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1.
鸡新城疫病毒分离株与La Sota株灭活疫苗效力比较试验   总被引:1,自引:0,他引:1  
用NDV分离株及La Sota株为抗源液,经福尔马林灭活后,与油佐剂混合,分别制成分离株灭活苗、La Sota株灭活苗及分离株与La Sota株二价灭活苗。将这三种灭活疫苗分别免疫SPF鸡后,均获得100%抵抗NDV分离株及F48株强毒攻击的保护力;而用这3种灭活苗与La Sota活苗单独或联合使用,免疫带有ND母源抗体的普通鸡后,3种灭活苗的免疫效力不同,分离株灭活苗与价灭活苗对NDV分离株攻击的免疫保护效力明显优于La Sota灭活苗;灭活苗与活苗同时使用,其免疫效力明显优于单独使用灭活苗或活苗。  相似文献   

2.
为了评价疫苗免疫保护效果,进而筛选出最佳的免疫方案,将分离到的鸡新城疫病毒(Newcas-tle disease virus,NDV)流行毒株制备成灭活疫苗进行交叉免疫保护试验研究。把采集到的疑似发生新城疫的病鸡肺、气管环等组织经处理后接种10日龄SPF鸡胚进行病毒的分离和增殖,并用血清学和分子生物学方法进行毒株的鉴定;用分离到的NDV/Chicken/TC/1/2011毒株制成油乳剂灭活苗,与La Sota疫苗以不同的疫苗组合免疫SPF鸡,进行交叉免疫保护试验。结果显示,共分离到9株新城疫病毒,其F蛋白裂解位点的氨基酸均为112 R-R-Q-K-R-F117,表现为强毒株的分子特征,与致病指数结果一致。分离株灭活苗组和分离株灭活苗+La Sota弱毒苗对试验鸡的免疫保护力最高,其次是La Sota灭活苗+La Sota弱毒苗和LaSota灭活苗,La Sota弱毒苗对试验鸡的免疫保护力最低。NDV分离株与疫苗株La Sota存在明显抗原性差异,这将对新城疫疫苗的发展和疾病控制策略制定至关重要。  相似文献   

3.
正韩国建国大学的科研人员应用昆虫细胞表达系统研制出表达新城疫病毒(NDV)F蛋白和流感病毒M1蛋白的NDV病毒样颗粒(VLP)。SPF鸡分别免疫含不同剂量VLP(0.8、4、20、100μg/mL)的NDV VLP油乳剂疫苗。免疫3周后,应用商品化ELISA试剂盒检测NDV VLP疫苗的免疫力;同时用NDV强毒株进行攻毒试验以评估NDV VLP疫苗对SPF鸡的保护效果。结果显示,NDV VLP疫苗免疫后可产生大量抗NDV的抗体,且SPF鸡对NDV强毒株的抵抗力与NDV VLP疫苗免疫剂量相关。尽管含0.8、4μg/mL VLP的NDV VLP疫苗不能  相似文献   

4.
用新城疫病毒(NDV)疫苗株La Sota和NDV基因Ⅶ型致弱株AND/Ⅶ为免疫原,分别以活苗和灭活苗的形式免疫2周龄试验鹅,免疫后第7、14天和21天采血分离血清用于抗体效价测定.免疫后3周以基因Ⅶ型强毒分离株JS2-06进行攻毒,攻毒后每天观察各组鹅的发病情况,并于第2、4天和7天分别采集喉气管和泄殖腔棉拭样品,用于病毒的分离.试验结果表明,活疫苗免疫后不能产生有效的免疫应答,而灭活苗免疫鹅对强毒的感染具有较强的抵抗能力,但基因Ⅶ型致弱株AND/Ⅶ能更有效抑制鹅体的排毒,其免疫效力明显高于疫苗株La Sota.  相似文献   

5.
鸡新城疫的流行与免疫   总被引:1,自引:0,他引:1  
门诊病例统计表明,我国鸡群中ND的发病率仍非常普遍。近些年来,世界各地对NDV分离株的研究结果发现,其HN基因和F基因序列的某些位点发生的变化,致使毒株间的毒力差异较大,抗原性亦有差异,但其主要抗原表位未发生变化。山东家禽研究所禽病室对1998-1999年的6个NDV分离株做了比较研究,各毒株的毒力不同且都比经典的F48E9强,其中二个属基因Ⅶ型。但交叉免疫保护试验表明,用La Sota株弱毒苗及其灭活油乳苗免疫的鸡,在用这6个分离毒分别攻毒后,均有1005保护率。同样,用这6个分离毒制成的灭活油乳苗免疫鸡后,对经典毒E48F9亦产生100%保护率。这表明,从目前发病鸡群中分离的NDV毒株与La Sota弱毒株、标准F48E9强毒株间有很好的交叉免疫保护作用。  相似文献   

