乌鲁木齐市3~5岁儿童口腔微生物与肠道微生物的构成差异

目的探索乌鲁木齐市3～5岁儿童口腔微生物与肠道微生物的菌群构成及多样性等差异。方法从本团队前期流行病学调查的乌鲁木齐市3～5岁儿童中,按调查时间顺序随机抽取12名儿童。分别收集唾液及粪便样本共计24份,分为口腔微生物组和肠道微生物组。利用16S V3-V4区设计引物来进行PCR扩增,使用MiSeq测序仪进行二代测序,比较两组的微生物构成及多样性差异。结果门水平上:放线菌门(t=5.98,P0.001)、变形菌门(z=20.0,P=0.005)、TM7(z=78.0,P0.001)在口腔中丰度较高;厚壁菌门(z=134.0,P0.001)在肠道中丰度较高。厚壁菌门/拟杆菌门的值在肠道中较大(z=113.0,P=0.017)。属水平上:罗斯菌属、普雷沃菌属、链球菌属为口腔中丰度较高的菌属;粪杆菌属、Ruminococcaceae、拟杆菌属为肠道中丰度较高的菌属(P0.001)。奈瑟菌属、卟啉单胞菌属等仅存在于口腔中。Catenibacterium、肠杆菌属等仅存在于肠道中。菌群功能显示:在细胞运动(z=136.0,P0.001)、碳水化合物代谢(t=-4.71,P0.001)等方面表现出肠道组占优势;在遗传信息的翻译(t=8.17,P0.001)、神经退行性疾病(z=78.0,P0.001)等方面表现出口腔组占优势。结论放线菌门、变形菌门、TM7在口腔中丰度较高;厚壁菌门在肠道中丰度较高。口腔和肠道微生物在菌群功能上差异较大。奈瑟菌属、卟啉单胞菌属、Catenibacterium等可能为某些全身系统性疾病的标志性菌属。     

工业模式微生物膜有序性的活细胞定量分析

作为一种相位敏感的荧光探针,Di-4-ANEPPDHQ可以特异性标记膜的有序相和无序相,在理论上可以对细胞膜的有序性进行定量成像。通过将Di-4-ANEPPDHQ和激光扫描共聚焦显微术相结合,对多种具有代表性的工业模式微生物进行了有序相和无序相活细胞成像,结合极性归一化数值的统计比较,最终实现对上述工业模式微生物细胞膜有序性的定量分析,为细胞膜工程提供了一种直观且快速的活细胞检测方法。     

重组酶介导扩增技术及其在病原微生物快速检测中的应用进展*

建立快速的病原学诊断方法对动物疫病的预防和控制、公共卫生安全等方面具有重要意义。重组酶介导扩增法(RAA)是一种新型恒温体外核酸扩增技术,在体外较低温度下就可以实现对DNA或RNA的快速扩增。RAA具有操作简便、快速、准确、节能、便捷等优点。重组酶、单链结合蛋白和DNA聚合酶是该技术的三大核心物质,利用这三种物质可替代传统PCR的热循环解链过程。该技术将会在病原微生物检测方面发挥重要作用。对RAA技术及其在病原检测方面的应用进行了综述,以期为相关领域的研究提供参考。     

阿莫西林克拉维酸钾或头孢他啶联合布地奈德对肺炎患儿的疗效

目的探讨阿莫西林克拉维酸钾或头孢他啶联合布地奈德对肺炎患儿的治疗效果及对肠道微生物的影响。方法选择2016年9月至2018年12月我院儿科收治的90例肺炎患儿为研究对象,入选患儿随机分为对照组(n=45)和研究组(n=45)。另外选取本院同期健康体检的40例儿童为健康组。对照组患儿接受头孢他啶联合布地奈德疗法,研究组患儿采用阿莫西林克拉维酸钾联合布地奈德疗法。连续治疗7 d后,比较两组患儿临床疗效、临床症状(发热、咳嗽、啰音及扁桃体充血)消失时间及不良反应,同时比较各组患儿肠道微生物(乳杆菌、双歧杆菌、真杆菌、肠杆菌及肠球菌)变化情况。结果研究组患儿总有效率为95.56%,对照组总有效率为91.11%,两组比较差异无统计学意义(χ~2=0.714,P=0.398)。研究组患儿发热、咳嗽、啰音及扁桃体充血消失时间与对照组比较差异无统计学意义(均P0.05)。治疗前,研究组和对照组患儿肠道菌群数量与健康组比较差异无统计学意义(均P0.05)。治疗后,研究组和对照组患儿肠道菌群数量与健康组比较差异有统计学意义(均P0.05)。治疗后,研究组和对照组患儿肠道乳杆菌、双歧杆菌、真杆菌及肠球菌水平较治疗前显著下降,肠杆菌数量明显上升,差异均有统计学意义(均P0.05)。治疗后,研究组和对照组患儿肠道菌群数量比较差异无统计学意义(P0.05)。研究组(8.89%)和对照组(13.33%)总不良反应率比较差异无统计学意义(P0.05)。结论阿莫西林克拉维酸钾联合布地奈德治疗小儿肺炎疗效显著,能有效缩短患儿临床症状持续时间,其疗效与头孢他啶联合布地奈德疗效相当,且药物副作用较小,但对肠道菌群平衡有破坏作用。因此,扶植肠道菌群可以作为综合治疗的一部分。     

