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为探明近年来河南省猪伪狂犬病病毒(PRV)的遗传变异情况,本研究于2017年采集河南漯河和中牟地区疑似伪狂犬病发病养殖场送检的脑组织病料,通过细胞盲传、噬斑纯化、间接免疫荧光试验、Western blotting和透射电镜技术进行病毒分离鉴定。TCID_(50)法测定分离毒株的病毒滴度、生长曲线,通过小鼠感染试验测定分离毒株对小鼠的致死性。对gB、gC和gE基因进行PCR扩增、测序,并与参考毒株序列进行比对分析。结果显示,对PCR鉴定阳性的病料在PK-15细胞盲传后,两份病料在6代内均出现细胞病变,通过间接免疫荧光试验、噬斑纯化和透射电镜技术,成功分离鉴定了两株PRV,分别命名为HeN-LH株及HeN-YM株。分离毒株在PK-15细胞上的生长曲线显示,HeN-LH和HeN-YM株在感染后36 h病毒滴度分别可达10~(8.35)和10~(6.63) TCID_(50)/mL。用不同浓度的病毒接种小鼠,结果显示,HeN-LH和HeN-YM株LD_(50)分别为10~(2.13)及10~(3.25) TCID_(50)。对gB、gC和gE基因全长扩增测序后构建遗传进化树,结果显示,两株PRV毒株与Bartha、Fa和Ea等经典株的亲缘关系相对较远,而与2011年以来国内不同省份分离的PRV变异株亲缘关系较近。氨基酸序列比对分析显示,与其他变异株相似,gB、gC和gE基因均发生了多个氨基酸的变异,且在特定的位点存在特征性的氨基酸插入和缺失。本研究成功分离鉴定了两株PRV变异株,分离株对小鼠均表现出一定的致病性,本试验结果可为河南省伪狂犬病的防控工作和疫苗株的选择提供科学依据。 相似文献
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采集自江苏某猪场临床表现为疑似断奶仔猪多系统衰竭综合征(PMWS)的猪组织病料,经PCR检测为猪圆环病毒2型(PCV2)阳性,阳性病料经无菌处理后接种PK-15细胞进行PCV2分离并进行测序。采用间接免疫荧光(IFA)和相关基因序列分析软件进行鉴定、分析。用分离的毒株人工感染BALB/c小鼠,观察其对小鼠的致病性。结果显示,成功分离到2株PCV2毒株,分别命名为X46和5123,两毒株基因全长均为1 767 bp,遗传进化和同源性分析显示两毒株分别为PCV2d和PCV2b亚型,分离株P20代毒在PK15细胞上的TCID_(50)分别为10~(5.5)TCID_(50)/0.1 mL和10~(4.5)TCID_(50)/0.1 mL。小鼠感染试验结果显示PCV2对小鼠增重有抑制作用,对肝、脾和肾有较强的侵袭能力。研究结果为深入研究PCV2的致病机理及开发新型疫苗奠定了一定的基础。 相似文献
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《中国兽医学报》2020,(4)
为了探索伪狂犬病病毒(PRV)流行株的基因变异及遗传演变规律,本试验对福建福州疑似发生猪伪狂犬病的猪场病料,首先选用PCR技术、小鼠接种试验、细胞接种试验及间接免疫荧光鉴定等方法分离鉴定病原,再对病原进行毒价测定、TK和gE基因克隆及序列比对分析。结果显示,病原为PRV野毒,命名为PRV-FJFZ株;PRV-FJFZ株TCID_(50)为10~(-7.2)/0.1 mL,LD_(50)为10~(-3.56)/0.1 mL,对比分析PRV-FJFZ与国外PRV参考毒株的TK和gE基因序列同源性发现,核苷酸的同源性分别为99.5%～100.0%和99.8%～99.9%。TK和gE基因遗传进化树表明,PRV-FJFZ株与当前国内流行的变异PRV毒株在同一分支上,PRV-FJFZ株与国外PRV参考毒株在不同的分支上。本研究结果可为我国PRV的防控净化工作和疫苗株的筛选提供理论依据。 相似文献
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《中国畜牧兽医》2019,(12)
