不同牙周状态下分离的血链球菌和口腔链球菌H2O2产生能力的比较

目的：比较研究不同牙周状态下分离的血链球菌和口腔链球菌过氧化氢（H2O2）生产能力。方法：随机选出不同牙周状态下分离的血链球菌和口腔链球菌各30株,采用酚红还原-微量板法测定厌氧条件下两种细菌H2O2的产量。结果：血链球菌各组和口腔链球菌各组H2O2的产量差异未见显著性;口腔链球菌产生H2O2的能力强于血链球菌。结论：提示牙周病变部位与健康部位的血链球菌和口腔链球菌产生H2O2的能力基本相似,是否存在基因型的差异尚待进一步研究。     

血链球菌在不同牙周状态下的分布及相关研究

目的：探讨口腔主要过氧化氢产生菌血链球菌和口腔链球菌在不同牙周健康状态下龈下菌群中的分布,及与牙周健康状态和牙龈卟啉单胞菌群中分布的相互关系。方法：纳入符合标准的受试者30人,受试位点86个,其中健康组11人,位点30个,龈炎组9人,位点29个,慢性牙周炎组10人,位点27个,检查记录牙周健康状态[包括牙龈指数（GI）和牙周袋深度（PD）],采集龈下菌斑标本,经厌氧菌培养基和AP-PCR及PCR鉴定后,将各受试组进行比较分析。结果：共获得草绿色链球菌523株,产黑色素菌241株。经AP-PCR及PCR鉴定后,得到血链球菌112株,口腔链球菌56株,牙龈卟啉单胞菌84株,健康组龈下菌斑中血链球菌,口腔链球菌和牙龈卟啉单胞菌构成比与牙周炎组相比有差异显著性;血链球菌和口腔链球菌与GI、PD呈负相关,牙龈卟啉菌与GI、PD呈正相关;血链球菌的构成与牙龈卟啉单胞菌的构成比呈负相关。结论：血链球菌等过氧化氢产生菌在龈下菌斑中比例的下降。可能是微生态失衡,致病菌过度增殖的重要机制。     

口腔血链球菌质粒的初步研究

口腔血链球菌是牙周主要有益菌,质粒是细胞染色体外辅助性遗传物质可以赋予细胞不同表型。本研究目的提检测血链球菌质粒ＤＮＡ存在情况,鉴定其分子大小,初步了解血链菌质粒与耐药性的关系,为今后更深入地在分子水平研究血链菌奠定实验基础。     

向口腔细菌导入重组葡聚糖酶

日清食品和大阪大学微生物病原研究所教授松代爱三等把从节杆菌属微生物中分离的葡聚糖酶的基因导入口腔内常见的血链球菌并表达成功.在日本生化学会上发表了.血链球菌是存在口腔内最多的链球菌、而且无害.将以在口腔内分泌分解牙垢的葡聚糖酶作为“龋预防剂”.这项技术实用化的障碍有3点.首先是法规问题.在口腔内使用基因重组细     

血液链球菌与牙周可疑致病菌间的关系

生态系中微生物间存在拮抗或协同关系,口腔微生物也不例外。在牙齿周围这一复杂的微生态环境中,许多这些微生物间的拮抗或协同关系对人类的牙周健康并无妨害,但有时,尤其是当牙周这一微生态环境中侵入牙周可疑致病菌时,细菌间的拮抗或协同关系对保持牙周健康或激发疾病进展起着决定性的作用。伴放线嗜血菌(A.a.),具核梭杆菌(F.n.)为牙周可疑致病菌,在活跃性牙周损害部位,其检出率高,所占比例大,链球菌包括血液链球菌(S.sanguis)减少;在健康龈沟内,则正好相反。本实验即在体外观察S.sanguis与A.a.和F.n.间的     

血链球菌产生过氧化氢机理研究

作者在国内首次建立两种确定细菌产生过氧化氦的方法,可以定性和定量分析。本文探讨了血链球菌产生过氧化氢的条件,研究其在牙周微生态环境中的作用。     

铍对口腔链球菌生长及粘附性能的影响

目的 研究铍离子(Be2+)对口腔链球菌的生长及粘附性能的影响,探讨口腔修复治疗后牙周损伤的微生物机制.方法 含有不同浓度Be2+(5、10、20和40 mg/L)的培养液厌氧培养口腔链球菌24h.检测不同浓 度Be2作用后细菌形态和菌落形成单位(CFU),以及口腔链球菌在唾液包被羟基磷灰石微粒表面的粘附抑制率.结果 铍离子作用后口腔链球菌长链缩短,菌体出现集结趋势.20 mg/L时,菌体表面出现“触角样”变化.随Be2+浓度增加,CFU值减小(P＜0.05),口腔链球菌生长抑制.各实验组口腔链球菌粘附抑制率高于阳性对照组(P＜0.05),但各Be2+浓度组之间粘附抑制率差异无统计学意义(P＞0.05).结论 铍离子抑制口腔链球菌的生长和在牙面的粘附,可能会导致修复体周围正常微生态环境失衡,引起牙周疾病.提示临床应尽量选用理化性能稳定的修复材料.     

