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《畜牧与兽医》2015,(12):84-89
为建立简便、快速检测H3N8亚型禽流感病毒(Avian influenza virus,AIV)的方法,本研究根据H3和N8亚型AIV的HA和NA基因保守序列,设计合成了2对特异性引物和2条Taq Man探针,通过优化反应条件建立了H3N8亚型AIV一步法实时荧光定量RT-PCR。结果表明:该方法敏感型好,对H3N8亚型AIV检测敏感性达100个模板拷贝数。该方法特异性强,仅对H3和N8亚型AIV检测为阳性;应用该方法对96份临床样品进行检测,结果与病毒分离鉴定结果一致。因此,本研究建立的H3N8亚型AIV一步法实时荧光定量RT-PCR检测方法具有简便、快速、敏感和特异等优点,可为H3N8亚型AIV感染的有效防控提供技术支撑。 相似文献
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根据GenBank中H6、N1亚型禽流感病毒(AIV)的HA、NA基因序列,设计2对特异性引物和2条用不同荧光基团标记的TaqMan探针.经反应条件优化,本试验建立了检测H6N1亚型AIV的二重荧光RT-PCR方法.该法特异性强,只对H6亚型和N1亚型AIV进行特异性扩增,对其他H亚型AIV、N亚型AIV及新城疫病毒、传染性支气管炎病毒等病原体的检测均为阴性;该法敏感性好,对H6N1亚型AIV的检测限为100拷贝/μL.本试验建立的H6N1亚型AIV的二重荧光RT-PCR方法,具有快速、敏感、特异的优点,为H6N1亚型AIV的防控提供技术支撑. 相似文献
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为建立一种简单、快速鉴别H4亚型和N2亚型禽流感病毒(AIV)的方法,针对H4亚型AIV HA基因和N2亚型AIV NA基因的保守区域,分别设计筛选出1对特异性引物,通过优化反应条件,建立了H4亚型和N2亚型AIV二重RT-PCR检测方法。该法可特异性扩增H4亚型和N2亚型AIV,对其他亚型AIV和常见禽病病原体无交叉反应;对H4亚型和N2亚型AIV的检测下限均为10~4拷贝/μL;对152份临床样品的检测结果与病毒分离鉴定结果一致。本研究建立的二重RT-PCR方法为H4亚型和N2亚型AIV的诊断提供了快速、特异、敏感和有效的检测方法。 相似文献
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为建立检测禽流感病毒(AIV)且同时区分H3N2亚型AIV的方法,本研究根据H3、N2亚型AIV HA、NA基因及AIV最保守M基因的保守区域,设计并筛选出3对特异性引物,通过优化反应条件,建立了AIV H3N2亚型和M基因三重RT-PCR的检测方法。对该法进行特异性及敏感性检测,并通过该三重RT-PCR方法对96份临床样品进行检测。结果显示,H3N2亚型AIV可扩增出3条特异性条带,其中518bp为AIV M基因、418bp为N2亚型AIV NA基因、271bp为H3亚型AIV HA基因;H3亚型和N2亚型AIV均可扩增出2条特异性条带,大小分别为518bp、271bp和518bp、418bp;其他亚型AIV可扩增出一条特异性条带,大小为518bp;常见禽病病原体均未扩增出任何条带。敏感性试验表明该法对H3N2亚型AIV的检测下限为100pg,96份临床样品检测结果与病毒分离鉴定结果一致。本研究所建立的AIV H3N2亚型和M基因三重RT-PCR为一种简便、快速、有效的检测方法。 相似文献
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为建立一种同时检测H4、N2和所有亚型禽流感的方法,分别针对H4亚型禽流感病毒(AIV)HA基因、N2亚型AIV NA基因和所有亚型AIV M基因保守序列,设计筛选出3对特异性引物,优化引物之间的浓度,对三重反应体系进行特异性和敏感性验证,建立了H4、N2和所有亚型AIV三重RT-PCR检测方法,并用该法对临床样品进行检测。建立的方法能特异性扩增H4、N2和所有亚型AIV,与其他禽病病原体不发生交叉反应;对H4、N2和所有亚型AIV至少能检测到6 pg/μL。在185份临床样品的检测中,检出4份H4、10份N2和19份AIV阳性。所建立的三重RT-PCR方法特异性强、灵敏度高,为快速检测H4、N2和所有亚型AIV提供了有效的方法。 相似文献
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《中国兽医学报》2017,(1)
针对H7N9亚型欧亚谱系AIV的血凝素(HA)基因和神经氨酸酶(NA)基因的序列保守区分别设计特异性引物和TaqMan探针。通过优化反应条件,建立了H7N9亚型禽流感病毒实时荧光定量RT-PCR检测方法。利用该方法对泰安市活禽市场11个月的空气状况进行监测。结果显示:H7和N9基因的最低检测限度分别为100copies/μL和101 copies/μL,检测H7和N9基因的R2值均为0.999。批内和批间试验的变异系数均小于3%。采用该技术,活禽市场空气样品3/114份检测出H7N9阳性。结果表明:本试验建立的H7N9亚型AIV实时荧光定量RT-PCR方法与其他方法相比具有快速、特异和敏感的优点,可为H7N9亚型AIV的监测及早期诊断提供理论依据。 相似文献
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《畜牧与兽医》2015,(8):24-27
根据GenBank中H6、N1亚型禽流感病毒(AIV)HA、NA基因,分别设计并筛选出2对特异性引物,用于H6亚型AIV和N1亚型AIV的检测,优化反应条件,建立了H6N1亚型AIV的二重RT-PCR检测方法。对该法进行特异性、敏感性检验,并用该法对临床样品进行检测。所建立的方法对H6N1亚型AIV可特异性扩增出447 bp(H6亚型)和325 bp(N1亚型)目的条带,对H6Ny亚型AIV仅扩增出447 bp目的条带,对HXN1亚型AIV仅扩增出325 bp目的条带,对常见禽病病原体均未扩增出任何条带;该法对H6N1亚型AIV检测下限为5×102拷贝/μL;341份临床样品检测结果与病毒分离鉴定一致。本研究所建立的H6N1亚型AIV RT-PCR特异性强、灵敏度高,一管可同时检测H6和N1亚型AIV,为H6N1亚型AIV的检测提供一种简便、快速和有效的检测方法。 相似文献
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禽流感病毒H9和N2亚型双重RT-PCR检测方法的建立 总被引：1，自引：0，他引：1
《动物医学进展》2015,(1)
为建立简便快速检测H9及N2亚型禽流感病毒(AIV)的方法,根据AIV H9亚型和N2亚型基因序列,分别设计了2对针对H9亚型AIV的HA基因和N2亚型AIV的NA基因的引物,建立了H9亚型和N2亚型AIV双重RT-PCR检测方法。对H9N2亚型AIV的RNA模板进行RT-PCR扩增,可得到545bp H9基因特异性条带和341bp N2基因的特异性条带;对非H9亚型的N2亚型AIV进行扩增,则仅出现1个特异性扩增条带,即341bp N2基因条带;对非H9或N2亚型AIV和其他禽呼吸道病原体进行PCR扩增,结果均为阴性。结果表明该双重RT-PCR最低能检出100fg H9N2亚型AIV的cDNA模板。 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