Fisheries College, Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture, Jimei University, Xiamen, China.
State Key Laboratory of Large Yellow Croaker Breeding, Ningde, China.
Front Cell Infect Microbiol. 2018 Jun 21;8:207. doi: 10.3389/fcimb.2018.00207. eCollection 2018.
is a facultative pathogen that is associated with diseases of multiple fish, mainly at 15-20°C. Although fish disease caused by has led to significant economic losses, the mechanisms of the temperature-dependent virulence are unclear. Here, we identify potential pathogenicity mechanisms and demonstrate the direct regulation of several virulence factors by temperature with transcriptomic and proteomic analyses, quantitative real-time PCR (qRT-PCR), RNAi, pyoverdine (PVD) quantification, the chrome azurol S (CAS) assay, growth curve measurements, a biofilm assay, and artificial infection. The principal component analysis, the heat map generation and hierarchical clustering, together with the functional annotations of the differentially expressed genes (DEGs) demonstrated that, under different growth temperatures, the animation and focus of are quite different, which may be the key to pathogenicity. Genes involved in PVD synthesis and in the type VI secretion system (T6SS) are specifically upregulated at the virulent temperature of 18°C. Silencing of the PVD-synthesis-related genes reduces the iron acquisition, growth, biofilm formation, distribution in host organs and virulence of the bacteria. Silencing of the T6SS genes also leads to the reduction of biofilm formation, distribution in host organs and virulence. These findings reveal that temperature regulates multiple virulence mechanisms in , especially through iron acquisition and T6SS secretion. Meanwhile, integration of transcriptomic and proteomic data provide us with a new perspective into the pathogenesis of , which would not have been easy to catch at either the protein or mRNA differential analyses alone, thus illustrating the power of multi-omics analyses in microbiology.
是一种兼性病原体，与多种鱼类疾病有关，主要在 15-20°C 时发生。虽然由 引起的鱼类疾病导致了重大的经济损失，但温度依赖性毒力的机制尚不清楚。在这里，我们确定了潜在的致病性机制，并通过转录组和蛋白质组分析、定量实时 PCR (qRT-PCR)、RNAi、绿脓菌素 (PVD) 定量、铬天青 S (CAS) 测定、生长曲线测量、生物膜测定和人工感染，证明了几个毒力因子受温度的直接调控。主成分分析、热图生成和层次聚类，以及差异表达基因 (DEGs) 的功能注释表明，在不同的生长温度下， 的活力和焦点大不相同，这可能是致病性的关键。参与 PVD 合成和 VI 型分泌系统 (T6SS) 的基因在 18°C 的毒力温度下特异性地上调。与 PVD 合成相关基因的沉默降低了铁的获取、生长、生物膜形成、在宿主器官中的分布和细菌的毒力。T6SS 基因的沉默也导致生物膜形成、在宿主器官中的分布和毒力降低。这些发现揭示了温度调节 在多个毒力机制，特别是通过铁的获取和 T6SS 分泌。同时，转录组和蛋白质组数据的整合为 提供了一种新的发病机制的视角，如果仅单独进行蛋白质或 mRNA 差异分析，将很难捕捉到这些机制，从而说明了多组学分析在微生物学中的强大作用。
