唾液抗PAc抗体对变形链球菌和茸链球粘附的抑制作用

作者采用同位素标记液闪技术研究唾液抗变形链球菌表面蛋白（ＡＰｃ）抗体对变形链球菌和茸毛链球菌在全唾液包被的羟基磷灰石（ＳＨＡ）上粘附的抑制作用。结果显示，含有高效价的特异性护ＰＡｃ抗体的兔唾液使变形链球菌Ｉｉｇｂｒｉｔｔ在ＳＨＡ土的粘附数明显减少，而对茸毛链球菌６７１５的粘附无影响。提示抗ＰＡｃ抗体能抑制变形链球球在唾液获得性膜上的粘附，这可能是特异性抗体龋作用的机制之一。     

抗S.mutans（血清型c）细胞表面蛋白P1抗体对各型变链粘附…

目的：观察Ｓ．ｍｕｔａｎｓ遗传Ⅰ型（血清ｃ型）Ｐ１抗体对遗传Ⅱ－Ⅴ型（血清ａ－ｇ型）变链菌在唾液包羟磷灰石微珠（Ｓ－ＨＡ）表面粘附的影响。方法：用提纯的变链Ｓ．ｍｕｔａｎｓＭＴ６Ｒ的细胞表面蛋白Ｐ１加弗氏佐剂通过局部唾液腺和背部皮下注射免疫ＢＡＬＢ／ｃ鼠，得到含高效价Ｐ１抗体的鼠血清和唾液。结果：发现遗传Ⅰ型变链菌的抗Ｐ１抗体可抑制除Ｓ．ｒａｔｔｕｓ遗传Ⅱ型，血清ｂ型）以外的各型变链在Ｓ－ＨＡ表面     

抗S.mutans(血清型c)细胞表面蛋白P_1抗体对各型变链粘附的影响

目的：观察Ｓ．ｍｕｔａｎｓ遗传Ｉ型（血清ｃ型）Ｐ１抗体对遗传Ⅱ～Ｖ型（血清ａ～ｇ型）变链菌在唾液包被的羟磷灰石微珠（Ｓ－ＨＡ）表面粘附的影响。方法：用提纯的变链Ｓ．ｍｕｔａｎｓＭＴ６Ｒ的细胞表面蛋白Ｐ１加弗氏佐剂通过局部唾液腺和背部皮下注射免疫ＢＡＬＢ／ｃ鼠，得到含高效价Ｐ１抗体的鼠血清和唾液。结果：发现遗传Ｉ型变链菌的抗Ｐ１抗体可抑制除Ｓ．ｒａｔｕｓ（遗传Ⅱ型，血清ｂ型）以外的各型变链在Ｓ－ＨＡ表面的粘附（Ｐ＜０．０５）。结论：蛋白Ｐ１可作为各型变链菌间的共同抗原。     

唾液对变链粘附作用的影响

用放射性同位素３Ｈ－胸腺嘧啶核苷标记变链Ｓ．ｍｕｔａｎｓＪＢＰ株（血清Ｃ型）及Ｓ．ｓｏｂｒｉｎｕｓ６７１５株（血清ｇ型），观察兔全唾液对这两种细菌在羟磷灰石（ＨＡ）表面粘附的影响．结果发现，ＪＢＰ和６７１５在无唾液包被的ＨＡ上的粘附无明显差异（Ｐ＞０．０５），但经唾液包被ＨＡ后ＪＢＰ粘附量明显多于６７１５（Ｐ＜０．０１），说明唾液成分可促进Ｃ型变链的粘附，但对ｇ型变链的粘附影响不大．     

变形链球菌表面粘结素与唾液受体结合特异性的初步研究

目的 研究变形链球菌表面粘结素与唾液受体间的对应结合关系。方法 采用＾３Ｈ标记的变形链球菌（简称变链）竞争性粘附抑制实验及自行设计的间接酶联免疫受体结合实验，检测纯化唾液受体与纯化变链表面粘结素间的结合特异性及其强度。结果 唾液ＩｇＡ降解片段和相对分子质量为１３０００的酸性蛋白仅促进变链粘附，唾液淀粉酶具有促进粘附及抗粘附双重作用。相对分子质量为１２７０００的变链表面粘结素及ＧＴＦ组分分别可竞争抑     

