Motile aeromonad septicemia (MAS) at Cyprinus carpio L., 1758 (Actinopterygii:Cyprinidae) in Lake Tödürge (Sivas/Turkey)

ABSTRACT In this study, fish’s morphologic and anatomic lesions caused by motile aeromonad septicemia (MAS) depending on environmental stress in carp, Cyprinus carpio population living in Lake Tödürge were identified. Various morphological and anatomical deformations and lesions were observed in the body of approximately 17% (252 fish specimens) of a total of 1488 carp samples. Bacteria are grown from all wipe samples. Bacterial colonies have a gray-white appearance with round, convex and smooth edges. 15-20 cfu colonies were observed in each aerop culture. As a result of analysis of wet wipe samples from infected fish’s skin, gill, kidney and liver, it is determined that the bacteria which causes septicemia is Aeromonas sobria from the Aeromonadaceae family (with 99.2% confidence value). No bacteria were grown in cultures except A. sobria. Some symptoms of the infection are inflammation on different parts of the fish bodies, eruption on skin and scales, dermal necrosis, degeneration at soft rays of the fins, exophthalmos, and purulent liquid accumulation in the abdominal cavity, etc. Infected fish were most commonly encountered in July and August (water temperature above 20ºC), the lowest in October and November (water temperature below 10ºC).摘要 本研究针对生活在托德格尔湖（Lake Tödürge）的普通鲤（Cyprinus carpio）种群，鉴定了由环境应激诱发的能动气单胞菌败血症（motile aeromonad septicemia, MAS）所导致的鱼类形态学与解剖学病变。在总计1488尾鲤样本中，约17%（252尾鱼体标本）的个体体表与体内出现了多种形态学及解剖学畸形与病变。所有拭子样本均分离培养出细菌，细菌菌落呈灰白色，边缘圆润、凸起且表面光滑，每份需氧培养物中可观察到15~20个菌落形成单位（colony-forming unit, cfu）的菌落。对病鱼皮肤、鳃、肾脏及肝脏的湿拭子样本进行分析后，确定此次败血症的致病菌为气单胞菌科（Aeromonadaceae）的温和气单胞菌（Aeromonas sobria），置信度达99.2%；除温和气单胞菌外，未分离培养出其他细菌。该感染的典型症状包括鱼体不同部位出现炎症、皮肤与鳞片破溃、皮肤坏死、鳍条软棘变性、眼球突出以及腹腔积脓等。病鱼检出率最高的时段为7月和8月（水温高于20℃），最低为10月和11月（水温低于10℃）。