马动脉炎病毒实时RT-PCR检测方法的建立

选取马动脉炎病毒基因组中高度保守的开放阅读框7序列,设计了特异性引物和TaqMan探针,利用一步法的实时定量RT-PCR来定量检测马动脉炎病毒.分别使用马动脉炎病毒的总RNA和含有选定检测序列的克隆标准品做扩增曲线,两曲线斜率之差小于0.1,证明两者的扩增效率相同,可用选定检测序列的克隆标准品对马动脉炎病毒进行定量检测.该方法敏感,快速,准确,且无交叉污染,能满足海关及检疫部门对马动脉炎病毒快速、准确的检测要求.     

定量检测马动脉炎病毒方法的建立

为建立快速、敏感、准确的马动脉炎病毒检测方法,笔者选取病毒基因组中高度保守的ORF7序列设计引物和TaqMan探针,分别使用马动脉炎病毒的总RNA和含有选定检测序列的克隆标准品进行一步法实时定量RT-PCR,绘制扩增曲线,两曲线斜率之差小于0.1,证明两者的扩增效率相同,可用选定检测序列的克隆标准品对马动脉炎病毒进行定量检测。     

山东、河南、河北驴群马动脉炎病毒和马疱疹病毒8型的检测与分析

为了解我国山东省、河南省、河北省驴群中马动脉炎病毒(EAV)和马疱疹病毒8型(EHV-8)的感染现状,于2020年从3个省份的屠宰场和驴场收集驴血样品共计860份.通过RT-PCR和PCR方法分别对血样进行EAV和EHV-8检测,统计其阳性率和混合感染率,并分析其流行情况;同时,对3个省份EAV和EHV-8阳性样品的O...     

中国华南、华中、东北和西北地区马动脉炎病毒（EAV）感染马血清流行病学调查

马病毒性动脉炎(EVA)是一种由马动脉炎病毒(EAV)引起马属动物主要通过呼吸系统和生殖系统传播的传染病,是危害养马业及赛马业的重要疾病之一.本试验应用纯化EAV全病毒为抗原建立EAV-IgG间接ELISA方法与西班牙INGEZIM-ARTERITIS试剂盒分别检测华南、华中、东北和西北地区共计383份马血清样品.其结果为:华南地区赛马动脉炎阳性率为26%,华中地区赛马动脉炎阳性率为0,东北地区役用马动脉炎阳性率为8.26%,西北地区役用马动脉炎阳性率为7.55%.鉴于此,有必要加强EVA检测,掌握EVA在我国分布,以有效的预防和控制本病传播.     

RT-PCR检测猪瘟病毒方法的建立与应用

建立RT PCR检测猪瘟病毒的方法。根据已发表的猪瘟病毒E2基因 (囊膜糖蛋白gP55基因 )序列 ,设计合成了一对特异性引物 ,扩增片段的大小为 50 7bp ,用RT PCR技术对石门系标准株和 1 0株分离株进行检测。结果这对引物对标准株和 1 0株分离株均能扩增出与预期大小相符 50 7bpRT PCR产物 ,而对其他 6种猪病病原核酸的扩增结果为阴性。该RT PCR可检出 1 0 0pg的猪瘟病毒RNA模板 ,对人工感染猪不同组织样品进行检测 ,结果对白细胞抽提的核酸样品检出率最高为 1 0 0 % (2 4 / 2 4 ) ,其次为扁桃体、脾、肾 ,检出率为 83 3 % (2 0 / 2 4 ) ,再者为淋巴结 ,检出率为66 7% (1 6/ 2 4 )。对送检的 1 9份疑似猪瘟的病死猪病料组织进行RT PCR检测 ,结果有 1 6份样品为猪瘟病毒阳性。兔体交叉反应试验结果RT PCR阳性的 1 6份病料中 ,有 1 4份样品被判为含有猪瘟病毒 ,其他病料兔体交叉反应试验结果全为阴性     

猪流行性腹泻病毒实时荧光定量RT-PCR检测方法的建立及初步应用

为建立一种特异、灵敏、量化、快速的猪流行性腹泻病毒(PEDV)检测方法,设计1对PEDV N基因的特异性引物,建立Eva Green染料的实时荧光定量RT-PCR的检测方法,并对疑似PEDV感染的临床样品进行检测。结果显示,所建立的实时荧光定量RT-PCR方法的标准曲线具有良好的线性关系,线性相关系数R2=0.999;不与猪传染性胃肠炎病毒(TGEV)、猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)发生交叉反应,具有较强的特异性;灵敏度比常规RT-PCR方法高100倍;重复性试验的变异系数均小于5%,重复性良好。对43份临床样品进行检测,结果比普通PCR多检出2份阳性。结果表明,建立的实时荧光定量RT-PCR检测方法在特异性、灵敏度和重复性方面都很好,可用于临床PEDV检测。     

