Deficiency of BrpB causes major defects in cell division, stress responses and biofilm formation by Streptococcus mutans
Deficiency of BrpB causes major defects in cell division, stress responses and biofilm formation by Streptococcus mutans
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DOI：
10.1099/mic.0.072884-0
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发表时间：
2014-01-01
期刊：
影响因子：
2.8
通讯作者：
Wen, Zezhang T.
中科院分区：
文献类型：
--
作者：
Bitoun, Jacob P.;Liao, Sumei;Wen, Zezhang T.
变形链球菌（Streptococcus mutans）是龋齿的主要病原体，其具有由基因座SMU.409编码的YjeE样蛋白，在此称为brpB。在这项研究中，一个BrpB缺陷型突变体，JB 409，和一个双缺陷型的BrpB和BrpA（一个paranatomy的LytR-CpsA-Psr家族的细胞壁相关蛋白），JB 819，并使用功能测定和显微镜分析进行了表征。与野生型UA 159相比，JB 409和JB 819在脑心浸液培养基中生长期间均显示延长的滞后期和显著减慢的生长速率。相对于UA 159，JB 409和JB 819在pH 2.8下对酸杀灭的敏感性分别超过60倍和10倍，对过氧化氢的敏感性分别超过1和2个对数。缺陷突变体与相应基因的野生型拷贝的互补部分地将酸和氧化应激反应恢复到与野生型相似的水平。与UA 159相比，113409和JB 819的生物膜形成显著减少（P
Streptococcus mutans, the primary aetiological agent of dental caries, possesses an YjeE-like protein that is encoded by locus SMU.409, herein designated brpB. In this study, a BrpB-deficient mutant, JB409, and a double mutant deficient of BrpB and BrpA (a paralogue of the LytR-CpsA-Psr family of cell wall-associated proteins), JB819, were constructed and characterized using function assays and microscopy analysis. Both JB409 and JB819 displayed extended lag phases and drastically slowed growth rates during growth in brain heart infusion medium as compared to the wild-type, UA159. Relative to UA159, JB409 and JB819 were more than 60- and 10-fold more susceptible to acid killing at pH 2.8, and more than 1 and 2 logs more susceptible to hydrogen peroxide, respectively. Complementation of the deficient mutants with a wild-type copy of the respective gene(s) partly restored the acid and oxidative stress responses to a level similar to the wild-type. As compared to UA159, biofilm formation by 113409 and JB819 was drastically reduced (P