肠球菌主要毒力基因多重PCR方法的建立与应用     

王亚宾  陈丽颖  胡慧  段志刚  崔保安 《中国兽医学报》2012,32(12)

根据GenBank公布的基因序列,分别针对肠球菌属及其毒力基因cylA、esp和AS设计合成了4对引物。通过改进模板DNA提取方法和优化反应条件,建立了可以同时测定肠球菌和其携带的3种主要毒力基因的多重PCR方法。经过对不同来源的疑似肠球菌分离株进行检测,该多重PCR方法具有快速、可靠的特点。在不同来源的疑似肠球菌菌株中,临床感染分离株携带上述3种毒力基因的比例均高于鲜肉分离株和粪便分离株（分别为84．2％、55．7％和27．1％）;而且在各种来源肠球茵菌株中这3种毒力基因的携带率以cylA最高。  相似文献   

Probiotics in pigs — modulation of their intestinal distribution and of their impact on health and performance     

D. Taras  W. Vahjen  O. Simon 《Livestock Science》2007,108(1-3):229-231

Two probiotics of different ecological origin, Enterococcus faecium NCIMB 10415 and Bacillus cereus var. toyoi, were chosen as model organisms. Feed for sows during gestation/lactation and for piglets pre-/postweaning was supplemented with either of these probiotics. To evaluate the effect of different starting points of E. faecium NCIMB 10415 initiations the probiotic was administered to piglets of sows, which have not received the probiotic, from birth onwards or just postweaning. Here we report the impact of these variants on probiotic distribution in the gut, on the gut microbiota, on diarrhea and on performance. Both probiotic strains were detected immediately after the start of the supplementation in feces of sows and piglets. The vertical transfer of both probiotic strains with sow feces to piglets could be demonstrated already before suckling piglets had access to the supplemented diets. Both probiotics were recovered from all intestinal segments of piglets. The dominant autochthonous colonic microbiota of young piglets as revealed by denaturing gradient gel electrophoresis was more similar within than between treatment groups (control vs. probiotic). Both probiotics reduced the incidence of postweaning diarrhea (p < 0.05). For the E. faecium probiotic the relative magnitude of this effect was largely independent of dietary probiotic concentration or starting time of supplementation. Significant overall influence on piglet performance was observed only with the B. cereus probiotic.  相似文献   

Isolation,Drug Sensitivity Test and Construction of Prokaryotic Expression Vector of Virulence Genes of Enterococcus from Dairy Cow with Mastitis in Gansu Province     

SHEN Yulong  MEN Qianyun  CHEN Tingting  LI Zongshuai  LI Haijiang  YANG Yang  ZHANG Yong  ZHAO Xingxu 《中国畜牧兽医》2007,47(10):3389-3400

The aim of this study was to isolate Enterococcus in clinical dairy cow mastitis,detect its drug resistance and virulence genes,a total of 93 milk samples were collected from 41 dairy cosw with clinical mastitis in eastern,central and western regions of Gansu province,and then construct a prokaryotic expression vector for virulence genes.This experiment used selective medium to isolate and purify bacteria.16S rRNA and biochemical experiments combined method to identify the isolated strains.16 antibiotics were selected for drug sensitivity test,and conventional PCR method was used to detect the carrying of 11 virulence genes.Finally,the detected virulence genes with immunogenicity were selected for the construction of prokaryotic expression vectors.The separation and identification results showed that 18 strains of Enterococcus were isolated and identified from the 93 milk samples,which were divided into 9 species.Drug susceptibility results showed that most of the isolates were multiple resistant to bacteria,accounting for 88.89%.No vancomycin-resistant Enterococcus was found,vancomycin sensitivity rate was 94.12%,and all isolates were resistant to at least one antibiotic.Virulence gene test results demonstrated that 11 virulence genes were detected,the detection rate of cob gene (44.44%) was the highest,the detection rates of efaA,hyl,ccf and esp genes were 33.33%,27.78%,27.78% and 22.22% respectively,the detection rates of Asa1,cylA,EF3314 and gelE genes were all 16.67%,while Ace and cylM genes had the lowest detection rate (11.11%).The virulence genes combination was different due to different strains.Ace and gelE genes with immunogenicity were selected and the prokaryotic expression vector pET32a-Ace and pET32a-gelE were successfully constructed.The results provided basic data and biological materials for subsequent mapping of regional epidemiology of cow mastitis in three regions and preparation of corresponding antibodies and subunit vaccines.  相似文献   

