifty-two strains of 186 strains of Edwardsiella tarda collected from eel culture ponds in various areas in Japan in 1983 and 1984 showed resistance to one or a combination of the following drugs; chloramphenicol (CP), tetracycline (TC), streptomycin (SM), nalidixic acid (NA), furazolidone (NF), and/or sulfonamide (SA). Strains resistant to NA and NF were detected at high frequency. Transferable R plasmids were detected in 31 of the 152 resistant strains. R plasmids encoding for resistance to CP, TC, and SA were predominant. Other R plasmids encoded for resistance to TC, SA; CP, SA; and CP, TC, SM, and SA. The Hindlll or PstI digestion patterns of the R plasmids with different resistant markers were similar except one R plasmid with resistance to CP, TC, SM, and SA. Southern blot hybridization¹⁾ showed these R plasmids to have high homology with pK4, a typical R plasmid from E. tarda detected in the 1970's.²⁾ Therefore, drug resistant strains of E. tarda carrying R plasmids with the same DNA structure have pre-vailed in Japanese eel culture ponds since 1972.