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为观察鸡传染性支气管炎病毒(IBV)HN99株对新城疫病毒(NDV)增殖的干扰作用,该试验采用不同浓度的IBV标准株M41和地方株HN99与鸡新城疫病毒(NDV)分别按不同接种顺序同胚增殖,利用病毒血凝试验(HA)测定NDV的效价,观察IBV对NDV的干扰作用,从而为检测IBV地方株HN99提供方法,也为同胚增殖两种病毒提供一系列的数据参考。试验结果表明,鸡传染性支气管炎病毒地方株HN99对NDV的干扰作用与其浓度和接种顺序有关。 相似文献
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试验旨在观察鸡传染性支气管炎病毒(infectious bronchitis virus,IBV)和鸡新城疫病毒(newcastle disease virus,NDV)之间的增殖干扰现象,分析在免疫过程中两种疫苗存在的免疫干扰,为确定疫苗的免疫程序提供依据。采用完全随机试验设计,选取10日龄鸡胚尿囊腔接种不同浓度的IBV、NDV以及不同浓度混合的IBV和NDV,收集尿囊液测定其血凝效价(HA);用不同浓度的IBV、NDV以及不同浓度混合的IBV和NDV分别免疫BALB/c小鼠及SPF雏鸡,收集血清,间接酶联免疫吸附法(ELISA)和血凝抑制(HI)试验测定IBV和NDV的抗体效价及抑制效价。结果表明,同胚培养时,无论先接种IBV后接种NDV还是先接种NDV后接种IBV或IBV和NDV同时接种,IBV对NDV均有干扰作用,而NDV对IBV没有干扰作用;接种IBV和NDV的小鼠,其产生IBV和NDV的抗体效价均低于单独免疫组,免疫的次序及免疫间隔时间对IBV和NDV的抗体效价均有影响,IBV对NDV的免疫效果具有较大的干扰作用。不同针混合免疫方式能提高IBV和NDV的抗体效价;接种IBV和NDV的雏鸡,免疫次序及免疫相隔时间对IBV和NDV的抗体效价均有影响,IBV对NDV的免疫效果具有较大的干扰作用;雏鸡和小鼠免疫血清HI试验数据表明,免疫次序及免疫间隔时间对IBV和NDV抗体的产生均有影响,但对NDV抗体的产生影响更明显,随着免疫间隔时间的增加,IBV和NDV的抗体水平呈增加趋势,雏鸡比小鼠更能敏感地反映出IBV对NDV的免疫干扰作用。混合注射时IBV和NDV的抗体水平均降低,IBV对NDV的免疫效果有干扰作用。因此,在同胚培养、小鼠及雏鸡的免疫中,IBV对NDV有干扰作用,而NDV对IBV无干扰作用。混合接种时IBV和NDV抗体效价均下降,IBV对NDV的免疫效果有干扰作用。免疫次序及免疫间隔时间对IBV和NDV抗体的产生均有影响,但随着免疫间隔的增加,IBV和NDV的抗体水平呈增加趋势。 相似文献
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传染性支气管炎病毒(IBV)干扰鸡新城疫病毒(NDV)在鸡胚上的生长现象已被作为一种诊断传染性支气管炎的方法。用IBV—NDV干扰试验对十五株来自疑为传染性支气管炎鸡群的病毒进行分析:接种IBV10小时后再接种NDV La Sota毒株,后通过血凝(HA)试验测定,有八株能干扰La Sota在鸡胚上的生长。 IBV这种干扰作用具有特异性,因为它可被相应的IBV抗血清所抑制。此种方法证明干扰作用是敏感的。在一些IBV继代代数少的情况下、虽然IBV不引起鸡胚产生病变,但可干扰NDV的HA活性。此外,血清学反应IBV阴性的样品不能干扰NDV在鸡胚上的生长。从以上情况看,对于分离IBV野毒来说,IBV—NDV干扰试验显然是一种改进的诊断方法。 相似文献
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鸡新城疫病毒与传染性支气管炎病毒同胚培养的试验研究 总被引:2,自引:1,他引:1
将鸡新城疫病毒(NDV)和鸡传染性支气管炎病毒(IBV)按一定的稀释比例等量混合接种9~10日龄SPF鸡胚,让其在同一鸡胚中增殖(简称同胚培养)。试验结果表明,用5倍稀释的ND-Lasota病毒液与 5000倍稀释的IBH120病毒液等体积混合后尿囊腔接种鸡胚,能在同一鸡胚中正常增殖,接种后96 h收毒,用红细胞凝集试验(HA)测得NDV、IBV两种病毒的血凝价分别为11 log2和12 log2,不低于各自病毒单独增殖的HA滴度,病毒的增殖基本趋于平衡。同时也证实了在合适的培养条件下,IBV对NDV的复制不会产生干扰。 相似文献
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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
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为了解乌鲁木齐市鸡传染性支气管炎(IB)的流行特征,本研究利用鸡胚培养、RT-PCR、新城疫病毒(NDV)干扰及鸡胚半数感染量(EID50)测定等多种方法分离到一株鸡传染性支气管炎病毒(IBV),将其命名为IBV/CK/CH(XJ)/01/2020。对其S1基因进行序列测定及比对分析发现,该分离株在鸡胚上连传5代出现侏儒胚现象,并且可以抑制NDV在鸡胚中的增殖,经计算其EID50为10-4.58/0.1 mL,为中等毒力毒株,攻毒组与正常组比较,雏鸡气管内有大量黏液且肺脏肿大,表现为呼吸型毒株特征,且其S蛋白裂解位点序列为HRRKR,与TC07-2、GX-NN0903等毒株形成一个独立的发育进化群,均属于TC07-2/GVI-1型IBV;与国内常用的H120、H52、M41等疫苗株的同源性仅为59%~65%。本研究为新疆地区IB的流行病学提供参考,也为当地IB的防控提供了理论依据。 相似文献
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本研究对分离自上海某养鸡场的疑似鸡传染性支气管炎病毒(Infectious bronchitis virus,IBV)进行了分离和鉴定.所采用的方法有:鸡胚致病性试验、对鸡新城疫病毒(Newcastle disease virus,NDV)的干扰试验、动物回归试验以及RT-PCR鉴定等.试验结果表明,该病原接种鸡胚后,48 h可引起鸡胚死亡,胚体呈侏儒样变化,对NDV感染有明显干扰作用;用分离的病毒接种SPF雏鸡可产生明显呼吸道症状,肾脏表现肿大和大量尿酸盐沉积等病理变化;用IBV特异性引物可以从分离物中扩增出IBV的N基因序列,测序结果表明,该毒株属于肾型IBV.综上所述,本研究在上海流行区域成功分离到一株IBV,将其命名为SH11株. 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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以国际标准强毒R株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离MG,并收集感染鸡所产蛋分离MG。结果表明,人工感染48小时后上、下呼吸道及肺已被全面感染,96小时气囊已被感染,120小时输卵管已能分离到MG,卵巢始终分离不到MG。人工感染鸡自144小时便能在其所产蛋中分离出MG。药物治疗能在72小时内消除感染,油乳剂苗则需24天后逐渐降低蛋内MG分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内MG,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献