基于文献可视化分析的近30年肠道菌群研究趋势及展望

目的全面分析近30年国内外肠道菌群相关研究的发展现状、研究热点及前沿动态,为本领域研究方向提供可视化分析数据。方法以中国知网、Web of Science为来源数据库,检索肠道菌群相关文献,应用CiteSpace(5.5.R2)软件对作者、机构、关键词和被引文献进行共现分析、聚类分析和可视化表达,并对关键词进行突显分析。结果共纳入中文文献912篇,英文文献10 249篇。近30年肠道菌群相关研究年发文量整体呈上升趋势,中文文献发文量明显低于英文文献发文量;英文文献国家总体发文量中,美国排名第一,影响力也最高,中国发文量排名第二,但影响力较低。国外核心研究人员为Rob Knight、Patrice D Cani,国内核心研究人员有王军、赵立平,中文文献发文量较高的作者是段金廒、谭周进、余倩;国外主要机构有哥本哈根大学、法国农业科学研究院等,国内的主要研究机构是中国科学院,其英文文献发文量排名第一;中文文献发文量较多的是中医药类大学。主要研究内容涉及菌群结构、肠道菌群与疾病的关系以及菌群检测技术3个方面。近年来,肠道菌群相关研究多围绕与疾病的相关性及新技术、新方法展开。比较中英文热点关键词,英文关键词丰富,涉及生理、病理各个方面,其中肠道菌群与免疫相关研究成果颇丰。结论作为生物医学领域的研究热点,近30年来肠道菌群研究领域取得了突出的成果,提升肠道菌群检测技术、关注肠道菌群研究成果的应用价值是未来本领域研究的关键。     

Moderate exercise ameliorates osteoarthritis by reducing lipopolysaccharides from gut microbiota in mice

Lipopolysaccharides (LPSs) released by gut microbiota are correlated with the pathophysiology of osteoarthritis (OA). Exercise remodels the composition of gut microbiota. The present study investigated the hypothesis that wheel-running exercise prevents knee OA induced by high-fat diet (HFD) via reducing LPS from intestinal microorganisms. Male C57BL/6 J mice were treated with sedentary or wheel-running exercise, standard diet (13.5% kcal) or HFD (60% kcal), berberine or not according to their grouping. Knee OA severity, blood and synovial fluid LPS, cecal microbiota, and TLR4 and MMP-13 expression levels were determined. Our findings reveal that HFD treatment decreased gut microbial diversity. Increase in endotoxin-producing bacteria, decrease in gut barrier-protecting bacteria, high LPS levels in the blood and synovial fluid, high TLR4 and MMP-13 expression levels, and severe cartilage degeneration were observed. By contrast, voluntary wheel running caused high gut microbial diversity. The gut microbiota were reshaped, LPS levels in the blood and synovial fluid and TLR4 and MMP-13 expression levels were low, and cartilage degeneration was ameliorated. Berberine treatment reduced LPS levels in the samples, but decreased the diversity of intestinal flora with similar changes to that caused by HFD. In conclusion, unlike taking drugs, exercising can remodel gut microbial ecosystems, reduce the circulating levels of LPS, and thereby contribute to the relief of chronic inflammation and OA. Our findings showed that moderate exercise is a potential therapeutic approach for preventing and treating obesity-related OA.     

