肉食兽细小病毒核酸探针的制备及其初步应用研究

将提纯的貂肠炎病毒(MEV)中间复制型DNA(RF-DNA),以HinaⅡ酶切,回收0.7kbC片段并克隆至质粒pBR322中,构成重组质粒pBM,经转化大肠杆菌RRⅠ并扩增后,提纯pBM,酶切电泳回收克隆的C片段,以[α-32P]dATP标记C片段和pBM,用光生物素标记pBM,分别制成放射性同位素和光生物素核酸探针。采用打点杂交技术检测了5种肉食兽细小病毒的细胞培养物和非细小病毒科5种病毒的细胞培养物,同时检测了貂和犬的粪便样品33份。结果表明,32P标记的C片段和pBM探针与光生物素际记的pBM探针均具有相同的杂交特异性,与5种肉食兽细小病毒及感染细小病毒的貂、犬粪样呈杂交阳性反应,与其他科病毒及健貂、犬粪样呈阴性。同位素32P和光生物素标记探针分别检出1 pg和10 pg貂肠炎病毒RF-DNA,敏感性比血凝试验分别离100倍和10倍。     

肉食兽细小病毒通用基因探针研制成功

本校军事兽医研究所病毒研究室赵永军等通过酶切,由貂肠炎细小病毒(MEV)的复制型DNA(RF-DNA)获得HindⅢ C,将其克隆至pBR322中,构成重组质粒pBM,经转化大肠杆菌RRI扩增后,提纯pBM,再作HindⅢ酶切,用低融点琼脂糖凝胶电泳回收C片段。用随机引物法以α—~(32)P—dATP标记C片段和pBM,采用打点杂交技术,以这两种探针检测了6种动物的细小病毒细胞培养物和其它科5种病毒,同时检测了貂和犬的粪便标本33份。     

应用生物素标记的重组质粒作为探针的杂交条件及敏感性研究

貂肠炎细小病毒复制中间型 DNA(MEV-RF-DNA)的 HindⅢ-C 片段被克隆到 pBR322中形成重组质粒pBM。用光生物素(photo biotin)标记 pBM 和 HindⅣ酶切片段的 pBM 作为探针分别与貂,太细小病毒感染的细胞培养物人工感染细小病毒的貂和犬粪便进行斑点杂交试验,结果发现两种探针检测的敏感性相差10倍以上.光生物素标记的完整重组质粒探针具有放大作用,酶切后的 pBM 敏感性不如前者.另外,本实验还证明在用生物素标记的探针杂交时,被检样品用热变性处理比碱变性处理效果更佳,而且简便。     

西宁地区犬棘球绦虫感染情况调查

为了了解青海省西宁地区犬棘球绦虫的感染情况,用ELISA对采自于青海省西宁地区4个县的466份犬粪进行棘球绦虫抗原检测,结果总体阳性率为6%。其中西宁市犬粪样121份,阳性3份,阳性率2.48%;湟源县犬粪样105份,阳性5份,阳性率4.76%;湟中县犬粪样123份,阳性9份,阳性率7.32%;大通县犬粪样117份,阳性11份,阳性率9.4%。结果表明西宁市区犬棘球绦虫的感染率低于郊县,说明西宁市区犬棘球绦虫感染引起注意。     

细粒棘球绦虫感染终末宿主检测方法的评价

对细粒棘球绦虫感染家/牧犬常用的检测方法开展比对试验,并予以评估。对人工感染细粒棘球绦虫试验犬含卵粪样在不同时段用饱和蔗糖液(1.28 g/m L)漂浮虫卵,镜检;经化学药物驱虫,收集人工感染试验犬驱虫前、后粪样,流行病学调查中收集的家/牧犬粪样,用粪抗原抗体夹心ELISA检测试剂盒检测,同时,对检出的家/牧犬阳性粪样,再用虫卵漂浮法复检;通过氢溴酸槟榔碱下泻法检查家/牧犬感染细粒棘球绦虫虫体,同时,对下泻犬粪样用粪抗原检测和虫卵漂浮法进行复检。饱和蔗糖液漂浮虫卵最佳时段为2 h,可检出虫卵量与其他时段差异显著(P0.05);人工感染犬驱虫前、后粪样经粪抗原检测,OD值差异极显著(P0.01);对12 288份家/牧犬粪样进行粪抗原检测,阳性样品991份,感染率为8.1%(991/12 288),对991份阳性粪样进行虫卵漂浮法复检,检查出54份粪样中含虫卵。经下泻法检查312只家牧犬,其中,262只犬下泻,检查出27只犬感染细粒棘球绦虫成虫;对262份下泻犬粪样进行粪抗原检测,阳性29份;对262份下泻犬粪样用虫卵漂浮法检查,仅14份粪样检出虫卵。犬粪抗原抗体夹心ELISA检测犬感染细粒棘球绦虫可及时区分驱虫前、后感染状况,其更为安全、快捷、准确。     

