CAJ | 학술논문

目的：探讨临床分离的对环丙沙星和左氧氟沙星均耐药的铜绿假单胞菌耐药机制。方法收集临床分离经 VITEK-2 Compact 细菌鉴定仪检测环丙沙星和左氧氟沙星均耐药的铜绿假单胞菌，琼脂稀释法测定环丙沙星和左氧氟沙星的 MIC值，PCR 扩增 DNA 促旋酶基因 gyrA 和 gyrB 以及 DNA 拓扑异构酶Ⅳ的 parC 和 parE 基因，实时-RT-PCR 分析细菌外排系统表达情况。结果琼脂稀释法检测结果与 VITEK-2 Compact 细菌鉴定仪检测结果相符。PCR 扩增测序发现以 DNA 促旋酶基因 gyrA（在位点941处插入碱基 C）和 gyrB （3株在位点1588处缺失碱基 A，其他菌株在位点1543处插入碱基 T）基因缺失或者插入导致移码突变为主，parE 基因有3株在位点1895处插入碱基 C。实时定量 PCR 检测发现以 mexA 和mexC表达增加为主。结论检出的耐环丙沙星和左氧氟沙星铜绿假单胞菌是由于 DNA 促旋酶基因 gyrA 和 gyrB 基因的突变和mexAB-OprM 和mexCD-OprJ 表达增加共同作用的结果。
목적：탐토림상분리적대배병사성화좌양불사성균내약적동록가단포균내약궤제。방법수집림상분리경 VITEK-2 Compact 세균감정의검측배병사성화좌양불사성균내약적동록가단포균，경지희석법측정배병사성화좌양불사성적 MIC치，PCR 확증 DNA 촉선매기인 gyrA 화 gyrB 이급 DNA 탁복이구매Ⅳ적 parC 화 parE 기인，실시-RT-PCR 분석세균외배계통표체정황。결과경지희석법검측결과여 VITEK-2 Compact 세균감정의검측결과상부。PCR 확증측서발현이 DNA 촉선매기인 gyrA（재위점941처삽입감기 C）화 gyrB （3주재위점1588처결실감기 A，기타균주재위점1543처삽입감기 T）기인결실혹자삽입도치이마돌변위주，parE 기인유3주재위점1895처삽입감기 C。실시정량 PCR 검측발현이 mexA 화mexC표체증가위주。결론검출적내배병사성화좌양불사성동록가단포균시유우 DNA 촉선매기인 gyrA 화 gyrB 기인적돌변화mexAB-OprM 화mexCD-OprJ 표체증가공동작용적결과。
Objective To investigate the mechanisms of both levofloxacin and ciprofloxacin resistance in clinical strains of Pseudomonas aeruginosa isolated from our hosptial.Methods Twenty P .aeruginosa isolates resistant to both levofloxacin and ciprofloxacin as tested by VITEK-2 Compact were collected.Agar dilution method was used to confirm their minimum inhibito-ry concentrations (MICs)of levofloxacin and ciprofloxacin.DNA gyrase (gyrA and gyrB )and topoisomerase IV (parC and parE)were analyzed by PCR amplification.The expression of efflux systems were analyzed by real-time RT-PCR.Results The MIC results were consistent between Agar dilution method and Vitek-2 Compact system.DNA gyrase (gyrA and gyrB )se-quencing analysis showed that the mutations were mainly frame-shifting mutation characteristic of base (C)insertion at position 941 in gyrA gene,deletion of base (A)at position 1588 in gyrB gene,and insertion of base (T)at position 1543 in gyrB gene.Insertion of base (C)at position 1895 in parE gene was identified in 3 strains.Overexpression of MexAB-OprM and MexCD-OprJ was detected by real-time RT-PCR.Conclusions The insertion and/or deletion of bases in DNA gyrase (gyrA and gyrB)genes and overproduction of MexAB-OprM and MexCD-OprJ efflux systems may contribute to the resistance to both ciprofloxacin and levofloxacin in clinical isolates of P .aeruginosa.