天津地区鲍曼不动杆菌16SrRNA甲基化酶基因的检测与耐药性分析

摘要

目的:了解天津地区鲍曼不动杆菌16SrRNA甲基化酶基因的携带情况,并进行耐药分析.方法:收集天津地区2所医院2010年8月-12月临床分离的152株鲍曼不动杆菌,采用琼脂稀释法或纸片扩散法测定菌株药敏情况；聚合酶链反应(PCR)对鲍曼不动杆菌扩增7种16SrRNA甲基化酶基因(armA、rmtA、rmtB、rmtC、rmtD、rmtE、npmA)并测序.结果:152株鲍曼不动杆菌对多黏菌素B的耐药率最低(0),其次是头孢哌酮/舒巴坦(15.79％)和左氧氟沙星(36.84％),对其他11种抗菌药物耐药率均在45％以上.83株耐氨基糖苷类菌株中armA阳性率为87.95％ (73/83),占实验菌株的48.03％(73/152),未检出其他6种16SrRNA甲基化酶基因.armA阳性菌株耐药严重,除多黏菌素B外,armA阳性菌株对其余13种抗菌药物的耐药率明显高于armA阴性菌株(均p＜0.01).多重耐药和泛耐药占的比例在armA阳性株中(100％和69.86％)也明显高于阴性株(21.52％和11.39％).结论:armA广泛存在于鲍曼不动杆菌中,未检出其他6种基因.%Objective:To investigate the prevalence of 16SrRNA methylase genes and the rate of drug resistance in Aci-netobacter baumannii isolates in Tianjin District. Methods: A total of 152 strains of Acinetobacter baumannii were collected from clinical specimens in Tianjin District from August 2010 to December 2010. The primary antimicrobial susceptibility test-ing was performed by either Broth dilution or Kirby-Bauer Disk diffusion. Seven 16SrRNA methylase genes (armA, rmtA, rm-IB, rmtC, rmtD, rmtE and npmA) were amplified by polymerase chain reaction (PCR) and sequenced. ResultS:The polymyxin resistance rate (0) was the lowest among 152 strains of Acinetobacter baumannii, followed were cefoperazone/sulbactam (15.79%) and levofloxacin (36.84%). The resistance rates to the other 11 antibiotics were above 45%. The positive rate of ar-mA genes was 87.95% (73/83) in 83 Aminoglycoside resistant strains, which account for 48.03% (73/152) of all the experimental strains. The other 6 kinds of 16SrRNA methylase genes were not delected. There was a higher resistance in armA gene positive strains. Except the polymyxin, the rates of drug resistance to the rest 13 antibiotics were significantly higher in armA gene positive strains than those of armA gene negative strains (P < 0.01). The multidrug-resistance and pandrug-resistance were also higher in armA gene positive strains (100% and 69.86%) than those of armA gene negative strains (21.52% and 11.39% respectively). Conclusion: ArmA gene is widely existed in Acinetobacter baumannii strains. Other six genes were not found in Acinetobacter baumannii.