Antimicrobial Drug Resistance and R Plasmids of Serratia marcescens

Serratia marcescens의 항균제 내성 및 R plasmid

  • Huh, Chan-Hee (Department of Neuropsychiatry, Kyungpook National University, School of Medicine) ;
  • Lee, Yoo-Chul (Department of Microbiology, Kyungpook National University, School of Medicine) ;
  • Seol, Sung-Yong (Department of Microbiology, Kyungpook National University, School of Medicine) ;
  • Cho, Dong-Taek (Department of Microbiology, Kyungpook National University, School of Medicine) ;
  • Chun, Do-Ki (Department of Microbiology, Keimyung University Medical College)
  • 허찬희 (경북대학교 의과대학 신경정신과학교실) ;
  • 이유철 (경북대학교 의과대학 미생물학교실) ;
  • 설성용 (경북대학교 의과대학 미생물학교실) ;
  • 조동택 (경북대학교 의과대학 미생물학교실) ;
  • 전도기 (계명대학교 의과대학 미생물학교실)
  • Published : 1986.03.31

Abstract

Forty clinical isolates of Serratia marcescens were tested for their susceptibility to 19 antimicrobial drugs and studied on the molecular characteristics of R plasmids. Cefotaxime (Ct) was the most effective drug and only 2 (5%) strains were resistant to this drug. Thirteen to 18% of strains were resistant to cefoperazone (Cz), amikacin (Ak). and trimethoprim (Tp), and 28 to 40% were resistant to piperacillin (Pi), nalidixic acid (Na), gentamicin (Gm), and cefoxitin (Cx). A majority of strains were resistant to carbenicillin (Cb), tobramycin (Tp), kanamycin (Km), and cefamandole (Cd), and all to cephalothin. One half of the isolates were resistant to 10 or more drugs. $MIC_{90}$ of Pi to Gm-resistant strains (Gm') were 8 times higher than that to Gm-susceptible strains (Gm'), but $MIC_{90}$ of Ak, Cx, Ct, and Cz were almost the same between both Gm' and Gm' strains. Nine (23.7%) strains among 38 of multiply drug-resistant S. marcescens transferred conjugally their partial patterns of resistance to E. coli or Klebsiella strains, and two S. marcescens strains producing bacteriocin transferred their resistance to Klebsiella only, but not to E. coli. The plasmid profiles of S. marcescens were studied by the methods of SDS lysis and agarose gel electrophoresis. Twenty-four (60%) strains carried one to four plasmids of 1.4. to 144 Mdal, and conjugative R plasmids of 49 to 127 Mdal were noted in transconjugants. MIC levels of drugs in transconjugants were variable by the R plasmids and recipient strains.

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