羊源肠球菌溶血素特性分析及其对兔红细胞作用的观察     

康立超 马勋王静梅  薄新文 《中国兽医科技》2007,37(12):1069-1073

对致羔羊脑炎肠球菌E129-3菌株溶血素进行检测分析，并利用光学显微镜和电子显微镜观察其对兔红细胞的作用，探讨了肠球菌溶血素的特性及溶血类型。结果表明，小白鼠、兔、犬红细胞对该溶血素最敏感，牛红细胞不敏感。该溶血素可以被DTT、Ca^2＋活化，被蛋白酶K、EDTA、Zn^2＋、Cu^2＋抑制。在培养后2h，细胞浆内着色不一致或密度降低，5h时红细胞数量明显减少，细胞膜较完整。提示，肠球菌溶血素为成孔蛋白类溶血素。  相似文献   

盐胁迫下粪产碱菌在水稻根表的定殖(英文)     

伍红  平淑珍  KA Malik  林敏 《核农学报》2000,14(5):305-310

粪产碱菌A1 5 0 1能在氯化钠浓度高达 4%的固体和液体介质中良好生长 ,合成IAA和固定空气中的氮素。当氯化钠浓度超过 3 %时 ,A1 5 0 1丧失运动和趋化能力。一定盐浓度胁迫下A1 5 0 1能定殖在水稻根表和根毛区和侧根伸出部位 ,表现出较高的联合固氮活性。0 5 %的氯化钠能促进A1 5 0 1在水稻根表的定殖能力。A1 5 0 1能通过侧根伸出部位侵入根内。  相似文献   

Prevalence of vancomycin-resistant Enterococcus faecium (VREF) in pig faeces from slaughterhouses in Spain     

Inmaculada A. Herrero  Tirushet Teshager  Julian Garde  Miguel A. Moreno  Lucas Domínguez 《Preventive veterinary medicine》2000,47(4)

A study to estimate the prevalence of vancomycin-resistant Enterococcus faecium in faecal samples from pigs at slaughterhouses in Spain was carried out between November 1998 and January 1999 with 900 samples taken from four abattoirs representing 9.7% of all pig slaughtered in 1998. Using a selective enrichment broth with vancomycin (8 μg/ml), 64 samples (7.1%; 95% CI: 5.5, 9.0%) had E. faecium vancomycin-resistant strains that showed minimal inhibitory concentrations of 256 μg/ml (62 strains) and 512 μg/ml (two strains). Results by farm showed that 43 of the 240 pig farms represented in the sampling had at least one faecal sample with vancomycin-resistant E. faecium.  相似文献   

pH调控对生物反应器发酵生产粪链球菌的影响     

王红波  陈禅友  刘洁  童佩  李硕 《中国饲料》2015,(14)

p H是影响生物反应器高效发酵生产粪链球菌的关键因素,粪链球菌生长的适宜p H范围为6.3~7.5。本试验对粪链球菌的发酵过程进行了p H调控与非调控的比较研究。结果表明:p H非调控,发酵10 h,发酵液p H下降至4.67,菌体生长受到抑制;发酵14 h,发酵液中活菌数达到4.4×109cfu/m L。p H调控,间歇流加Na OH溶液,维持发酵液p H 6.3~7.8,能提高菌体细胞耗氧量,增加蔗糖的分解代谢速率,解除菌体生长抑制,延长菌体的对数生长期;发酵16 h,活菌数达到7.3×109cfu/m L,较非调控提高了65.9%。  相似文献   

