Functional Analysis of Pneumococcal Drug Efflux Pumps Associates the MATE DinF Transporter with Quinolone Susceptibility
Functional Analysis of Pneumococcal Drug Efflux Pumps Associates the MATE DinF Transporter with Quinolone Susceptibility
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DOI：
10.1128/aac.01298-12
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发表时间：
2013-01-01
影响因子：
4.9
通讯作者：
Oggioni, Marco Rinaldo
中科院分区：
文献类型：
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作者：
Tocci, Nadia;Iannelli, Francesco;Oggioni, Marco Rinaldo
肺炎球菌染色体编码约 140 个转运蛋白，其中许多转运蛋白预计参与流出。为了严格评估肺炎球菌的流出，构建了一系列转运蛋白突变体，并通过纸片扩散、微量稀释药物敏感性测试（MIC测试）、亚MIC浓度下的培养物生长和表型微阵列分析来测定它们的表型。在肺炎链球菌菌株 DP1004 中获得了 7 个 ATP 结合盒 (ABC) 转运蛋白、3 个多重抗菌挤出 (MATE) 家族外排泵和 1 个主要促进子超家族 (MFS) 转运蛋白突变的突变体。将这 11 个突变体对 250 多种不同物质的敏感性与亲本菌株进行了比较。在测试的转运蛋白中，只有 ABC 转运蛋白 PatAB (SP2073-5) 表现出明显的多药耐药性 (MDR) 特征，因为该突变体对溴化乙锭、吖啶黄和小檗碱的敏感性显着增加。在分析的其他转运蛋白中，缺乏 MATE 外排泵 SP2065 的突变体表现出对新生霉素的敏感性降低，而具有 MATE 家族 DinF 转运系统 (SP1939) 突变的突变体表现出对莫西沙星、环丙沙星和左氧氟沙星的敏感性增加。发现喹诺酮类药物 MIC 的这种变化与喹诺酮类药物对 cinA-recA-dinF 操纵子的能力介导作用无关。此外，与亲本菌株相反，dinF突变体在暴露于莫西沙星时允许选择喹诺酮抗性突变体。这些数据证实了 PatAB ABC 转运蛋白的清晰 MDR 谱，并表明 MATE DinF 的表型与喹诺酮敏感性相关，特别是莫西沙星。
The pneumococcal chromosome encodes about 140 transporters, many of which are predicted to be involved in efflux. In order to critically evaluate pneumococcal efflux, a series of transporter mutants were constructed, and their phenotypes were assayed by disk diffusion, microdilution drug susceptibility testing (MIC testing), growth of cultures at sub-MIC concentrations, and phenotype microarray analysis. Mutants with mutations in seven ATP binding cassette (ABC) transporters, three multiantimicrobial extrusion (MATE) family efflux pumps, and one major facilitator superfamily (MFS) transporter were obtained in Streptococcus pneumoniae strain DP1004. The susceptibility of these 11 mutants to over 250 different substances was compared to that of the parent strain. Of the tested transporters, only the ABC transporter PatAB (SP2073-5) presented a clear multidrug resistance (MDR) profile, as the mutant showed significantly increased susceptibility to ethidium bromide, acriflavine, and berberine. Among the other transporters analyzed, the mutants devoid of the MATE efflux pump SP2065 exhibited reduced susceptibility to novobiocin, and those with mutations of the MATE family DinF transport system (SP1939) exhibited increased susceptibility to moxifloxacin, ciprofloxacin, and levofloxacin. This change in quinolone MIC was found to be independent from the competence-mediated effect of quinolones on the cinA-recA-dinF operon. Furthermore, the dinF mutant, in contrast to the parental strain, allowed selection for quinolone-resistant mutants when exposed to moxifloxacin. These data confirm the clear MDR profile of the PatAB ABC transporter and suggest for the MATE DinF a phenotype associated with quinolone susceptibility, particularly for moxifloxacin.