Chen Liting, Yan Xin, Luo Yongju, Lu Zhuanling, Wei Xinxian, Tang Zhanyang, Xia Liqun, Chen Fuyan, Li Ming, Guo Zhongbao, He Zhichang, Huang Ting
Guangxi Key Laboratory of Aquatic Genetic Breeding and Healthy Aquaculture, Guangxi Academy of Fishery Science, Nanning, Guangxi, China.
Key Laboratory of Comprehensive Development and Utilization of Aquatic Germplasm Resources of China (Guangxi) and ASEAN (Co-Construction by Ministry and Province), Ministry of Agriculture and Rural Affairs, Nanning, Guangxi, China.
Front Microbiol. 2025 Aug 25;16:1623741. doi: 10.3389/fmicb.2025.1623741. eCollection 2025.
A bacterial strain (No. 20230510) was isolated from the kidneys of diseased in Guangxi, China, since 2023. Artificial infection experiments demonstrated that this strain caused the observed disease in . The isolate underwent morphological, pathological, genomic (whole-genome sequencing, WGS), and antibiotic susceptibility analyses. Infection trials revealed 100% mortality in high-concentration groups, with an LD50 of 3.89 × 104 CFU/mL, indicating high virulence. WGS results showed a circular chromosome of 8,123,106 bp (GC content: 68.14%), containing 7,638 CDSs, 72 tRNAs, and 12 rRNAs. Phylogenomic analysis revealed that strain 20230510 (CP130742) clusters with three strains with 98% bootstrap supporting, confirming its identification as e. Further analysis identified 403 potential virulence genes linked to nutrient metabolism, regulatory factors, immune modulation, effector delivery systems, and exotoxins. Chromosomal comparisons also detected multiple antibiotic resistance genes. Susceptibility testing confirmed sensitivity to nine antibiotics, including enrofloxacin, doxycycline, florfenicol, and sulfamethoxazole. Histopathology revealed chronic granulomatous lesions, most severe in the kidneys, with similar but milder damage in the liver, spleen, gills, and intestines. These results confirm strain 20230510 as the pathogenic agent behind mortality, offering key insights for developing control strategies.
自2023年起，从中国广西患病鱼的肾脏中分离出一株细菌（编号：20230510）。人工感染实验表明，该菌株在[具体物种]中引发了所观察到的疾病。对该分离株进行了形态学、病理学、基因组学（全基因组测序，WGS）和抗生素敏感性分析。感染试验显示，高浓度组的死亡率为100%，半数致死剂量（LD50）为3.89×104 CFU/mL，表明其毒力很高。WGS结果显示，该菌株有一条8,123,106 bp的环状染色体（GC含量：68.14%），包含7,638个编码序列（CDS）、72个转运RNA（tRNA）和12个核糖体RNA（rRNA）。系统发育基因组分析表明，菌株20230510（CP130742）与另外三株菌株聚类，自展支持率为98%，证实其被鉴定为[具体菌名]。进一步分析确定了403个与营养代谢、调节因子、免疫调节、效应物递送系统和外毒素相关的潜在毒力基因。染色体比较还检测到多个抗生素抗性基因。药敏试验证实，该菌株对恩诺沙星、强力霉素、氟苯尼考和磺胺甲恶唑等九种抗生素敏感。组织病理学显示存在慢性肉芽肿性病变，在肾脏中最为严重，在肝脏、脾脏、鳃和肠道中也有类似但较轻的损伤。这些结果证实菌株20230510是[具体物种]死亡背后的病原体，为制定控制策略提供了关键见解。
