Tu Yun-Yao, Lu Qun, Zhang Na, Leng Jie, Yang Qin, Yu Jie, Zhu Cheng-Ke, He Tao, Hu Jian-Yong, Lv Ming-Ji, Zhu Song
College of Fisheries, Southwest University, Chongqing 400715, China.
Key Laboratory of Freshwater Fish Reproduction and Development (Ministry of Education), Key Laboratory of Aquatic Science of Chongqing, Southwest University, Chongqing 400715, China.
Microorganisms. 2025 Jun 17;13(6):1413. doi: 10.3390/microorganisms13061413.
In the study, a comprehensive investigation on potential bacterial pathogens affecting largemouth bass () was performed. Monthly surveys were conducted from April to October 2024. Diseased largemouth bass exhibited diverse clinical symptoms, such as rot of gill and fin, ulcers on body surface, and petechial hemorrhages in liver. Following isolation and identification, a total of 21 potential bacterial pathogens (numbered strain 1 to 21, respectively) were identified. The genus had the highest proportion (67.14%), among which the frequency of was 24.60%. TEM analysis revealed that the bacterial strains exhibited three predominant shapes (rod-shaped, spherical, and curved) with length ranging from 0.5 to 3 μm. Flagellar structures were observed in strains 1-4, 6-8, 11-17, and 19-21, with variations in number and growth sites. Three isolates (strains 9, 10, 18) demonstrated Gram-positive characteristic, and strains 5, 11, and 18 have capsule structures. Strains 5, 9, 10, and 18 were non-motile, and strains 1-4, 6, 7, 9-11, 16-18, and 21 exhibited β-hemolysis. Physiological and biochemical characteristics of the 21 bacterial isolates were comprehensively analyzed. Antibiotic sensitivity testing revealed that florfenicol and enrofloxacin exhibited excellent antibacterial effects. These data will enrich the potential bacterial diseases information and promote the healthy development of the largemouth bass industry.
在该研究中，对影响大口黑鲈（ ）的潜在细菌病原体进行了全面调查。于2024年4月至10月进行了月度调查。患病的大口黑鲈表现出多种临床症状，如鳃和鳍腐烂、体表溃疡以及肝脏点状出血。经过分离和鉴定，共鉴定出21种潜在细菌病原体（分别编号为菌株1至21）。 属的比例最高（67.14%），其中 出现的频率为24.60%。透射电子显微镜分析显示，这些细菌菌株呈现出三种主要形态（杆状、球状和弯曲状），长度范围为0.5至3μm。在菌株1 - 4、6 - 8、11 - 17和19 - 21中观察到鞭毛结构，其数量和生长部位存在差异。三株分离菌（菌株9、10、18）表现出革兰氏阳性特征，菌株5、11和18具有荚膜结构。菌株5、9、10和18不运动，菌株1 - 4、6、7、9 - 11、16 - 18和21表现出β - 溶血。对这21株细菌分离株的生理生化特性进行了全面分析。药敏试验表明，氟苯尼考和恩诺沙星具有优异的抗菌效果。这些数据将丰富潜在细菌性疾病信息，并促进大口黑鲈产业的健康发展。
