摘要
2020年6月湖北荆州太湖某养殖场黄颡鱼发生大量死亡,临床症状表现为鱼体腹部出现明显的腹水症状。本试验从患腹水病黄颡鱼体内分离到1株优势菌,采用形态特征、革兰氏染色、生理生化鉴定、16S rRNA基因序列分析确定分离株的特性和生物学地位,通过人工回归感染及组织病理学研究确定该菌株的致病性,并开展药物敏感性试验筛选其敏感药物。经生理生化和16S rRNA序列比对确定此次从患病黄颡鱼中分离到的菌株为嗜水气单胞菌,革兰氏染色显示为阴性。病理组织切片结果显示,该分离菌株可以引起黄颡鱼肝脏中央静脉和肝血窦淤血,炎性细胞浸润和实质细胞变性;肠道黏膜上皮细胞脱落坏死,黏膜下层出血和发生空泡化;脾脏细胞核裂解,细胞坏死或出现空泡化;肾小管细胞发生水肿或坏死,肾小球发生纤维化。人工回归感染试验显示,菌株可使黄颡鱼出现与自然发病鱼相似症状,其对黄颡鱼的半致死量为7.94×10^(5)CFU/mL。药敏试验结果表明该菌株已呈现多重耐药性,仅对少数检测抗生素(恩诺沙星、头孢曲松和四环素)敏感,根据药敏试验结果及农业部水产用药规定,推荐使用恩诺沙星治疗该疾病。综上所述,本试验确认了此次黄颡鱼腹水病的病原菌,并初步研究了病原菌致病性以及药物敏感性,试验结果将为黄颡鱼腹水病的有效防控提供科学指导。
In June 2020,a large number of Pelteobagrus fulvidraco with abdominal distension cultured in Taihu Lake,Hubei province,were found dead.In this research,the dominant bacterial were isolated from diseased fish,and then morphological characteristics,gram staining,physiological and biochemical identification,as well as 16S rRNA gene sequence were used to determine the characteristics and biological features of this bacteria.The pathogenicity of this strain was measured by artificial experimental infection and histopathological study,and drug sensitivity testing was carried out to analyze its sensitive drugs.The isolate was identified as Aeromonas hydrophila detected by its morphological,physiological,and biochemical features,as well as 16S rRNA gene sequence.The gram staining showed negativity.The HE staining revealed that the bacteria induced lymphocyte infiltration,congestion of liver sinusoids and parenchymal cell lysis.The intestine showed the symptom of necrosis and exfoliation of intestinal epithelial cells,hemorrhage and vacuolization of intestinal submucosal.The vacuolar degeneration,karyolysis and damaged red blood cells were observed in spleen tissue.Moreover,cellular necrosis and swelling appeared in kidney interstitial,and fibrotic occurred in glomerular.Artificial experimental infection revealed that the median lethal dosage(LD_(50))of the bacteria for Pelteobagrus fulvidraco was determined as 7.94×10^(5)CFU/mL.Drug sensitivity testing showed that the isolate had multiple resistance and was only susceptible to a few antibiotics(such as enrofloxacin,ceftriaxone and tetracycline).Enrofloxacin was recommended for the treatment of the disease according to the results of the drug sensitivity test and the regulations of the Ministry of Agriculture.These results provided a scientific basis for the identification of Aeromonas hydrophila and treatment for Pelteobrus fulvidrus infected by this pathogen.
作者
孙浩然
王丽
杨洋
余登航
胡兵
苏应兵
罗静波
徐洪森
SUN Hao-ran;WANG Li;YANG Yang;YU Deng-hang;HU Bing;SU Ying-bing;LUO Jing-bo;XU Hong-sen(Engineering Research Center of Feed Protein Resources on Agricultural By-products,Ministry of Education,School of animal science and nutrition engineering,Wuhan Polytechnic University,Wuhan 430023,China;School of Animal Science and Nutritional Engineering,Wuhan Polytechnic University,Wuhan 430023,China;Fujian Province Key Laboratory of Special Aquatic Formula Feed,Fujian Tianma Science and Technology Group,Fuqing 350308,China;School of Animal Science,Yangtze University,Jingzhou 434020,China)
出处
《武汉轻工大学学报》
2021年第5期1-8,39,共9页
Journal of Wuhan Polytechnic University
基金
福建省特种水产配合饲料重点实验室开放课题(TMKJZ1912)
农副产品蛋白质饲料资源教育部工程研究中心资助项目(DKXY2020015)
湖北美琪生物科技有限公司课题(HBMQ202012)
国家自然科学基金项目(31902389).
关键词
黄颡鱼
嗜水气单胞菌
腹水病
分离
鉴定
组织病理
Pelteobrus fulvidrus
Aeromonas hydrophila
ascites
isolation
identification
histopathology
