共查询到20条相似文献,搜索用时 109 毫秒
1.
鸭疫里默氏菌病和大肠杆菌病鉴别诊断双重PCR方法的建立和应用 总被引:4,自引:1,他引:3
本研究从鸭疫里默氏菌提取基因组DNA,采用细菌16S rRNA基因的通用引物,用PCR方法成功扩增出鸭疫里默氏菌的部分16S rRNA基因,克隆及测序结果表明其全长1512bp,G+C含量为51%,该序列已登人GenBank,登录号为DQ078779。同时利用生物软件对GenBank收录的鸭疫里默氏菌和大肠杆菌的16S rRNA基因序列进行分析后,设计了鸭疫里默氏菌和大肠杆菌的种特异性引物,分别能从各自的16S rRNA基因中扩增出长度为342和718bp的DNA片段。并据此建立了一种能快速准确鉴别诊断鸭疫里默氏菌和大肠杆菌病的双重PCR方法,该方法能从肝脏组织悬液煮沸后的上清、细菌培养物或提取的细菌基因组DNA中快速扩增出相应的片段,进行鉴别诊断。 相似文献
2.
鸭疫里默氏菌病和大肠杆菌病多重PCR诊断方法的建立 总被引:3,自引:0,他引:3
参考GenBank中鸭疫里默氏菌和大肠杆菌的外膜蛋白A(OmpA)基因序列,应用PrimerPremier5.0软件在二者高度保守区设计了2对引物,建立了适合鸭疫里默氏菌和大肠杆菌的快速检测的多重PCR检测方法。以该方法对已分离并保存的鸭疫里默氏菌和大肠杆菌进行PCR扩增,分别扩增出与试验设计相符的670、408bp的特异性DNA片段。将扩增所得的DNA片段进行克隆测序,测序结果表明分别为鸭疫里默氏菌和大肠杆菌OmpA基因序列。该方法对鸭疫里默氏菌和大肠杆菌的检测下限分别为4×104CFU/mL和3×104CFU/mL。表明所建立的PCR方法具有特异、快速和敏感的特点,可用于诊断鸭疫里默氏菌、大肠杆菌以及两者的混合感染。 相似文献
3.
本研究根据鸭疫里默氏菌铁依赖抑制子(RaDtxR)基因序列特征设计特异性引物,利用PCR方法从已鉴定为2型鸭疫里默氏菌RA-FJ株的基因组DNA中扩增目的基因片段,胶回收PCR扩增片段,克隆到pMD18-T载体后进行序列测定.采用生物信息学软件对测序结果进行分析,结果表明所获得的RaDtxR基因编码完整的开放阅读框,全基因长度为654 bp,编码217个氨基酸.所编码的蛋白大小为24.82 ku,理论等电点为5.69,不稳定系数为38.45,属于稳定蛋白质类.将其与GenBank中已发表的RaDtxR基因序列进行核苷酸同源性比对分析,结果显示其与鸭疫里默氏菌疫苗株RA-CH-1株(GenBank登录号:CP003787)的核苷酸同源性为100.0%,与其他4株核苷酸同源性均为99.8%,仅在186位处存在无义突变.利用该基因对福建省农业科学院畜牧兽医研究所分离鉴定的鸭大肠杆菌、禽多杀性巴氏杆菌和沙门氏菌进行扩增,结果显示均未扩增到条带,对福建省农业科学院畜牧兽医研究所分离鉴定的1型、2型、3型、11型和13型鸭疫里默氏菌均可扩增出特异性目的条带,表明RaDtxR基因可作为鸭疫里默氏菌鉴别诊断的靶基因.试验结果表明,本研究成功克隆到鸭疫里默氏菌RaDtxR基因,为研究其功能奠定基础. 相似文献
4.
