低龄儿童龋病牙菌斑的菌群结构分析

目的通过低龄龋齿儿童与口腔健康儿童的微生物组检测,探讨低龄儿童龋病牙菌斑的菌群组成特征。方法在深圳地区招募轻度龋齿、重度龋齿及口腔健康儿童共100名,采集其牙菌斑或健康牙齿表面微生物样本,采用MiSeq测序平台进行16S V4-V5区域的高通量测序。同时,通过生物信息分析方法,对低龄龋齿儿童的牙菌斑的微生物组成的特征进行挖掘分析。结果相对口腔健康儿童,重度龋齿患儿的牙菌斑微生物多样性增加,轻度龋齿患儿则减少,但变化不显著。门水平的优势菌主要为放线菌门、变形菌门及拟杆菌门,虽有相对丰度变化但差异无统计学意义。前10位的优势菌属中,轻度及重度龋齿儿童的最高丰度优势菌属为棒状杆菌属,重度龋齿儿童与健康儿童中的棒状杆菌丰度差异有统计学意义(t=-2.195 5, P=0.028 1)。健康儿童口腔的优势菌属包含了卟啉单胞菌属,但在轻度及重度龋齿儿童的优势菌属则替换为月形单胞菌属。种水平的菌群结构分析显示,前10位的优势菌丰度变化差异无统计学意义,而低丰度的致病菌如变异链球菌(H=27.302 1, P<0.000 1)、Atopobium parvulum(H=17.418 2, P=0.000 2)、栖牙普氏菌(H=10.598 9, P=0.005 0)、唾液普氏菌(H=10.035 0, P=0.006 6)等则在重度龋齿儿童中显著富集。结论低龄龋齿儿童的牙菌斑微生物结构发生了改变,部分口腔有害菌的丰度显著增加与龋病严重程度密切相关。     

肝硬化患者与健康人群唾液菌群的对比分析

目的 分析肝硬化患者（LC组）与健康人群（N组）唾液菌群丰度及多样性的差异,为后续研究提供参考。方法 收集45例肝硬化患者和44例健康人群唾液样本,应用高通量测序技术进行测序分析,对有效序列进行物种注释及多样性分析。结果 共获得7 729 352条有效序列,平均每个样本获得有效序列86 847条。两组人群唾液样本内菌群丰度及多样性差异无统计学意义（均P>0.05）;而唾液菌群结构差异有统计学意义（F=20.13,P<0.01）。肝硬化患者口腔中厚壁菌门（Firmicutes）、拟杆菌门（Bacteroidota）、梭杆菌门（Fusobacteriota）相对丰度较高,而在健康人群口腔中变形菌门（Proteobacteria）相对丰度较高（均P<0.05）。结论 肝硬化患者与健康人群唾液菌群结构有差异,肝硬化患者相较于健康人群可能更易患龋病、牙周炎。重视口腔健康,防治口腔菌群失调对肝硬化的治疗具有重要意义。     

儿童唾液中细菌总数的测定

本文将昆明地区１１－１５岁健康儿童９０名按不同的口腔条件分为三组,每组３０人。采用培养基表面主培养主数法,分别测定唾液中厌氧菌和需氧菌细菌总数。结果表明：儿童唾液中细菌总数,牙颌畸形组、正畸组、正常组,三组间结果在统计学无显著差异。     

幽门螺杆菌相关胃炎患者唾液菌群的研究

目的 探究幽门螺杆菌（Helicobacter pylori,H. pylori）相关胃炎（HpAG）患者和健康人群的唾液菌群特征,找出HpAG患者与无H. pylori感染人群唾液菌群之间的差异。方法 选取符合纳入标准的门诊及住院HpAG患者30例（HP组）,无H. pylori感染者30例（HC组）,收集2组人群唾液标本,通过PCR法扩增16S r RNA基因V3―V4区,经过高通量测序后,对测序数据处理后进行ASV注释、群落结构及多样性分析。结果 群落结构分析表示HpAG患者有其特征性的菌群结构。门水平上,HC组与HP组患者均以拟杆菌门（Bacteroidota）、变形菌门（Proteobacteria）、厚壁菌门（Firmicutes）、梭杆菌门（Fusobacteriota）和放线菌门（Actinobacteriota）为主要优势菌门。与HC组比较,HP组患者唾液菌群中Fusobacteriota相对丰度显著增加（t=2.01,P<0.05）。属水平上,HC组与HP组患者均以普雷沃菌属（Prevotella）、奈瑟菌属（Neisseria）、嗜血杆菌属（Haemophi...     

