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伤寒Vi多糖菌稳定性研究 总被引:1,自引:0,他引:1
为研究国产伤寒Vi多糖菌苗的稳定性,将保存三年以上的伤寒Vi多糖菌苗成品采用自然风干和37℃恒温干燥两种方法浓缩后,用CL-4B柱层析分析系统,测定KD在0.25前多糖的回收率,结果均大于50%,同时对保存三年以上的制品按规程进行了全球,结果均符合规程要求,表明国产菌苗放置三年依然合格。 相似文献
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湖北地区伤寒沙门菌耐药性检测 总被引:1,自引:0,他引:1
目的 报道1999年湖北地区15所医院分离的80侏伤寒沙门菌对11种抗菌药物的耐药状况并与1996年资料比较。方法 药敏试验采用纸片扩散法。用WHONET-4软件进行数据分析。结果 氨苄西林(P<0.05)、哌拉西林(P<0.01)、头孢噻肟(P<0.01)敏感性下降具有统计学意义;临床常用于治疗伤寒的氨苄西林、氯霉素、环丙沙星对伤寒沙门菌仍保持高敏感性,分别为89.5%、96%、95.7%。结论 相似文献
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目的:比较伤寒沙门菌和甲型副伤寒沙门菌流行菌株的外膜蛋白谱差异。方法:运用二维蛋白电泳方法,对我国伤寒沙门菌株XJ90和甲型副伤寒沙门菌株JX2005-92在实验室通用营养条件下培养提取的外膜蛋白进行分离,比对其差异,对差异蛋白点进行质谱鉴定,对鉴定蛋白点的基因序列也进行比较。结果:菌株XJ90中发现20个特异蛋白点,质谱鉴定出16个;菌株JX2005-92中发现29个特异蛋白点,鉴定出18个。在这些蛋白中,OmpA是数目最多的同种差异蛋白。这些差异蛋白点中的大部分编码基因在2种细菌中序列高度相似或相同。结论:伤寒沙门菌和甲型副伤寒沙门菌基因序列高度相似的外膜蛋白具有不同的修饰形式,提示其不同遗传背景在相同的环境条件下表现出精细的功能差异。 相似文献
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目的 以小鼠为模型,研究双歧杆菌在体内对鼠伤寒沙门菌(Salmonella typhimurium ,STM) 感染的防治作用。方法 分别用大剂量悉复欢、B.bifidum 、生理盐水(NS) 给三组小鼠灌胃,再用STM 攻击,观察小鼠经上述不同处理前后肠道双歧杆菌数量和STM 攻击后粪便STM 培养阳性率,阳性标本STM 分离值及小鼠STM 感染率;同时用双歧杆菌、悉复欢、双歧杆菌加悉复欢分别治疗STM 感染的小鼠,观察并比较疗效。结果 1. 大剂量悉复欢使用可使小鼠肠道内双歧杆菌明显降低,而双歧杆菌灌胃则肠道双歧杆菌明显增多。双歧杆菌灌胃的小鼠粪便STM培养阳性率、阳性粪便STM 值明显低于用大剂量悉复欢和NS 的小鼠,小鼠STM 感染发病率也明显较低。2. 对于STM 感染鼠,双歧杆菌与悉复欢联合治疗效果最好。结论 1. 双歧杆菌在体内对STM 有拮抗作用;能预防和减少STM 感染发生;2. 在STM 感染时,先用悉复欢,再用双歧杆菌可以达到预期疗效,双歧杆菌对鼠伤寒沙门菌感染有辅助治疗作用。 相似文献
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本文对鼠伤寒沙门菌(STM)微孔蛋白的免疫学研究作了阐述,分析了STM-微孔蛋白的结构、功能及遗传学,展示了研究STM-微孔蛋白所面临的问题及实际应用价值。 相似文献
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目的 检测多重耐药伤寒沙门菌对抗菌药物的敏感性及其耐药基因携带情况,为伤寒沙门菌引起的腹泻治疗提供科学依据。 方法 采用微量肉汤稀释的方法测定大连地区临床分离的78株伤寒沙门菌对12种抗生素的敏感性;用PCR方法检测TEM型β内酰胺酶基因、catA和catB氯霉素乙酰基转移酶基因以及cmlA氯霉素外排泵蛋白基因、aac(6′)Ⅰb和aac3Ⅱ型氨基糖苷类修饰酶基因、qacEΔ1sul1耐消毒剂和磺胺基因、多重耐药外排基因acrB等8种耐药基因。 结果 78株沙门菌对12种药物有不同程度耐药(1.28%~74.35%)。得到9株多重耐药菌株,其中5株检出TEM型β内酰胺酶基因;7株耐氯霉素的伤寒沙门菌菌株中,2株仅检出catA基因,1株仅检出catB基因,1株仅检出cmlA氯霉素外排泵蛋白基因,2株同时检出catA基因和cmlA氯霉素外排泵蛋白基因;2株检出aac(6′)Ⅰb基因,1株检出aac3Ⅱ型氨基糖苷类修饰酶基因;4株检出耐消毒剂和磺胺基因qacEΔ1sul1;6株检出多重耐药外排基因acrB。 结论 大连地区临床分离的伤寒沙门菌存在严峻的耐药现象,多种耐药基因存在于耐药伤寒沙门菌中,可能是导致菌株对多种抗菌药物耐药的原因。 相似文献
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为探索伤寒沙门菌Ⅵ型分泌系统(type 6 secretion system, T6SS)对SopE表达的影响,阐明其中的分子机制,本研究利用自杀质粒同源重组法构建携带sopE∷3×Flag的伤寒沙门菌野生株(WT-pBAD33)、T6SS功能分子缺陷株(ΔsciG-pBAD33)和回补株(C-ΔsciG),用构建成功的菌株感染巨噬细胞THP-1并在模拟巨噬细胞内环境(LPM培养基、微需氧)下培养,通过实时荧光定量聚合酶链反应(real-time fluorescence quantitative polymerase chain reaction,qRT-PCR)与蛋白质印迹法(Western blot, WB)试验探索T6SS对SopE表达的影响,采用β-半乳糖苷酶活性检测来进一步验证sopE基因启动子的转录水平,Ni柱纯化T6SS功能蛋白SciG,电泳迁移率变动分析(electrophoretic mobility shift assay,EMSA)研究SciG蛋白对sopE基因启动子的调控作用。结果显示:ΔsciG-pBAD33中SopE表达水平较于WT-pBAD33明显降低;SciG蛋白不能直接与sopE基因启动子区域结合。本研究结果表明,伤寒沙门菌T6SS影响了SopE的表达,但是其功能蛋白SciG不能直接调控sopE基因的表达。 相似文献
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Si Hong Park Hyun Joong Kim Woo Hee Cho Jae Hwan Kim Mi Hwa Oh Sung Hun Kim Bok Kwon Lee Steven C. Ricke & Hae Yeong Kim 《FEMS microbiology letters》2009,301(1):137-146