试验旨在分析鸭疫里默氏菌(RA)感染不同时期鸭肠道菌群结构变化规律,探讨鸭疫里默氏菌对鸭肠道微生物的影响及引起鸭致病的可能机制。采用细菌16S V4-V5区扩增通用引物,扩增鸭疫里默氏菌未感染组(鸭疫里默氏菌感染0 d组),鸭疫里默氏菌感染后1、2、3、5、9和14 d的鸭直肠内容物样本DNA,将扩增得到的产物进行DNA建库后基于Ion S5TMXL测序平台测序。测序得到的Raw Reads数据总量为4 710 688条序列,平均每个样本84 119条序列。共注释到数据库的操作分类单元(OTUs)数目为4 528。Alpha多样性分析结果表明,菌群多样性指数Shannon和Simpson在鸭疫里默氏菌感染组和未感染组间差异不显著(P>0.05),菌群丰富度指数Chao1、Ace、Observed-species和PD-whole-tree在鸭疫里默氏菌感染后0~5 d逐渐降低,从5~14 d又逐渐增加,尤其在鸭疫里默氏菌感染后3和5 d均显著低于未感染组(P<0.05)。Beta多样性分析表明,未感染组与6个时间点的感染组间菌群差异均显著(P<0.05),其中,未感染组与感染后3 d的物种差异最大,之后依次为感染后2、5、9、1和14 d。物种丰度聚类热图显示,在未感染组和不同时间感染组,物种丰度相对较高的微生物菌属均不同。在门水平,鸭疫里默氏菌感染组主要以厚壁菌门(Firmicutes)、unidentified-Bacteria、拟杆菌门(Bacteroidetes)、梭杆菌门(Fusobacteria)及变形菌门(Proteobacteria)为主;在属水平,Bacteroides在感染组和未感染组均为优势菌属,感染组中弯曲杆菌属(Campylobacter)和梭杆菌属(Fusobacterium)明显增加。本试验分析了鸭疫里默氏菌未感染组和感染不同时间组肠道菌群的差异,寻找到一些特征菌属,可为鸭疫里默氏菌的致病性研究提供理论依据。 相似文献
5.
为建立一种更加准确、敏感的鸭疫里默氏杆菌检测方法,根据鸭疫里默氏杆菌16S rRNA基因序列设计2对巢式PCR引物,在完成最佳反应条件筛选、特异性、敏感性、重复性试验的基础上,建立巢式PCR检测方法.结果表明,建立的巢式PCR对1、2、10、X型鸭疫里默氏杆菌的16S rRNA都能扩增出特异性片段,而对大肠杆菌、多杀性巴氏杆菌、沙门菌、鸭源金黄色葡萄球菌的基因组不能扩增出特异性片段,DNA最小检测量为0.392 fg/μL,是常规PCR的1 000倍.该巢式PCR方法具有快速、敏感、特异、通用的优点,可用于鸭疫里默氏杆菌感染的检测、分子流行病学调查和分离菌株的快速鉴定. 相似文献
6.
7.
为了探讨鸭疫里默氏杆菌(Riemerella anatipestifer, RA)云南流行株的外膜蛋白A (OmpA)的基因序列差异及其与16S rRNA序列的相关性,PCR扩增18株云南流行株鸭疫里默氏杆菌OmpA基因及16S rRNA核苷酸序列,分别构建其系统进化树,分析其系统进化关系。结果表明,18株鸭疫里默氏杆菌OmpA基因分为2个群,其同源性分别为86%~99.2%和92.6%~100%。18株鸭疫里默氏杆菌16S rRNA基因同属1个群,同源性高达96.1%~100%。 RA-1、RA-2、RA-11和RA-39 4株分离株的OmpA基因位于进化树的同一个亚群,其16S rRNA基因也位于进化树的同一亚群,两者呈现出明显的相关关系,其他14株分离株的OmpA基因系统进化树与16S rRNA基因系统进化树无明显的相关关系。 相似文献
8.
为明确珠三角地区鸭疫里默菌的主要生物学特性,对从珠三角地区分离到的87株鸭疫里默菌进行生化试验、玻片凝集试验、药敏试验、致病性检测及16 S rRNA基因测序,以比较相互间的生物学特性及其同源性.结果表明,分离株的生化特性基本一致;血清型以2型为主,占65.5%,其次是1型,占14.9%,此外还有16株未定型,占18.4%;代表株对雏鸭具有很强的致病性,对头孢类药物(头孢噻肟、头孢曲松、头孢吡肟、头孢唑林)非常敏感,而对常用抗菌药物(青霉素、氨苄西林、氯霉素、链霉素、卡那霉素)普遍耐药;本试验检测的19株代表菌的16 S rRNA基因序列的同源性较高,16 S rRNA基因与菌株的血清型和致病性无直接关系. 相似文献
9.
10.
为揭示鸭疫里默氏菌在鸭组织中的分布规律,用荧光定量PCR检测法,对人工感染鸭疫里默氏菌鸭组织中鸭疫里默氏菌进行检测。结果表明,获得的熔解曲线为单一的峰,扩增曲线为"s"形,标准曲线扩增效率为99.7%。人工感染鸭疫里默氏菌1、2、3、5、9、14 d鸭脾脏、脑、心脏、肺脏和肝脏组织中的鸭疫里默氏菌载菌量均在2 d达定殖高峰,载菌量多少按组织排序依次为脑>心>脾>肺>肝,按时间排序依次为2 d>3 d>1 d>5 d>9 d>14 d。 相似文献
11.
12.
13.
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
14.
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
15.
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
16.
17.
18.
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
19.
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