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家蚕消化道来源蒙氏肠球菌的鉴定 总被引:1,自引:1,他引:0
研究了从家蚕消化道内分离出的4株肠球菌(C1、GC、FD、A20)的生理生化特征和16S rDNA序列,并与肠球菌种特异性探针序列进行了比较。生理生化特征测定结果表明,除A20外,C1、GC和FD与蒙氏肠球菌种的特征基本一致。由16S rDNA序列分析结果可知,分离菌株均与蒙氏肠球菌(Ent.mundtiiAJ301836)有高度同源性,在系统发育树内位于同一分支。分析肠球菌种特异性探针序列,分离菌株的16S rDNA含有与蒙氏肠球菌种特异性探针完全相同的序列。因此认为家蚕消化道内存在蒙氏肠球菌。 相似文献
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选用通过常规生理生化特性鉴定的疑似粪肠球菌菌株3株,采用16S rDNA的通用引物对其可变区基因进行克隆、测序和同源性比对,并用CLUSTAL和MEGA软件分析其遗传距离并构建系统进化树.结果表明,此3株菌株通过同源性比对,与GenBank数据库中粪肠球菌的同源性均大于99.8%,经遗传距离分析和系统进化树的构建均表明为粪肠球菌.肠球菌属细菌有40个种,各种之间的生化生理特性差别甚微,在无法通过生化生理特性准确鉴定到种的情况下,用粪肠球菌的16S rDNA全序列的测定及系统进化树的分析是鉴定该菌的一个科学可靠的方法. 相似文献
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一株致仔猪关节炎粪肠球菌的鉴定 总被引:1,自引:0,他引:1
对1株分离自关节炎病仔猪的肠球菌进行鉴定。选用常规方法进行染色特性、培养特性观察以及药物敏感性和致病试验,然后利用Vitek-32全自动细菌鉴定系统进行生化特性鉴定,并用PCR方法扩增分离株的16 S rRNA基因,克隆并测序,与GenBank上登录的相关菌株及3个粪肠球菌标准菌株进行16 SrRNA序列比较、同源性分析并构建系统发育树。结果显示,该分离株形态及染色特性与肠球菌一致,对仔猪具有一定的致病性,并对临床常用的7种药物产生了耐受性;Vitek-32生化鉴定和16 S rRNA基因同源性分析及比对结果均显示其为粪肠球菌(E.faecalis)。试验证实了粪肠球菌可导致仔猪关节炎。 相似文献
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《中国兽医学报》2019,(8)
为确定某养殖场患病死亡狐狸的病原菌,本试验对病死狐狸进行剖检和细菌分离培养、生化鉴定以及16S rDNA鉴定、动物致病性试验和药敏试验。结果显示,分离菌株为革兰阳性球菌,经过生化鉴定和16S rDNA序列分析,确定分离菌株为小肠肠球菌,并命名为E.hirae QHD-1;动物回归试验结果显示,分离菌株E.hirae QHD-1对小鼠具有较强的致病性,LD_(50)为1.26×10~4 CFU;药敏试验结果显示,分离菌株E.hirae QHD-1对氨苄西林和恩诺沙星等药物敏感,对替米考星、阿米卡星等耐药;毒力因子检测结果显示,该分离株具有较强的致病力。毛皮动物小肠肠球菌的感染病例尚未见有报道,本试验丰富了狐狸病原菌相关的研究,并为防控该菌引起的疾病提供了重要参考资料。 相似文献
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试验结合革兰氏染色及16S rRNA分子鉴定,对分离自红原县的17份牦牛粪便样中的肠球菌进行鉴定。结果显示,通过细菌分离纯化及PCR扩增,从牦牛粪便样品中分离出8株疑似肠球菌,分离菌的扩增产物经凝胶电泳后均产生1 500 bp特异性条带。16S rRNA测序结果显示,8株疑似肠球菌中,6株为粪肠球菌,2株为屎肠球菌。同源性比对分析显示,粪肠球菌与参考序列同源性为99.7%~100.0%,屎肠球菌与参考序列同源性为98.2%~99.2%,说明牦牛源肠球菌在遗传进化过程中高度保守。运用K-B纸片法进行药敏试验,结果显示,分离株对氨基糖苷类抗生素耐受性较高,2株屎肠球菌中,11-1-2菌株表现为5重耐药,且该菌株耐万古霉素,粪肠球菌主要表现为3重耐药,药敏结果提示牦牛源肠球菌耐药较严重,应引起高度重视。 相似文献
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《中国预防兽医学报》2016,(6)
为分离及种属鉴定引起牛乳腺炎相关的链球菌和肠球菌,本研究于兰州及周边地区采集疑似奶牛乳腺炎乳样382份,通过THB(Todd-Hewitt Broth)固体选择培养基初步分离到67株疑似链球菌或疑似肠球菌。参照已发表文献合成链球菌属16S r RNA和16S~23S r RNA间隔区基因引物序列,扩增分离菌株16S~23S r RNA间隔区序列,产物分别利用AluⅠ和RsaⅠ单酶切消化,并以参考菌株的16S~23S r RNA酶切图谱为参考,对分离株进行限制性片段多态性(RFLP)分类分析;再选取各RFLP类群的任一菌株,扩增其16S r RNA基因并测序,并经NCBI核酸数据库进行比对,结果显示67株疑似链球菌中有53株为粪肠球菌(79.1%)、3株为屎肠球菌(4.5%)、3株为肠道肠球菌(4.5%)、8株为无乳链球菌(11.9%)。结果表明肠球菌属细菌(粪肠球菌、肠道肠球菌、屎肠球菌)与兰州市及周边地区奶牛乳腺炎的发病紧密相关,肠球菌属细菌与链球菌属细菌16S r RNA基因同源性很高,但可以通过分子生物学方法准确区分。 相似文献
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Streptococcus agalactiae and Streptococcus difficile 16S-23S intergenic rDNA: genetic homogeneity and species-specific PCR 总被引:1,自引:0,他引:1
