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多杀性巴氏杆菌毒力因子及基因表达的研究进展 总被引：1，自引：0，他引：1
《中国畜牧兽医文摘》2015,(9)
多杀性巴氏杆菌(Pasteurella multocida,Pm)是引起多种动物巴氏杆菌病(又称出血性败血症)的一种重要的人兽共患病原菌,主要使动物发生出血性败血症或传染性肺炎,如家禽的禽霍乱、猪的猪肺疫、牛的牛出败等,给养殖业造成了严重的经济损害。目前,多杀性巴氏杆菌的各种基因表达产物已成为全球范围的研究热点,笔者在本文对其毒力因子和基因表达技术进行分析综述。 相似文献
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为确定疑似禽霍乱病例病原种类及其病原基因型,本研究采用细菌分离技术对病原菌进行实验室分离培养,应用传统方法和分子生物学方法对分离细菌进行鉴定,并应用PCR扩增和基因序列分析对分离细菌进行基因分型。结果显示,分离菌具有多杀性巴氏杆菌（Pasteurella multocida,Pm）典型培养特征,菌落形态和菌体染色特征、生理生化特性均与多杀性巴氏杆菌相符;PCR扩增到457 bp的基因片段。采用5对分型引物对分离菌进行基因分型显示,仅有A型引物扩增到大小1 050 bp的目的基因片段,序列分析也显示分离菌荚膜基因与A型多杀性巴氏杆菌参考菌株荚膜特异性基因同源性高达97.6%~100.0%,系统进化与A型多杀性巴氏杆菌处于同一进化分支。结果表明,疑似禽霍乱病例病原为A型多杀性巴氏杆菌,本研究结果将为禽霍乱的防控提供参考资料。 相似文献
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禽源多杀性巴氏杆菌多位点序列分型研究 总被引：1，自引：0，他引：1
为了解国内禽源多杀性巴氏杆菌流行情况,对分离自18省份的84株多杀性巴氏杆菌采用荚膜多重PCR分型和多位点序列分型对其血清型和基因型进行鉴定。结果表明:禽源多杀性巴氏杆菌主要以血清A型为主,占96.4%(81/84);多位点序列分型可将禽源多杀性巴氏杆菌分为5种ST型,其中ST129为主要流行型,占94.0%(79/84)。本研究为我国禽源多杀性巴氏杆菌的流行病学监测和基因多样性提供了数据支持。 相似文献
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牛源多杀性巴氏杆菌荚膜血清型及毒力基因检测 总被引：1，自引：0，他引：1
《中国兽医杂志》2017,(9)
为了确定12株牛源多杀性巴氏杆菌的血清型及毒力基因的携带情况,本研究采用PCR技术对12株牛源多杀性巴氏杆菌(pasteurella maltocida,Pm)进行荚膜血清型鉴定和6种毒力基因(tbp A、hgb A、hgb B、ptf A、pfh A、tox A)的检测,并对其序列进行比对分析。结果显示:12株多杀性巴氏杆菌均为荚膜血清A型;100%的荚膜血清A型Pm携带hgb A毒力基因和pfh A毒力基因;41.67%的荚膜血清A型Pm携带nan H毒力基因;58.33%的荚膜血清A型Pm携带ptf A毒力基因;而对于tbp A与tox A两种毒力基因在12株牛源荚膜血清A型Pm中均未检测到。 相似文献
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为了克隆从患肺炎犊牛和健康犊牛上分离的多杀性巴氏杆菌血红素结合受体(heme acquisition system receptor,HasR)基因并进行序列分析,分别以致犊牛肺炎和健康犊牛携带的多杀性巴氏杆菌DNA为模板,通过PCR反应扩增出血红素结合受体基因的全部序列,PCR产物纯化后克隆到pMD19-T载体上,经菌液PCR和酶切鉴定后进行序列测定。各菌株HasR基因序列比对结果发现,Pm-BS-a、Pm142-x-4、Pm142-x-3、Pm149-x、Pm-BS-d的序列之间亲源关系较近,而Pm149-xby与参考菌株Pm70的同源性较高。健康牛源的多杀性巴氏杆菌与致犊牛肺炎多杀性巴氏杆菌之间HasR基因的同源性非常高,说明致犊牛肺炎多杀性巴氏杆菌是一种条件性致病菌,其引起的犊牛肺炎可能属内源性感染。 相似文献
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禽巴氏杆菌病是由禽多杀性巴氏杆菌引起的一种败血性传染病,该文主要介绍禽巴氏杆菌的流行特点、临床症状、病理变化、诊断及防治措施。 相似文献
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《中国预防兽医学报》2017,(7)
<正>巴氏杆菌病(Pasteurellosis)是由多杀性巴氏杆菌(Pasteurella multocida,Pm)引起的多种畜禽、野生动物及人类的一类传染病的总称。动物急性病例以败血症和炎性出血为主要特征。Pm由路易斯·巴斯德于1880年首次从禽霍乱病例中分离获得并以其名字命名~([1])。该菌广泛分布于世界各地。在同种或不同种动物间可以相互传染,也可以感 相似文献
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禽巴氏杆菌病又称禽霍乱,俗称禽出败,是由多杀性巴氏杆菌引起家禽的接触性传染病。湖北某鸡场发生一起疑似多杀性巴氏杆菌感染的疾病,后经流行病学和临床症状体征的观察以及病原菌分离鉴定,确诊为多杀性巴氏杆菌引起,现将结果报道如下。 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