6.
用新城疫(ND)分离强毒油佐剂灭活苗和NDV La Sota油佐剂灭活苗分别免疫母源抗体平均为2 log2的12日龄公雏。免疫后每隔1周采集血清,用微量血凝抑制试验检测HI抗体。免疫后21 d抗体水平达到峰值,抗体水平在6log2以上,维持30 d以上。免疫40 d后,用ND分离强毒株和NDVF48E9分别进行攻毒试验,2种疫苗的保护率均为100%,攻毒结果表明,ND分离强毒株和NDVF48E9株的免疫原性差异不显著。  相似文献   

7.
强毒鸡新城疫病毒的分离鉴定及免疫防制研究   总被引:3,自引:0,他引:3  
从陕西发病鸡群中分离出8株病毒,分离毒大多为速发型NDV强毒株,对经典NDV La Sota株免疫的雏鸡及52周龄高抗体母鸡仍有强的致病力,采用NDV SH1-SH8病株制备成多价油乳剂灭活苗,免疫鸡群有良好的保护力。  相似文献   

8.
旨在分离筛选免疫原性好的新城疫病毒(NDV)流行毒株。从发病鸡组织中分离到4株病毒,经血凝和血凝抑制试验鉴定为NDV,进而完成致病指数测定、F基因高变区测序和遗传进化分析,并通过鸡胚交叉中和试验和攻毒试验研究PLK-N-06株对比La Sota疫苗株的抗原差异和免疫保护效力。结果显示,4个分离株的致病指数均属速发型NDV范围,且PLK-N-06株毒力最强;F蛋白裂解位点均为112R-R-Q-K-R-F117,符合强毒株特征。遗传进化分析表明,分离株均为Ⅶd亚型。交叉中和试验结果显示,PLK-N-06株和La Sota株存在显著的抗原性差异。用PLK-N-06株油乳剂灭活苗免疫接种SPF鸡后产生的HI抗体效价几何平均值为1∶338,显著高于La Sota疫苗(1∶69),且其对PLK-N-06株感染的排毒率为0/10,明显低于La Sota株油乳剂灭活苗的4/10,结果表明PLK-N-06株具有良好的免疫原性,为新城疫基因Ⅶ型新型疫苗的研发奠定了基础。  相似文献   

9.
将ND-AI(H9亚型)二联苗分别以1.0、0.5、0.2、0.1、0.05、0.02 mL 6个不同剂量免疫5周龄SPF鸡,免疫后3周采血测NDV及AIV 的HI抗体,并用H9亚型AIV及NDV F48株攻击.结果表明,这6个免疫组鸡的NDV HI抗体几何平均效价分别为2 10、2 8.8、2 8.5、2 7.0、2 6.1、2 5.7;AIV HI抗体水平分别为2 9.3、2 8.4、2 7.7、2 5.7、2 5.1、2 2.8;对照组鸡的NDV及AIV HI抗体均为零.攻毒试验证实,以0.1~1.0 mL剂量免疫鸡获得了100%的抵抗NDV及AIV强毒攻击的保护力;0.02 mL和 0.05 mL的免疫剂量也可使其对NDV与AIV的保护率达到90%~100%.  相似文献   

10.
将不同新城疫病毒疫苗免疫SPF鸡和商业用肉鸡,对免疫后抗体水平变化和对野毒株攻击的保护率进行了监测。利用Clone 30、F48E8和NXF3单联苗和联苗免疫过的SPF和商业肉鸡,对10^5EID50两次攻毒保护率均为100%;而只用La Sota疫苗免疫的SPF鸡保护率为40%。试验数据表明,分离株NXF3具有较好的免疫原性和对强毒攻击的保护,可以作为候选疫苗用于商业肉鸡。  相似文献   

11.
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.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
16.
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.  相似文献   

17.
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  相似文献   

18.
A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

19.
Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L3) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L3 developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.  相似文献   

20.
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