伊犁黑蜂蜂胶对口腔主要致龋细菌及生物膜生长的实验研究

目的研究伊犁黑蜂蜂胶对口腔常见致龋细菌及其生物膜生长的影响,观察其防龋效果。方法 (1)通过液体稀释法测定伊犁黑蜂蜂胶对口腔常见致龋菌的最小抑菌浓度(MIC)及最小杀菌浓度(MBC);(2)生物膜形成抑制试验测定伊犁黑蜂蜂胶对口腔常见致龋菌的最小生物膜形成抑制浓度(MBIC50);(3)通过结晶紫染色法测定伊犁黑蜂蜂胶对口腔常见致龋菌的最小生物膜清除浓度(MBEC);结果(1)伊犁黑蜂蜂胶对变形链球菌、远缘链球菌、嗜酸乳杆菌、血链球菌、粘性放线菌和内氏放线菌的最低抑菌浓度分别是0.78、0.39、1.56、0.39、0.20和0.20 mg/mL,最低杀菌浓度分别为1.56、0.78、3.125、0.78、0.39和0.39mg/mL;(2)伊犁黑蜂蜂胶对变形链球菌、远缘链球菌、血链球菌、粘性放线菌和内氏放线菌的MBIC50分别是0.39、0.39、0.39、0.05和0.10mg/mL;(3)伊犁黑蜂蜂胶对变形链球菌、远缘链球菌、血链球菌、粘性放线菌和内氏放线菌的MBEC分别是6.25、1.56、3.1256、0.78和0.78mg/mL。结论伊犁黑蜂蜂胶对口腔主要致龋细菌的生长具有抑制作用,能够抑制主要致龋细菌单菌生物膜的形成,并具有一定清除作用,是具有一定防龋效果的天然药物。     

牙周致病菌与阿尔茨海默病相关性研究进展

阿尔茨海默病(Alzheimer′s disease, AD)是一种进行性神经退行性疾病,其主要致病机制目前尚不清楚,临床上也缺乏有效的药物缓解病程的发生和发展。牙周病(periodontal disease, PD)是口腔常见病和多发病,牙周致病菌是其主要始动因子,越来越多的研究表明牙周致病菌与AD密切相关。本文主要围绕牙周致病菌与AD的相关性机制进行归纳总结,建议AD患者应重视口腔健康,PD的防治选择对AD具有重要作用,也为找寻AD治疗新靶点提供理论帮助。     

高龋菌株产生的变链素对口腔链球菌抑制活性的比较

目的 通过比较高龋和无龋儿童变形链球菌临床分离株产生的变链素对口腔链球菌的抑制活性,探讨变链素的产生与其致龋性及口腔微生态的关系.方法 从10例高龋儿童和10例无龋儿童牙菌斑内分离、鉴定得到80株变形链球菌临床分离株,分为高龋组和无龋组.用平板法检测两组菌株产生的变链素对口腔链球菌Streptococcus oralis ATCC 10557的抑制情况,观察两组菌株产生的抑菌环大小, 测量记录数据,T检验比较两组菌株抑菌环均数差异.结果 高龋组产生的抑菌环平均值为10.4 mm,无龋组平均值为6.9 mm,T检验显示差异具有显著性(t值为3.098,P<0.05).结论 高龋菌株产生的变链素对ATCC 10557有更大的抑制活性,变链素对口腔链球菌的抑制活性与其致龋力呈正相关.     

