College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, China.
College of Fisheries, Guangdong Ocean University, Zhanjiang, Guangdong, China; Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, Guangdong, China; Guangdong Provincial Laboratory of Southern Marine Science and Engineering, Zhanjiang, Guangdong, China.
Fish Shellfish Immunol. 2022 Nov;130:194-205. doi: 10.1016/j.fsi.2022.09.008. Epub 2022 Sep 7.
Vibrio is an important conditional pathogen in shrimp aquaculture. This research reported a dominant bacteria strain E1 isolated from a shrimp tank with the method of biofloc culture, which was further identified as Vibrio owensii. To understand the interaction between V. owensii and the host shrimp, we studied the pathogenicity of the V. owensii and the molecular mechanisms of the Fenneropenaeus merguiensis immunity during the Vibrio invasion. Drug susceptibility tests showed that V. owensii was resistant to antibiotics streptomycin oxacillin, tetracycline, minocycline, and aztreonam, but highly sensitive to cefazolin, cefotaxime, and ciprofloxacin, and moderately sensitive to cefotaxime, ampicillin, and piperacillin. Lethal concentration 50 (LC) test was performed to evaluate the toxicity of V. owensii to F. merguiensis. The LC of V. owensii infected F. merguiensis after 24, 48, 72, 96, 120, 144 and 168 h were 1.21 × 10, 1.68 × 10, 6.36 × 10, 2.15 × 10, 7.58 × 10, 5.55 × 10 and 4.33 × 10 CFU/mL. In order to explore the molecular response mechanism of F. merguiensis infected with V. owensii, the hepatopancreas of F. merguiensis were sequenced at 24 hpi and 48 hpi, and a total 40,181 of unigenes were obtained. Through comparative transcriptomic analysis, 86 differentially expressed genes (DEGs) (including 38 up-regulated DEGs, and 48 down-regulated DEGs) and 305 DEGs (including 150 up-regulated DEGs, and 155 down-regulated DEGs) were identified at 24 hpi and 48 hpi, respectively. Annotation and classification analysis of these 391 DEGs showed that most of the DEGs were annotated to metableolic and immune pathways, which indicated that F. merguiensis responded to the invasion through the regulation of material metableolism and immune system genes during V. owensii infection. In the KEGG enrichment analysis, some pathways related to immune response were significantly influenced by V. owensii infection, including phagosome, MAPK signalling pathway and PI3K-Akt signalling pathway. In addition, some pathways related to the warburg effect were also significantly enriched after V. owensii infection, including pyruvate metableolism, glycolysis/gluconeogenesis, and citrate cycle (TAC cycle). Further analysis showed that C-type lectins and ficolin were also play important roles in the immune response of F. merguiensis against V. owensii infection. The current research preliminarily revealed the immune response of F. merguiensis to V. owensii infection at the molecular level, which provided valuable information to further understand the disease control and the interaction between shrimp and Vibrio.
弧菌是虾类养殖中的重要条件致病菌。本研究采用生物絮凝培养的方法，从虾池中分离出一株优势细菌菌株 E1，经鉴定为欧文氏弧菌。为了了解弧菌与宿主虾之间的相互作用，我们研究了欧文氏弧菌的致病性以及在弧菌入侵期间中国明对虾的免疫分子机制。药敏试验表明，欧文氏弧菌对链霉素、苯唑西林、四环素、米诺环素和氨曲南耐药，但对头孢唑林、头孢噻肟和环丙沙星高度敏感，对头孢噻肟、氨苄西林和哌拉西林中度敏感。采用半数致死浓度（LC）试验评价弧菌对中国明对虾的毒性。感染中国明对虾 24、48、72、96、120、144 和 168 h 后，弧菌的 LC 分别为 1.21×10、1.68×10、6.36×10、2.15×10、7.58×10、5.55×10 和 4.33×10 CFU/mL。为了探讨中国明对虾感染欧文氏弧菌的分子应答机制，在感染后 24 和 48 hpi 时对中国明对虾的肝胰腺进行测序，共获得 40181 个基因。通过比较转录组分析，在 24 hpi 和 48 hpi 时分别鉴定到 86 个差异表达基因（DEGs）（包括 38 个上调 DEGs 和 48 个下调 DEGs）和 305 个 DEGs（包括 150 个上调 DEGs 和 155 个下调 DEGs）。对这些 391 个 DEGs 的注释和分类分析表明，大多数 DEGs 被注释到代谢和免疫途径，这表明中国明对虾在欧文氏弧菌感染期间通过调节物质代谢和免疫系统基因来对入侵作出反应。在 KEGG 富集分析中，一些与免疫反应相关的途径受到欧文氏弧菌感染的显著影响，包括吞噬体、MAPK 信号通路和 PI3K-Akt 信号通路。此外，一些与沃伯格效应相关的途径在欧文氏弧菌感染后也显著富集，包括丙酮酸代谢、糖酵解/糖异生和柠檬酸循环（TAC 循环）。进一步分析表明，C 型凝集素和 ficolin 在中国明对虾对欧文氏弧菌感染的免疫反应中也发挥着重要作用。本研究初步从分子水平揭示了中国明对虾对欧文氏弧菌感染的免疫反应，为进一步了解虾类疾病控制和虾与弧菌的相互作用提供了有价值的信息。