本研究旨在了解重庆地区羊口疮病毒(orf virus,ORFV)流行情况。从重庆大足等地区羊场采集18份临床疑似羊口疮病料,提取病料DNA,经PCR鉴定为ORFV阳性;将阳性病料做常规处理,接种羔羊睾丸细胞(LT),并盲传至5代,观察接毒LT细胞病变,将F5代细胞培养物进行间接免疫荧光试验(IFA)、PCR扩增、测序、同源性比对、遗传进化分析和TCID_(50)测定。结果显示,经PCR检测,18份疑似羊口疮病料ORFV核酸阳性率为61.1%(11/18);大足株病料接种LT细胞36 h后,长梭型细胞变圆、融合、呈拉网状、皱缩,72 h后大部分细胞脱落;间接免疫荧光试验在显微镜下观察到细胞浆中出现特异性绿色荧光,且荧光绕核分布;F1至F5代细胞培养物经PCR扩增出特异性目的条带,大小为1 137 bp;将测序结果与GenBank中19株ORFV B2L基因进行同源性比对,其核苷酸同源性在97.9%～100%之间,与美国SA00分离株同源性达100%,且遗传进化分析显示处于同一进化分支,亲缘关系较近;测定F5代细胞培养物TCID_(50)值为10~(-5.68)/0.1 mL,在细胞中能稳定增殖。综上所述,本研究成功分离并获得1株ORFV,为后续ORFV研究提供了生物材料,同时为防控重庆地区的羊口疮奠定基础。 相似文献
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《黑龙江畜牧兽医》2020,(1)
为了研究马疱疹病毒1型(Equine herpesvirus 1,EHV-1)在不同细胞系中的增殖规律,试验将该病毒分别接种至Vero细胞、BHK-21细胞和MDBK细胞中进行连续传代培养,观察细胞病变(CPE)情况;对第3代收获的病毒gE基因进行PCR检测及同源性比对;按照Reed-Meunch方法分别测量3种细胞7个时间点的TCID_(50),并绘制一步生长曲线。结果表明:EHV-1对3种细胞有很好的亲嗜性,产生明显CPE;3种细胞都扩增出大小为438 bp的片段,与所选的参考株同源性在99.99%以上;EHV-1在感染3种细胞后0～12 h进入静止期,12～48 h进入快速增长期;感染BHK-21细胞后在36小时时达到最高病毒毒价,TCID_(50)为1×10~(-8.40)/0.1 mL,感染MDBK细胞及Vero细胞后在48小时时达到最高病毒毒价,TCID_(50)分别为1×10~(-7.35)/0.1 mL和1×10~(-5.80)/0.1 mL。说明BHK-21细胞适合作为EHV-1-XJ2015株体外研究的细胞系。 相似文献
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《中国兽医学报》2020,(9)
将猪伪狂犬病病毒(PRV)转移质粒pUC-TKLR与含增强型绿色荧光蛋白(EGFP)的gE/gI/TK三基因缺失PRV变异株rPRV NY-gE~-/gI~-/TK~-/EGFP~+基因组经脂质体转染至ST细胞中,进行无荧光重组病毒蚀斑筛选、纯化,并对该病毒在多种细胞上增殖特性、病毒滴度、一步生长曲线和遗传稳定性及其对小鼠的安全性等进行初步研究。结果显示,成功获得重组病毒rPRV NY-gE~-/gI~-/TK~-,不含EGFP。经PCR及测序鉴定,证实获得的rPRV NY-gE~-/gI~-/TK~-在TK基因上缺失311 bp。rPRV NY-gE~-/gI~-/TK~-在ST、PK-15、VERO和MDCK细胞上的TCID_(50)分别为10~(6.375)/0.1 mL,10~(5.625)/0.1 mL,10~(5.375)/0.1 mL,10~(3.875)/0.1 mL;与亲本毒株NY在ST细胞中的毒力(10~(6.5)/0.1 mL)相近;当rPRV NY-gE~-/gI~-/TK~-传至20代时,病变细胞仍无绿色荧光,缺失部分TK基因(311 bp),且对小鼠是安全的。 相似文献
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为了解猪伪狂犬病病毒（PRV）变异毒株的特点,本研究采集临床疑似PRV感染发病猪的淋巴结等组织样品进行PCR鉴定,选取仅PRV阳性的组织样品经研磨除菌后取上清接种于PK-15细胞进行病毒分离培养、蚀斑纯化、PCR和间接免疫荧光法（IFA）鉴定,采用Reed-Muench法测定PRV的TCID50,接种小鼠并观察临床症状,对纯化的PRV和死亡小鼠脑组织样品进行gE基因PCR扩增及测序分析。结果显示,PRV阳性病料接种于PK-15细胞24 h后出现典型细胞病变（CPE）,经3轮蚀斑纯化后PCR和IFA鉴定结果均为阳性,分离株命名为HeNZK-2014,其TCID50为10-9.77/0.1 mL;以1×108个TCID50病毒悬液接种小鼠22 h后可引起小鼠出现奇痒、撕咬、死亡等典型猪伪狂犬病症状,死亡小鼠脑组织样品PRV PCR检测结果为阳性;纯化病毒和死亡小鼠脑组织样品gE基因核苷酸序列同源性为100.0%,与GenBank中2011年以前登录的经典毒株位于不同分支,与2011年之后中国流行毒株位于同一分支,在第48和496位各有1个天冬氨酸（D）的插入,具有变异毒株的典型特征。本研究成功分离了1株PRV变异毒株,为进一步开展针对PRV变异毒株的疫苗及其防控研究奠定了基础。 相似文献
