mapZ基因缺失对变异链球菌生长分裂及氯己定作用下生物膜形成能力的影响  

Effect of mapZ Gene Deletion on the Growth,Division and Biofilm Formation Ability Induced by Chlorhexidine of Streptococcus mutans

作　　者：乔丹 李永亮[2] 葛学军[1] QIAO Dan;LI Yong-liang;GE Xue-jun(Schl.of Stomatol.,Hosp.of Stomatol.,Shanxi Med.Uni,Taiyuan 030001;Schl.of Stomatol.&Hosp.of Stomatol.,Peking Uni.,Beijing 100081)

机构地区：[1]山西医科大学口腔医学院口腔医院,山西太原030001 [2]北京大学口腔医学院口腔医院,北京100081

出　　处：《微生物学杂志》2021年第5期63-68,共6页Journal of Microbiology

基　　金：中国科协青年人才托举工程项目(2019QNRC001)。

摘　　要：探究变异链球菌(Streptococcus mutans)分裂调控基因mapZ缺失对变异链球菌生长分裂、氯己定(Chlorhexidine,CHX)作用下生物膜形成能力的影响。针对前期课题组成功构建的变异链球菌的mapZ基因缺失突变株(ΔsmmapZ),通过扫描电镜(SEM)观察细菌细胞生长形态及分裂隔膜的位置变化;通过实时定量PCR技术检测mapZ基因缺失对分裂基因ftsZ相对表达含量的影响;通过检测氯己定最小抑菌浓度(MIC)并在不同药物浓度下培养生物膜来探究mapZ基因缺失对变异链球菌生物膜形成能力的影响。结果表明:与野生株相比,ΔsmmapZ突变株形态发生改变(变为短圆球状),分裂隔膜位置错乱;ΔsmmapZ突变株分裂基因ftsZ相对表达含量较UA159下降四分之一,具有统计学差异;ΔsmmapZ突变株MIC值为0.12500μg/mL,UA159野生株MIC值为0.25000μg/mL,且在药物浓度为0.12500μg/mL的氯己定作用下,野生株可以形成生物膜,而ΔsmmapZ则无生物膜形成。变异链球菌缺失mapZ基因影响细菌细胞的胞质分裂,降低分裂基因ftsZ的表达和氯己定下变异链球菌生物膜的形成能力。mapZ可作为潜在的抗菌药物研发靶点。The effect of deletion of division and regulation gene mapZ on the growth,division and biofilm formation ability of S.mutans was dived.Aiming at the mapZ gene deletion mutant(ΔsmmapZ)of S.mutans successfully constructed by previous research group,the changes of cell growth morphology and division septum were observed by scanning electron microscope(SEM);the effect of mapZ gene deletion on the expression of division gene ftsZ was detected by real-time quantitative PCR;the effect of mapZ gene deletion on biofilm formation ability induced by chlorhexidine of S.mutans to chlorhexidine(CHX)was investigated by detecting the minimal inhibitory concentration(MIC)and culturing biofilm under different concentrations of chlorhexidine.The results showed that as compared with wild S.mutans strain,the morphology ofΔsmmapZ mutant was changed(changed into short round ball)and the position of division septum was disordered;the relative expression content of ftsZ inΔsmmapZ mutant was decreased by a quarter compared with UA159 with statistical difference;and minimum inhibitory concentration ofΔsmmapZ and wild strain was at 0.12500μg/mL and 0.25000μg/mL respectively.Also when concentration of chlorhexidine was at 0.12500μg/mL,wild strain could form biofilm,whileΔsmmapZ none biofilm was formed.Therefore,the deletion of mapZ gene in S.mutans affected cell growth and division,decreased the expression of ftsZ and biofilm formation ability induced by chlorhexidine.mapZ can be used as a potential target point for antimicrobial R and D.

关 键 词：龋病 变异链球菌(Streptococcus mutans) mapZ 生物膜 氯己定 最小抑菌浓度(MIC) 

分 类 号：Q939.93[生物学—微生物学]