鲍曼不动杆菌耐药基因aac（6’）－Ib和aac（6’）－Ib－cr的检测

Identification of aac（6＇）-Ib and aac（6＇）-Ib-cr gene in Acinetobacter baumannii

目的了解阿米卡星耐药的鲍曼不动杆菌中aac（6’）－Ib—cr基因的分布情况。方法收集2007年1月到2009年10月临床标本中分离对阿米卡星耐药的鲍曼不动杆菌73株，利用聚合酶链反应（PCR）方法扩增aac（6’）-Ib基因，PCR产物进行电泳分析和测序，aac（6’）-Ib基因阳性PCR产物用内切酶FOKI酶切后电泳分析。统计菌株对亚胺培南等12种抗生素的耐药率。结果aac（6＇）-Ib基因的检出率为89．0％，其中7．7％为突变了的aac（6’）-Ib-cr基因。所有菌株对除亚胺培南外的其它抗生素的耐药率均大于80％。结论aac（6＇）-Ib基因广泛存在于这些耐药菌株中，突变成aac（6’）-Ib—cr基因的发生率较低。这些对阿米卡星耐药的菌株，对其它抗生素的耐药也十分严重。

Objective To investigate the distribution of aac（6＇）-Ib-er gene in acinetobacter baumannii resistant to amikacin. Methods A total of 73 amikacin-resistant acinetobacter baumannii from Jan 2007 to Oct.2009 were collected. Aac（6＇）-lb gene were amplified by PCR-based assays. PCR products of aac（6＇）-Ib gene were digested with FOK I, electrophoretically analyzed and sequenced. Resistant rates to 12 antibiotics were calculated. Results The aac（6＇）-Ib and aac（6＇）-Ib-cr gene were amplified from 89.0% and 7.7% samples out of 73 acinetobacter baumannii, respectively. The resistant rates of 73 strains to other antibiotics were more than 80% except imipenem. Conclusions aac（6＇）Ib gene existed widely in clinical isolates of acinetobacter baumannii. These amikacin-resistant acinetobacter baumannii also confer high-level resistance to other antibiotics.