title: Efflux pump-mediated benzalkonium chloride resistance in Listeria monocytogenes isolated from retail food.
abstract: In this study, efflux pump-mediated benzalkonium chloride (BC) resistance, including plasmid-encoded (Qac protein family and BcrABC) and chromosome-borne efflux pumps, was investigated in Listeria monocytogenes from retail food in China. Among the 59 L. monocytogenes strains, 13 (22.0%) strains were resistant to BC. The PCR results showed that bcrABC was harbored by 2 of 13 BC resistant strains. However, none of the qac genes were detected among the 59 strains. The bcrABC was absent in both of the plasmid cured strains, indicating that this BC resistance determinant was plasmid-encoded in the two bcrABC-positive strains. In the presence of reserpine, most of the bcrABC-negative strains had decreases in the MICs of BC, suggesting the existence of other efflux pumps and their role in BC resistance. After exposed to reserpine, the reduction in BC MICs was observed in the two cured strains, indicating that efflux pumps located on chromosome was also involved in BC resistance. Our findings suggest that food products may act as reservoirs for BC resistant isolates of L. monocytogenes and plasmid- and chromosome-encoded efflux pumps could mediate the BC resistance of L. monocytogenes, which is especially relevant to the adaption of this organism in food-related environments with frequent BC use.
authors.affiliation: College of Life Sciences, Henan Normal University, Xinxiang 453007, China.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Jiang
authors.affiliation: College of Life Science and Technology, Xinxiang University, Xinxiang 453000, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
authors.affiliation: College of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang 453000, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liang
authors.affiliation: College of Life Sciences, Henan Normal University, Xinxiang 453007, China.
authors.forename: Shengdong
authors.initials: S
authors.lastname: Ji
authors.affiliation: College of Chemistry and Chemical Engineering, Xinxiang University, Xinxiang 453000, China.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Guo
authors.affiliation: College of Life Sciences, Henan Normal University, Xinxiang 453007, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Ma
authors.affiliation: Central Laboratory of Navy General Hospital, Beijing 100048, China. Electronic address: hzzhoulj@126.com.
authors.forename: Lijun
authors.initials: L
authors.lastname: Zhou
mesh_terms: D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002681:China; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005516:Food Microbiology; D008089:Listeria monocytogenes / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D026901:Membrane Transport Proteins / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D010957:Plasmids / Q000235:genetics*; D012110:Reserpine / Q000494:pharmacology
chemical_list: D001548:Benzalkonium Compounds; D026901:Membrane Transport Proteins; D012110:Reserpine
keywords: Benzalkonium chloride; Efflux pump; Listeria monocytogenes; Resistance