Streptococcus difficile is a non-hemolytic Gram-positive bacterial coccus that causes septicemia and meningoencephalitis in farmed tilapia (Oreochromis sp.) and rainbow trout (Oncorhynchus mykiss). Recent studies have demonstrated S. difficile to be a group B, type Ib streptococcus with a whole cell protein electrophoretic profile indistinguishable from S. agalactiae and a biochemical profile similar to that observed for other group B, type Ib streptococci isolated from fish and frogs. The aim of this study was to expand on these findings by comparative nucleic acid sequence analysis of the 16S-23S ribosomal DNA (rDNA) intergenic spacers of S. difficile and S. agalactiae. The 97.7% sequence homology identified in these studies supports the taxonomic relationship of these two organisms. The sequence data generated were also used to construct a pair of species-specific PCR primers for use in molecular detection and identification schemes. 相似文献
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Corinne Marois Laëtitia Le Devendec Marcelo Gottschalk Marylne Kobisch 《Canadian journal of veterinary research》2007,71(1):14-22
Streptococcus suis is an important pathogen of swine, causing meningitis, arthritis, polyserositis, septicemia, and sudden death in weaning piglets as well as fattening pigs. Recently, 3 molecular tests have been developed in our laboratory: a multiplex polymerase chain reaction (m-PCR) assay for the detection of S. suis species and serotypes 2 and 1/2, and 2 molecular typing methods, pulsed-field gel electrophoresis and an approach based on PCR amplification of a fragment of rRNA genes, including a part of the 16S and 23S genes and the 16S-23S rDNA intergenic spacer region (ISR), followed by restriction fragment length polymorphism (RFLP) analysis (ISR-RFLP). In the present study, we used these tests to analyze tonsil samples from clinically healthy pigs and to identify individual isolates of S. suis during epidemiologic investigations of 8 related herds with a history of septicemia caused by S. suis serotype 2. Capsular typing showed that 58% of the strains were nontypable. Of the 17 serotypes present, serotype 22 was the most prevalent. In the 7 farms without clinical signs on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, in less than 5% of the pigs by m-PCR or by bacteriologic culture. In the 8th farm, on which 2 pigs had clinical signs of septicemia on the day of sampling, we detected S. suis serotype 2 or 1/2, or both, by m-PCR in the tonsils of 40% of fattening pigs (21 wk old) that lacked symptoms. Molecular typing of the serotype 2 strains showed a common origin of contamination in these herds, given that 1 pattern (C1) was detected in the isolates from 6 of the 8 herds. However, up to 4 patterns were associated with septicemia and sudden death. Several patterns of S. suis serotype 2 can be responsible for disease in the same herd. These molecular tools may be useful for confident studies of the transmission of S. suis, thereby contributing to the control of S. suis infection. 相似文献
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广州桑树植原体分子检测及多样性初探 总被引:3,自引:1,他引:2
采用植原体16S-23S rDNA区段的通用引物对P1/P7和巢式引物对Rm16F2/Rm16R1,建立了快速准确的桑树植原体巢式PCR检测技术。对广州的两个桑树品种资源圃中的部分桑树品种进行了植原体分子检测,结果在两个资源圃中均发现有植原体存在。对巢式PCR的扩增产物(16S rDNA片段)进行了限制性片断长度多态性(RFLP)分析,显示出3种RFLP带型,暗示桑树植原体存在多样性。对所得植原体16S rDNA片段进行序列测定,并与其它植物植原体作亲缘关系分析,结果表明该植原体的16S rDNA序列与其它植物病原植原体之间的同源性为83.3%~99.9%,并初步判断所检测到的桑树植原体属于16S rI组。 相似文献
