两株携带blaNDM-1基因布氏柠檬酸杆菌耐药性及同源性分析

目的 探讨携带blaNDM-1基因布氏柠檬酸杆菌的耐药特点及同源性。方法 试验菌株为从临床尿液标本中分离到的两株耐碳青霉烯类的布氏柠檬酸杆菌。采用Vitek-2全自动微生物鉴定与药敏分析系统进行鉴定及药敏试验，PCR扩增blaNDM-1基因并测序验证，质粒接合试验了解blaNDM-1基因是否可通过质粒进行水平传播，并对两菌株进行多位点序列分型(MLST)及ERIC-PCR分析。结果 两株菌对青霉素类、头孢菌素类、氨基糖苷类、四环素类、喹诺酮类和碳青霉烯类均高度耐药，并携带blaNDM-1基因。接合试验成功将两株菌的blaNDM-1基因转移至大肠埃希菌EC600。MLST分型为ST171，ERIC-PCR发现扩增条带位置完全相同，即为同一基因型。结论 检出两株具有相同基因型ST171携带blaNDM-1基因的布氏柠檬酸杆菌，且菌株对碳青霉烯类在内的多种抗生素均高度耐药。

Drug resistance and homology analysis of two strains of Citrobacter braakii harboring blaNDM-1

Objective To investigate resistance characteristics and homology of Citrobacter braakii harboring blaNDM-1. Methods Two strains of carbapenem resistant C. braakii isolated from urine were identified by Vitek-2 automatic identification and antimicrobial sensitivity analysis system. The blaNDM-1 gene was amplified by PCR and sequenced. Plasmid conjugation tests were performed to explore the conjugating transfer of plasmids, and the multi locus sequence typing (MLST) and ERIC-PCR analysis of the two isolates were carried out. Results Two isolates were highly resistant to penicillins, cephalosporins, aminoglycosides, tetracyclines, quinolones and carbapenems, and harbored blaNDM-1. The MLST suggested sequence typing of ST131, ERIC-PCR showed identical profile indicating same genotype. Conclusion Two isolates of C. braakii were discovered harboring blaNDM-1 with the same genotype ST171which were highly resistant to various antibiotics including carbapenems.