河流弧菌(Vibrio fluvialis)对牙鲆(Paralichthys olivaceus)粘液的趋化和粘附作用

采用生长曲线法测定了河流弧菌在牙鲆表皮、鳃和肠粘液中的生长情况,结果表明,河流弧菌在3种粘液中都能生长,生长前期符合Logistic模型,然后进入Gompertz模型,在鳃粘液中的生长量高于肠粘液和表皮粘液。采用毛细管法研究了河流弧菌对牙鲆3种粘液的趋化作用,结果表明,河流弧菌对牙鲆3种粘液具有较强的趋化应答,在粘液总蛋白含量相同的情况下,河流弧菌对牙鲆鳃粘液的趋化应答显著强于对表皮粘液的趋化应答（P〈0．05）,而对肠粘液的趋化应答极显著低于对鳃粘液和表皮粘液的趋化应答（P〈0．01）。采用^3H—TdR示踪法进行了河流弧菌对牙鲆3种粘液的粘附作用研究,结果表明,河流弧菌对牙鲆表皮粘液和鳃粘液的粘附率较高,而对肠粘液的粘附率较低,特别是孵育30、60和90min时河流弧菌对牙鲆表皮粘液和鳃粘液的粘附率显著高于对肠粘液的粘附率（P〈0．05）。这些结果表明,河流弧菌能够在牙鲆粘液,尤其是鳃粘液中生长和定植,有利于其进一步感染、致病。     

土霉素在牙鲆体内的药代动力学研究

采用高效液相色谱法为定性、定量手段,研究土霉素在牙鲆(Paralichthys olivaceus)体内的药代动力学过程,采用DAS(Drug and Statistics)药代动力学程序对数据进行分析.结果表明,牙鲆单剂量口服土霉素后(200 mg/kg),血药经时过程符合二室模型,主要动力学参数如下:吸收半衰期(T(1/2)a)为10.043 h,单剂量给药后牙鲆体内出现最高质量分数的时间(Tmax)为4.000 h,单剂量给药后牙鲆体内最高血药质量分数(Cmax)为0.54 mg/L,药时曲线下总面积(CAU0-72)为17.15 (mg*h)/L,吸收速率常数(Ka)为0.223,消除速率常数(k)为0.476 h-1.牙鲆肌肉中土霉素的经时过程符合一级吸收一室模型,主要动力学参数:T(1/2)a为74.893 h,Tmax为4.000 h,Cmax为3.58 mg/L,CAU0-72为148.56 (mg*h)/L,Ka为0.731,k为2.991 h-1.牙鲆肝脏中土霉素的经时过程符合一级吸收一室模型,主要动力学参数:T(1/2)a为31.376 h,Tmax为4.000 h,Cmax为13.78 mg/L,CAU0-72为494.14 (mg*h)/L,Ka为0.876,k为4.940 h-1.     

杜氏鰤的一种细菌病病原菌研究

从患病的杜氏（鱼师）肾脏分离出Y-1菌.人工感染试验,当注射9.0×107CFU/尾时,Y-1菌可致试验鱼100%死亡;注射9.0×106CFU/尾时,死亡率为50%,症状与自然发病相似,结果表明该分离菌为致病菌.Y-1菌为革兰氏阴性,有动力,杆状,极生单鞭毛;发酵葡萄糖,还原硝酸盐,氧化酶、触酶阳性,赖氨酸脱羧酶、鸟氨酸脱羧酶、精氨酸双水解酶阴性.根据形态及生理生化特性,Y-1菌应为弧菌Vibriosp..药敏试验结果表明,该菌对氨基糖甙类、呋喃类、喹诺酮类及大环内脂类药物敏感.     

Immune response of Pseudosciaena crocea to the injection of Vibrio alginolyticus

For the investigation of anti-infection immune response of Pseudosciaena crocea, 160 healthy fish samples were categorized into infected and control groups. Each individual fish in the infected group was injected intraperitoneally (i.p.) with 0.2 ml bacterial suspension of Vibrio alginolyticus in density of 2×107 CFU/ml, while each individual in the control group was injected i.p. with 0.2 ml sterile saline solution (0.85%). It was observed that the artificial injection of V. alginolyticus significantly inc...     

河流弧菌对牙鲆表皮黏液黏附作用的研究

为了解河流弧菌对牙鲆表皮黏液的黏附特性,采用3H-TdR同位素示踪方法研究了细菌浓度、孵育时间、孵育温度、pH值、阳离子、碳水化合物等因子对河流弧菌黏附作用的影响。试验结果表明:河流弧菌能很好地黏附于牙鲆表皮黏液,黏附量随菌浓度升高而增大并符合饱和黏附动力学:y=417.89ln(x)+691.57(R2=0.986);在30℃下黏附量随着孵育时间的延长而增加,180min趋于饱和;孵育温度在4~30℃范围内黏附量随温度升高而增多,30℃时黏附量最大;pH值酸性较碱性黏附作用明显,pH为5时最强;NaCl浓度在0.5%~4.5%范围内,细菌黏附作用随着浓度升高而增强,较纯水存在显著性差异(P<0.05);Ca2+,Mg2+能显著加强河流弧菌的黏附作用,但Ca2+作用明显超过Mg2+;葡萄糖等8种碳水化合物能显著促进河流弧菌的黏附作用(P<0.05)。以上结果说明:河流弧菌对牙鲆表皮黏液的黏附量较大,这有利于进一步感染、致病;河流弧菌的黏附作用受温度、pH值、阳离子、碳水化合物等多种环境因子的影响,较高的水温有利于河流弧菌的黏附,有利于疾病的发生。     

Vaccination in three different ways against vibriosis of <Emphasis Type="Italic">Seriola dumerili</Emphasis> caused by <Emphasis Type="Italic">Vibrio hollisae</Emphasis>

Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili （amberjack） suffering from vibriosis. Healthy S. dumeriIi were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1：40 at 7 d, and reached its peak of 1：320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of 〈1：10, 1：20, 1：160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities （P〈0.05）. Upon challenge with virulent strain, the relative percent survival （RPS） of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.     

