Department of Veterinary Preventive Medicine, College of Veterinary Medicine, The Ohio State University, Columbus, OH, USA.
J Antimicrob Chemother. 2010 Feb;65(2):228-32. doi: 10.1093/jac/dkp427. Epub 2009 Dec 11.
Biocides and dyes are commonly employed in hospital and laboratory settings. We investigated the biocide susceptibilities of a rapidly emerging pathogen, Acinetobacter baumannii, and the underlying molecular mechanisms, with a primary focus on resistance-nodulation-cell division (RND) efflux systems.
Biocide susceptibilities, efflux and in vitro inactivation profiles were monitored in the presence/absence of efflux pump inhibitors. The RND transporters encoded by adeB and adeJ were detected by PCR; null mutants were constructed in the native host. Expression of adeB and adeJ in clinical isolates was assayed by semi-quantitative RT-PCR.
Susceptibility testing and phenotypic assays demonstrated the role of active efflux in mediating decreased susceptibility to biocides. Inactivation of either the adeB or adeJ transporter gene led to increased susceptibility to biocides. RT-PCR analysis exhibited increased adeB and adeJ expression in clinical isolates.
This is the first study demonstrating the role of efflux pumps in mediating decreased susceptibility to disinfectants and other chemical substrates in A. baumannii.
消毒剂和染料在医院和实验室环境中被广泛应用。我们研究了一种快速出现的病原体——鲍曼不动杆菌的杀菌敏感性及其潜在的分子机制，主要集中在耐药性-结节-分裂（RND）外排系统上。
在存在/不存在外排泵抑制剂的情况下，监测杀菌敏感性、外排和体外失活动态。通过 PCR 检测 adeB 和 adeJ 编码的 RND 转运蛋白；在原始宿主中构建缺失突变体。通过半定量 RT-PCR 检测临床分离株中 adeB 和 adeJ 的表达。
药敏试验和表型分析表明，主动外排在介导对杀菌剂的低敏感性中起作用。adeB 或 adeJ 转运蛋白基因的失活导致对杀菌剂的敏感性增加。RT-PCR 分析显示临床分离株中 adeB 和 adeJ 的表达增加。
这是第一项研究，证明了外排泵在介导鲍曼不动杆菌对消毒剂和其他化学底物的敏感性降低方面的作用。
