State Key Laboratory of Agricultural Microbiology, College of Resources of Environment, Huazhong Agricultural Universitygrid.35155.37, Wuhan, China.
College of Oceanography, Hohai Universitygrid.257065.3, Nanjing, China.
mSystems. 2022 Apr 26;7(2):e0122621. doi: 10.1128/msystems.01226-21. Epub 2022 Mar 1.
Vibrio parahaemolyticus is a seafood-borne pathogen that poses a great threat to public health worldwide. It is found in either a planktonic cell or a biofilm form in the natural environment. The locus has been the only extensively studied polysaccharide biosynthesis gene cluster involved in biofilm formation for this bacterium. In this study, we found that an additional polysaccharide biosynthesis locus, , is also necessary for biofilm maturation. The locus is composed of two operons, and a loss of their expression leads to a defective biofilm phenotype. The transcription of the locus is under the control of a sigma 54-dependent response regulator, ScvE. In contrast, the quorum-sensing regulator AphA stimulates the expression of the locus and the operon found in the locus. Bioinformatic analyses demonstrated that loci are divergent and widely distributed among 28 genera, including 26 belonging to the and 2 within the . We also determined that all locus-positive species are water-dwelling. Some strains of , Aliivibrio salmonicida, Pseudomonas anguilliseptica, Vibrio breoganii, and Vibrio scophthalmi probably acquired loci through insertion sequences and/or integrase-mediated horizontal gene transfer. Gene duplication and fusion were also detected in some homologs. Together, our results suggest that the genome of V. parahaemolyticus harbors two distinct polysaccharide biosynthesis loci, which may play a role in fine-tuning biofilm development, and that loci likely evolved by horizontal gene transfer, gene loss, gene duplication, and fragment fusion. Polysaccharides are the major component of biofilms, which provide survival advantages for bacteria in aquatic environments. The seafood-borne pathogen V. parahaemolyticus possesses a functionally uncharacterized polysaccharide biosynthesis locus, . We demonstrated that the locus is important for biofilm maturation and that expression is positively regulated by ScvE. Strains from 148 aquatic bacterial species possess homolog loci. These bacterial species belong to 28 genera, most of which belong to the class. The evolution and diversification of loci are likely driven by horizontal gene transfer, gene loss, gene duplication, and fragment fusion. Our results provide new insights into the function and evolution of this widespread polysaccharide biosynthesis locus.
副溶血性弧菌是一种食源性病原体，对全球公共健康构成了巨大威胁。它存在于自然环境中的浮游细胞或生物膜形式中。该基因座是该细菌中唯一广泛研究的多糖生物合成基因簇，涉及生物膜形成。在这项研究中，我们发现另一个多糖生物合成基因座， ，对于生物膜成熟也是必需的。该基因座由两个操纵子和组成，它们的表达缺失导致生物膜表型缺陷。该基因座的转录受依赖 sigma 54 的响应调节子 ScvE 控制。相比之下，群体感应调节因子 AphA 刺激该基因座和基因座中的 操纵子的表达。生物信息学分析表明， 基因座是不同的，广泛分布于 28 个属中，包括 26 个属属于和 2 个属属于 。我们还确定，所有 基因座阳性物种都是水生的。一些 ，鲑鱼弧菌，鳗弧菌，Breoganii 弧菌和狭盐弧菌的菌株可能通过插入序列和/或整合酶介导的水平基因转移获得 基因座。在一些 同源物中还检测到基因重复和融合。总之，我们的结果表明，副溶血性弧菌的基因组包含两个不同的多糖生物合成基因座，这可能在微调生物膜发育中起作用，并且 基因座可能通过水平基因转移、基因缺失、基因重复和片段融合进化而来。多糖是生物膜的主要成分，为水生环境中的细菌提供了生存优势。食源性病原体副溶血性弧菌具有功能未被表征的多糖生物合成基因座， 。我们证明该基因座对于生物膜成熟很重要，并且 表达受 ScvE 正向调节。来自 148 种水生细菌物种的菌株具有 同源基因座。这些细菌物种属于 28 个属，其中大多数属于 类。 基因座的进化和多样化可能是由水平基因转移、基因缺失、基因重复和片段融合驱动的。我们的研究结果为该广泛存在的多糖生物合成基因座的功能和进化提供了新的见解。
