Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Fujian Agriculture and Forestry University, Fuzhou, 350002, China; Key Laboratory of Fujian-Taiwan Animal Pathogen Biology, College of Animal Sciences (College of Bee Science), Fujian Agriculture and Forestry University, Fuzhou, 350002, China.
Microb Pathog. 2021 Jan;150:104732. doi: 10.1016/j.micpath.2021.104732. Epub 2021 Jan 8.
Streptococcus suis (S. suis) is a gram-positive coccus that causes disease in humans and animals. The codon usage pattern of bacteria reveals a range of evolutionary changes that assist them to enhance tolerance to environments. To better understand the genetic features during the evolution of S. suis, we performed codon usage analysis. Nine pathogenic strains of different serotypes and different geographical distribution were analyzed to better understand the differences in their evolutionary process. Nucleotide compositions and relative synonymous codon usage (RSCU) analysis revealed that A/T-ending codons are dominant in S. suis. Neutrality analysis, correspondence analysis and ENC-plot results revealed that natural selection is the predominant element prompting codon usage. Cluster analysis based on RSCU was roughly consistent with the dendrogram rooted genomic BLAST analysis. Comparison of synonymous codon usage pattern between S. suis and susceptible hosts (H. sapiens and S. scrofa) revealed that the codon usage of S. suis is separated from the synonymous codon usage of susceptible hosts. The CAI values implied that S. suis includes a series of predicted highly expressed coding sequences contained in metabolism and transcriptional regulation, revealing the necessity of this pathogen to deal with various environmental conditions. The study of codon usage in S. suis may provide evidence involving the molecular evolution of bacteria and a better understanding of evolutionary relationships between S. suis and its corresponding hosts.
猪链球菌（S. suis）是一种革兰氏阳性球菌，可引起人类和动物的疾病。细菌的密码子使用模式揭示了一系列进化变化，帮助它们增强对环境的耐受性。为了更好地了解 S. suis 进化过程中的遗传特征，我们进行了密码子使用分析。分析了 9 株不同血清型和不同地理分布的致病性菌株，以更好地了解它们进化过程中的差异。核苷酸组成和相对同义密码子使用（RSCU）分析表明，A/T 结尾的密码子在 S. suis 中占优势。中性分析、对应分析和 ENC-plot 结果表明，自然选择是促使密码子使用的主要因素。基于 RSCU 的聚类分析与基于基因组 BLAST 分析的系统发育树大致一致。比较 S. suis 和易感宿主（H. sapiens 和 S. scrofa）之间的同义密码子使用模式表明，S. suis 的密码子使用与易感宿主的同义密码子使用分离。CAI 值表明 S. suis 包含一系列预测的高度表达的编码序列，包含在代谢和转录调节中，揭示了该病原体应对各种环境条件的必要性。对 S. suis 密码子使用的研究可为细菌的分子进化提供证据，并更好地了解 S. suis 与其相应宿主之间的进化关系。