中国茶预防龋病的实验研究

目的 探讨茶浸液中氟对变形链球菌（简称变链菌）致龋作用的动物实验研究分析。方法 用致龋性食物和茶浸液饲养接种了Ｓ．Ｓｏｂｒｉｎｕｓ６７１５菌株的大鼠磨牙，观察茶浸液对变链菌的生长及致龋作用影响，设龙井茶（Ｂ组）、乌龙茶（Ｃ组）、涪陵红茶（Ｄ组）各实验组与双蒸馏水对照组（Ａ组）比较。结果 实验组与对照组牙菌斑指数和龋蚀指数有显著性差异，组间差异顺序为Ｄ组〉Ｂ组〉Ａ组。此抑菌程度与茶氟含量呈正相关关系     

超氧化物歧化酶对变链菌生长和粘附影响的实验研究

目的：了解超氧化物歧化酶（ＳＯＤ）对变链菌Ｉｎｇｂｒｉｔ、６７１５生长和粘附的影响情况。方法：用麦氏比浊法分别比较不同浓度ＳＯＤ对两种变链菌蔗糖琼脂培养基纯培养的细菌生长量；用液闪计数值比较ＳＯＤ对两种变链菌体外在羟基磷灰石（ＨＡ）上的粘附量。结果：在ＳＯＤ存在时，两种致龋菌的生长量大于没有ＳＯＤ时的生长量；ＳＯＤ作用于获得性膜和致龋菌的体外粘附过程时，两种致龋菌的粘附量显著降低，ＳＯＤ作用于致龋菌生长过程，变链菌Ｉｎｇｂｒｉｔ的粘附量升高，变链菌６７１５的粘附量显著降低。结论：外源性ＳＯＤ促进致龋菌的生长，使致龋菌的粘附量发生改变     

单克隆抗体对变链球菌粘附的影响

分别用抗ＯＭＺ１７６菌（ｄ血清型）和抗ＭＴ６Ｒ菌（ｃ血清型）表面蛋白抗原２２０ＫＤ和１８５ＫＯ分子量的单克隆抗体（ＭｃＡｂ）对血清型变链球菌ｃ、ｄ作用后，通后３Ｈ核素标记测试细菌的粘附性。结果显示：抗２２０ＫＤ、抗１８５ＫＤ表面蛋白抗原的ＭｃＡｂｓ对相应血清型的变链球菌的粘附均呈现明显的抑制作用，两种ＭｃＡｂｓ对不相应血清型变链球茵的粘附也有一定的抑制作用。因而认为ＭｃＡｂ通过局部被动免疫抗粘附原理对变链球菌粘附具有抑制作用。     

茶多酚影响致龋菌在唾液获得性膜粘附的研究

目的：研究茶多酚对致龋菌在唾液获得性膜粘附的影响,进一步探讨茶多酚的防龋机制。方法：采用唾液包被羟磷灰石（Ｓ－ＨＡ）形成实验性膜的体外模式,以变形链球菌和粘性放线菌作为主要致龋菌,用茶多酚分别处理Ｓ－ＨＡ和细菌,观察细菌在Ｓ－ＨＡ粘附的情况。结果：两组实验中,茶多酚溶液浓度为１～４ｍｇ／ｍｌ时都能显著抑制变形链球菌和粘性放线菌在Ｓ－ＨＡ上的粘附,且抑制作用随茶多酚溶液浓度的升高而逐渐增强。结论：茶     

ELISA检测抗变形链球菌的单克隆抗体和多克隆抗体与人心脏组织的免疫交叉反应

变形链球菌与人类龋病发生具有最密切的关系。在龋病（变链菌）的免疫学研究中，备受关注的问题之一是抗变链菌的抗体与人心脏组织是否存在免疫交叉反应。本文采用酶联免疫吸附试验（ＥＬＩＳＡ），分别检测了抗变链菌和多克隆抗体和单克隆抗体，与正常人胚心脏匀浆、正常成人心脏匀浆和乙型溶血链球菌的免疫交叉反应性。结果表明：抗变链菌Ｃ血清型全菌的多克隆抗体，与上述三种抗原均存在一定程度的免疫交叉反应；而抗变链菌１８５—ＳＡ的单克隆抗体，则未检测出免疫交叉反应。     

小沟聚合物探针实时检测变形链球菌和远缘链球菌

目的　寻求一种快速检测变形链球菌(S.mutans)和远缘链球菌(S.sobrinus)的方法,研究变形链球菌群在儿童猛性龋患者口中的分布。方法　设计并合成针对S.mutans和S.sobrinus葡糖基转移酶基因(gtf)的特异性引物和小沟聚合物探针(MGB探针),对9株变形链球菌群参考菌株直接提取DNA及扩增纯培养后提取DNA分别进行检测,比较二者检测结果的异同。采集92例猛性龋儿童菌斑样本,用MGB探针进行实时检测。结果　采用MGB 探针可以特异性地鉴别S.mutans和S.sobrinus,直接检测和扩增纯培养后的定性检测结果完全一致,前者荧光出现的时间略迟。92例猛性龋患儿中S.mutans检出率为96.7%,S.sobrinus检出率为32.6%,所有检出S.sobrinus的菌斑样本均可检出S.mutans。结论　采用特异性MGB探针方法可以对菌斑中S.mutans和S.sobrinus进行实时检测, 提高检测效率。     

