肝移植受者中多重耐药革兰阴性菌的检测和同源性分析

Characterization and homology analysis of the multidrug-resistant gram-negative bacteria isolated from liver transplant recipients

目的了解肝移植受者中分离的多重耐药革兰阴性菌及各菌种的同源性。方法对上海交通大学附属第一人民医院2007年1月—2010年4月肝移植受者的各种标本中分离菌进行微量稀释法药敏试验,ESBLs和金属β内酰胺酶(MBL)检测并应用重复序列PCR(REP-PCR)技术测定菌株的同源性。结果从250例肝移植受者中,分离出124株革兰阴性菌,其中多重耐药革兰阴性菌67株(54.0%),包括鲍曼不动杆菌20株(29.9%)、大肠埃希菌16株(23.9%)、肺炎克雷伯菌13株(19.4%)、嗜麦芽窄食单胞菌8株(11.9%)、铜绿假单胞菌6株(9.0%)和阴沟肠杆菌4株(6.0%)。产ESBLs菌株主要为肺炎克雷伯菌(61.5%,8/13)和大肠埃希菌(81.3%,13/16);产金属酶的细菌为嗜麦芽窄食单胞菌(8/8)、铜绿假单胞菌(5/6)和鲍曼不动杆菌(95.0%,19/20);REP-PCR检测鲍曼不动杆菌4个基因型,其中C型17株,均在同一段时间内发现;大肠埃希菌分12个基因型,B型5株;肺炎克雷伯菌7个基因型,E型6株;铜绿假单胞菌5个基因型,C型2株;嗜麦芽窄食单胞菌7个基因型,F型2株;阴沟肠杆菌4个基因型,A型、B型、C型和D型各1株。结论肝移植术后多重耐药革兰阴性菌感染发生率较高;病原菌中鲍曼不动杆菌呈泛耐药,并且可能在肝移植病房暴发流行。

Objective To investigate the prevalence and homology of muhidrug resistant gram negative bacilli in liver transplant recipients. Methods The bacterial strains were isolated from the liver transplant recipients in First People＇s Hospital affiliated to Shanghai Jiaotong University during January 2007 and April 2010. Antimicrobial susceptibility of these isolates was tested by microdilution method. ESBI.s and metallo-β-lactamase （MBL） were analyzed. Bacterial homology was analyzed by REP-PCR. Results A total of 124 strains of gram-negative bacteria were isolated from 250 liver transplant recipients. Sixty-seven （54.0%） of these strains were confirmed as multidrug resistant, including A. baumannii （20 strains, 29.90%）, E. coli （16, 23.9%）, K. pneumoniae （13, 19. 4%）, S. maltophilia （8, 11. 9%）, P. aeruginosa （6, 9. 0%）, and E. cloacae （4, 6.0%）. ESBLs-producers were primarily K. pneumoniae （61. 5%） and E. coli （81. 3%）. The metalloenzyme-producing strains were mainly S. rnaltophilia （8/8）, P. aeruginosa （5/6）, and A. baumannii （95.0%, 19/20）. REP-PCR analysis of A. baumannii revealed 4 genotypes, of which 17 genotype C strains were isolated in the same period. Of the 12 genotypes of E. coli, 5 strains belonged to genotype B. Seven geno-types were identified in K. pneumoniae, including 6 strains of genotype E. Five genotypes were identified in P. aeruginosa, including 2 strains of type C. S. maltophilia showed 7 genotypes, including 2 strains of type F. E. cloacae had four genotypes, including A, B, C, and D, one strain each. Cibckysuibs Multidrug-resistant gram negative bacilli are highly prevalent in patients following liver transplantation. A. bau-mannii strains are pan-drug resistant, which may lead to outbreaks in liver transplant unit.