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《湖南畜牧兽医》2019,(6)
为了解猪胸膜肺炎放线杆菌fbp C基因转录翻译后的ferric transporter ATP-binding subunit的结构和功能,根据Gene Bank中猪传染性胸膜肺炎放线杆菌fbp C基因碱基序列和氨基酸序列,对fbp C基因及其编码的铁转运ABC蛋白进行生物信息学分析利用。结果显示,App fbp C由1068个核苷酸所组成,编码355氨基酸的蛋白质。该蛋白质的分子量为(MW)39523.2,理论等电点(pI)为6.26。为以外膜蛋白,与转铁蛋白一起共同完成转铁功能。蛋白序列与App不同血清型的同源性很高,与其它的放线杆菌进化上处于同一分支,与嗜血杆菌的亲缘关系高于大肠杆菌。结果表明,猪胸膜肺炎放线杆菌铁离子转运ABC蛋白为一非跨膜蛋白,其离子转运与ATP结合有关。 相似文献
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猪传染性胸膜肺炎放线杆菌毒素apxⅢA基因的克隆和表达 总被引：4，自引：3，他引：4
以猪传染性胸膜肺炎放线杆菌血清2型参考株基因组DNA为模板，PCR方法扩增出apx ，ⅢA基因3．1kb的片段，扩增产物克隆于pMD18-T中，重组质粒经酶切鉴定后进行核苷酸序列测定，并与GenBank中不同血清型胸膜肺炎放线杆菌apx11A基因进行比较，结果显示核苷酸同源性均在96％以上。将该基因片段亚克隆到原核表达载体pGEX-6P-1的BamHⅠ／Sal Ⅰ位点，成功构建了重组表达载体pGEX—apx ⅢA，转化大肠杆菌BL-21（DE3）中并获得表达。SDS—PAGE结果显示，表达的融合蛋白分子量约为140Ku，与预测相符，Western blot证明该融合蛋白具有免疫学活性。该融合蛋白的成功表达为猪传染性胸膜肺炎亚单位疫苗的研制奠定了基础。 相似文献
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为治疗猪胸膜肺炎放线杆菌(App)寻找新的药物靶点,试验根据GeneBank中猪传染性胸膜肺炎放线杆菌DOXP消旋酶基因序列,对DOXP消旋酶基因及其编码蛋白进行生物信息学分析。结果表示App DOXP消旋酶由687个核苷酸所组成,编码228氨基酸的蛋白质。该蛋白质的分子量为(MW)25.636kd,理论等电点(pI)为7.83,该序列与APP7型的同源性为100%;与副嗜血杆菌为不同的分支。该蛋白具有螺旋,折叠,转角等明显的二级结构成分。对猪胸膜肺炎放线杆菌中MEP途径的研究,为治疗App寻找新的药物提供了线索。 相似文献
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Apx毒素在胸膜肺炎放线杆菌致病性和免疫原性方面具有重要作用。为研究ApxI毒素的免疫活性，参照胸膜肺炎放线杆菌血清10型ApxIA基因核酸序列（D16582）设计1对引物．利用PCR自该菌株基因组DNA中扩增出3158bp的ApxIA基因片段，经克隆和序列测定后转入原核表达载体pET-32a中，通过转化BL21（DE3）并在IPTG诱导下进行原核表达，表达出约的融合蛋白，SDS-PAGE和Westernblotting鉴定结果显示表达产物大小约120kDa，且表达产物可与该菌株免疫兔血清发生结合反应。ApxIA基因的克隆和原核表达为研究ApxI毒素的免疫原性以及在胸膜肺炎放线杆菌中的生物学活性奠定了基础。 相似文献
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用设计的引物对胸膜肺炎放线杆菌1、3、6、9型标准株的荚膜多糖输出部分基因序列进行了扩增，克隆，测序，分别获得4个型的部分cpxDC基因序列和3型的部分cpxD基因序列。对克隆序列和GenBank中已知序列进行序列拼接，分别拼接出1、3、6型的荚膜输出cpxD基因全序列。通过基因序列分析发现，胸膜肺炎放线杆菌1、3、5、6、9型荚膜多糖输出基因已知序列间的同源性很高，达89％～99．88％。1、3、5、6型cpxD基因的推导氨基酸序列间的同源性为93％～99％。在cpxDC基因的保守区内设计出1对种特异性引物，对胸膜肺炎放线杆菌进行鉴定和检测，结果从8个标准型菌株和3株分离株中均扩出约720bp的阳性片段，其他6种能引起猪呼吸道疾病的细菌均呈阴性。所建立的PCR方法最低检出量为10Pg，最适模板量为5ng（50ptL）。试验结果表明，胸膜肺炎放线杆菌不同血清型间的荚膜多糖输出基因存在着高度的保守性。设计出的种特异性引物能用于胸膜肺炎放线杆菌的检测和鉴定。 相似文献
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猪胸膜肺炎放线杆菌新疆株的分离鉴定及ApxⅣA基因的克隆与序列分析 总被引：1，自引：1，他引：0
从新疆北疆4个规模化猪场的20份发病猪病料中分离到1株细菌。经形态染色镜检、培养特性、生化特性和部分生物学特性试验鉴定为猪胸膜肺炎放线杆菌。根据猪胸膜肺炎放线杆菌ⅣA毒素基因特异性引物进行PCR扩增,得到1条与预期大小一致的2427bp的条带,将PCR产物纯化后克隆至pMD19-T载体上并测序。结果表明,该片段的碱基序列与GenBank中参考序列的同源性为98%,并与三株标准株比较,同源性分别为98.23%、99.46%和98.06%。 相似文献
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《中国兽医学报》2014,(9):1453-1457
flp(fimbrial low-molecular-weight protein)操纵子由1315个基因组成,在细菌中广泛存在,主要编码一种类菌毛(Flp菌毛)的束状纤维蛋白,与细菌在宿主中的黏附和定植有关。本试验利用同源重组技术获得了无抗性标记的猪胸膜肺炎放线杆菌血清Ⅰ型4074菌株的flp基因缺失菌株,通过对基因缺失菌株进行一系列的生物学特性研究,探索胸膜肺炎放线杆菌的flp基因功能。结果表明,flp基因的缺失不会对胸膜肺炎放线杆菌在体外的生长和其溶血活性产生明显影响,但能导致猪胸膜肺炎放线杆菌4074菌株丧失形成菌毛的能力;以小鼠为模型的动物试验结果显示,基因缺失菌株的致病力较亲本菌株有所降低。 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