CAJ | 학술논문

目的对从同一标本中分离的碳青霉烯类药物耐药的肺炎克雷伯菌和摩根摩根菌进行耐药机制相关性分析.方法琼脂稀释法进行药物敏感试验;特异性PCR扩增和序列分析检测介导耐碳青霉烯类药物的相关基因;接合试验、质粒提取和耐药基因周围序列分析耐药的可传递性、耐药质粒的同源性及耐药基因的遗传背景;提取外膜蛋白分析菌株外膜蛋白的改变.结果 2株分离菌均产碳青霉烯酶并扩增出介导碳青霉烯类耐药的KPC-2型基因;质粒接合试验成功传递了对碳青霉烯类药物的耐药性,耐药基因被携带在2个大小不同但耐药基因周围序列完全相同的质粒上;其中摩根摩根菌耐药株缺失了相对分子质量约为38×103的外膜蛋白同时出现36×103的外膜蛋白而肺炎克雷伯菌则缺失了外膜蛋白OMPK36.结论 2株分离菌均携带KPC-2基因.该基因由2个大小不同的质粒携带,同一复合转座子介导了KPC-2基因在2株细菌的不同质粒上转移.同时外膜蛋白缺失参与了对碳青霉烯类抗生素耐药.
목적 대종동일표본중분리적탄청매희류약물내약적폐염극뢰백균화마근마근균진행내약궤제상관성분석.방법 경지희석법진행약물민감시험;특이성PCR확증화서렬분석검측개도내탄청매희류약물적상관기인;접합시험、질립제취화내약기인주위서렬분석내약적가전체성、내약질립적동원성급내약기인적유전배경;제취외막단백분석균주외막단백적개변.결과 2주분리균균산탄청매희매병확증출개도탄청매희류내약적KPC-2형기인;질립접합시험성공전체료대탄청매희류약물적내약성,내약기인피휴대재2개대소불동단내약기인주위서렬완전상동적질립상;기중마근마근균내약주결실료상대분자질량약위38×103적외막단백동시출현36×103적외막단백이폐염극뢰백균칙결실료외막단백OMPK36.결론 2주분리균균휴대KPC-2기인.해기인유2개대소불동적질립휴대,동일복합전좌자개도료KPC-2기인재2주세균적불동질립상전이.동시외막단백결실삼여료대탄청매희류항생소내약.
Objective To investigate the relationship of resistance mechanisms of a Klebsiella pneumoniae strain and a Morganella morganii strain resistance to carbapenems isolated from a single specimen. Methods Sensibility of antimicrobial agents was detected by agar dilution method. Specific PCR and DNA sequence analysis were performed to detect resistance genes. Plasmid feature was detected by plasmid conjugation and electrophoresis analysis. Genetic environment around blaKPC was analyzed with sequencing. The changes of outer membrane permeability were analyzed with electrophoresis of outer membrane proteins. Results blaKPC-2 was detected in 2 original isolates strains and their transconjugants. Carbapenem-resistance was successfully transfered by conjugation experiments. blaKPC-2 was located on dissimilar plasmids, but genetic environment around blaKPC-2 was the same sequence. The Morganella morganii isolate showed a loss of 38 ×103 OMPs and an additional 36 ×103 OMPs appearance, while the Klebsiella pneumoniae isolate showed a loss of OMPK36. Conclusion blaKPC-2 was detected in 2 isolates. This gene encoded by two plasmids with different sizes was located on the same composite transposon. The lack of outer membrane proteins could also play an important role causing isolates to exhibite resistance to carbapenems.