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《中国兽医学报》2019,(8):1435-1440
为建立猪伪狂犬病病毒(PRV)变异株人工感染小鼠动物模型,将本实验室分离鉴定的猪PRV变异株(Fujian-LY)进行连续10倍稀释后,对6周龄SPF级BALB/c小鼠进行腹股沟皮下接种攻毒,每个稀释度接种5只小鼠,测定其LD_(50),观测小鼠感染、致病的多项指标,试验期为7 d。结果显示,该毒株对小鼠的LD_(50)为3.7×10~3 TCID_(50)/0.1 mL,在不同的感染剂量下各攻毒组小鼠的临床症状、死亡率等各项指标差异明显,其中以2.3×10~5 TCID_(50)的攻毒剂量接种后小鼠未发生急性死亡,且能表现出以神经症状为主的典型伪狂犬病症状;病理剖检可见发病小鼠脑膜充血,肺脏出血,胸腺、脾脏严重萎缩等病理变化;病理组织学检查结果显示该毒株对攻毒小鼠全身多个重要组织器官均造成了严重的病理损伤,同时采用PCR及免疫组化的方法在这些组织内均能检测到PRV抗原。结果表明,本研究已成功建立了PRV变异株感染小鼠动物模型。 相似文献
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为了对疑似猪流行性腹泻病毒(PEDV)感染病例进行确诊,并掌握致病原与其他流行毒株的基因差异性,试验采用病毒分离与细胞病变观察、PCR检测、中和试验、间接免疫荧光试验、S1基因序列分析等方法对该病例进行了研究。结果表明:临床病料接种Vero细胞盲传至18代后可产生典型的细胞病变,临床病料样品及各代次分离株病毒的PCR检测均为阳性,该毒株的TCID_(50)为1×10~(-6.61)/mL,该病毒可被PEDV阳性血清特异性中和,间接免疫荧光试验中可见明显的特异性绿色荧光,该病毒的S1基因核苷酸序列与GenBank中PEDV S1基因序列同源性在65.2%~100%之间,遗传进化关系中该病毒与近几年新分离株属于同一个大分支,与CV777等经典毒株亲缘关系较远。说明分离株病毒为国内近几年流行的新型PEDV。 相似文献
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伪狂犬病病毒Guizhou-T1株的分离鉴定及其遗传变异研究 总被引：1，自引：0，他引：1
为了解贵州猪伪狂犬病病毒(PRV)流行株的病原形态特征、致病性及遗传变异情况,本实验对收集自贵州规模化猪场伪狂犬病净化过程中PCR检测的阳性病料样品,采用细胞接毒分离培养、病毒的形态结构观察和易感动物接种试验对其病原进行鉴定。结果显示,本研究分离到一株PRV,命名为PRV Guizhou-T1株;并对其进行病毒效价的测定及g E基因核苷酸和氨基酸序列差异性分析。结果显示:PRV Guizhou-T1株gE基因序列与GZ-Z1株和Guizhou-DY株同源性分别为97.5%和99.3%,其TCID_(50)为10~(-10.11)/100μL;PRV Guizhou-T1株在gE基因编码的氨基酸序列第48和第496位均有天冬氨酸(Asp D)的插入,与PRV变异株变异位点一致,且在其第48位缺失酪氨酸(Tyr Y)。表明本研究分离得到了一株PRV变异株。本研究可为贵州PRV病原学的研究提供参考。 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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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
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献