Isolation, Characterization, and Pathogenicity of an <i>Aeromonas veronii</i> Strain Causing Disease in <i>Rhinogobio ventralis</i>
Xingbing Wu,
Baolin Cheng,
Mingyang Xue,
Nan Jiang,
Xuemei Li,
Xiaona Hu,
Xiaoli Li,
Tingbing Zhu,
Yongjiu Zhu,
Yong Zhou
Affiliations
Xingbing Wu
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Baolin Cheng
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Mingyang Xue
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Nan Jiang
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Xuemei Li
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Xiaona Hu
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Xiaoli Li
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Tingbing Zhu
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Yongjiu Zhu
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Yong Zhou
Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Wuhan 430223, China
Rhinogobio ventralis is a rare fish found in the Yangtze River in China and has significant ecological and economic value. In this study, a bacterial strain (RV-JZ01) was isolated from the livers of diseased R. ventralis. This isolate was identified as Aeromonas veronii based on its morphology, biochemical features and 16S rDNA phylogenetic analysis. The artificial infection of healthy R. ventralis (16 ± 2 cm) with RV-JZ01 resulted in the manifestation of clinical symptoms, in accordance with those of naturally infected fish. The 50% lethal dose (LD50) of RV-JZ01 for R. ventralis was 6.3 × 106 CFU/mL. Histopathological examination revealed various pathological changes in the diseased fish, including intestinal villus swelling and rupture, hepatocyte vacuolization, renal tubular cell nuclear enlargement and pyknosis, and myocardial fiber fracture and atrophy. RV-JZ01 infection significantly reduced the gut flora diversity of R. ventralis, with the relative abundances of Firmicutes and Fusobacteria increasing, and those of the Proteobacteria and Bacteroidetes decreasing. The abundance of Lactobacillus and Streptococcus dramatically increased, and the abundance of Clostridium and Escherichia reduced in the intestinal microbiota of R. ventralis infected with RV-JZ01. Antibiotic sensitivity testing revealed that RV-JZ01 was highly susceptible to 12 antimicrobials, including erythromycin, cefalexin, norfloxacin, furazolidone, sulfonamides, enrofloxacin, doxycycline, piperacillin, florfenicol, gentamicin, and lincomycin. These results contribute to the understanding of pathological alterations in R. ventralis following A. veronii infection, offering valuable data to support the implementation of disease treatment.
