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31.
为研究牦牛肠黏膜源屎肠球菌G2对健康小鼠肠道微生物、形态和免疫功能的影响,试验设置对照组(CON)、热灭活菌组(EHK)、活菌组(ENT)3个处理组,每组8只C57BL/6小鼠,共计24只。CON组、EHK组、ENT组于正式试验期第1、2、4、6天按0.1 mL/只分别灌胃M17培养基、热灭活菌液和活菌菌液,灌胃前无菌收集小鼠粪便进行乳酸菌总菌计数,第8天处死小鼠取样。结果表明:ENT组乳酸菌总菌数量在第3、5天显著大于CON组与EHK组(P <0.05);各组小鼠结肠病理学评分无显著差异,但ENT组隐窝深度显著高于CON组与EHK组(P <0.05);各组间肠黏膜免疫因子Reg3β、Reg3γ和MUC2基因mRNA表达量差异不显著,TNF-α表达量ENT组显著低于CON组(P <0.05)。综上可知,牦牛源屎肠球菌G2可能为一种肠道过路菌,能在短时间内提高肠道乳酸菌的总数,一定程度上具有改善肠道形态和促进肠道健康的作用。  相似文献   
32.
为了构建粪肠球菌人工感染小鼠脑部损伤模型,以清洁级昆明小鼠为实验动物,将实验室保存的致羔羊脑膜炎粪肠球菌进行复苏,用寇氏法测定小鼠半数致死量(LD50),并以LD50剂量、1/2 LD50的剂量、2/3 LD50剂量感染小鼠,观察临床症状,选择2、4、8、12、24、36、48、60、72、84 h共10个时间点,无菌取其脑部、内脏组织进行细菌的分离鉴定,并观察病理组织学变化。结果显示,粪肠球菌的LD50为7.59×10^8CFU;感染小鼠后,其致死率1/2 LD50剂量组为3.7%,小于2/3 LD50剂量组的13.0%;1/2 LD50剂量组脑组织开始出现病理变化是在感染后12 h,晚于2/3 LD50剂量组(6 h),病理变化与后者相比较轻。结果表明,选择以2/3 LD50剂量为小鼠感染模型的最佳剂量。该动物模型的建立为进一步研究粪肠球菌感染小鼠导致脑炎奠定了基础。  相似文献   
33.
为了解江淮地区猪链球菌(SS)和肠球菌分离株的血清型或基因型分布特征及临床耐药性,本研究对江淮地区临床病例196株分离菌进行SS与肠球菌的鉴定,采用PCR方法进行SS及其1、2、7、9血清型和mrp、ef、sly毒力基因型鉴定;脉冲场凝胶电泳(PFGE)分析SS和肠球菌基因型;K-B法测定其药物敏感性。结果显示,在196株分离菌中,鉴定出112株SS,40株肠球菌。血清型2型SS 44株(39.3%)为优势血清型,ef^-/mrp^-/sly^-型SS 36株(32.1%)为优势毒力基因型,Ps28 18株(16.1%)和Ps27 14株(12.5%)为优势PFGE基因型。肠球菌中屎肠球菌21株(52.5%)为优势菌,Pe12 9株(22.5%)和Pe7 7株(17.5%)为肠球菌优势PFGE基因型。SS和肠球菌对20种药物均表现出不同程度的耐药,耐8种以上药物的菌株数分别占85.7%(96/112)和95%(38/40)。结果表明,江淮地区SS和肠球菌种型复杂,已经成为引起猪细菌性疾病的重要致病菌。分离菌株PFGE基因型均呈多态性,在传播过程中可能存在遗传变异。SS PFGE基因型与血清型、毒力基因型不呈现相关性。菌株耐药现象严重,多重耐药普遍,且耐药谱越来越广。本研究为江淮地区SS和肠球菌的分子流行病学研究及相关疫病防控提供科学依据。  相似文献   
34.
This study was to investigate the ribosome genotyping and antimicrobial resistance in Enterococcus faecalis strains isolated from 2 large-scale farms in Shanghai.40 isolates were evaluated for their sensitivity to 12 antimicrobial agents by broth microdilution,and the ribosome genotyping (ribotype) was characterized by the Riboprinter® Microbial Characterization System.The resistance rates of most antimicrobial drug were relatively high and multidrug resistant strains were detected with more than 80%.4 strains of Enterococcus faecalis isolated from pigs were resistant to vancomycin,including 2 strains of vancomycin highly resistant (MIC>64 mg/L) with the same time highly resistant to gentamicin and streptomycin (MIC>2 048 mg/L).The results showed that multidrug resistance of Enterococcus faecalis was a serious issue,and the resistant phenotypes of the same type of ribotype was not entirely consistent.  相似文献   
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旨在研究单独添加屎肠球菌和枯草芽孢杆菌及二者混合添加对乳鸽生长性能、屠宰性能、免疫功能的影响,从而探究益生菌对乳鸽生长的调控机制。试验选取240只12日龄、体重接近的健康白羽王鸽,随机分成4组,分别为对照组、屎肠球菌组、枯草芽孢杆菌组、混合组,每组6个重复,每个重复10只乳鸽,试验期16 d。试验期结束时,每个重复随机选取2只乳鸽(共48只乳鸽)称重,测定其血清免疫指标、肌肉品质、肝组织抗氧化指标和生长相关基因表达量等。试验结果表明:1)与对照组相比,屎肠球菌组显著提高了乳鸽的平均日增重(P<0.05),且显著高于其余各组(P<0.05),而枯草芽孢杆菌组显著降低了乳鸽的平均日增重(P<0.05);2)与对照组相比,3个处理组对乳鸽的屠宰率、半净膛率、全净膛率、腿肌率、胸肌率、腹脂率均无显著影响(P>0.05),屎肠球菌组和混合组显著提高了乳鸽胸肌亮度(P<0.05),混合组还显著提高了乳鸽胸肌红度(P<0.05);3)与对照组相比,屎肠球菌组和混合组能显著提高乳鸽血清中IgG含量(P<0.05),混合组能显著提高乳鸽胸腺指数和法氏囊指数(P<0.05),除屎肠球菌组GLB显著高于对照组(P<0.05)外,3个处理组对乳鸽的其余血清生化指标均无显著影响(P>0.05);4)与对照组相比,屎肠球菌组超氧化物歧化酶(SOD)活性显著提高(P<0.05),混合组谷胱甘肽过氧化物酶(GSH-Px)活性显著提高(P<0.05);5)3个处理组肝组织的GHIGF-1基因mRNA表达水平均显著高于对照组(P<0.05),枯草芽孢杆菌组GHR基因mRNA表达水平显著高于对照组(P<0.05)。综上所述,屎肠球菌可显著提高乳鸽平均日增重,而枯草芽孢杆菌显著降低了乳鸽的平均日增重;屎肠球菌能改善乳鸽肌肉品质,提高乳鸽抗氧化性能和免疫功能,从而促进乳鸽生长。  相似文献   
38.
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   
39.
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   
40.
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   
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