反转录聚合酶链式反应检测猪繁殖与呼吸综合征持续性感染

猪繁殖与呼吸综合征感染的特点之一，是持续性的感染和病毒血症。本研究利用反转录滞酶链式反应检测了ＰＲＲＳＶ ＢＪ－４株单独感染ＳＰＦ仔猪和接种ＰＲＲＳＶ ＢＪ－４后再接种猪瘟疫苗不同时间的血清中病毒的存在，结果显示在感染２４h后的血甭样口 中就发现有病毒ＲＮＡ存在，病毒血症及少持续到感染后３７天，到５０天时已经消失，ＰＲＲＳＶ ＢＪ－４感染后再接种猪疫苗的仔猪的ＰＲＲＳＶ病毒血症没有受到影响。这些结果提供了ＰＲＲＳＶ持续感染的直接证据，解释了实际生产中通过引进临床正常但已经感染了猪繁殖与呼吸综合征病毒的猪群造成猪场内病毒的传和长期感染的存在，为采用合理的措施控制疾病提供了依据。     

猪繁殖与呼吸综合征病毒反转录环媒恒温检测方法的建立

本研究利用PrimerExplorer V4软件设计了针对猪繁殖与呼吸综合征病毒(PRRSV)N基因保守区6个特异性部位的4种引物,建立了PRRSV的反转录环媒恒温检测方法.利用该方法所建立的反应体系在恒温水浴锅中作用1 h即可得到其特有的阶梯状条带,而且猪细小病毒、猪圆环病毒、猪瘟病毒、伪狂犬病毒和健康猪睾丸细胞的扩增结果均为阴性.本方法对PRRSV的最低检出量为1 ×100个～1×101个基因拷贝.反转录环媒恒温检测方法和普通RT-PCR方法检测临床样品的符合率为96.2%.该方法为现地开展猪繁殖与呼吸综合征的快速诊断和综合防治方案的提出提供了有力的诊断工具.     

Simultaneous detection of porcine circovirus type 2, classical swine fever virus,porcine parvovirus and porcine reproductive and respiratory syndrome virus in pigs by multiplex polymerase chain reaction

Results from a previous study indicated that there are specific arena surface characteristics that are associated with an increased likelihood of lameness in dressage horses. It is important to understand what modifiable arena factors lead to these detrimental surface characteristics. The aim of this study was to describe the use of training surfaces and arenas for United Kingdom dressage horses and to investigate any relationships between arena/surface variables and detrimental surface characteristics. Data from a questionnaire returned by 22.5% of all 11,363 registered members of British Dressage were used for the study. Univariate and multivariable logistic regression models were developed with each of the previously identified surface characteristics as dependent variables. Respondents reported that the majority of arenas were privately owned, sized 20 × 40 m and had a sand and rubber surface. The results indicated that wax-coated and sand and rubber surfaces were associated with less detrimental surface properties than sand, sand and PVC, woodchips or grass. Woodchips were most strongly associated with the detrimental characteristic of slipping, and sand with tripping. The findings indicated that any arena surface should have a base, with limestone the recommended surface, and that crushed concrete was best avoided. This information supported previous studies in racehorses that indicated that surface maintenance is essential, especially when many horses are using an arena daily. Problems were less likely if an arena was privately owned.     

RT-PCR快速诊断禽流感

目前,禽流感检测方法较多,但均费时费力,且灵敏度不高.本研究立足于临床实际,选择A型流感病毒核蛋白(NP)基因序列保守区,设计了一对特异性引物,从临床病料中提取RNA,建立了一步法单管逆转录-聚合酶链反应(RT-PCR)快速诊断方法,该方法快速、灵敏,为RT-PCR用于禽流感的临床早期确诊和分子流行病学调查奠定了基础.     

RT-PCR检测猪传染性胃肠炎病毒方法的建立

猪传染性胃肠炎 ( TGE)是一种以严重腹泻、呕吐和脱水为临床特征的高度接触性传染病 ,属于国际兽疫局 ( OIE)法典中 B类疫病必检的猪传染病。TGEV是一种有囊膜的正链 RNA冠状病毒。目前检测 TGEV的方法主要有中和试验、免疫荧光抗体试验、酶联免疫吸附试验和电镜技术 ,这些方法对于检测 TGEV和防制 TGE起到了重要作用 ,但也存在特异性不强、灵敏性差、耗时长等缺点。c DNA探针、RT- PCR近年来已成为国际上用于检测病原微生物的主要方法。由于 c DNA探针与临床样品中非相关核酸有一定的非特异性结合 ,尤其是检测粪便、尿液等…