病原性副溶血弧菌在天然海水中的饥饿耐受研究

将副溶血弧菌培养至对数生长期,用天然海水洗脱,调整菌浓度至107个/cm3左右后置于27℃恒温培养箱进行饥饿试验.结果表明:饥饿初期细菌总数、可培养菌数和活菌数都有较大幅度上升;饥饿中、后期,总菌数与活菌数缓慢下降,而可培养菌数下降速度较快.饥饿前副溶血弧菌呈短杆状,染色均匀;饥饿后许多细胞中央出现染色较浅的区域,细胞形态变为椭圆形.副溶血弧菌对大黄鱼表皮黏液的黏附量随着饥饿时间延长而急剧下降,饥饿7 d后的黏附量接近于空白.用SDS-PAGE分析不同饥饿时期菌体蛋白质的差异,结果表明:饥饿30 d后菌体蛋白条带比饥饿前的蛋白质条带少;饥饿60 d后菌体蛋白质条带比饥饿30 d时的多,但比饥饿前少.研究结果对于揭示副溶血弧菌的流行病学特征有重要的参考价值.     

河流弧菌(Vibrio fluvialis)感染后牙鲆(Paralichthys olivaceus)血清抗菌物质的研究

采用1×107cells/ml的河流弧菌悬液背部肌肉注射感染牙鲆,注射后24h、48h试验组的血清抗菌活力分别极显著性(P0.01)和显著性(P0.05)高于对照组。用Sephadex G-25凝胶柱对第二次人工注射感染后24h牙鲆血清进行分离,其中第7—15收集管对河流弧菌具有抗菌活性,对大肠杆菌、枯草芽孢杆菌等指示菌也具有明显的抗菌作用,在4—100℃范围内,大部分活性分离组分随着温度的升高其抗菌活力有所增强。具有抗河流弧菌活性收集管(第9管)经弱阳离子交换柱分离后,OD280显示出2个蛋白吸收峰,具有抗河流弧菌活性的物质主要集中在第1吸收峰。SDS-PAGE分析显示经Sephadex G-25凝胶柱和弱阳离子交换柱分离的抗菌蛋白分子量较大。以上结果表明,牙鲆被河流弧菌感染后能很快产生大量抗菌物质释放到血清中;主要抗菌物质的分子量较大,且热稳定性较好;这些活性物质的抗菌活性具有较强的特异性。     

拮抗菌对病原性溶藻弧菌(Vibrio alginolyticus)粘附大黄鱼(Pseudosciaena crocea)表皮粘液的影响

采用3H-TdR同位素示踪法研究了病原性溶藻弧菌和9株拮抗菌对大黄鱼表皮粘液的粘附动力学。结果表明,10株细菌的粘附作用都符合饱和粘附动力学特征;R4、R13和R32等3株拮抗菌的最大粘附量高于溶藻弧菌;9株拮抗菌的分离常数都高于溶藻弧菌;R32的亲和指数大于溶藻弧菌,其余8株拮抗菌的亲和指数都小于溶藻弧菌。测定了9株拮抗菌对病原性溶藻弧菌粘附大黄鱼表皮粘液的竞争、排斥和置换作用,结果显示:9株拮抗菌在竞争条件下都能极显著减少溶藻弧菌对表皮粘液粘附(P<0.01);在粘附排斥方面,R4、R13、J26、J28、J312、Y59等6株拮抗菌能显著排斥病原性溶藻弧菌对大黄鱼表皮粘液的粘附作用(P<0.05);在粘附置换方面,J26、J28等2株拮抗菌能极显著(P<0.01)降低病原性溶藻弧菌对大黄鱼表皮粘液的粘附量。研究结果表明,病原性溶藻弧菌对大黄鱼表皮粘液有较强的粘附作用;9株拮抗菌能够抑制溶藻弧菌对大黄鱼表皮粘液的粘附作用,其中竞争作用效果最好,排斥作用次之,置换作用的效果最差;拮抗菌对病原菌粘附的抑制效果受多种因素的影响,各菌株的粘附动力学参数有重要的影响作用。     

Vaccination in three different ways against vibriosis of Seriola dumerili caused by Vibrio hollisae

Bacterin was prepared by formalin-inactivating the virulent strain of Vibrio hollisae isolated from diseased Seriola dumerili (amberjack) suffering from vibriosis. Healthy S. dumerili were vaccinated by respective procedures of intramuscular injection, immersion, and orally administration. Results of the three different vaccinations were compared. Blood was drawn from the vaccinated fish every 7 days, and the antibody titers and lysozyme activities of the sera were determined. The antibody titer of injected fish was 1:40 at 7 d, and reached its peak of 1:320 at 28 d, while the fish vaccinated by immersion and orally administration exhibited weak antibody responses, the antibody titres of <1:10, 1:20, 1:160 were observed at 7 d, 14 d, 35 d respectively. Compared with the control, the vaccinated fish exhibited significantly higher lysozyme activities (P<0.05). Upon challenge with virulent strain, the relative percent survival (RPS) of injected, immersed and oral administrated fish were 75%, 45%, and 40% respectively, and the injected fish showed significantly higher RPS than immersed and oral administrated fish. The results suggested that vaccination of S. dumerili by the injection would be the best strategy to prevent the vibriosis in S. dumerili farm.