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经鉴定,Apx毒素是猪胸膜肺炎的病原体—胸膜肺炎放线杆菌的重要毒力因子。在一些胸膜肺炎放线杆菌血清型中,Apx毒素是由apxⅢB和apxⅢD编码后经细胞膜分泌的。为了构建1株抗胸膜肺炎放线杆菌的活疫苗株,笔者将胸膜肺炎放线杆菌血清2型菌株-1536的apxⅢB和apxⅢD基因进行灭活,从而构建DeltaapxⅢB/DapxⅢD突变株(1536DeltaBDeltaD)。用活的1536DeltaBDeltaD胸膜肺炎放线杆菌对猪进行免疫后,能保护猪免于同源的野生型胸膜肺炎放线杆菌1536的攻击。因此,被损坏的Apx毒素分泌物可使胸膜肺炎放线杆菌的毒力减弱,并可作为开发胸膜肺炎放线杆菌弱毒疫苗的有效策略。 相似文献
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阿莫西林对副猪嗜血杆菌和猪胸膜肺炎放线杆菌的药敏试验 总被引:1,自引:0,他引:1
以大肠杆菌ATCC25922为质控菌株,采用阿莫西林对5株猪胸膜肺炎放线杆菌和6株副猪嗜血杆菌进行药敏试验,测定其最小抑菌浓度(MIC)。结果表明,胸膜肺炎放线杆菌和副猪嗜血杆菌对阿莫西林敏感。 相似文献
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为确定洛阳某猪场疑似猪传染性胸膜肺炎的病原种类及其血清型,为其临床科学防疫和合理用药提供参考方案,本试验无菌采集了病猪肺脏等病料,采用病菌培养后形态观察、革兰氏染色、生理生化特性试验、PCR诊断等技术对病原菌进行实验室分离鉴定,通过基因测序和同源性分析方法对其进行确诊,通过动物攻毒试验和药敏试验分析分离菌株的致病性和耐药性,采用5对分型引物对分离菌进行基因分型以确定病原菌血清型。结果显示,分离菌2007菌落形态为光滑、透明、边缘整齐、圆形、隆起的小菌落,革兰氏染色特征为阴性杆菌且呈多型性,具有猪传染性胸膜肺炎放线杆菌(APP)的典型培养特征,且生化结果符合猪传染性胸膜肺炎放线杆菌的生化特性。同源性分析结果显示,分离菌株2007与猪传染性胸膜肺炎放线杆菌菌株FJ848573.1同源性为99.4%,说明分离株2007是猪传染性胸膜肺炎放线杆菌。动物攻毒试验结果显示,分离菌株2007对小鼠有强致病性。药敏试验结果显示,分离株2007对泰妙菌素、氨苄西林和头孢噻呋钠等高敏,对替米考星、红霉素、氟苯尼考等20种抗菌药完全耐药,对34种抗生素的耐药率高达76.5%,具有较强的多重耐药性。分离菌2007基因分型扩增到目的基因片段与血清型5型结果相符。本试验结果为发病猪场提出了解决该病的具体防治措施,并最终获得了良好的效果,为猪传染性胸膜肺炎放线杆菌临床耐药折点的制定提供了一些参考。 相似文献
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猪胸膜肺炎放线杆菌PCR诊断方法的建立与应用 总被引:5,自引:3,他引:5
根据胸膜肺炎放线杆菌ApxⅣ基因设计1对引物,扩增特异的650bp棱酸片段,建立了应用PCR检测猪胸膜肺炎放线杆菌的方法。特异性试验结果表明,12个血清型的放线杆菌参考菌株均能扩增出650bp特异性的核酸片段,而大肠杆菌、多杀性巴氏杆菌、猪肺炎支原体、伤寒沙门氏菌和支气管败血性波氏杆菌的扩增结果均为阴性。敏感性试验结果表明,PCR的最低检出限量为500个放线杆菌。利用建立的PCR检测方法对22株从山东省不同地区分离的疑似胸膜肺炎放线杆菌菌株进行检测.结果14株为阳性。对感染猪病变组织的检测结果表明,病变部位不同,胸膜肺炎放线杆菌的检出率不同,其中以扁桃体的检出率最高。 相似文献
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猪传染性胸膜肺炎放线杆菌PCR检测方法的建立及应用 总被引:1,自引:0,他引:1
猪传染性胸膜肺炎是由胸膜肺炎放线杆菌引起猪的一种高度接触性呼吸道传染病,该病可给养猪业造成巨大的经济损失。为有效控制和确诊该病,根据报道的猪胸膜肺炎放线杆菌APXIV毒株的基因序列,合成了2对可扩增长度分别为442 bp和378 bp的特异引物,建立检测胸膜肺炎放线杆菌的巢式PCR方法。利用合成的引物在扩增猪肺疫巴氏杆菌、猪链球菌、副猪嗜血杆菌和大肠杆菌等细菌DNA时,结果均为阴性。用引物检测猪胸膜肺炎放线杆菌的标准菌株可扩增出442 bp和378 bp的特异性条带。表明运用PCR法检测猪胸膜肺炎放线杆菌的特异性和灵敏性均较高,可作为猪传染性胸膜肺炎的快速诊断和流行病学调查的手段。 相似文献
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《中国畜牧兽医》2020,(4)
为确定洛阳某猪场疑似猪传染性胸膜肺炎的病原种类及其血清型,为其临床科学防疫和合理用药提供参考方案,本试验无菌采集了病猪肺脏等病料,采用病菌培养后形态观察、革兰氏染色、生理生化特性试验、PCR诊断等技术对病原菌进行实验室分离鉴定,通过基因测序和同源性分析方法对其进行确诊,通过动物攻毒试验和药敏试验分析分离菌株的致病性和耐药性,采用5对分型引物对分离菌进行基因分型以确定病原菌血清型。结果显示,分离菌2007菌落形态为光滑、透明、边缘整齐、圆形、隆起的小菌落,革兰氏染色特征为阴性杆菌且呈多型性,具有猪传染性胸膜肺炎放线杆菌(APP)的典型培养特征,且生化结果符合猪传染性胸膜肺炎放线杆菌的生化特性。同源性分析结果显示,分离菌株2007与猪传染性胸膜肺炎放线杆菌菌株FJ848573.1同源性为99.4%,说明分离株2007是猪传染性胸膜肺炎放线杆菌。动物攻毒试验结果显示,分离菌株2007对小鼠有强致病性。药敏试验结果显示,分离株2007对泰妙菌素、氨苄西林和头孢噻呋钠等高敏,对替米考星、红霉素、氟苯尼考等20种抗菌药完全耐药,对34种抗生素的耐药率高达76.5%,具有较强的多重耐药性。分离菌2007基因分型扩增到目的基因片段与血清型5型结果相符。本试验结果为发病猪场提出了解决该病的具体防治措施,并最终获得了良好的效果,为猪传染性胸膜肺炎放线杆菌临床耐药折点的制定提供了一些参考。 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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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