摘要
<span "="" style="line-height:1.5;"><span style="font-family:Verdana;">Chlorhexidine is a widely used antiseptic agent;however, its bactericidal effect against bacterial endospores is limited. The genus </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> is spore-</span></span><span "="" style="line-height:1.5;"><span style="font-family:Verdana;">forming gram-positive bacteria that are ubiquitously found in the environment and cause opportunistic infection and food poisoning. The susceptibility of bacterial endospores to chlorhexidine was previously evaluated in </span><i><span style="font-family:Verdana;">Bacillus</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;">, but the primary target for disinfection with antiseptic agents, including chlorhexidine, should be harmful strains. We aimed to evaluate the susceptibility of harmful </span><i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group including </span><i><span style="font-family:Verdana;">Bacillus</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;">, and to compare that with harmless </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> species, containing </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;">. We evaluated the susceptibility of the 15 strains of the </span><i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group to chlorhexidine in comparison with the 5 other strains, named the </span><i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> group in this study. Our results indicated that chlorhexidine exerted a bacteriostatic effect against </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> species at practical concentrations, especially during long-term exposure. The strains of </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group in this study displayed relatively lower susceptibility to the antiseptic than the </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> group according to the minimum inhibitory and bactericidal concentrations. We concluded that there are intrinsic differences in the susceptibility to chlorhexidine between the groups, but the molecular mechanisms are unknown. The minimum inhibitory or bactericidal concentrations of disinfectants other than chlorhexidine may also need to be clarified in the </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> groups.
<span "="" style="line-height:1.5;"><span style="font-family:Verdana;">Chlorhexidine is a widely used antiseptic agent;however, its bactericidal effect against bacterial endospores is limited. The genus </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> is spore-</span></span><span "="" style="line-height:1.5;"><span style="font-family:Verdana;">forming gram-positive bacteria that are ubiquitously found in the environment and cause opportunistic infection and food poisoning. The susceptibility of bacterial endospores to chlorhexidine was previously evaluated in </span><i><span style="font-family:Verdana;">Bacillus</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;">, but the primary target for disinfection with antiseptic agents, including chlorhexidine, should be harmful strains. We aimed to evaluate the susceptibility of harmful </span><i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group including </span><i><span style="font-family:Verdana;">Bacillus</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;">, and to compare that with harmless </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> species, containing </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;">. We evaluated the susceptibility of the 15 strains of the </span><i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group to chlorhexidine in comparison with the 5 other strains, named the </span><i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> group in this study. Our results indicated that chlorhexidine exerted a bacteriostatic effect against </span><i><span style="font-family:Verdana;">Bacillus</span></i><span style="font-family:Verdana;"> species at practical concentrations, especially during long-term exposure. The strains of </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> group in this study displayed relatively lower susceptibility to the antiseptic than the </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> group according to the minimum inhibitory and bactericidal concentrations. We concluded that there are intrinsic differences in the susceptibility to chlorhexidine between the groups, but the molecular mechanisms are unknown. The minimum inhibitory or bactericidal concentrations of disinfectants other than chlorhexidine may also need to be clarified in the </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">cereus</span></i><span style="font-family:Verdana;"> and </span><i><span style="font-family:Verdana;">B.</span></i> <i><span style="font-family:Verdana;">subtilis</span></i><span style="font-family:Verdana;"> groups.
