青岛两所医院鲍曼不动杆菌碳青霉烯酶基因及同源性分析

目的了解青岛市两所医院鲍曼不动杆菌(AB)耐药情况、分布特征,碳青霉烯酶基因携带情况。方法收集两所医院临床分离的145株(A院78株,B院67株)AB进行药敏试验,采用聚合酶链反应(PCR)扩增碳青霉烯酶基因,肠杆菌科基因间一致重复序列(ERIC)-PCR对菌株进行同源性分析。结果 A院AB对临床常用的16种抗菌药物普遍耐药,对头孢哌酮/舒巴坦耐药率最低(3.85%),其次是米诺环素(16.67%),对其他抗菌药物耐药率均73%。B院AB对常用的23种抗菌药物普遍耐药,对米诺环素和替加环素均不耐药,对阿米卡星和左氧氟沙星的耐药率分别为23.88%、38.81%,对其他抗菌药物的耐药率均64%。两院所有菌株均携带OXA-51基因,A、B两院碳青霉烯耐药组OXA-23基因的携带率分别为86.76%(59/68),56.67%(34/60),差异有统计学意义(χ2=14.53,P0.001);A院3株菌携带OXA-58基因,B院未检出OXA-58基因。145菌株共分为8个基因型,其中A型71株和E型37株,为主要流行株;A院主要流行A型(46.15%)和E型(41.03%),B院主要流行A型(52.24%)和C型(17.91%)。结论两所医院临床分离的AB耐药情况严重,且存在医院流行,OXA型酶OXA-23、OXA-51基因在介导AB对碳青霉烯类药物耐药中发挥重要作用。

Carbapenemase genes and homology of Acinetobacter baumannii in two hospitals of Qingdao

ObjectiveTo investigate antimicrobial resistance, distribution, and carriage of carbapenemase genes of Acinetobacter baumannii(AB) from two hospitals in Qingdao.Methods145 AB isolates collected from two hospitals (78 from hospital A，67 from hospital B) were performed antimicrobial susceptibility testing， carbapenemase genes were amplified by polymerase chain reaction (PCR); homology analysis were conducted with enterobacterial repetitive intergenic consensus (ERIC) PCR.ResultsAB from hospital A were generally resistant to 16 commonly used antimicrobial agents， with the lowest resistant rate of 3.85% to cefoperazone/sulbactam， followed by resistance rate of 16.67% to minocycline， resistant rates to the other antimicrobial agents were all> 73%. AB from hospital B were generally resistant to 23 commonly used antimicrobial agents, but the resistance rates to minocycline and tigecycline were both 0, resistance rates to amikacin and levofloxacin were 23.88% and 38.81% respectively, resistant rates to the other antimicrobial agents were all >64%. All strains carried OXA 51 gene, the carriage rates of OXA 23 gene in carbapenem resistant group were 86.76%(59/68) and 56.67%(34/60) in hospital A and B respectively, the difference was significant（χ2=14.53,P＜0.001）; OXA 58 gene was detected in 3 isolates in hospital A but not detected from hospital B. 145 AB strains were classified into 8 types， the major prevalence types were type A (n=71) and E(n=37); the major prevalence types in hospital A were type A (46.15%) and E（41.03%）, hospital B were type A (52.24%) and C (17.91%).ConclusionAntimicrobial resistance of clinically isolated AB is serious and prevailed in two hospitals. OXA 23 and OXA 51 genes play an important role in AB resistance to carbapenems.