金鱼两个品种皇冠珍珠和兰寿鳞片组织学比较

珍珠鳞金鱼(Carassius auratus)是一种名贵的金鱼品种。为了解该品种金鱼的鳞片变异机制,本文采用H.E染色以及硝酸银法和Mallory三色法特殊染色对皇冠珍珠与兰寿金鱼鳞片的组织学特点进行研究。结果表明:1皇冠珍珠比兰寿鳞片中央部分明显增厚;2皇冠珍珠鳞片纤维层中胶原纤维排列比兰寿鳞片疏松且无规则;3皇冠珍珠鳞片纤维层中充满了疏松结缔组织基质和细胞。珍珠鳞金鱼鳞片的变异为其鳞片下层纤维层的改变。     

Recent trends in ionic liquid (IL) tolerant enzymes and microorganisms for biomass conversion

Second generation biofuel production depends on lignocellulosic (LC) biomass transformation into simple sugars and their subsequent fermentation into alcohols. However, the main obstacle in this process is the efficient breakdown of the recalcitrant cellulose to sugar monomers. Hence, efficient feedstock pretreatment and hydrolysis are necessary to produce a cost effective biofuel. Recently, ionic liquids (ILs) have been recognized as a promising solvent able to dissolve different biomass feedstocks, providing higher sugar yields. However, most of the hydrolytic enzymes and microorganisms are inactivated, completely or partially, in the presence of even low concentrations of IL, making necessary the discovery of novel hydrolytic enzymes and fermentative microorganisms that are tolerant to ILs. In this review, the current state and the challenges of using ILs as a pretreatment of LC biomass was evaluated, underlining the advances in the discovery and identification of new IL-tolerant enzymes and microorganisms that could improve the bioprocessing of biomass to fuels and chemicals.     

麦田套种玉米共生期农田生态环境特征及对夏玉米苗期生长的影响

以登海661、郑单958为试验材料,设置麦田套种和麦收后接茬直播两种不同种植方式对比试验,研究了麦田套种玉米共生期的农田生态环境特征及对玉米苗期生长的影响.结果表明： 麦田套种玉米与直播玉米相比,土壤含水量差异较小;麦田套种玉米耕层（0～5 cm）土壤的种际最高温度比直播玉米低4.8～5.2 ℃,最低温度相近,日平均温度低1.4～1.7 ℃,日变化较小,但均达到种子萌发要求;麦田套种玉米苗期冠层光照强度比直播显著减少,套种玉米地表光强为自然光强的4.4%～10.6%,光照不足是玉米苗弱、迟发的主要原因.与直播相比,套种玉米种子萌发出苗速度和干物质积累速度较慢,叶龄较小,叶片瘦长,株高较矮,玉米苗健壮度下降,单株叶面积较小且叶绿素含量较低;随共生期延长,玉米苗生长受抑制程度增加.在大田生产中,直播可促进种子萌发出苗,有利于夏玉米幼苗的生长发育,形成壮苗.     

Thermophilic anaerobic oxidation of methane by marine microbial consortia

The anaerobic oxidation of methane (AOM) with sulfate controls the emission of the greenhouse gas methane from the ocean floor. AOM is performed by microbial consortia of archaea (ANME) associated with partners related to sulfate-reducing bacteria. In vitro enrichments of AOM were so far only successful at temperatures ⩽25 °C; however, energy gain for growth by AOM with sulfate is in principle also possible at higher temperatures. Sequences of 16S rRNA genes and core lipids characteristic for ANME as well as hints of in situ AOM activity were indeed reported for geothermally heated marine environments, yet no direct evidence for thermophilic growth of marine ANME consortia was obtained to date. To study possible thermophilic AOM, we investigated hydrothermally influenced sediment from the Guaymas Basin. In vitro incubations showed activity of sulfate-dependent methane oxidation between 5 and 70 °C with an apparent optimum between 45 and 60 °C. AOM was absent at temperatures ⩾75 °C. Long-term enrichment of AOM was fastest at 50 °C, yielding a 13-fold increase of methane-dependent sulfate reduction within 250 days, equivalent to an apparent doubling time of 68 days. The enrichments were dominated by novel ANME-1 consortia, mostly associated with bacterial partners of the deltaproteobacterial HotSeep-1 cluster, a deeply branching phylogenetic group previously found in a butane-amended 60 °C-enrichment culture of Guaymas sediments. The closest relatives (Desulfurella spp.; Hippea maritima) are moderately thermophilic sulfur reducers. Results indicate that AOM and ANME archaea could be of biogeochemical relevance not only in cold to moderate but also in hot marine habitats.