title: Selenium-mediated protection in reversing the sensitivity of bacterium to the bactericidal antibiotics.
abstract: Inducing production of damaging reactive oxygen species (ROS) is an important criterion to distinguish the bactericidal antibiotics from bacteriostatic antibiotics. Selenoenzymes were generally recognized to be a powerful antioxidant capable of scavenging free radicals, protecting the cells from the harmful effects of ROS. Therefore, the present study was carried out to investigate the selenium (Se)-mediated protection in reversing antibiotic sensitivity and the role of selenoenzymes in alleviating the negative effects of oxidative stress. The cellular antioxidant activity of Se-enriched bacteria was analyzed, as well as intracellular ROS production and elimination when Se-enriched bacteria in the presence of various antibiotics. Compared to complete inhibition of the parental strain by bactericidal antibiotics, it only exhibited slight and reversible inhibition of Se-enriched Escherichia coli ATCC25922 and Staphylococcus aureus ATCC25923 at the same conditions, which indicated that intracellular selenium provided substantial protection against antibiotics. ROS generation caused by bactericidal antibiotics was confirmed by fluorescence spectrophotometry using 2', 7'-dichloro- uorescein diacetate (DCFH-DA) as substrate. The time course experiments of pretreatment with selenium showed significant decrease of ROS level at 2h. In summary, the present study provides experimental evidence supporting selenoenzymes has good scavenging effect to ROS and can protect bacteria from oxidative stress injury induced by bactericidal antibiotics.
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China; China State Institute of Pharmaceutical Industry, Shanghai Institute of Pharmaceutical Industry, Shanghai 201203, China.
authors.forename: Zhonglei
authors.initials: Z
authors.lastname: Li
authors.affiliation: China State Institute of Pharmaceutical Industry, Shanghai Institute of Pharmaceutical Industry, Shanghai 201203, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.affiliation: China State Institute of Pharmaceutical Industry, Shanghai Institute of Pharmaceutical Industry, Shanghai 201203, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Shao
authors.affiliation: China State Institute of Pharmaceutical Industry, Shanghai Institute of Pharmaceutical Industry, Shanghai 201203, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Dong
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: yedequan@sjtu.edu.cn.
authors.forename: Richard D
authors.initials: RD
authors.lastname: Ye
authors.affiliation: School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, China; China State Institute of Pharmaceutical Industry, Shanghai Institute of Pharmaceutical Industry, Shanghai 201203, China. Electronic address: hccb001@163.com.
authors.forename: Daijie
authors.initials: D
authors.lastname: Chen
mesh_terms: D000900:Anti-Bacterial Agents / Q000032:analysis / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008826:Microbial Sensitivity Tests; D018384:Oxidative Stress / Q000187:drug effects; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism; D012643:Selenium / Q000032:analysis / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D017382:Reactive Oxygen Species; D012643:Selenium
keywords: Antibacterial; Reactive oxygen species (ROS); Selenium; Total antioxidant capacity (T-AOC)