日粮中添加屎肠球菌对AA肉鸡生产性能、免疫器官指数和血液脂质代谢相关指标的影响   总被引：1，自引：1，他引：0  

彭众  董丽  王淑楠  毛俊舟  韩冬  喻礼怀 《中国畜牧兽医》2018,45(6):1502-1509

本试验旨在研究日粮中添加屎肠球菌对AA肉鸡生产性能、免疫器官指数和血液脂质代谢相关指标的影响，探讨屎肠球菌替代抗生素在肉鸡日粮中应用的可行性及其最适添加量。试验选取1日龄AA肉鸡公仔鸡600只（50 g/只），随机分成5组，每组6个重复，每个重复20只鸡。对照组（CON）饲喂基础日粮；抗生素组（ANT）饲喂基础日粮+0.1%金霉素；3个屎肠球菌试验组（LEF、MEF和HEF组）在基础日粮中分别添加50、100、200 mg/kg屎肠球菌。试验分2期，分别为1~21日龄（前期）和22~42日龄（后期）。结果显示：①各试验组肉鸡生长性能与CON组相比均无显著差异（P>0.05）；从饲养全期看，MEF组和HEF组AA肉鸡的死淘率最低。②在饲养后期，与CON组相比，MEF组胸腺指数显著提高（P<0.05），MEF组脾脏指数有提高的趋势（0.05 < P < 0.1）。③在饲养前期，与CON组和ANT组相比，LEF组和HEF组血清总胆固醇（TC）含量极显著降低（P<0.01）；与ANT组相比，LEF组和MEF组血清甘油三酯（TG）含量极显著降低（P<0.01）；与CON组相比，MEF组和HEF组血清高密度脂蛋白（HDL）含量极显著提高（P<0.01）；与ANT组相比，添加屎肠球菌试验组的低密度脂蛋白（LDL）含量极显著降低（P<0.01）。在饲养后期，与CON组和ANT组相比，LEF组肉鸡血清中TG含量极显著降低（P<0.01），LEF组和MEF组HDL含量极显著提高（P<0.01）。综上所述，在肉鸡饲养中，添加屎肠球菌可以在一定程度上降低死淘率，并有促进免疫器官发育的趋势，还具有一定的降低血脂的作用。综合考虑，建议在AA肉鸡日粮中添加100 mg/kg屎肠球菌。  相似文献   

Detection on Biofilm and Biofilm-associated Genes of Enterococcus faecalis Inducing Lamb Encephalitis     

KONG Jing-ya  GUO Qiang-qiang  KONG Ke-wei  LI Jie  ZHOU Xia  QI Ya-yin 《中国畜牧兽医》2017,44(3):679-685

The purpose of this study was to observe and analyze the ability of biofilm formation of the Enterococcus faecalis (E.faecalis) XJ05 and to detect if the E.faecalis which could induce lamb encephalitis carried the biofilm-associated genes. The E.faecalis XJ05 was used as the sample. The biofilm model was established by the 96-well microtiter plate and read by microplate reader in the D_{595 nm} at the same time observed by the inverted microscope. The primers were designed to examine if the 11 strains of E.faecalis carried the biofilm related genes and then the amplified products were sequenced and analyzed for homology. The results showed that the amount of BF produce in XJ05 strain was significantly different from blank control group at different time (P<0.05), and the highest D_{595 nm} value was at 24 h and significant difference compared with other time (P<0.05). The biofilm of 6 h was scattered when observed under the microscope and the time between 12 to 24 h biofilm to be more denser, after 24 h the biofilm became to degradate and loose gradually. It turned out that the 11 strains of bacteria carried different biofilm-associated genes, 8 biofilm-associated genes were found in 6 strains of bacteria, 7 biofilm-associated genes were find in 1 strain of bacterium, 6 biofilm-associated genes were found in 1 strain of bacterium, 2 biofilm-associated genes were found in 1 strain of bacterium, 2 strains of bacteria could not text out anyone of the detected genes.The homology of all detected genes were all between 93.3% to 100.0%. It concluded that the E.faecalis XJ05 could form the completed biofilm and there were 9 kinds carried the biofilm-associated genes in 11 strains of E.faecalis.  相似文献   

Temporal trends in prevalence of bacteria isolated from foals with sepsis: 1979–2010     

M. J. P. Theelen  W. D. Wilson  J. M. Edman  K. G. Magdesian  P. H. Kass 《Equine veterinary journal》2014,46(2):169-173

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