Functional analysis of luxS in Streptococcus suis reveals a key role in biofilm formation and virulence
Functional analysis of luxS in Streptococcus suis reveals a key role in biofilm formation and virulence
复制标题
猪链球菌中 luxS 的功能分析揭示了其在生物膜形成和毒力中的关键作用。
DOI：
10.1016/j.vetmic.2011.04.029
复制
发表时间：
2011-08-26
影响因子：
3.3
通讯作者：
Lu, Chengping
中科院分区：
文献类型：
--
作者：
Wang, Yang;Zhang, Wei;Lu, Chengping
猪链球菌（Streptococcus suis，SS）是一种重要的猪源性致病菌，可引起猪和人类多种疾病。据报道，LuxS在调节大量细菌的各种行为和物种间群体感应方面发挥着关键作用。本研究利用同源重组技术构建了SS的luxS缺失突变体，并对其生物膜形成、溶血活性、细胞粘附、毒力及毒力因子表达进行了研究。与亲本菌株相比，luxS突变株的生物膜形成和溶血活性显著降低。添加合成的自诱导物2可以补充突变菌株中生物膜产生的缺陷。此外，与亲本菌株相比，其对HEp-2细胞系的粘附显著降低了51%。实时荧光定量PCR检测结果表明，突变株中已知毒力基因gdh、cps、mrp、gapdh、sly、fbps和ef的表达量分别降低了0.66、0.61、0.45、0.48、0.29、0.57和0.38。在斑马鱼感染模型中，突变株的50%致死剂量增加至10倍。研究结果表明，luxS基因缺失导致SS中细菌生物膜形成、细胞粘附、溶血活性和许多毒力基因的转录水平显着下降，这些因素可能与斑马鱼毒力的减弱有关。这些结果表明，luxS可能参与中断细菌通讯和生物膜形成，有助于细菌的毒力。(C)2011爱思唯尔有限公司版权所有。
Streptococcus suis (SS) is an important pathogen of pigs, responsible for diverse diseases in swine and human. LuxS has been reported to play critical roles in both regulating various behaviors and interspecies quorum sensing in a large spectrum of bacteria. In this study, the luxS deletion mutant of SS was constructed using homologous recombination and its biofilm formation, hemolytic activity, cell adherence, virulence and expression of virulence factors were evaluated. Compared to the parental strain, the biofilm formation and hemolytic activity were significantly decreased in the luxS mutant. The addition of synthetic autoinducer 2 could complement the deficiencies of biofilm production in the mutant strain. Furthermore, its adherence to the HEp-2 cell line was dramatically decreased by 51% compared to the parental strain. Expressions of the known virulence genes gdh, cps, mrp, gapdh, sly, fbps and ef in the mutant strain were decreased by 0.66, 0.61, 0.45, 0.48, 0.29, 0.57 and 0.38, respectively, as quantified by real-time PCR. In a zebrafish infection model, the 50% lethal dose of the mutant strain was increased up to 10-fold. The findings demonstrated that the luxS gene deletion resulted in a significant decrease of bacterial biofilm formation, cell adhesion, hemolytic activity and transcription levels of many virulence genes in SS, and these factors may be associated with the attenuation of virulence in zebrafish. These results suggest that luxS may be involved in the interruption of bacterial communication and biofilm formation that contribute to the virulence of the bacterium. (C) 2011 Elsevier B.V. All rights reserved.