This study was designed to develop a multiplex PCR method with five specific primer pairs for the detection of Salmonella spp., Salmonella subspecies I, Salmonella enterica serovars Typhimurium, Typhi and Enteritidis. A multiplex PCR was constructed with five primer pairs for the detection of Salmonella and pathogenic Salmonella serovars, including a specific primer pair for Salmonella Typhi, based on the sequence comparison between genomic DNA sequences of 12 Salmonella strains. Each primer pair was specifically targeted to Salmonella spp., Salmonella subspecies I, Salmonella Typhimurium, Typhi and Enteritidis. This multiplex PCR was evaluated with various DNAs of Salmonella serovars that yielded high specificity for amplifying the expected PCR products of Salmonella serovars. Using this primer pair, a set of multiplex PCR was performed for the rapid identification of salmonellae and major pathogenic Salmonella serovars. Although this multiplex PCR method will need to be evaluated for a wide range of Salmonella serovars among multilaboratories, it should be useful for identifying clinically significant strains of Salmonella serovars rapidly and accurately without the need for serological testing. 相似文献
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本研究旨在探讨伤寒沙门菌(Salmonella enterica serovar Typhi, S. Typhi)中非编码RNA617(non-coding RNA617,ncRNA617)的分子特性,并研究其对生物膜形成的影响及作用机制。采用Northern blot方法检测ncRNA617的表达,通过cDNA 5’末端快速扩增技术(5’-rapid amplification of cDNA end,5’RACE)和逆转录-聚合酶链式反应(reverse transcriotion-polymerase chain reaction,3’RT-PCR)实验分析ncRNA617可能的转录起始位点和终止位点;构建ncRNA617缺陷菌株、回补菌株和过表达菌株等相关菌株,通过生物膜形成实验,观察ncRNA617对伤寒沙门菌生物膜形成的影响,并用实时荧光定量聚合酶链式反应(quantitative real-time polymerase chain reaction,qPCR)分析生物膜形成相关基因表达水平的变化,综合运用生物信息学方法预测ncRNA617和差异基因的结合区域,初步分析ncRNA617发挥调控作用的机制。结果显示,伤寒沙门菌确有ncRNA617的表达,长度约300 nt,其转录起始位点位于mig-14终止密码子下游967 nt处,终止位点位于t2681起始密码子上游 2 378~2 560 nt处。与野生对照菌株相比,ncRNA617缺陷菌株生物膜形成能力增强(P<0.05),回补菌株的生物膜形成能力恢复至野生菌株水平,过表达菌株的生物膜形成能力有所下降(P<0.05)。qPCR结果表明,ncRNA617可负向调控多个生物膜形成相关基因的转录表达水平(P<0.05)。经生物信息学方法预测发现,ncRNA617与差异基因有不同的结合区域。本研究结果提示,ncRNA617在伤寒沙门菌中存在,其长度约270~452 nt。ncRNA617可能通过靶向结合生物膜形成相关基因下调基因表达,从而负向调控伤寒沙门菌生物膜的生成。 相似文献
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During infectious disease episodes, pathogens express distinct subsets of virulence factors which allow them to adapt to different environments. Hence, genes that are expressed or upregulated in vivo are implicated in pathogenesis. We used in vivo induced antigen technology (IVIAT) to identify antigens which are expressed during infection with Salmonella enterica serovar Typhi. We identified 7 in vivo induced (IVI) antigens, which included BcfD (a fimbrial structural subunit), GrxC (a glutaredoxin 3), SapB (an ABC-type transport system), T3663 (an ABC-type uncharacterized transport system), T3816 (a putative rhodanese-related sulfurtransferase), T1497 (a probable TonB-dependent receptor) and T3689 (unknown function). Of the 7 identified antigens, 5 antigens had no cross-immunoreactivity in adsorbed control sera from healthy subjects. These 5 included BcfD, GrxC, SapB, T3663 and T3689. Antigens identified in this study are potential targets for drug and vaccine development and may be utilized as diagnostic agents. 相似文献
