Periplasmic adaptor protein AcrA has a distinct role in the antibiotic resistance and virulence of Salmonella enterica serovar Typhimurium
Periplasmic adaptor protein AcrA has a distinct role in the antibiotic resistance and virulence of Salmonella enterica serovar Typhimurium
复制标题
DOI：
10.1093/jac/dkp311
复制
发表时间：
2009-11-01
影响因子：
5.2
通讯作者：
Piddock, Laura J. V.
中科院分区：
文献类型：
--
作者：
Blair, Jessica M. A.;La Ragione, Roberto M.;Piddock, Laura J. V.
目的：AcrA在多种RND三联外排泵中作为周质衔接蛋白（PAP）发挥作用，其中AcrAB-TolC被认为是最重要的外排泵。该系统赋予先天的多种抗生素耐药性。acrB或tolC的破坏损害鼠伤寒沙门氏菌在宿主中定殖和持续存在的能力。本研究的目的是探讨AcrA单独在多重耐药和致病性中的作用。方法：将acrA基因插入鼠伤寒沙门氏菌SL 1344中，使其失活，并与pWKS 30 acrA互补。测定了突变株对6种抗生素以及各种染料和洗涤剂的抗菌敏感性。此外，定量外排活性。结果：acrA被破坏后，RT-PCR和western blotting证实acrB/AcrB在acrA被破坏后仍能表达。acrA突变体对抗生素、染料和洗涤剂过敏。在一些情况下，观察到比acrB或tolC突变体更低的MIC。流出的荧光染料Hoechst H33342是小于野生型以下中断acrA。acrA也需要粘附，和入侵，组织培养cells.Conclusions：acrA失活赋予不同的表型的acrB：：aph和tolC：：aph。这些数据表明，AcrA的作用不同的其他蛋白质的合作伙伴在流出的基板和毒力。
Objectives: AcrA can function as the periplasmic adaptor protein (PAP) in several RND tripartite efflux pumps, of which AcrAB-TolC is considered the most important. This system confers innate multiple antibiotic resistance. Disruption of acrB or tolC impairs the ability of Salmonella Typhimurium to colonize and persist in the host. The aim of this study was to investigate the role of AcrA alone in multidrug resistance and pathogenicity.Methods: The acrA gene was inactivated in Salmonella Typhimurium SL1344 by insertion of the aph gene and this mutant complemented with pWKS30acrA. The antimicrobial susceptibility of the mutant to six antibiotics as well as various dyes and detergents was determined. In addition, efflux activity was quantified. The ability of the mutant to adhere to, and invade, tissue culture cells in vitro was measured.Results: Following disruption of acrA, RT-PCR and western blotting confirmed that acrB/AcrB was still expressed when acrA was disrupted. The acrA mutant was hypersusceptible to antibiotics, dyes and detergents. In some cases, lower MICs were seen than for the acrB or tolC mutants. Efflux of the fluorescent dye Hoechst H33342 was less than in wild-type following disruption of acrA. acrA was also required for adherence to, and invasion of, tissue culture cells.Conclusions: Inactivation of acrA conferred a phenotype distinct to that of acrB::aph and tolC::aph. These data indicate a role for AcrA distinct to that of other protein partners in both efflux of substrates and virulence.