伪狂犬病病毒、猪细小病毒和流行性乙型脑炎病毒检测基因芯片的制备

对伪狂犬病病毒（PRV）、猪细小病毒（PPV）和流行性乙型脑炎病毒（JEV）检测基因芯片的制备及该芯片的检测技术进行了研究。选定靶基因最佳点样质量浓度为200 mg/L,用基因芯片点样仪将其点制在氨基化基片上,经干燥、水合、紫外线交联和洗涤后,成功制备了PRV-PPV-JEV检测基因芯片。以CY3荧光素标记的dCTP经PCR扩增制备探针,对芯片的质量进行了评价。结果表明,制备的芯片质量好,探针最佳使用质量浓度为3 000μg/L,芯片系统检测灵敏度可达3μg/L。该芯片可同时检测PRV、PPV和JEV,其灵敏度高、特异性强,芯片可重复使用,室温下至少可保存4个月。     

猪传染性胃肠炎病毒检测基因芯片的构建

采用PCR扩增制备TGEV的靶基因并进行纯化,对基因芯片的最佳靶基因点样质量浓度、探针质量浓度、杂交温度、杂交时间进行筛选,选择构建检测芯片的最适靶基因,进行基因芯片探针最佳标记方法试验.结果表明,质粒PCR扩增和采用异丙醇沉淀纯化的靶基因质量好,基因芯片最佳靶基因点样质量浓度为200mg/L,最佳探针质量浓度为3 000 μg/L,预杂交时间为1 h,杂交时间为3～6 h,杂交温度为48℃,以S、S3、sM、M、N、ORF7、POL等7个靶基因为构建TGEV检测芯片的最适靶基因,确定了多重PCR扩增标记TGEV探钟的最佳体系,Cy3-dCTP标记浓度为2.5 μmol/L,构建的TGEV检测芯片与标记的混合探针杂交效果好.     

PCV2、PRV、PPV多重PCR检测方法的建立及其应用

根据GenBank中已发表的猪圆环病毒2型(PCV2)、猪伪狂犬病毒(PRV)、猪细小病毒(PPV)有关基因序列,通过序列比对及参考相关文献,设计了3对特异性引物。通过优化,建立了可同时检测PCV2、PRV及PPV 3种病毒的多重PCR方法。结果表明,该方法能同时检测到PCV2、PRV及PPV的最低核酸量分别为40pg、72pg、46pg。对猪圆环病毒3型(PCV3)、猪细环病毒(TTSuV)、猪流行腹泻病毒(PEDV)、猪蓝耳病毒(PRRSV)、猪瘟病毒(CSFV)无扩增。应用该方法对87份临床样品进行检测,PCV2阳性检出率为28.7%(25/87),PRV野毒检出率为11.5%(10/87),PPV检出率为12.6%(11/87)。其中2种以上病毒混合感染阳性率为13.8%(12/87),3种病毒同时感染的阳性率为2.3%(2/87),其结果也与单一PCR结果一致。研究结果提示,该方法可用于PCV2、PRV、PPV三种病原的单一感染或混合感染的鉴别诊断。     

猪伪狂犬病病毒和猪博卡病毒混合感染的检测

为了检测猪伪狂犬病病毒和猪博卡病毒混合感染的情况,研究建立了快速,简便,灵敏度高,特异性强的鉴别猪伪狂犬病病毒(PRV)和猪博卡病毒(PBoV)的双重检测方法。针对PRV gE基因和PBoV NS1基因的序列,分别设计了2对特异性引物,通过对引物浓度、模板加入量、退火温度等的优化,建立了快速鉴别PRV和PBoV的双重PCR检测方法,并进行了特异性和敏感性试验。特异性试验表明,该方法可以扩增出PRV gE长度为316 bp和PBoV NS1长度为996 bp的目的片段,对大肠杆菌、猪圆环病毒Ⅱ型、猪捷申病毒、猪瘟病毒、猪繁殖与呼吸综合征病毒均无扩增;敏感性试验表明,PRV、PBoV的最低核酸检出量分别为6.44×10~2拷贝和9.51×10~3拷贝,与单一PCR敏感性相同。应用该方法对49份送检病料样品进行检测,其中PRV和PBoV的单纯感染检出率分别为34.69%和14.28%,混合感染检出率为8.16%,与单一PCR检测结果符合率为93.88%。     