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Typhoid is a life‐threatening febrile illness that affects ~24.2 million people worldwide and is caused by the intracellular bacteria Salmonella Typhi (S. Typhi). Intestinal epithelial invasion by S. Typhi is essential for the establishment of successful infection and is traditionally believed to depend on Salmonella pathogenicity island 1‐encoded type 3 secretion system 1 (T3SS‐1). We had previously reported that bacterial outer membrane protein T2942/STIV functions as a standalone invasin and contributes to the pathogenesis of S. Typhi by promoting epithelial invasion independent of T3SS‐1 (Cell Microbiol, 2015). Here, we show that STIV, by using its 20‐amino‐acid extracellular loop, interacts with receptor tyrosine kinase, Met, of host intestinal epithelial cells. This interaction leads to Met phosphorylation and activation of a downstream signalling cascade, involving Src, phosphatidylinositol 3‐kinase/Akt, and Rac1, which culminates into localized actin polymerisation and bacterial engulfment by the cell. Inhibition of Met tyrosine kinase activity severely limited intestinal invasion and systemic infection by S. Typhi in vivo, highlighting the importance of this invasion pathway in disease progression. This is the first report elucidating the mechanism of T3SS‐1‐independent epithelial invasion of S. Typhi, and this crucial host–pathogen interaction may be targeted therapeutically to restrict pathogenesis. 相似文献
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目的:建立定量检测伤寒沙门菌表面呈现表达的流感病毒抗原的间接ELISA方法。方法:ELISA板以2.5%的戊二醛溶液预处理,将呈现表达M2e等流感病毒抗原表位的伤寒沙门菌的全细胞抗原在ELISA板上进行干燥包被,通过间接ELISA确立全菌抗原的最佳包被浓度;分别采用化学合成多肽M2e和GST-M2e融合蛋白干燥包被ELISA板,绘制标准曲线,对沙门菌表面呈现表达的抗原进行定量分析;对多肽和融合蛋白干燥包被进行比较,同时确立用于定量表面展示量的回归方程。结果:用多肽包被测定的呈现表达的M2e分子数为9.8×104,以GST-M2e包被测定的呈现表达的M2e分子数为1.3×105。结论:利用全菌干燥包被ELISA板可以对伤寒沙门菌表面呈现表达的抗原进行很好的定量分析。 相似文献
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Thomsen LE Chadfield MS Bispham J Wallis TS Olsen JE Ingmer H 《FEMS microbiology letters》2003,228(2):225-231
Signature-tagged mutagenesis (STM) is a widely used technique for identification of virulence genes in bacterial pathogens. While this approach often generates a large number of mutants with a potential reduction in virulence a major task is subsequently to determine the mechanism by which the mutations influence virulence. Presently, we have characterised a Salmonella enterica serovar Dublin STM mutant that, in addition to having reduced virulence, was also impaired when growing under various stress conditions. The mutation mapped to the manC (rfbM) gene of the O-antigen gene cluster involved in O-antigen synthesis. The O-antigen is a component of the lipopolysaccharide (LPS) forming a unique constituent of the outer membrane of Gram-negative bacteria. While mutations in the O-antigen genes usually eliminate the entire O-antigen side chain we found that the transposon mutant produced intact O-antigen, however, the mutation reduced the amount of LPS. 相似文献