锯缘青蟹细菌性传染病的病原菌研究

从宁波市青蟹主要养殖海区5－9月间不同症状的病蟹体分离到6株细菌，S9901，S9902，S9903，S9904，S9905和S9906，经感染试验确定S9902、S9903、S9905和S9906均为病原菌；此4株菌革兰氏染色呈阴性，具1根极生鞭毛，氧化酶反应阳性，发酵葡萄糖，不产气，不发酵肌醇，对0／129试剂敏感，为弧菌属种类；经赖氨酸、精氨酸、乌氨酸脱羧酶、蔗糖、甘露醇发酵、6％氯化钠胨水生长、水杨素、枸橼酸盐利用等试验，根据第二代GYZ－9V系统，分别将其归为辛辛那提弧菌、溶藻弧菌和副溶血弧菌。4株菌对氯霉素、环丙沙星和硫酸庆大霉素等抗菌素表现出强敏感性，对诺氟沙星、磺胺甲异恶唑等中度敏感，而对头咆唑啉钠、呋喃唑酮不敏感；中草药五倍子和五味子煎出液对4株菌均 表现出较强的抑菌性能。     

大黄鱼假单胞菌病的初步研究

从网箱养殖的患病大黄鱼(Pseudosciaena crocea)的脾、肾内分离到2株优势菌BP-1,BS-2,经人工感染试验,证实所分离的2株菌均为大黄鱼的致病菌。经形态、生理、生化等几项指标鉴定,该2株菌均为假单胞菌属Pseudomonas的细菌。药物敏感试验结果表明,氟哌酸、庆大霉素、乙基西羧霉素、妥布霉素、丁胺卡那霉素、氟嗪酸、环丙沙星、四环素、多粘菌素等17种药物对该2株菌均有明显的抑制作用。     

罗氏沼虾(Macrobrachium rosenbergii)幼体新暴发病病原阴沟肠杆菌的分离鉴定

2010 年, 浙江湖州部分罗氏沼虾(Macrobrachium rosenbergii)育苗场在幼体培育阶段, 暴发 了幼体大规模发病死亡的新病害。从2 个育苗场6 个发病育苗池的发病幼体匀浆液中分离得到6 株 优势生长菌株(编号为NTH01、NTH02、NTH03、316D、316X、316C), 菌落形态较为一致。取代表 菌株NTH01, 以浸泡方式进行人工回感, 结果菌株NTH01 能够导致幼体发病死亡, 且症状与生产表 现一致。经形态学观察、生理生化鉴定、16S rRNA 与gyr B 基因序列系统发育关系构建, 鉴定菌株 NTH01 为阴沟肠杆菌(Enterobacter cloacae).以阴沟肠杆菌omp A 基因片段为靶序列, 建立了PCR 检测方法, 对另外5 株优势菌进行检测, 结果该5 株菌都是阴沟肠杆菌。2011 年, 对4 个发病育苗场 幼体与亲虾进行检测, 结果发病幼体中分离的优势菌检测呈阳性, 亲虾肝胰腺与肠道组织检测到该 菌存在, 但亲虾不表现病症。对30 种抗生素的药敏试验结果表明, 菌株NTH01 对恩诺沙星、氧氟 沙星、庆大霉素等6 种抗生素敏感, 对发病幼体进行针对性用药, 效果明显。本试验结果表明, 阴沟 肠杆菌是导致罗氏沼虾育苗期间幼体大规模发病死亡的致病菌。     

基于RNA-seq数据分析长牡蛎(Crassostrea gigas)天然免疫的可变剪接事件

大部分无脊椎动物缺乏基于经典抗体和记忆细胞的适应性免疫, 因而天然免疫在无脊椎动物免疫防御中发挥不可或缺的作用。可变剪接正是产生天然免疫多样性和特异性的重要途径。牡蛎(Crassostrea)是全球范围内的大宗养殖贝类和我国产量最高的海水养殖贝类, 理解其天然免疫系统的多样性和特异性对牡蛎病害防治和养殖业健康可持续发展至关重要。通过对不同病原诱导以及诱导后不同时间的转录组进行生物信息分析, 系统地研究了长牡蛎天然免疫应激反应的可变剪接事件。发现在弧菌诱导下可变剪接事件的总数显著增加, 表明弧菌的感染会诱导长牡蛎可变剪接事件的产生。对病原诱导后可变剪接体的组成类型及表达量显著变化的基因的功能富集分析, 表明免疫系统相关功能被显著富集, 病原感染不同阶段以及不同病原感染后可变剪接体的组成类型和表达量均不一致, 表明长牡蛎免疫系统可通过可变剪接产生免疫响应的特异性和多样性。研究结果为长牡蛎等无脊椎动物天然免疫多样性和特异性提供了典型实例, 也为长牡蛎病害防御提供了理论支撑。     

Antagonism between coral pathogen Vibrio coralliilyticus and other bacteria in the gastric cavity of scleractinian coral Galaxea fascicularis

