Department of Microbiology, Key Laboratory of Medical Microbiology and Parasitology, Guizhou Medical University, Guiyang, China.
Institute of Pathogen Biology, School of Basic Medical Sciences, Shandong University, Jinan, China.
Helicobacter. 2020 Aug;25(4):e12715. doi: 10.1111/hel.12715. Epub 2020 Jun 16.
The multidrug resistance of Helicobacter pylori is becoming an increasingly serious issue. It is therefore necessary to study the mechanism of multidrug resistance of H pylori. We have previously identified that the HP0939, HP0497, and HP0471 transporters affect the efflux of drugs from H pylori. As efflux pumps participate in bacterial multidrug resistance and biofilm formation, we hypothesized that these transporters could be involved in the multidrug resistance and biofilm formation of H pylori.
We therefore constructed three knockout strains, Δhp0939, Δhp0497, and Δhp0471, and three high-expression strains, Hp0939 , Hp0497 , and Hp0471 , using the wild-type (WT) 26 695 strain of H pylori as the template. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of wild strains, knockout strains, and high-expression strains to amoxicillin, metronidazole, and other antibiotics were measured. The efflux capacity of high-expression strains and wild strains was compared by Hoechst 33 342 accumulation assay.
Determination of the MIC and MBC of the antibiotics revealed that the knockout strains were more sensitive to antibiotics, while the high-expression strains were less sensitive to antibiotics, compared to the WT. The ability of the high-expression strains to efflux drugs was significantly higher than that of the WT. We also induced H pylori to form biofilms, and observed that the knockout strains could barely form biofilms and were more sensitive to several antibiotics, compared to the WT. The mRNA expression of hp0939, hp0497, and hp0471 in the clinically sensitive and multidrug-resistant strains was determined, and it was found that these genes were highly expressed in the multidrug-resistant strains that were isolated from the clinics.
In this study, we found three transporters involved in intrinsic multidrug resistance of H pylori.
幽门螺杆菌的多药耐药性正变得日益严重。因此，有必要研究幽门螺杆菌多药耐药的机制。我们之前已经确定 HP0939、HP0497 和 HP0471 转运蛋白影响幽门螺杆菌药物的外排。由于外排泵参与细菌的多药耐药性和生物膜形成，我们假设这些转运蛋白可能参与幽门螺杆菌的多药耐药性和生物膜形成。
因此，我们使用野生型（WT）26695 幽门螺杆菌菌株作为模板，构建了三个敲除菌株Δhp0939、Δhp0497 和Δhp0471，以及三个高表达菌株 Hp0939、Hp0497 和 Hp0471。测量野生株、敲除株和高表达株对阿莫西林、甲硝唑等抗生素的最小抑菌浓度（MIC）和最小杀菌浓度（MBC）。通过 Hoechst 33342 积累测定比较高表达菌株和野生菌株的外排能力。
抗生素的 MIC 和 MBC 测定表明，与 WT 相比，敲除菌株对抗生素更敏感，而高表达菌株对抗生素的敏感性较低。高表达菌株的药物外排能力明显高于 WT。我们还诱导幽门螺杆菌形成生物膜，观察到与 WT 相比，敲除菌株几乎不能形成生物膜，对几种抗生素更敏感。测定临床敏感和多药耐药株中 hp0939、hp0497 和 hp0471 的 mRNA 表达，发现这些基因在临床分离的多药耐药株中高度表达。
在这项研究中，我们发现了三种参与幽门螺杆菌固有多药耐药性的转运蛋白。
