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猪细小病毒结构蛋白VP2及其疫苗的研究进展 总被引:1,自引:0,他引:1
猪细小病毒(porcine parvovirus,PPV)是引起母猪繁殖障碍性疾病的主要病原之一,该病毒在世界范围内广泛存在并呈地方性流行, 给生猪的繁殖、发展带来了巨大的经济损失,故防制猪细小病毒病非常重要。PPV VP2蛋白是病毒粒子的主要衣壳蛋白,在体外能自我装配成病毒样颗粒,并能刺激机体产生抗PPV中和抗体,且可作为抗原转运载体,所以研究VP2对PPV新型疫苗研制至关重要。文章综述了猪细小病毒结构蛋白VP2及其疫苗的研究进展。 相似文献
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猪细小病毒研究进展 总被引:10,自引:1,他引:10
猪细小病毒 (PPV)是引起母猪繁殖障碍的主要病原体之一。 PPV最早是从培养细胞中发现并分离得到的一种小 DNA病毒。PPV按照其致病性与组织嗜性大致可以分为 4个类型。研究表明 ,PPV不仅是引起母猪繁殖障碍的主要病原体之一 ,而且能够引起多种猪病。PPV基因组为单股负链 DNA,大小约为 50 0 0 bp,基因组有两个主要的开放阅读框架 ,基因组共编码 3种结构蛋白和两种非结构蛋白 ,即 VP1、VP2、VP3和 NS1、NS2。VP2蛋白是主要的免疫原性蛋白 ,可以诱导机体产生强烈的免疫反应 ,NS1蛋白是 PPV基因组本身编码的反式激活蛋白 ,对PPV早期和晚期的转录发挥着重要作用 ,另外有研究表明 ,NS1蛋白是具有多种功能的锚定蛋白 ,在 PPV体外感染过程中具有重要功能。随着对猪细小病毒研究的不断深入 ,目前已经在猪细小病毒病原学、诊断与防制以及分子生物学方面取得了进展。 相似文献
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《中国兽医学报》2019,(11):2101-2106
猪细小病毒(porcine parvovirus,PPV)和伪狂犬病病毒(pseudorabies virus,PRV)均可引起母猪的繁殖障碍疾病。本试验以PRV基因工程弱毒株rPRVSMX为载体,构建了表达PPV流行毒株VP2基因的重组PRV(rPRVSMX-VP2)。Western blot和IFA试验均证明了重组病毒在细胞中成功表达了VP2蛋白。动物试验结果证明重组病毒可以诱导猪体产生特异性的PPV抗体,首免后40 d血凝抑制抗体(HI)为1∶192±73.9,虽然低于PPV商品化灭活疫苗免疫后所产生的HI抗体,但此时免疫系统被认为是激活的水平;重组病毒诱导产生的PRV抗体与载体毒株rPRVSMX诱导产生的抗体相当。由此可见该重组毒株经过优化后,可以作为二联疫苗的候选毒株防控猪伪狂犬病和细小病毒病。 相似文献
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猪细小病毒病是由猪细小病毒(PPV)感染引起以母猪繁殖障碍为主要特征的病毒性传染病,其特征是母猪孕前期感染该病毒后,经胎盘使胚胎或胎儿受到侵袭,引起母猪流产、胎儿死亡、胎儿畸形、胎儿木乃伊化及不孕等,同时还可引起仔猪的皮炎和腹泻。为了解贵州省猪PPV的隐性感染率和使用疫苗后血清抗体状况,对贵州省规模化养猪场和农村散养户共764头份猪血清样本分别进行了PPV抗体水平检测,并系统分析在我省猪群中的感染及流行情况,为制定PPV的综合防控措施提供科学依据。 相似文献
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猪细小病毒病(PPI)又称猪繁殖障碍病,是由猪细小病毒(PPV)引起以胚胎和胎儿感染及死亡,而母猪本身不表现症状的母猪繁殖障碍性传染病。1病原PPV属细小病毒科、细小病毒属。病毒粒子呈圆形或六角形,无囊膜。病毒粒子分为实心和空心2种,都具有血凝活性,但后者无感染性。 相似文献
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正猪细小病毒病是由猪细小病毒(PPV)引起的繁殖障碍病,该病主要表现为胚胎和胎儿的感染及死亡,特别是初产母猪发生死胎畸形胎和木乃伊胎,而其他年龄的猪感染后一般不见明显的临床症状。(一)病原猪细小病毒(PPV)为细小病毒科细小病毒属成员。病毒对热具有较强抵抗力,56℃48 h、70℃2 h病毒的感染性和血凝性均无明显改 相似文献
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《畜牧兽医科技信息》2015,(11)
<正>猪细小病毒(PPV)是一类小DNA病毒,是引起猪繁殖障碍的主要病原之一。PPV危害主要表现为受感染的母猪,特别是初产母猪及血清学阴性经产母猪发生流产、不孕、产死胎、畸形胎、木乃伊胎及弱仔等。该病毒对理化因素有很强的抵抗力,广泛分布于世界各地并在大多数猪场呈地方性流行,严重地影响着养猪业的发展。1临床症状猪感染细小病毒后主要表现为生殖系统症状。头胎的妊娠母猪在妊娠期内感染细小病毒可发生 相似文献
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猪细小病毒病是由猪细小病毒(PPV)引起的猪以胚胎和胎儿感染及死亡,而母猪本身不显临床症状的一种母猪繁殖障碍性传染病。由于被感染妊娠母猪临床症状不明显,其它猪感染后无明显临床症状,目前已在我国各地猪群广泛分布存在,严重影响我国养猪业的发展,笔者通过对淮安区马甸镇养殖户刘某饲养的4头患病母猪进行调查与分析,探讨猪细小病毒病的综合防治措施。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献