Interactions between and within Streptococcus mutans and Streptococcus sobrinus isolated from humans harboring both species

Abstract— The prevalence of Streptococcus mutans and Streptococcus sobrinus was examined in plaque samples from small discrete areas of the buccal tooth surfaces of seven subjects. Strains of S. mutans and S. sobrinus were isolated and tested for bacteriocin-mediated interactions between and within the two species, using the stab inoculation technique. S. mutans and S. sobrinus did not colonize each tooth surface uniformly and, in plaque from small discrete sites, S. mutans and S. sobrinus were either undetected or present in different interspecies proportions. Within the same subject, there were no bacteriocin-mediated interactions between strains of the same mutans species and no difference in bacteriocin activity was found between the strains of S. mutans and S. sobrinus from different sites. When bacteriocin interactions were tested between isolated strains from all seven subjects a somewhat higher inhibition ability was found for producer strains isolated from plaque compared with those isolated from saliva. S. mutans appeared to be more bacteriocinogenic than S. sobrinus . Replacing the glucose in the medium with sucrose enhanced the bacteriocin activity of S. mutans towards other S. mutans strains but reduced the inhibitory interaction towards strains of S. sobrinus .     

Interactions between and within Streptococcus mutans and Streptococcus sobrinus isolated from humans harboring both species.

The prevalence of Streptococcus mutans and Streptococcus sobrinus was examined in plaque samples from small discrete areas of the buccal tooth surfaces of seven subjects. Strains of S. mutans and S. sobrinus were isolated and tested for bacteriocin-mediated interactions between and within the two species, using the stab inoculation technique. S. mutans and S. sobrinus did not colonize each tooth surface uniformly and, in plaque from small discrete sites, S. mutans and S. sobrinus were either undetected or present in different interspecies proportions. Within the same subject, there were no bacteriocin-mediated interactions between strains of the same mutans species and no difference in bacteriocin activity was found between the strains of S. mutans and S. sobrinus from different sites. When bacteriocin interactions were tested between isolated strains from all seven subjects a somewhat higher inhibition ability was found for producer strains isolated from plaque compared with those isolated from saliva. S. mutans appeared to be more bacteriocinogenic than S. sobrinus. Replacing the glucose in the medium with sucrose enhanced the bacteriocin activity of S. mutans towards other S. mutans strains but reduced the inhibitory interaction towards strains of S. sobrinus.     

变形链球菌遗传Ⅰ型JBP和Ⅲ型6715表面形态的电镜观察

对变形链球菌遗传Ⅰ型和Ⅲ型菌力表面形态的电镜观察显示，仅遗传Ⅲ型菌体表面存在毛状外膜。但此差异形成的机理以及是否影响变形链球菌的粘附尚需进一步探讨。     

Susceptibility of Streptococcus mutans and Streptococcus sobrinus to cell wall inhibitors and development of a novel selective medium for S. sobrinus

Representative strains of Streptococcus mutans and Streptococcus sobrinus showed differences in susceptibility to members of the monobactam group of beta-lactam antibiotics: S. sobrinus was less sensitive than S. mutans. The minimum inhibitory concentrations of aztreonam (AZT) and carumonam, both of which belong to this group, were 2,000 microg/ml for S. sobrinus and 125 microg/ml for S. mutans. Further addition of fosfomycin, bacitracin and sodium chloride to Mitis Salivarius agar (MS) supplemented with AZT resulted in growth inhibition of S. mutans and oral streptococci other than S. sobrinus, and was therefore used as a selective medium for S. sobrinus (MS-SOB medium). The average growth recovery of laboratory and clinically isolated strains of S. sobrinus on MS-SOB medium was 74.1% compared to that on MS medium. Seventy-eight percent of clinical samples in which S. sobrinus was detected yielded pure growth of S. sobrinus on MS-SOB medium.     