广西猪细小病毒与PRRSV、CSFV、PCV2、PRV混合感染的检测

应用PCR技术,对广西南宁、玉林、贵港、柳州、钦州和桂林6个市的10个规模化猪场送检的141份病猪组织样品进行猪细小病毒(PPV)的检测;同时,对鉴定为PPV阳性的样品进行了猪繁殖与呼吸综合征病毒(PRRSV)、猪瘟病毒(CS-FV)、猪圆环病毒2型(PCV2)和猪伪狂犬病毒(PRV)的检测,以确定猪群中PPV与其它病毒混和感染情况。结果,所有样品诸病毒的阳性检出率达17.73%(25/141);流产胎儿PPV阳性率为19.57%(9/46),繁殖障碍母猪扁桃体的PPV阳性率为17.74%(11/62),发病断奶仔猪组织病料的PPV阳性率为15.15%(5/33),PPV与PRRSV、CSFV、PCV2和/或PRV4种病毒均有混合感染现象,混合感染样品占PPV阳性样品的48.00%(12/25)。     

用地高辛标记核酸探针检测猪细小病毒的研究

根据猪细小病毒(PPV)基因组序列,设计引物克隆了PPV YK株保守序列NS1基因,将NS1基因纯化,利用地高辛标记制备了NS1基因PCR产物探针和克隆NS1探针,两种核酸探针的标记都达到了0.1 pg/μL。特异性试验结果表明,这两种探针都能与PPV DNA发生特异的阳性杂交,而与对照的PRV、PCV、PRRSV和HCV的核酸杂交呈阴性。敏感性试验结果表明,克隆NS1探针敏感度为0.5 pg/μL,NS1基因PCR产物探针敏感度为1 pg/μL。综上所述,这两种DIG标记探针特异性强,敏感性高,可用于PPV的检测。     

猪呼吸和繁殖障碍类病毒性疫病多重PCR检测方法的建立及应用

根据GenBank中PRRSV ORF6、PCV2 ORF2、PPV NS1、PRV gB、SIV M、JEV NS1、CSFV E2等基因的部分片段,分别设计特异性引物,用实验室已保存的病毒及阳性病料,通过对7个病毒单一PCR的退火温度和敏感性进行优化和检测,再选择合适的多重PCR缓冲体系及酶,优化退火温度、模板及引物浓度,最后检测多重PCR的敏感性、特异性及重复性,建立一种能够同时且快速鉴别PRRSV、PCV2、PPV、PRV、SIV、JEV和CSFV这7种常见猪呼吸道和繁殖障碍类病毒的多重PCR检测方法,并用其对2017-2019年贵州部分地区的150份临床病料进行检测。多重PCR特异性检测结果表明:从混合病毒基因组中分别扩增出大小为224,353,424,549,684,831,1 137 bp的特异性片段,未扩增出E.coli、APP、PEDV及正常组织的DNA/RNA;敏感性试验表明,该方法对病毒的最低检测量分别为PRRSV 94 pg、PCV2 66 pg、PPV 68 pg、PRV 20 pg、SIV 35 pg、JEV 17 pg、CSFV 14 pg;重复性试验表明:相同条件下的6次重复试验均能扩增出7个病毒的目的条带;应用试验表明:150份临床病料中二重感染阳性率高达66.00%(99/150);三重感染阳性率达11.33%(17/150);四重感染阳性率达2.00%(3/150);五重感染阳性率达0.67%(1/150);六重感染阳性率为0,七重感染阳性率为0,阳性PRRSV、PCV2、PPV、JEV、SIV的多重PCR与单一PCR的符合率均为100.00%,阳性CSFV和PRV的符合率为90.00%以上,研究建立的多重PCR检测方法具有敏感性高、特异性强、重复性好的特点,对猪场猪呼吸和繁殖障碍类病毒病混合感染的快速诊断具有十分重要的意义。     