Scleractinian corals host numerous microbial symbionts with different types of interactions. The gastric cavity of scleractinian coral, as a semiclosed subenvironment with distinct chemical characteristics(e.g., dissolved O2, pH, alkalinity, and nutrients), harbors a distinct microbial community and a diverse array of bacteria that can be pathogenic or beneficial. Galaxea fascicularis is one of the dominant massive scleractinian coral species on inshore fringing reefs in the northern South China Sea.Although the abundance of coral-associated bacteria has been investigated in G. fascicularis, less is known about the microorganisms in the gastric cavity. In this study, we specially isolated cultivable bacterial strains from the gastric cavity of G.fascicularis collected from Hainan Island using a noninvasive sampling approach. Among the 101 representative bacterial strains, one Vibrio coralliilyticus strain, SCSIO 43001, was found to be a temperature-dependent opportunistic pathogen of G.fascicularis. The antagonistic activity between the 100 strains and V. coralliilyticus SCSIO 43001 was tested using a modified Burkholder diffusion assay. Our results showed that V. coralliilyticus SCSIO 43001 inhibits the growth of Erythrobacter flavus and Sphingomonas yabuuchiae. Additionally, we found that three Pseudoalteromonas strains showed moderate to high antibacterial activity against V. coralliilyticus SCSIO 43001 and several other coral-associated Gram-negative bacterial strains.These results suggest that competition between the coral pathogen and other bacteria also occurs in the gastric cavity of coral, and Pseudoalteromonas strains in the gastric cavity of G. fascicularis may provide a protective role in the defense against coinhabiting coral pathogens at elevated temperature.     

南方杂色鲍苗大规模死亡病原菌的分离鉴定及其回归感染试验

自2002年下半年开始,南方杂色鲍苗出现大规模死亡的问题,严重影响到南方鲍鱼产业的发展。从汕尾鲍鱼场发病杂色鲍苗中分离到一批菌株,本研究对16号优势菌株进行了比较深入的工作,回归感染试验证明其为病原菌,API 20E条带分析表明其为溶藻弧菌(Vib-rio alginolyticus),药敏试验揭示其对卡那霉素、氯霉素、氨苄西林、链霉素、四环素有抗药性,但对青霉素、复方新诺明、庆大霉素、多粘霉素敏感。本研究结果为我国南方杂色鲍苗掉板症的防治提供科学依据。     

Analysis of Cryptosporidium parvum oocyst transport in porous media

Cryptosporidium parvum is a protozoan parasite, transmitted through aqueous environments in the form of an oocyst. In this study, a transport model into which sorption, filtration and inactivation mechanisms are incorporated is applied to simulate laboratory column data, and the suitability of a kinetic model to describe the C. parvum oocyst transport and removal in porous media is compared with an equilibrium model. The kinetic model is applied to simulate previous column experimental data and successfully simulates the concentration peak; the late time tailing effect appeared in the breakthrough curves, indicating that the kinetic model is more suitable than the equilibrium one at simulating the fate and transport of the oocysts in porous media. Simulation illustrates that sorption causes retardation along with a tailing in the breakthrough curve. Additionally, filtration acts as a major mechanism of removing the oocysts from the aqueous phase, whereas the role of inactivation in reducing the viable oocyst concentration is minimal. Copyright © 2004 John Wiley & Sons, Ltd.     

姜提取物生物合成纳米银及其对水产病原菌抑菌性的研究

With the development of aquaculture, there is an urgent demand for an alternative antibacterial agent to reduce the drug resistance and environmental pollution caused by the abuse of antibiotics. Recently, silver nanoparticles(Ag NPs) have been viewed as a novel type of antimicrobial agents due to their unique advantages. In this study,Ag NPs were biosynthesized with the ginger rhizomes extract. The biosynthesized Ag NPs were characterised by UV–visible spectroscopy, transmission electron microscopy, X-ray diffraction and fourier transform infrared spectroscopy. Furthermore, the antimicrobial activities of the Ag NPs were fully analyzed against six typical aquatic pathogens. The results indicated that the components in ginger extract could function as the chemical reductant to synthesize Ag NPs. Moreover, compared with the Ag NPs synthesized by chemical methods, the biosynthesized Ag NPs were smaller, and had higher stability and antibacterial activity. Therefore, the biosynthesized Ag NPs using ginger extract may have prospective applications in aquaculture.     

Emissions of Oxygenated Volatile Organic Compounds from Plants Part I: Emissions from Lipoxygenase Activity

Emissions of oxygenated volatile organic compounds (OVOC) from several plant species were measured in continuously stirred tank reactors (CSTR). High emission pulses of OVOCs were observed when plants were exposed to stress. Absolute emission rates were highly variable ranging up to 10^–13 mol · cm^–2 · s^–1. The temporal shape of these emissions was described by a formalism similar to that of a consecutive reaction of pseudo first order kinetics. The main emitted OVOC was (Z)-3-hexenol together with other C₆-aldehydes and alcohols, suggesting that lipoxygenase activity on linolenic acid was mainly responsible for OVOC production. Various stress factors induced lipoxygenase activity and subsequent emissions of OVOCs. These factors were exposure to high ozone concentrations, pathogen attack, and wounding. The pattern of OVOC emissions from tobacco was similar for different stress applications and the same products of lipoxygenase activity were emitted from all investigated plant species. Our results imply that these emissions occur as general response of the plants to stress. Since plants experience various abiotic or biotic stress factors in the environment, OVOC emissions as a response to stress are likely to be of significant importance for atmospheric chemistry.Now at     

无特定病原中国对虾种群选育的研究

报道了无特定病原中国对虾种群（SPF）选育的结果，主要介绍1999－2000年选育子3代和子4代的养殖结果。1999年选育对虾子3代养殖平均1788kg/ha，对虾平均体长13．69cm。而对照池中暂养池对虾体长3－4cm发病死亡，养殖池对虾体长6cm发病死亡；2000年选育对虾子4代养殖平均3168kg/ha，对虾平均体长15．00cm；对照池产量为3450kg/ha，对虾平均体长13．30cm。说明经过连续几代的人工选育，对虾生长速度明显加快。