Liu S, Liu Y, Zhang R, Lu X, Hu H, Hu J, Zhang K, Sun Y
Department of Stomatology, First Affiliated Hospital of Bengbu Medical College, Bengbu 233004, China.
Department of histology and Embryology, Bengbu Medical College, Bengbu 233030, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2021 Jun 20;41(6):876-882. doi: 10.12122/j.issn.1673-4254.2021.06.10.
To investigate the types of gene mutations and their distribution in clinical isolates of () and explore the association of gene mutation with the capacity of mutacin Ⅳ production by S. mutans.
We assessed the capacity of mutacin Ⅳ production in 80 clinical isolates of using an inhibition zone assay. The minimum spanning tree and phylogenetic tree of these isolates were constructed using core genome multilocus sequence typing and maximum likelihood method, respectively. GeneMarkS software was used to predict the coding genes of these isolates, and the predicted genes were blasted against the gene sequence of the reference genome UA159 to determine gene mutations and their distribution characteristics in the clinical isolates. The mutation types affecting mutacin Ⅳ production were identified by analyzing the differentially distributed mutations between mutacin Ⅳ-producing isolates and mutacin Ⅳ-free isolates and by comparing the inhibition zones between isolates with gene mutations and those without mutations.
Among the 80 clinical isolates of , 25 isolates were capable of mutacin Ⅳ production and 55 did not produce mutacin Ⅳ. The minimum spanning tree showed that the allelic differences were less among the mutacin Ⅳproducing isolates than among the mutacin Ⅳ-free isolates, and the origins of the mutacin Ⅳ-producing isolates were similar. We identified a total of 34 single base mutations in the 80 clinical isolates, and among them, C31T (=0.001), G533A ( < 0.001), C756T (=0.025), and C1036T (=0.003) showed significant differential distributions between the mutacin Ⅳ-producing and mutacin Ⅳ-free isolates. These differentially distributed mutations were positively correlated with the capacity of mutacin Ⅳ production of the bacteria.
gene mutations that affect the capacity of mutacin Ⅳ production are present in the clinical strains of .
研究变形链球菌临床分离株中基因突变的类型及其分布情况，并探讨基因突变与变形链球菌产变链菌素Ⅳ能力之间的关联。
我们采用抑菌圈试验评估了80株变形链球菌临床分离株产变链菌素Ⅳ的能力。分别使用核心基因组多位点序列分型和最大似然法构建了这些分离株的最小生成树和系统发育树。使用GeneMarkS软件预测这些分离株的编码基因，并将预测的基因与参考基因组UA159的基因序列进行比对，以确定临床分离株中基因突变的情况及其分布特征。通过分析产变链菌素Ⅳ的分离株和不产变链菌素Ⅳ的分离株之间差异分布的突变，并比较有基因突变的分离株和无基因突变的分离株之间的抑菌圈，来鉴定影响变链菌素Ⅳ产生的突变类型。
在80株变形链球菌临床分离株中，25株能够产变链菌素Ⅳ，55株不产变链菌素Ⅳ。最小生成树显示，产变链菌素Ⅳ的分离株之间的等位基因差异小于不产变链菌素Ⅳ的分离株，且产变链菌素Ⅳ的分离株来源相似。我们在80株临床分离株中总共鉴定出34个单碱基突变，其中，C31T（P = 0.001）、G533A（P < 0.001）、C756T（P = 0.025）和C1036T（P = 0.003）在产变链菌素Ⅳ的分离株和不产变链菌素Ⅳ的分离株之间显示出显著的差异分布。这些差异分布的突变与细菌产变链菌素Ⅳ的能力呈正相关。
变形链球菌临床菌株中存在影响产变链菌素Ⅳ能力的基因突变。