猪伪狂犬病、猪细小病毒病及猪流行性乙型脑炎多重PCR诊断方法的建立

根据Genbank上已发表的猪伪狂犬病毒(PRV)、猪细小病毒(PPV)和猪流行性乙型脑炎病毒(JEV)基因序列，用Array Designer2．0软件设计并合成了PRV gB、PPV VP2、JEV C基因片段的3对引物，以PRV Fa株、PPV B2株、JEV SA14-14-2株细胞培养物提取棱酸人为混合后作为模板，筛选PCR反应条件，扩增出长度分别为324bp、471bp和238bp的3条特异性片段，建立了检测3种病毒的多重PCR方法。应用该方法对PRVFa、PRV渝A、8F20、BUK株、德国Bartha-K61株、PRV Ea株、PRV疫苗毒，PPV132株、PPV SR标准株SR-1、SR-2、SR-3，JEV SA14-14-2株的病毒核酸进行扩增，均获得了特异性的目的片段，而扩增PRRSV、CFSV、PCV-2及相应的培养细胞核酸结果均为阴性。对PRV Fa、PPV B2和JEV SA14-14-2的最低检出量分别为17．5pg、13．7pg和20pg的DNA或cDNA。该试验方法适合对PRV、PPV和JEV的联合检测和鉴别诊断。     

猪细小病毒与猪伪狂犬病毒二重SYBR GreenⅠ实时荧光PCR方法的建立与检测

本研究旨在建立一种能快速、灵敏、同时检测出猪细小病毒与猪伪狂犬病毒的基于SYBR GreenⅠ实时荧光定量PCR方法。参照GenBank中登录的相关基因序列,设计了2对引物分别用于扩增PRV gH基因与PPV NS1基因的部分片段。将测序正确的PRV gH基因与PPV NS1基因片段克隆入pGEM-T Easy载体,转化大肠杆菌DH5α,经测序鉴定后得到阳性重组质粒,作为标准品模板建立SYBR GreenⅠ荧光定量PCR标准曲线和熔解曲线,并对其灵敏性、特异性和重复性进行验证。结果表明,猪细小病毒与猪伪狂犬病毒荧光定量PCR的标准曲线的Tm值分别为80.9℃和86.5℃,熔解曲线特异,灵敏度分别可达248拷贝/μL和160拷贝/μL,是普通PCR检测方法的100倍。本次建立的猪细小病毒与猪伪狂犬病毒荧光定量PCR检测方法实现了2种病毒的同时检测,能够对PRV、PPV混合感染的临床病料进行快速诊断。     

2014-2018年广西6种猪主要病毒性繁殖障碍疫病流行病学调查

试验旨在了解广西猪主要病毒性繁殖障碍疫病的发生态势,为预防和控制此类疫病提供科学依据。采用RT-PCR/PCR方法对2014年3月至2018年2月采自广西的349份流产胎儿样品进行猪瘟病毒(CSFV)、猪繁殖与呼吸综合征病毒(PRRSV)、猪圆环病毒2型(PCV2)、猪伪狂犬病病毒(PRV)、猪细小病毒(PPV)及猪乙型脑炎病毒(JEV)6种主要病毒性繁殖障碍疫病病原的检测并分析其阳性检出率在不同年份、季节之间的差异及病原混合感染情况。结果显示,2014-2017年,6种病原的猪场阳性率从高到低依次为JEV(36.00%)、PRRSV(16.00%)、PCV2(9.00%)、PRV(7.00%)、PPV(6.00%)和CFSV(5.00%),样品阳性检出率从高到低依次为JEV(27.06%)、PRRSV(6.18%)、PRV(5.88%)、PCV2(3.82%)、CSFV(2.35%)和PPV(2.35%)。季节因素对6种病毒性繁殖障碍疫病的发生有一定影响:JEV在夏季、秋季检出率较高,春季、冬季检出率较低;PRRSV一年四季检出率均较高,且无明显差异;PCV2在春季检出率较高,其次是夏季和冬季,秋季检出率较低;PRV在春季、冬季检出率较高,夏季、秋季检出率均为0;PPV在夏季检出率较高,其次是春季和秋季,冬季检出率为0;CSFV在冬季检出率最高,其次是夏季,春季和秋季检出率均为0。流产胎儿以单一感染为主,6种病毒均存在不同程度单一感染情况,单一感染率JEV最高(23.82%)、PCV2最低(0.59%);混合感染以双重感染为主,其中以2016年双重感染情况较多,且感染组合多样;三重感染情况较少、仅在2016年送检样品中发现1例,未发现四重及四重以上感染情况。调查结果表明,2014-2017年,JEV均有较高的阳性检出率,已成为广西部分猪场母猪流产最主要病毒性病原。PRRSV和PRV仍是目前引起广西猪场母猪流产的主要病毒性病原。     

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 -