임상가검물에서 분리한 Klebiella pneumonniae plasmid의 분자유전적 특성

Abstract

Ninety-one strains of Klebsiella pneumoniae isolated from various clinical specimens in Taegu area were tested for the antimicrobial susceptibility to 16 drugs and studied for molecular and genetic characterization of R plasmid. K. pneumoniae were most frequently isolated from urine(60.4%), and followed by pus(16.5%), sputum(15.4%), cervix(3.3% ) and etc. All strains were susceptible to amikacin (Ak) and norfloxacin (Nf). 1.1-8.8% of the strains were resistant to moxalactam(Mx), nalidixic acid(Na) and rifampin(Rf), and 16.5-26.4% were resistant to gentamicin, kanamycin, tobramycin (To), cefamandole, chloramphenicol, and trimethoprim. 31.9¬59.3% were resistant to streptomycin(Sm), cephalothin, ampicillin, tetracycline and sulfisomidine. MIC90 of Ak, Mx and Nf were below the antimicrobial concentration tested. MIC90 of Na, Rf and To were 3.9-15.9/μg/mI, and those of other drugs were 118.4-> 2048/^g/ml. Of 91 strains tested, 37 were multiply resistant to 5 or more drugs. The patterns of multiple drug resistance which were most frequently encountered were not found. The ratio of conjugal tansfer of K. pneumoniae was 25%. Plasmid profiles for molecular and ge¬netic characterization of R plasmids from K. pneumoniae were studied through the method of alkaline SDS lysis and agarose gel electrophoresis. Molecular size of R plasmids were 35.9 to 81.3 megadalton. There was a R plasmid derived from the strain which did not habor any other plasmids, in this case this plasmid was thought to be a episomal state in original strain. R plasmids which were able to be classified into incompatibility (Inc) FII group were analyzed by restriction endonuclease EcoRl, they did not show the simirality each other except pKM9431 and pKM9432. Key Words ： K. pneumoniae，R plasmid, Molecular characterization.