猪链球菌2型毒力因子研究进展

猪链球菌2型(SS2)是一种重要的人兽共患病病原菌,其主要毒力因子包括荚膜多糖、溶菌酶释放蛋白、溶血素、纤连蛋白结合蛋白、谷氨酸脱氢酶等,但是这些经典的毒力因子不足以解释猪链球菌病发病的临床症状,而且毒力表型往往与实际毒力及临床症状不符。近年来随着研究的深入,鉴定出一系列毒力相关元件,主要有Sao蛋白、存在于89K毒力岛的双信号转导系统(salk-salR)、dltA基因、pgdA基因、srtA基因、Ⅳ型二肽基肽酶(dipeptidyl peptidaseⅣ,DPPⅣ)、毒力调控子R(control of virulence R,CovR)、烯醇酶(enolase)、谷氨酰胺合成酶(glutamine synthetase,GlnA)等。论文对以上毒力因子研究进展进行综述,以期为SS2毒力因子及致病机制研究提供参考。     

Generation and characterization of aptamers against grass carp reovirus infection for the development of rapid detection assay

Grass carp reovirus (GCRV) causes devastating viral haemorrhagic disease in farmed grass carp (Ctenopharyngon idellus). As novel molecular probes, aptamers have been widely applied in rapid diagnosis and efficient therapies against virus or diseases. In this study, three single‐stranded DNA (ssDNA) aptamers were selected against GCRV‐infected CIK cells via SELEX (systematic evolution of ligands by exponential enrichment technology). Secondary structures predicted by MFOLD indicated that aptamers formed stem‐loop structures, and GVI‐11 had the lowest ΔG value of ?30.84 KJ/mol. Three aptamers could specifically recognize GCRV‐infected CIK cells, with calculated dissociation constants (Kd) of 220.86, 176.63 and 278.66 nM for aptamers GVI‐1, GVI‐7 and GVI‐11, respectively, which indicated that they could serve as specific delivery system for antiviral therapies. The targets of aptamers GVI‐1, GVI‐7 and GVI‐11 on the surface of GCRV‐infected cells could be membrane proteins, which were trypsin‐sensitive. Furthermore, FAM‐labelled aptamer GVI‐7 could be applied to detect GCRV infection in vivo. It is the first time to generate and characterize aptamers against GCRV‐infected cells. These aptamers have great potentials in development of rapid diagnosis technology and antiviral agents against GCRV infection in aquaculture.     

Biological control agents (BCAs) of verticillium wilt: influence of application rates and delivery method on plant protection,triggering of host defence mechanisms and rhizosphere populations of BCAs

Verticillium dahliae causes severe yield reductions in a variety of important annual crops worldwide. Control of verticillium wilt has relied on soil fumigation; however, the use of the main soil fumigant, methyl bromide, has been banned in the European Union since 2010, creating a demand for novel crop protectants. As such, the use of biocontrol agents (BCAs) is an appealing management strategy. Prerequisites for the development of a successful BCA are an understanding of the modes of action of the antagonist, its ecological fitness and an efficient and economically feasible delivery system. Therefore, two BCAs (Paenibacillus alvei K165 or the nonpathogenic Fusarium oxysporum F2) and two release strategies (seed coating or amendment of the transplant soil plug) were assessed against verticillium wilt of aubergine (eggplant). Mixing the transplant soil plug with K165 or F2, at a rate of 10 and 20% (v/v), respectively, reduced verticillium wilt symptom development. Furthermore, a positive correlation was revealed between the release strategy and the BCA rhizosphere population. Correlation analysis also showed that disease severity was negatively correlated to the rhizosphere size of the BCA population. In addition, qPCR analysis showed that both BCAs induced the expression of the pathogenesis‐related (PR) proteins PR1 and PR4 in the stem of aubergines before and after inoculation with V. dahliae in a manner that suggests a link with the rhizosphere size of the BCA population.     

多发性骨髓瘤中医病机分析及证治思路

多发性骨髓瘤（multiple myeloma,MM）是一种浆细胞恶性肿瘤,随年龄增长发病率升高,多经意义未明的单克隆免疫球蛋白血症（monoclonal gammopathy of undetermined significance,MGUS）发展而来。本文在前人经验基础上,提出了完整的肾虚血瘀证治思想;认为肾虚无制、瘀毒肆虐是MM发生的关键;提出了补肾阴、扶正气、破瘀毒、解症状基本治法,使MM恢复到MGUS状态。     

艰难梭菌毒素致病机理的研究进展

艰难梭菌是一种革兰氏阳性厌氧芽胞梭菌,是人类肠道感染的主要致病菌,其主要致病因素为毒素A(肠毒素)和毒素B(细胞毒素).毒素A引发细胞损伤后,毒素B即可侵入肠黏膜,引起细胞病变,导致一系列与感染相关的临床表现.同时,艰难梭菌毒素也是引起猪、鸡等畜禽发生腹泻的重要因素,因此探讨艰难梭菌毒素对机体的损伤作用,有利于揭示艰难梭菌的致病机理,为其防控提供理论依据.     

无乳链球菌致病因子的研究进展

无乳链球菌是人和动物的主要致病菌之一,该菌可引起人和动物的脑膜炎、肺炎、败血症等疾病。目前已发现的无乳链球菌主要致病因子包括荚膜多糖、溶血素、透明质酸酶、环磷酸腺苷(CAMP)因子、超氧化物歧化酶和丝氨酸/苏氨酸蛋白激酶等。作者就上述几类致病因子进行综述,介绍了近年来国内外无乳链球菌的致病性及致病机理等方面的一些研究进展。     

志贺氏菌病发病机制的研究进展

志贺氏菌也称痢疾杆菌,属于革兰氏阴性细胞内致病菌,主要侵害结肠,引发炎症并形成溃疡,可引起频繁的粘液性血性腹泻,儿童和幼龄动物有较高的感染率和死亡率.目前志贺氏菌病的临床治疗很困难,对志贺氏菌病发病机制的研究可为临床治疗提供理论依据,本文从志贺氏菌的胞内入侵机制、分子机制和免疫机制等方面概述志贺氏菌病发病机制的研究进展.     

猪圆环病毒Ⅱ型流行病学新特点及致病机理研究进展

猪圆环病毒是猪圆环病毒病的主要致病因素,该病给养猪业带来很大的经济损失。猪圆环病毒变异较快,是单链DNA病毒中最高的;易感猪主要通过消化道和呼吸道水平传播而感染,猪圆环病毒Ⅱ型(PCV2)人工或自然感染猪的排泄物、鼻腔、口腔和扁桃体拭子和患畜的尿液和粪便中均能检测到PCV2。断奶仔猪多系统衰竭综合征(PMWS)的发病主要与猪体内PCV2含量有关。PCV2特异抗体对猪群的PCV2感染具有保护作用。PCV2诱导猪继发性免疫缺陷,淋巴细胞缺失,影响PCV2感染结果的因素有:病毒、宿主、混合感染和免疫调节等。     

新关节炎动物模型的研究进展

文章主要论述了近年来新关节炎动物模型的发展概况,具体包括3个方面的内容:新型的转基因关节炎模型的种类及发病机理、免疫复合物关节炎模型的种类及发病机理和关节炎发生发展过程中涉及到的相关细胞因子的研究。