拟态弧菌毒力因子的分子生物学研究进展

拟态弧菌的致病作用与其在生长繁殖过程中产生的毒力因子密切相关。该菌的毒力因子主要有外毒素、内毒素及黏附素等,其中外毒素是其重要的毒力因子,它包括毒性酶、肠毒素、溶血素和铁载体等。各毒力因子不仅在生物学活性上具有协同作用,而且在分子水平上也是相互影响,受毒力岛上调控基因调节。本文主要对拟态弧菌毒力因子的分子生物学特性及其致病机理进行了综述。     

胸膜肺炎放线杆菌毒素分子致病机理研究进展

胸膜肺炎放线杆菌是引起猪传染性胸膜肺炎的一种重要病原菌。该病具高度传染性，给养猪业造成巨大的经济损失,本文就病原、毒素成分，毒素分子结构，分子致病机理的研究作了综述。     

槟榔在口腔黏膜下纤维性变发病机制中的作用

口腔黏膜下纤维性变(O ra l Subm ucous F ibrosis,O SF)是一种以炎症和渐进性黏膜改变导致进行性张口困难为特征的口腔黏膜慢性病症.近年来相当多的流行病学研究资料指出槟榔是O SF的主要病源因子,在O SF的发病上,不论是嚼食槟榔的频率还是持续的时间都呈现了剂量依赖性.在嚼食槟榔时粗糙纤维对口腔黏膜产生的强烈机械刺激作用、槟榔中的生物碱与单宁对细胞外基质分子的影响以及槟榔中的铜在纤维化疾病中的作用等方面对槟榔在O SF发病原因与发病机制中的作用加以综述,旨在分析迄今为止国内外学者对槟榔在O SF上所做的研究,以期让基础科研人员、公共卫生工作者以及广大槟榔嗜好者对槟榔在人类O SF中的作用有更深入的了解.     

花椒锈病的初步研究

花椒锈病是危及花椒生产的严重病害之一。对西北主要产椒区的调查,其发病率均在60%以上,最高可达90～100%;病情指数一般都达到30～75。病害发生的空间动态符合逻辑斯蒂曲线。病害的发生程度与降雨、花椒品种有关,而与树龄、海拔高度关系不大。该病菌为害叶片、叶轴,引起叶子大量提前脱落,致使椒树再次萌叶。锈菌在花椒上产生夏孢子和冬孢子;冬孢子不经休眠阶段而萌发,萌发最适温度18～25℃。     

火龙果溃疡病研究进展

火龙果溃疡病是火龙果生产上的重要病害之一, 对我国火龙果产业构成严重威胁?目前, 我国对火龙果溃疡病及其抗病育种的研究基础非常薄弱?本文介绍了火龙果溃疡病发病症状?病原学研究?流行规律以及防治措施等方面的研究进展, 为溃疡病的发生机制研究?病害防治及抗性品种选育提供参考?     

量子点在兽医领域应用研究进展

量子点具有独特的光学性质,近年已在材料科学、分析化学、生命科学、医学检验等学科领域得到广泛研究和应用.作为一种新型的荧光标记材料,量子点在兽医领域越来越受到重视.作者就量子点的特性、种类及其在兽医领域的研究做一综述,并提出了未来研究方向,为拓展量子点在动物疫病诊断、兽药研发、致病机制等方面的研究提供参考.     

A study of gross,histological and blood biochemical changes in rainbow trout,Oncorhynchus mykiss (Walbaum), with rainbow trout gastroenteritis (RTGE)

The mechanisms behind the pathogenesis of rainbow trout gastroenteritis (RTGE) are still unknown. This study examined the macroscopic and microscopic changes in trout with RTGE (RTGE+), as well as the blood chemistry. A total of 464 rainbow trout were sampled from 11 sites in the UK, comprising 152 RTGE+ fish and 330 random, apparently healthy fish. A case definition for RTGE was assessed by the analysis of its agreement with three laboratory tests: histopathology, packed cell volume and kidney bacteriology. Cluster analysis indicated the presence of three distinct presentations within the population of RTGE+ fish. Cluster A included gross signs associated with moribund RTGE+ fish, and clusters B and C identified gross signs consistent with concurrent diseases, notably furunculosis, enteric redmouth and proliferative kidney disease. The information gained was used to select RTGE+ fish without concurrent disease for the analysis of RTGE pathogenesis with blood biochemistry. This analysis revealed a severe osmotic imbalance and a reduced albumin/globulin ratio as indicatives of selective loss of albumin. These findings are compatible with a protein losing enteropathy.     

Capsular polysaccharide of Streptococcus agalactiae is an essential virulence factor for infection in Nile tilapia (Oreochromis niloticus Linn.)

Streptococcus agalactiae (Group B Streptococcus, GBS) is associated with diverse diseases in aquatic animals. The capsule polysaccharide (CPS) encoded by the cps gene cluster is the major virulence factor of S. agalactiae; however, limited information is available regarding the pathogenic role of the CPS of serotype Ia piscine GBS strains in fish. Here, a non‐encapsulated mutant (Δcps) was constructed by insertional mutagenesis of the cps gene cluster. Mutant pathogenicity was evaluated in vitro based on the killing of whole blood from tilapia, in vivo infections, measuring mutant survival in tilapia spleen tissues and pathological analysis. Compared to wild‐type (WT) GBS strain, the Δcps mutant had lower resistance to fresh tilapia whole blood in vitro (p < 0.01), and more easily cleared in tilapia spleen tissue, and was highly attenuated in tilapia and zebrafish. Additionally, compared to the Δcps mutant, numerous GBS strains and severe tissue necrosis were observed in the tilapia spleen tissue infected with WT strains. These results indicated that the CPS is essential for GBS pathogenicity and may serve as a target for attenuation in vaccine development. Gaining a better understanding of the role, the GBS pathogenicity in fish will provide insight into related pathogenesis and host–pathogen interactions.