Role of the efflux proteins in multidrug resistant Haemophilus influenzae

外排蛋白在多重耐药流感嗜血杆菌中的作用

基本信息

批准号：
12670269
负责人：
NISHINO Takeshi
金额：
$ 2.05万
依托单位：
Kyoto Pharmaceutical University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670269/
关键词：
Haemophilus influenzae Multidrug resistance Macrolide antibiotics Efflux pumps AcrAB Specific antibody MIC Outer membrane proteins AcrAB排出系マクロライド薬 BLNAR 俳出蛋白薬剤耐性抗体外膜コンポーネント排出蛋白 14員環 16員環

项目摘要

In this study, we tried to determine the role of this acrAB efflux system in the multidrug resistant Haemophilus influenzae. We obtained the acrAB-like gene disruption mutants to study the function of efflux proteins in the resistance of H. influenzae. The MICs of 14- and 15-membered macrolides against these mutants are 4 to 16-fold more susceptible than against parent strain. On the other hand, the MICs of 16-membered macrolides against these mutants are 32 to 64-fold more susceptible than against parent strain. An outer membrane protein associated with the AcrAB system in H. influenzae has not yet been firmly identified. Therefore, we checked the outer membrane protein by computer analysis of whole genome of H. influenzae, and finally found HI1462 protein. And then we got HI1462 disrupted mutant by inserting the kanamycin resistance cartridge into HI1462 gene. The MICs of macrolide and aminoglycoside antibiotics against HI1462 disrupted mutant of H. influenzae are completely similar to MICs of both HI0894- and HI0895-deletion mutants. We made the antibody against AcrAB and HI1462 proteins to examine the expression in clinical isolates of H. influenzae. Our study showed that AcrAB-HI1462 system is normally expressed in H. influenzae ATCC and also wild-type strains. The expression of this efflux system in the wild-type strains produced only a small increase in the MIC. This does not mean, however, that this multidrug efflux system can never make a major contribution to the resistance phenotypes of the organism.

在这项研究中，我们试图确定这种 acrAB 外排系统在多重耐药流感嗜血杆菌中的作用。我们获得了 acrAB 样基因破坏突变体，以研究外排蛋白在流感嗜血杆菌抵抗中的功能。 14 元和 15 元大环内酯类药物针对这些突变体的 MIC 比针对亲本菌株的敏感性高 4 至 16 倍。另一方面，16 元大环内酯类药物针对这些突变体的 MIC 比针对亲本菌株的敏感性高 32 至 64 倍。流感嗜血杆菌中与 AcrAB 系统相关的外膜蛋白尚未得到明确鉴定。因此，我们通过计算机分析流感嗜血菌全基因组检查外膜蛋白，最终找到了HI1462蛋白。然后将卡那霉素抗性试剂盒插入HI1462基因中，得到HI1462破坏突变体。大环内酯类和氨基糖苷类抗生素对流感嗜血杆菌 HI1462 破坏突变体的 MIC 与 HI0894 和 HI0895 缺失突变体的 MIC 完全相似。我们制备了针对 AcrAB 和 HI1462 蛋白的抗体，以检查流感嗜血杆菌临床分离株中的表达。我们的研究表明，AcrAB-HI1462 系统在流感嗜血杆菌 ATCC 和野生型菌株中正常表达。该外排系统在野生型菌株中的表达仅产生 MIC 的小幅增加。然而，这并不意味着这种多药外排系统永远不能对生物体的耐药表型做出重大贡献。