变形链球菌Ⅰ型和Ⅲ型合成葡聚糖的研究

目的 通过对Ⅰ型ＪＢＰ（ｃ型）和Ⅲ型６７１５（ｇ型）变链菌在不同状态葡糖基转移酶（ＧＴＦ）所合成的水不溶性和葡聚糖（ＩＧ）和水溶性葡聚糖（ＳＧ）的测定来研究两种变链菌的ＧＴＦ－Ⅰ和ＧＴＦ－Ｓ是否存在差异。方法 制备ＪＢＰ和６７１５的含酶上清液（ｃｅｌｌ－ｆｒｅｅ ｅｎｚｙｍｅ）及含酶提取液（ｃｅｌｌ－ｂｏｕｎｄ ｅｎｚｙｍｅ），以蔗糖为底物，恒温培养后分别收集ＩＧ和ＳＧ。     

儿童猛性龋变链菌分离株的产酸性

目的：确定儿童猛性龋变链菌和远缘链球菌临床分离株的产酸性。方法：采用酸度计和自动气相色谱仪比较儿童猛性龋、非猛性龋、无龋变链菌（各6株）和远缘链球菌（儿童猛性龋6株,非猛性龋和无龋各3株）的临床株降低环境pH值的能力（ΔpH）和乳酸产量,并以此推测其致龋力。结果：远缘链球菌ΔpH及乳酸产量均高于变链菌,特别是在低pH水平下,二者差异更为显著（P＜0．05）。儿童猛性龋远缘链球菌分离株ΔpH和乳酸产量显著大于非猛性龋和无龋分离菌株（P＜0．05）。结论：远缘链球菌的产酸能力强于变链菌;儿童猛性龋远缘链球菌分离株较非猛性龋和无龋儿童分离菌株产酸性更强。     

变形链球菌和远缘链球菌耐氟菌株超微结构观察

目的：探讨变形链球菌和远缘链球菌耐氟突变后，其超微结构变化及氟化物对细菌结构的影响。方法：将变形链球菌和远缘链球菌分为3组：A为正常对照组；B为加氟孵育组；C为耐氟菌株组。透射电镜观察3组细菌的超微结构。结果：与正常亲代菌株相比，加氟孵育后的菌株及耐氟菌株菌体出现不同程度超微结构改变，包括胞浆电子密度减低，细胞肿胀，内容物外溢，远缘链球菌链状结构消失等。结论：变形链球菌和远缘链球菌与氟共同孵育及耐氟突变后，其超微结构发生了改变，表现为自溶活动及解链活动增强。     

套式PCR检测唾液中变形链球菌及远缘链球菌

目的 探索一种快速、简便地从人类唾液中同时检测变形链球菌和远缘链球菌的方法。方法 分别以变形链球菌gtfI和远缘链球菌gtfB基因设计两组成套引物，首先用套式PCR（二次PCR）检测变形链球菌和远缘链球菌标准株和临床株，然后用套式PCR直接从唾液中检测这两种细菌。结果 变链菌（血清型c,e,f)的标准株及临床株第1次PCR扩增产物为517bp，第2次扩增产物为468bp；远缘链球菌（血清型d,g)及道勒链球菌（血清型h)的标准株及临床株第1次PCR扩增产物为712bp，第2次扩增产物为663bp;其他异种菌均不能扩增出产物，因此该PCR检测具有高度的特异性。细菌纯培养物及唾液PCR检测的敏感性分别是：第1次PCR为10^5CFU，第2次PCR为10^3CFU。结论 套式PCR能快速在人类唾液中同时检测变形链球菌和远缘链球菌。该检测方法有望运用于临床检测，对揭示两种细菌与龋病发生关系的研究具有一定价值。     

Differences in cariogenicity between fresh isolates of Streptococcus sobrinus and Streptococcus mutans

Streptococcus sobrinus is known to possess cariogenic properties in vitro. It can produce acid in large amounts and it has the capacity to adhere to enamel and other surfaces. However, most studies on cariogenicity have been performed with laboratory strains that have been subcultured over long periods of time. Therefore, the cariogenicity and acidogenicity of 9 fresh isolates of both S. sobrinus and Streptococcus mutans from human dental plaque were compared. The bacteria were inoculated into the oral cavity of rats. The rats were fed diet SSP 20/5, containing 20% sucrose and 5% glucose. After the experimental period of 42 days, the amount of caries was assessed and bacterial counts were determined using monoclonal antibodies. Four out of 9 S. sobrinus strains and 3 out of 9 S. mutans strains did not colonize the rats. Colonizing strains constituted 39-78% of the total anaerobic cultivable microflora. The numbers of advanced dentinal lesions in the fissures of the rats colonized with S. mutans were significantly lower than those colonized with S. sobrinus (p less than 0.05). S. sobrinus produced acid more rapidly than S. mutans in a pH-stat system at pH values between 6.5 and 5.0 (p less than 0.01). The results indicate that fresh isolates of S. sobrinus are more cariogenic in rats than fresh isolates of S. mutans. This is possibly due to differences in glycolytic properties of these two species.