Chen Huijie, Zhao Yuanli, Chen Kuangxin, Wei Yulai, Luo Hongrui, Li Yongming, Liu Fei, Zhu Zuoyan, Hu Wei, Luo Daji
State Key Laboratory of Freshwater Ecology and Biotechnology, Hubei Hongshan Laboratory, Institute of Hydrobiology, Innovation Academy for Seed Design, Chinese Academy of Sciences, Wuhan, China.
College of Fisheries, Huazhong Agricultural University, Wuhan, China.
Front Immunol. 2022 Jun 30;13:872896. doi: 10.3389/fimmu.2022.872896. eCollection 2022.
Various bacterial diseases have caused great economic losses to the high-density and intensive aquaculture industry; however, the pathogenic mechanism underlying the large-scale challenged to caused by many bacteria remain unclear, making the prevention and treatment of these diseases difficult. In the present study, we isolated a bacterial strain from having a typical bacterial disease and named it Cc2021. Through subsequent morphological observations, a regression challenge, biochemical identification, and 16S rRNA gene sequence analysis, we determined Cc2021 to be . Subsequently, we comprehensively investigated the pathogenicity of in through a regression challenge and assessed the underlying the pathogenic mechanism. Mortality results revealed that is highly pathogenic and infects various tissues throughout the body, resulting in edema of the liver, spleen, and body and head kidneys. Histopathological analysis revealed obvious inflammation, bleeding, and necrosis in the intestine, spleen, and head kidney. The body's immune tissues actively produce complement C3, superoxide dismutase, and lysozyme after a challenge to resist bacterial invasion. With regard to the underlying pathogenesis of , comparative transcriptome analysis revealed 876 upregulated genes and 828 downregulated genes in the intestine of after the challenge. Analysis of differentially expressed unigenes revealed the involvement of major immune pathways, particularly the TNF signaling pathway, interleukin (IL)-17 signaling pathway, and Toll-like receptor signaling pathway. The present study provides new valuable information on the immune system and defense mechanisms of .
多种细菌性疾病给高密度集约化水产养殖业造成了巨大经济损失；然而，许多细菌引发大规模感染的致病机制仍不清楚，使得这些疾病的预防和治疗变得困难。在本研究中，我们从患有典型细菌性疾病的[具体来源未明确]中分离出一株细菌，并将其命名为Cc2021。通过随后的形态学观察、回归感染试验、生化鉴定和16S rRNA基因序列分析，我们确定Cc2021为[具体细菌种类未明确]。随后，我们通过回归感染试验全面研究了[该细菌]在[具体对象未明确]中的致病性，并评估了其致病机制。死亡率结果显示，[该细菌]具有高致病性，可感染全身各个组织，导致肝脏、脾脏以及体肾和头肾出现水肿。组织病理学分析显示，肠道、脾脏和头肾有明显的炎症、出血和坏死。机体的免疫组织在受到感染后会积极产生补体C3、超氧化物歧化酶和溶菌酶以抵抗细菌入侵。关于[该细菌]的潜在致病机制，比较转录组分析显示，感染后[具体对象未明确]肠道中有876个基因上调，828个基因下调。对差异表达单基因的分析揭示了主要免疫途径的参与，特别是肿瘤坏死因子信号通路、白细胞介素（IL）-17信号通路和Toll样受体信号通路。本研究为[具体对象未明确]的免疫系统和防御机制提供了新的有价值信息。