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为研究不同病例发病动物的发病原因,并对不同病例病料分离出的细菌进行16S rDNA同源性分析,本试验对10种不同病例发病动物病料进行细菌分离培养并对分离获得的细菌进行微生物学鉴定,设计1对16S rDNA基因引物,对分离出的10株细菌进行PCR扩增、测序及16S rDNA同源性分析。结果显示,分离获得的10株细菌经微生物学鉴定均为大肠杆菌,10株大肠杆菌中哺乳类动物病例犬乳房炎、犬子宫蓄脓、犬肺炎、犬皮肤化脓疮、奶牛乳房炎、犊牛腹泻6株大肠杆菌之间16S rDNA同源性为100.0%,家禽类动物病例肉鸽腹泻、肉鸡腹泻、野鸡腹泻和白孔雀腹泻4株大肠杆菌之间16S rDNA同源性也为100.0%,10株不同病例动物来源大肠杆菌之间16S rDNA同源性为97.5%~100.0%。本试验探明了10种不同病例发病动物的发病原因均为大肠杆菌感染引起,且10株大肠杆菌16S rDNA之间具有高度同源性。 相似文献
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A molecular technique based on the restriction fragment length polymorphism of the 16S ribosomal genes amplified by a polymerase chain reaction (PCR), referred to as amplified 16S ribosomal DNA restriction analysis (ARDRA), was designed to identify 19 Avibacterium paragallinarum strains isolated from infraorbital sinus and nasal turbinate bone samples of broiler chickens, breeders, and laying hens from different regions of Peru. The 16S rDNA was amplified by PCR using a pair of bacterial universal primers and restriction analysis of 16S rDNA sequences was done to select endonucleases with the highest number of cutting points inside the 16S rDNA. The DNA patterns with DdeI and RsaI endonucleases were identical for the 19 A. paragallinarum strains, but differed from those obtained for Ornithobacterium rhinotracheale, a bacterium with a high genetic and phenotypic resemblance to A. paragallinarum, as well as from Escherichia coli, a bacterium associated with infectious coryza. The ARDRA method could prove to be valuable for molecular identification of A. paragallinarum, a microorganism implicated in respiratory diseases in commercial birds. 相似文献
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Sasaki Y Yamamoto K Kojima A Norimatsu M Tamura Y 《Research in veterinary science》2000,69(3):289-294
In cattle, sheep, and other ruminants, clostridial myonecrosis (gas gangrene) is mostly caused by Clostridium chauvoei, C septicum, C novyi and C sordellii. A polymerase chain reaction (PCR) system using common primers designed from multiple alignment of the 16S rRNA and 23S rRNA genes of Clostridium species was developed to identify pathogenic clostridia. The PCR was performed with total DNA from 26 strains which included seven different Clostridia species. These bacteria were differentiated at species level by the different PCR product patterns. To characterise the 16S-23S rDNA spacer regions of these clostridia further, most PCR products of these bacteria were sequenced. The smallest PCR products of each bacterium represented the fundamental 16S-23S rDNA spacer region; larger PCR products of each bacterium were caused by insertion sequences, i.e. tRNA gene sequences. The authors' observations indicate that the PCR patterns of the 16S-23S rDNA spacer regions have the potential to be used as an identification marker of pathogenic clostridia in gas gangrene. 相似文献