马动脉炎病毒Eva Green荧光定量RT-PCR检测方法的建立及初步应用

为建立马动脉炎病毒(EAV)的快速检测方法,本研究设计了一对针对EAV Bucyrus株ORF7基因序列的特异性引物,建立了检测EAV的Eva Green荧光定量RT-PCR (qRT-PCR)方法.结果表明,该方法在102拷贝/μL～107拷贝/μL范围内具有良好的线性关系;最低检出量为1015 TCID50/mL病毒,敏感性为常规RT-PCR的100倍,与其他马常见病毒无交叉反应;组内及组间重复性试验的变异系数均小于2％,具有较好的重复性.此外,采用该方法测定了EAV Bucyrus株及其拯救病毒icEAV感染RK-13细胞后的复制动态,并与TCID50方法进行了比较.结果显示icEAV与其亲本病毒接种RK-13细胞后,0h测定病毒TCID50及拷贝数分别为103.33TCID50/mL(1 04 65拷贝/2μL)和10350 TCID50/mL(104 70拷贝/2μL);60 h时,细胞病变达到100％,icEAV及其亲本病毒的TCID50及拷贝数分别为105.67TCID50/mL(107 0拷贝/2μL)和105.57 TCID50/mL(106 98拷贝/2μL),两株病毒在RK-13细胞内的复制效率相似.本研究建立的Eva Green qRT-PCR方法可以为细胞培养物中EAV的检测提供有效的技术手段.     

RT-PCR检测猪繁殖障碍与呼吸道综合征病毒方法的建立与应用

作者参考国内外已发表猪繁殖障碍与呼吸道综合征病毒(PRRSV)的基因序列和PRRSV相关的RT—PCR检测方法报道，根据PRRSV高度保守、高特异性的NP蛋白基因设计了一对引物，通过对疫苗毒株、细胞分离株的检测，建立了PRRSVRT—PCR检测方法。进一步对40份临床样品进行了检测应用，结果有17份阳性样品，与临床症状和血清学结果相符。     

荧光定量RT-PCR检测公猪精液和血液中猪瘟病毒载量

为快速检测规模化猪场猪瘟病毒(Classical swine fever virus,CSFV),本研究参考GenBank中登录的CSFV序列设计引物,利用实时荧光PCR技术,构建重组质粒作为阳性标准品,建立特异、敏感、重复性好的CSFV快速定量检测方法.同时建立标准曲线,用于对猪瘟病毒的定量分析.本方法对规模化猪场的100份抗凝血和50份公猪精液样品进行检测,常规PCR检出27份占18％,荧光定量PCR检出123份占82％.表明荧光定量RT-PCR方法在检测猪瘟样品中具有潜在的应用价值,同时可检测猪群中猪瘟病毒持续性感染的状态存在.     

马疱疹病毒1型QuantStudio~(TM)3D数字PCR检测方法的建立

试验旨在建立一种高灵敏性的马疱疹病毒1(EHV-1) 3D数字PCR(3D-dPCR)检测方法,对EHV-1病毒含量较低的样品能准确定量检出,实现马鼻肺炎早期诊断及预防。根据EHV-1糖蛋白B基因保守区域设计特异性引物和探针,优化3D-dPCR反应体系中引物探针浓度和退火温度,对该方法进行灵敏性、特异性、重复性分析,建立了EHV-1的3D-dPCR方法。本研究建立的3D-dPCR方法,引物和探针最佳浓度分别为0.4和0.4μmol/L,最佳退火温度为60℃,该方法绝对定量曲线的R~2=0.998,线性关系良好,与实时荧光定量PCR方法相比灵敏度高10倍左右,最低检出限为5.83拷贝/μL;批内和批间重复性试验变异系数均3.2%;与EHV-4、马泰勒虫、马病毒性动脉炎的核酸无交叉反应;通过对123份临床样品进行3D-dPCR检测,结果显示,3D-dPCR方法阳性检出率为66.7%,高于世界动物卫生组织(OIE)中EHV-1的实时荧光定量PCR方法阳性检出率64.2%。3D-dPCR方法对病毒含量较高的样品与实时荧光定量PCR结果一致,对病毒含量较低的样品敏感性更高,能有效检出可疑样品。本试验结果表明,建立的3D-dPCR方法检测低拷贝数的临床样品时灵敏度高、特异性强、重复性好,可用于EHV-1的准确定量检测。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。