儿童呼吸道菌群的调查

目的了解儿童呼吸道菌群的分布特征。方法对重庆医科大学附属儿童医院的呼吸内科住院部500例小儿下呼吸道负压吸引法痰标本做分离培养;105例门诊未使用抗生素有咽部体征的上呼吸道患儿咽拭子标本做分离培养;同时对150例健康儿童上呼吸道咽拭子标本做分离培养,对他们的生长菌群进行分类鉴定和药敏试验,并对结果作对比分析讨论。结果草绿色链球菌、表皮葡萄球菌、金黄色葡萄球菌、溶血葡萄球菌、流感嗜血杆菌检出率差异无显著性（P〉0.05）;而儿童下呼吸道痰标本结果和105例门诊上呼吸道患儿咽拭子标本结果比较大肠埃希菌、肺炎克雷伯菌、阴沟肠杆菌、肺炎链球菌、副流感嗜血杆菌、卡他莫拉菌、真菌差异无显著性（P〉0.05）,与150例健康儿童上呼吸道咽拭子标本结果比较差异有显著性（P〈0.05）。革兰阴性杆菌对亚胺硫霉素（IMP）耐药率最低,对哌拉西林/他唑巴坦（TZP）、阿米卡星（AK）、环丙沙星（CIP）耐药率〈30%;革兰阳性球菌未发现耐万古霉素（VA）菌株,对利福平（RD）、哌拉西林/他唑巴坦（TZP）耐药率相对较低;流感嗜血杆菌、副流感嗜血杆菌、卡他莫拉菌对CIP、IMP耐药率〈10%;肺炎链球菌无VA耐药菌株,对氧氟沙星（OFX）、RD耐药率〈10%;草绿色链球菌也无耐VA菌株;对RD、复方磺胺（SXT）、四环素（TE）耐药率〈30%。结论儿童正常菌群的分布特征以草绿色链球菌为主。从病原菌来看,下呼吸道住院患儿痰标本分离的致病菌大于门诊上呼吸道感染患儿咽拭子分离的致病菌大于健康儿童咽拭子标本携带的致病菌。     

腹泻儿童肠道菌群分析

我们使用传统的稀释法和注射器金属棒磁力搅拌稀释法对３０例正常儿童的粪便菌群进行五类菌群的分析,健康儿童每克粪便中肠杆菌数６８９±０７７,肠球菌数为６１９±０５７,乳杆菌数为７３６±２０１,而类杆菌数为９２９±０４５,双歧杆菌数为８５８±０３２,而腹泻儿童肠杆菌数为７６１±０６１,肠球菌６７４±０５８,类杆菌数为８３６±０６０,乳杆菌７７３±０６９,双歧杆菌为７６７±０６６,两者相比主要是原籍菌中双歧杆菌、类杆菌减少,而过路菌中肠杆菌增加,出现了菌群失调。     

长春市儿童龋齿病变中变形链球菌各血清型的流行情况

调查了长春市１０６名患龋儿童,１０３名分离出变形链球菌,阳性率为９７．１％,对分得的变形链球菌用协同凝集方法鉴定血清型,结果为ａ型５７株,占５５．４％;ｄ型３９,占３７．８％;ｃ型３１株,占３０．１％;ｆ型１５株,占１４．６％;ｅ型１３株,占１２．６％;ｇ型８株,占７．８％;ｂ型２株,占１．９％。不同血清型变形链政治协商会议菌混合染率为４７．６％。     

腹泻儿童肠道菌群结构特征的ERIC-PCR指纹图分析

目的 :了解以粪检有无白细胞区分的两类腹泻儿童肠道菌群结构的特征及其与健康儿童的差别。方法 :提取健康儿童 (H)、临床门诊粪检无白细胞的腹泻儿童 (L )和粪检有白细胞的腹泻儿童 (L +)(各 11例 )粪便总DNA作模板 ,获得反映肠道菌群组成特征的ERIC PCR指纹图谱。结果 :以H、L 和L +为序 ,每类样品以独特的ERIC条带为代表的操作分类单元 (OTU)的总数分别为 5 4∶4 7∶2 6 ;每类样品ER IC图谱多样性指数范围分别为 :2 4 5± 0 14 ,2 11± 0 18和 1 76± 0 19。组内成对相似性系数累积曲线分析 :小于 0 6的CS 值在L 组占到总Cs值个数的 70 % ,在H组占 5 0 % ,而在L +组只占 30 %。结论 :腹泻儿童肠道的菌群结构多样性降低 ,粪检有白细胞腹泻个体较之粪检无白细胞腹泻个体肠道菌群结构偏离健康个体更远。     

