病毒、弧菌共同作用引发虾病的预防与治疗技术初探

近几年来,由于养虾强调产量,放养密度过大,而过量投饵和对虾排泄物引起底质恶化,水质发生突变,极易引起虾体的免疫力下降,弧菌乘机侵入虾体,从而引发了虾病的发生.     

病毒、弧菌共同作用引发虾病的预防与治疗技术初探

通过用肉眼观察、镜检,并配合核酸探针法检测池塘对虾病虾的病毒、细菌感染情况,结果发现,由细菌引起的白斑病症较多,携带病毒和感染上病毒的虾数量很少。经分离培养和人工感染试验,证实1号菌是很强的致病菌。经药敏试验找出了首选药物阿莫西林。     

河北省对虾养殖病毒病特点及控制技术

在河北省对虾养殖产区,每年因对虾病害造成的经济损失0．5亿～1．6亿元,占全省水产养殖病害损失的25％～50％,其中因对虾病毒病造成的经济损失占全省对虾养殖病害总损失的80％以上。2007年以来,我们结合公益性科研专项“对虾养殖信息管理系统研究与建立”和“养殖对虾病毒病控制技术”等项目的实施,     

A review of extracellular virulence product of Vibrio species important in diseases of cultivated shrimp

Shrimp aquaculture is an important industry that experiences significant losses from Vibrio species, especially at the larval and juvenile stages. Proteinaceous virulence factors, including alkaline proteases, metalloproteases, cysteine proteases and alkaline serine proteases, have been identified as important elements in Vibrio pathogenesis. This review summarizes current knowledge regarding the principal pathogenic Vibrio species in shrimp, with emphasis on relevant exotoxins and their modes of action, principal characteristics and molecular database. This pathogenic factors and their relation with other molecules produced by microorganisms may be help to understand the virulence mechanisms present in Vibrio strain.     

对饲料不足及营养不良引发的几种鱼病分析

水产动物在高度密养的情况下，天然饲料很少，只有投喂营养全面的人工配合饲料，才能使水产动物健康、迅速地生长。若饲料长期不足，则会引发一些鱼病；某种营养成分缺乏或过多，不仅会影响鱼类生长，还会导致饲料系数高，严重时引起鱼类生病死亡。最适合的饲料应含有蛋白质、脂肪、碳水化合物、     

噬菌蛭弧菌预防对虾弧菌感染的应用研究

采用16S rDNA特异引物对63F和842R对蛭弧菌标准菌株Bdellovi briobacteriovorus 109-J和实验菌株Bd-9913进行了PCR鉴定,使用Bd-9913菌株分别对3株虾类病原菌溶藻弧菌Vibrio alginolysticus LS01、HF09,副溶血弧菌V．parahaemolyticus V28以及1株大肠埃希氏菌Escherichia coli CH-42进行裂解。结果表明,10^5PFU／ml的Bd-9913对于10^9CFU／ml的宿主菌具有较好的裂解效果。采用3．0×10^5PFu／mlBd109-J和Bd-9913分别与饲料混合（v／w）后投喂3．0g左右的凡纳滨对虾幼虾,14d内未发现对虾异常,且在对虾肠道内检测不到Bd109-J及Bd-9913,证明二者对于凡纳滨对虾幼虾是安全的。对正常养殖了50d的室外集约化虾池水体分别泼洒终浓度0．3mg／L的二氯异氰脲酸、0．3mg／L季胺盐络合碘和3．0×10^5PFU／ml蛭弧菌,后者对于抑制水体弧菌活菌浓度的效果明显优于化学消毒剂。当每隔20d左右分别进行一次上述水体处理,通过比较体内弧菌感染的对虾个体数,发现从肝胰腺分离到弧菌的对虾数量二者无显著差异,但从血淋巴分离到弧菌的对虾数量,蛭弧菌处理组显著少于化学消毒剂处理组,显示了蛭弧菌在预防对虾弧菌感染方面的优越性。     

Comparison of histopathology caused by Vibrio anguillarum and Vibrio ordalii in three species of Pacific salmon*

Abstract. The histopathology associated with naturally acquired vibriosis in chum salmon, Oncorhynchus keta (Walbaum), fingerlings caused by Vibrio anguillarum was compared with that caused by infection with Vibrio ordalii. Pathogenesis of the two forms was found to be different. Bacteraemia caused by V. anguillarum occurred in the early stages with pronounced histopathological changes in blood, loose connective tissue, kidney, spleen, gills and posterior gastrointestinal tract. Bacterial cells appeared uniformly dispersed throughout the affected tissues but were most abundant in the blood. With V. ordalii, bacteraemia developed only in late stages of the disease and the concentration of bacterial cells per ml of blood was less than in the V. anguillarum infection by a factor of 10²–10³. Tissues with most pronounced changes were skeletal and cardiac muscle, anterior and posterior gastrointestinal tract and the gills. Vibrio ordalii observed in the tissues was not evenly dispersed but was present within tissue as colonies or aggregates of cells. The differences in pathology observed in naturally infected chum salmon were produced experimentally with each pathogen by waterborne exposure of chum; coho, Oncorhynchus kisutch (Walbaum); and chinook salmon, Oncorhynchus tshawytscha (Walbaum). Severe decreases in circulating leucocytes accompanied bacteraemia caused by either bacterial species.     

市售仔虾中副溶血性弧菌的检测

应用常规细菌分离法对西宁市某几个农贸市场采集的70份仔虾样品进行了副溶血性弧菌的检测,经细菌形态观察、嗜盐性试验、细胞色素氧化酶试验和生化特性测定,鉴定为副溶血性弧菌。结果检出阳性菌株4株,阳性率为5.7%(4/70),同时通过致病性试验证明4株分离菌对小白鼠有致死效应。     

我国对虾寄生虫病

<正> 我国养殖对虾主要有6种寄生虫病。1 微孢子虫病(原虫病)1.1 病原 国外报道有:奈氏微粒子虫[Ameson(=Nosema)nelsoni]、对虾匹里虫[(Pleisttphorapenaei]、桃红对虾人孢虫[Agmasoma=Theloha-nia duorara]、对虾八孢虫(A.penaei)。我国发现几种微孢子来鉴定。1.2 传播途径 可能由于:①摄食病虾的蜕壳