State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry; Southern Marine Science and Engineering Guangdong Laboratory (Zhanjiang), Zhanjiang, 524000, China.
State Key Laboratory of Mariculture Breeding, Fisheries College, Jimei University, Xiamen, Fujian, 361021, China, Engineering Research Center of the Modern Technology for Eel Industry.
Fish Shellfish Immunol. 2024 Oct;153:109863. doi: 10.1016/j.fsi.2024.109863. Epub 2024 Aug 27.
Aeromonas salmonicida is a common pathogenic bacterial species found in both freshwater and marine fish, leading to significant economic losses in the aquaculture industry. YidC is an accessory to SecYEG and is essential for the SecYEG transporter to insert into the bacterial membrane. However, the roles of the yidC gene on the host immune response remain unclear. Here, we compared the pathogenicity of yidC gene-deleted (ΔyidC) strain and wild-type (SRW-OG1) strain of mesophilic A. salmonicida to Orange-spotted grouper (Epinephelus coioides), and explored the impacts of yidC gene on the immune response of E. coioides to mesophilic A. salmonicida infection by using Red/ET recombineering. In this study, the E. coioides in the Secondary infected group had a 53.9 % higher survival rate than those in the Primary infected group. In addition, the adhesion ability of ΔyidC strain decreased by about 83.36 % compared with that of the wild-type (SRW-OG1) strain. Further comparison of the biological phenotype of SRW-OG1 and ΔyidC revealed that this yidC gene could regulate the expression of genes related to iron metabolism and have no effect on bacterial growth under the limited iron concentration. In the low concentration of Fe and Fe environment, SRW-OG1 can obtain iron ions by regulating yidC. Based on the above results, yidC gene contributed to the pathogenicity of mesophilic A. salmonicida to E. coioides, deletion of yidC gene promoted the inflammation and immune response of E. coioides to mesophilic A. salmonicida infection.
迟钝爱德华氏菌是一种常见的淡水和海水鱼类的致病性细菌，给水产养殖业造成了重大的经济损失。YidC 是 SecYEG 的辅助因子，是 SecYEG 转运蛋白插入细菌膜所必需的。然而，yidC 基因在宿主免疫反应中的作用尚不清楚。在这里，我们比较了嗜温迟钝爱德华氏菌 yidC 基因缺失（ΔyidC）株和野生型（SRW-OG1）株对橙点石斑鱼（Epinephelus coioides）的致病性，并通过 Red/ET 重组酶系统探索了 yidC 基因对嗜温迟钝爱德华氏菌感染的石斑鱼免疫反应的影响。在本研究中，次级感染组的石斑鱼存活率比初级感染组高 53.9%。此外，与野生型（SRW-OG1）株相比，ΔyidC 株的黏附能力下降了约 83.36%。进一步比较 SRW-OG1 和 ΔyidC 的生物学表型表明，该 yidC 基因可以调节与铁代谢相关的基因表达，并且在低铁浓度下对细菌生长没有影响。在低浓度的 Fe 和 Fe 环境中，SRW-OG1 可以通过调节 yidC 获得铁离子。基于上述结果，yidC 基因有助于嗜温迟钝爱德华氏菌对石斑鱼的致病性，yidC 基因的缺失促进了石斑鱼对嗜温迟钝爱德华氏菌感染的炎症和免疫反应。
