文献类型：期刊文献

英文题名：MdrL, a major facilitator superfamily efflux pump ofListeria monocytogenesinvolved in tolerance to benzalkonium chloride

作者：Jiang, Xiaobing[1,3];Yu, Tao[2,3];Xu, Yameng[1];Wang, Hailei[1];Korkeala, Hannu[3];Shi, Lei[4]

第一作者：Jiang, Xiaobing

通讯作者：Yu, T[1];Yu, T[2]

机构：[1]Henan Normal Univ, Coll Life Sci, Xinxiang, Peoples R China;[2]Xinxiang Univ, Coll Life Sci & Technol, Xinxiang, Peoples R China;[3]Univ Helsinki, Dept Food Hyg & Environm Hlth, Fac Vet Med, Helsinki, Finland;[4]Jinan Univ, Inst Food Safety & Nutr, Guangzhou, Guangdong, Peoples R China

第一机构：Henan Normal Univ, Coll Life Sci, Xinxiang, Peoples R China

通讯机构：[1]corresponding author), Xinxiang Univ, Coll Life Sci & Technol, Xinxiang, Peoples R China;[2]corresponding author), Univ Helsinki, Dept Food Hyg & Environm Hlth, Fac Vet Med, Helsinki, Finland.|[1107115]新乡学院生命科学技术学院;[11071]新乡学院;

年份：2019

卷号：103

期号：3

起止页码：1339-1350

外文期刊名：APPLIED MICROBIOLOGY AND BIOTECHNOLOGY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000459105000023)】；

基金：This work was supported by the National Natural Science Foundation of China (31601568) and the Key Project of Natural Science of the Education Department of Henan Province, China (16A180011).

语种：英文

外文关键词：Listeria monocytogenes; Benzalkonium chloride; Efflux pump; MdrL; LadR

摘要：Efflux pumps are recognized as an important mechanism for decreased susceptibility of benzalkonium chloride (BC) in Listeria monocytogenes. Previous studies showed that the efflux pump MdrL was overexpressed in L. monocytogenes exposed to BC. In the present work, we aimed to clarify the role of MdrL in tolerance to BC and environmental stresses including acid, alkali, osmotic, ethanol, and oxidative stresses, as well as resistance to other antimicrobial agents in L. monocytogenes EGD-e. In addition, regulation of the expression of mdrL by LadR was investigated. Gene deletion mutants were constructed by homologous recombination strategy. For the wild-type and mutant strains, minimum inhibitory concentrations (MICs) of antimicrobial agents were determined by the agar dilution, and the growth and survival analysis were also performed. LadR was expressed and the interaction between LadR and the mdrL promoter was investigated by electrophoretic mobility shift assay (EMSA). Compared to the wild-type strain, the growth of mdrL deletion mutant strain was impaired in the presence of sublethal concentration of BC. Moreover, the mutant showed a lower level of survival than that of the wild-type strain in the presence of lethal concentration of BC. However, the deletion of mdrL had no impact on cefotaxime resistance and ethidium bromide efflux. BC could induce the expression of mdrL in L. monocytogenes and the mdrL expression was regulated by LadR instead of SigmaB. LadR was able to specifically bind to the mdrL promoter. The results showed that efflux pump MdrL was associated with BC tolerance in L. monocytogenes EGD-e. Moreover, our results also provided strong evidence that LadR negatively regulated the expression of mdrL. Since BC is commonly used in the food industry, efflux pump MdrL is beneficial for L. monocytogenes to survive this stress in food processing environments.