儿童牙齿表面的菌群分布与龋齿的关系

本实验从幼儿园和小学一年级的学生中选择５－８岁的无龋齿和有龋齿的儿童各４５例,进行牙齿表面的菌群分布与龋齿关系的研究,结果在有龋组中分离到变形链球菌８株,放线菌６株及拟杆菌２６株,而在无龋组中未分离到变形链球菌,分离到放线菌１株,拟杆菌１４株,两组比较,以上三种菌有显著差异（Ｘ２检验Ｐ＜０．０５）。说明除变形链球菌是主要的致龋菌外〔１,２〕,还应考虑放线菌和拟杆菌在龋齿发生上的作用。此外,我们还发现两组的兼性厌氧菌的分布也有所不同,无龋组中分离到棒状杆菌２９株,而有龋组中分离到棒状杆菌１１株,小肠结肠炎耶尔森氏菌７株,两组也有明显差异,故我们认为龋齿发生的原因可能是多方面的,就病原菌来说,也可能是多种细菌的混合作用,从两组兼性厌氧菌与无芽胞厌氧菌的分布不同来看,亦应考虑龋齿的发生与口腔内生态平衡有关     

儿童肠道菌群的建立及影响因素研究进展

早期肠道菌群的建立与机体长远的健康状况密切相关,儿童肠道菌群具有动态、脆弱的特点,孕期菌群暴露、出生途径、喂养方式、出生环境、抗生素使用以及添加益生菌等多种因素均可影响其形成和功能;本文就相关影响因素研究进展进行综述.     

Salivary levels of immunoglobulin and dental caries in children

IgG, IgA, IgM and lysozyme levels were determined in whole unstimulated saliva from ten children aged seven-nine years. IgA levels were significantly higher (p less than 0.05) in caries-susceptible subjects when compared with the caries-free ones. High levels of IgG seemed to correlate with a high DMF score. No correlation was found between lysozyme levels and DMF score.     

An in vitro study of the pH-lowering potential of salivary lactobacilli associated with dental caries

AIMS: Lactobacilli are known to produce acids from sucrose or glucose. This acid production can cause a drop in pH which is sufficiently significant to demineralize the hard tissues of the teeth. Some authors have demonstrated the benefits of substituting sorbitol or xylitol for sucrose. The aim of this work was to study the acid production of salivary lactobacilli with one test sugar (glucose) and two polyols (sorbitol and xylitol). METHODS AND RESULTS: The pH-lowering potential of three strains of oral lactobacilli was recorded with glucose or one of the polyols at three different concentrations. The results showed that polyols were broken down by certain strains of lactobacilli. When this degradation took place, the pH dropped to values sufficiently low to demineralize the hard tissues of the teeth. CONCLUSIONS: Further studies must be carried out on the metabolism of polyols before encouraging their widespread substitution for sucrose.     

Association between ENAM polymorphisms and dental caries in children

AimDental enamel, the most rigid biological tissue of the tooth known to mankind, is the most integral and fundamental part of the tooth. Enamel matrixes compile 5% of Enamelin peptides and at the time of tooth development, they are considered to effect the formation and elongation of enamel crystallites. ENAM plays critical role in enamel formation. Any changes in ENAM may affect the thickness of enamel and may lead to dental caries. The present study is aimed to evaluate the association of ENAM gene polymorphisms and susceptibility of dental caries development risk.Material and methodsThe present study was carried out on 168 South Indian children, children’s with dental caries were included in study. Written consent was taken from their parents/guardians. Additionally 193 healthy individuals were enrolled as controls. Sampling was done after dental examination of the individuals. Three ENAM gene single nucleotide polymorphisms (SNPs) were rs7671281, rs3796704 and rs12640848 was genotyped to check their role in susceptibility of dental caries development risk.ResultsOut of three SNPs rs7671281 showed statistically significant risk association with dental caries susceptibility in this ethnic population at heterozygous allele CT (OR: 1.939, p = .01865) and with minor allele T (OR: 1.451, p = .001292). SNP rs3796704 showed significant protective association with dental caries in Indian population at heterozygous allele GA (OR: 0.409, p = .0192) and with minor allele A (OR: 0.645, p = .00875). SNP rs12640848 showed significant protective association with dental caries in Indian population at heterozygous allele AG (OR: 3.041, p = .00642) and with minor allele G (OR: 1.478, p = .02184). Preliminary insilico analysis also showed that rs7671281 (Ile648Thr) amino acid change will cause the structural and functional changes in ENAM protein.ConclusionsIn the present study significant association was observed between ENAM gene SNP rs7671281 and dental caries susceptibility in South Indian children. These results suggested that ENAM gene variants may contribute to dental caries in children.     

Trends in dental caries in 12-year old children in Croatia

In this epidemiological study the caries status of 12-year-old children was compared over time for the years 1968, 1973, 1980, 1985, 1990, 1991 and 1999. The mean number of decayed, missing and filled teeth (DMFT) decreased from 7.0 in 1968 to 2.6 in 1991. From 1991 to 1999 and increase of DMFT 2.6 in 1991, to 3.5 in 1999) has been seen which is result of war in Croatia and reorganisation of health care delivery system. With the expected continuing decline in the prevalence and severity of oral diseases, one of the main problems in the future seems to be the transition of the oral health care delivery system from a disease-oriented system to a health-oriented one.