貂肠炎病毒DNA探针打点杂交技术检测兔出血症病毒

采用HindⅢ酶切和琼脂糖凝胶电泳技术,从重组质粒pBM中回收0.7kb貂肠炎病毒(MEV)DNA片段.以[α-~(32)P]dATP和光生物素分別标记制备DNA探针。采用打点杂交技术,用上述探针检测提纯的兔出血症病毒(RHDV)和3份感染RHDV的兔肝脏样品,同时检测从貂、犬、豹、猫和貉分离的5种肉食兽细小病毒,并用电镜检查和血凝试验为对照。探针与上述5种肉食兽细小病毒呈杂交阳性反应,而RHDV及感染的肝脏样品为阴性反应.该结果表明,MEV和RHDV在该0.7kb DNA区域内没有同源性,而5种肉食兽细小病毒在此区域内具有遗传相关性。     

吡喹酮对犬细粒棘球蚴绦虫病防治效果

本文采用剖检法和ELISA法对青海省民和县22个乡镇的6条犬进行了剖检、180份犬粪样进行了包虫粪抗原检测,以此判定犬细粒棘球蚴绦虫病防治效果。试验结果表明,与2016年相比,2017年犬细粒棘球蚴绦虫感染率为0,犬包虫粪抗原阳性率为2.7%,阳性率明显下降,防治效果显著。     

四川省重点包虫病流行区土壤水等环境中虫卵污染情况监测

本试验通过已经建立的荧光PCR方法,对四川部分地区自然环境中的包虫虫卵进行检测,采集包虫流行地区石渠县、色达县、甘孜县、炉霍县、天全县和宝兴县的环境样本,提取样本总DNA,采用荧光PCR对细粒棘球绦虫和多房棘球绦虫ND1基因进行检测;结果显示,共采集犬粪850份,阳性82份,阳性率12. 4%;土壤61份,阳性8份,阳性率13. 1%;犬毛39份,阳性3份,阳性率7. 7%;水样80份,均未检出。本次调查显示,犬粪、土壤以及犬毛均检出包虫虫卵DNA,土壤是一个不可忽视的传播因素。提示有必要加强对环境中虫卵的监测并筛选杀灭环境中虫卵消毒剂,以确保包虫病流行区域人和家畜的安全。     

奶牛牛病毒性腹泻病毒与冠状病毒混合感染的PCR诊断

为了对河北省石家庄市某奶牛场发病及死亡奶牛进行确诊,试验对腹泻奶牛的粪样进行了牛病毒性腹泻病毒(BVDV)和牛冠状病毒(BCoV)PCR检测,同时对病死奶牛脏器样品进行BVDV、BCoV、传染性鼻气管炎病毒(IBRV)、牛轮状病毒(BRV)及牛细小病毒(BPV)的PCR检测。试验结果显示,6份粪样BVDV阳性率为50%,BCoV阳性率为33.3%,同一份粪样中可同时检测出BVDV和BCoV两种病毒。小肠、肺脏和肝脏中均检出BVDV和BCoV,未检测出IBRV、BRV和BPV。结果表明,BVDV和BCoV为阳性,IBRV、BRV和BPV结果为阴性。最后确诊为BVDV和BCoV的单一感染和混合感染。     

应用斑点酶联免疫吸附试验快速检测犬细小病毒的研究

应用斑点酶联免疫吸附试验(Dot—ELISA,简称斑点试验)能检出少至0.58ng/ml的犬细小病毒的病毒抗原,比常规ELISA及HA试验分别敏感8及64倍,与犬腺病毒等5种对照病毒不发生交叉反应,与病毒分离试验的阳性符合率为94.44％(17/18),比常规ELISA及HA试验提前24～48h检出实验感染犬粪中排毒。采用斑点试验、常规ELISA、HA试验三种方法对316份犬粪标本进行了检测比较,阳性率分别为33.23％、27.85％、23.10％(P<0.05)。该法可在4h内报告结果。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -