CAJ | 학술논문

目的探讨重症监护病房(TCU)出现的对碳青霉烯类敏感性降低的奇异变形杆菌的分子流行病学及耐药机制.方法收集2010年8-10月,从浙江大学医学院附属第二医院2个ICU病房分离到对碳青霉烯类耐药或敏感性降低的19株奇异变形杆菌.通过脉冲场凝胶电泳分析菌株之间的同源性.采用药物敏感性试验、接合试验、质粒图谱分析、特异性聚合酶链反应( PCR)扩增和序列分析等技术研究细菌对碳青霉烯类耐药的分子机制.结果 19株奇异变形杆菌均对碳青霉烯类耐药或敏感性降低,对头孢菌素类耐药或敏感.19株奇异变形杆菌共分为3个克隆株,克隆A 14株,克隆B4株(2株亚克隆B1,2株亚克隆B2),克隆C1株.14株克隆A的酶切条带完全相同.克隆B的2个亚克隆之间仅相差1条条带.接合试验使受体菌大肠埃希菌对碳青霉烯类和头孢菌素类抗生素敏感性明显降低.克隆A和亚克隆B2的菌株含相对分子质量约45 000 bp的质粒,而亚克隆B1的接合子Jzr69则含相对分子质量约54 000 bp的质粒,克隆C菌株接合失败.特异性PCR扩增、序列分析及质粒DNA电泳图谱证实该19株奇异变形杆菌均产KPC-2型碳青霉烯酶.结论产KPC-2型碳青霉烯酶奇异变形杆菌在医院ICU病房流行,存在克隆传播现象.
목적 탐토중증감호병방(TCU)출현적대탄청매희류민감성강저적기이변형간균적분자류행병학급내약궤제.방법 수집2010년8-10월,종절강대학의학원부속제이의원2개ICU병방분리도대탄청매희류내약혹민감성강저적19주기이변형간균.통과맥충장응효전영분석균주지간적동원성.채용약물민감성시험、접합시험、질립도보분석、특이성취합매련반응( PCR)확증화서렬분석등기술연구세균대탄청매희류내약적분자궤제.결과 19주기이변형간균균대탄청매희류내약혹민감성강저,대두포균소류내약혹민감.19주기이변형간균공분위3개극륭주,극륭A 14주,극륭B4주(2주아극륭B1,2주아극륭B2),극륭C1주.14주극륭A적매절조대완전상동.극륭B적2개아극륭지간부상차1조조대.접합시험사수체균대장애희균대탄청매희류화두포균소류항생소민감성명현강저.극륭A화아극륭B2적균주함상대분자질량약45 000 bp적질립,이아극륭B1적접합자Jzr69칙함상대분자질량약54 000 bp적질립,극륭C균주접합실패.특이성PCR확증、서렬분석급질립DNA전영도보증실해19주기이변형간균균산KPC-2형탄청매희매.결론 산KPC-2형탄청매희매기이변형간균재의원ICU병방류행,존재극륭전파현상.
Objective To investigate the molecular epidemiology and resistance mechanism of reduced carbapenem susceptibility of Proteus mirabilis from intensive care unit (ICU).Methods Nineteen carbapenem resistance or reduced carbapenem susceptibility of Proteus mirabilis were isolated from two ICUs in Second Afiliated Hospital of Zhejiang University from August 2010 to October 2010.Pulsed-field gel electrophoresis (PFGE) was performed to analyze the molecular epidemiology of isolates.Antibiotic susceptibilities were determined by agar dilution method.Conjugation experiments were carried out in mixed broth cultures.Plasmid DNAs were obtained by using an alkalinelysis technique.Specific polymerase chain reaction (PCR) and DNA sequencing were preformed to confirm the genotype of β-lactamases. Results Nineteen Proteus mirabilis showed resistance or reduced carbapenem susceptibility,and were resistant or susceptible to cephalosporins.PFGE analysis indicated that nineteen carbapenem-non-susceptible Proteus mirabilis belonged to 3 clones,named as clone A (14 isolates),clone B (2 isolates of subclone B1 and 2 isolates of subclone B2 ) and clone C (1 isolate).Fourteen clone A isolates were indistinguishable,and subclone B1 and subclone B2 were closely related with only one fragment disparity.Escherichia coli (EC600) acquired an approximately 45 000 bp,54 000 bp and 45 000 bp plasmids from clone A,subclone B1 and subclone B2 isolates separately by conjugation studies.PCRs and DNA sequence analysis confirmed that all Proteus mirabilis isolates and their transconjugants produced the KPC-2 carbapenemase. Conclusion Carbapenem-non-susceptible Proteus mirabilis were epidemic in two ICUs in our hospital,and were clonally disseminated.