Oral Microbial Ecology and the Role of Salivary Immunoglobulin A

In the oral cavity, indigenous bacteria are often associated with two major oral diseases, caries and periodontal diseases. These diseases seem to appear following an inbalance in the oral resident microbiota, leading to the emergence of potentially pathogenic bacteria. To define the process involved in caries and periodontal diseases, it is necessary to understand the ecology of the oral cavity and to identify the factors responsible for the transition of the oral microbiota from a commensal to a pathogenic relationship with the host. The regulatory forces influencing the oral ecosystem can be divided into three major categories: host related, microbe related, and external factors. Among host factors, secretory immunoglobulin A (SIgA) constitutes the main specific immune defense mechanism in saliva and may play an important role in the homeostasis of the oral microbiota. Naturally occurring SIgA antibodies that are reactive against a variety of indigenous bacteria are detectable in saliva. These antibodies may control the oral microbiota by reducing the adherence of bacteria to the oral mucosa and teeth. It is thought that protection against bacterial etiologic agents of caries and periodontal diseases could be conferred by the induction of SIgA antibodies via the stimulation of the mucosal immune system. However, elucidation of the role of the SIgA immune system in controlling the oral indigenous microbiota is a prerequisite for the development of effective vaccines against these diseases. The role of SIgA antibodies in the acquisition and the regulation of the indigenous microbiota is still controversial. Our review discusses the importance of SIgA among the multiple factors that control the oral microbiota. It describes the oral ecosystems, the principal factors that may control the oral microbiota, a basic knowledge of the secretory immune system, the biological functions of SIgA, and, finally, experiments related to the role of SIgA in oral microbial ecology.     

Salivary Mucins Protect Surfaces from Colonization by Cariogenic Bacteria

Understanding how the body''s natural defenses function to protect the oral cavity from the myriad of bacteria that colonize its surfaces is an ongoing topic of research that can lead to breakthroughs in treatment and prevention. One key defense mechanism on all moist epithelial linings, such as the mouth, gastrointestinal tract, and lungs, is a layer of thick, well-hydrated mucus. The main gel-forming components of mucus are mucins, large glycoproteins that play a key role in host defense. This study focuses on elucidating the connection between MUC5B salivary mucins and dental caries, one of the most common oral diseases. Dental caries is predominantly caused by Streptococcus mutans attachment and biofilm formation on the tooth surface. Once S. mutans attaches to the tooth, it produces organic acids as metabolic by-products that dissolve tooth enamel, leading to cavity formation. We utilize CFU counts and fluorescence microscopy to quantitatively show that S. mutans attachment and biofilm formation are most robust in the presence of sucrose and that aqueous solutions of purified human MUC5B protect surfaces by acting as an antibiofouling agent in the presence of sucrose. In addition, we find that MUC5B does not alter S. mutans growth and decreases surface attachment and biofilm formation by maintaining S. mutans in the planktonic form. These insights point to the importance of salivary mucins in oral health and lead to a better understanding of how MUC5B could play a role in cavity prevention or diagnosis.     

Aerobic Oral Bacteria in Healthy Captive Snakes

Cotton swab samples were taken from the ventral surface of the mouth and from the proximal esophagus from 23 captive nonpoisonous snakes. The samples were cultured and investigated for aerobic bacteria. Both the mouth and the esophagus) samples of 6 snakes were negative. When the bacterial isolates of the mouth and the esophagus of the whole snake population were compared, it was found that the flora isolated from both locations were similar. However, when the samples of individual snakes were compared it was found that the same isolates were seldom found in both the mouth and the esophagus. The most common bacteria found were Pseudomonas sp., Alcaligenes-like organisms, Gram-positive rods and Gram-positive cocci belonging to the family Micrococcaceae. Important pathogens were seldom isolated. Salmonella virchow could be found from 2 snakes. The presence of bacteriologically negative samples, great variations in the composition of the flora between individual snakes, and the occurrence of typical environmental bacteria in the oral cavity all suggest that snakes lack a specific autochtonous flora: and the bacteria isolated from the oral cavity may be occasional environmental bacteria. The source of pathogens may be the environment, too.     

How dogs lap: ingestion and intraoral transport in Canis familiaris

It has recently been suggested that the mechanism for lifting liquid from a bowl into the oral cavity during lapping is fundamentally different in cats and dogs: cats use adhesion of liquid to the tongue tip while dogs 'scoop' with their backwardly curled tongue. High-speed light videos and X-ray videos show that on the contrary, both cats and dogs use the mechanism of adhesion. Liquid is transported through the oral cavity to the oesophagus, against gravity, on the surface of the tongue as it is drawn upwards, then a tight contact between the tongue surface and palatal rugae traps liquid and prevents its falling out as the tongue is protruded. At least three cycles are needed for intraoral transport of liquid in the dog.     

Measurement of the surface free energy of bacterial cell surfaces and its relevance for adhesion

An experimental technique is described to determine contact angles on bacterial layers deposited on cellulose triacetate filters. Measurements with water, water-n-propanol mixtures, and alpha-bromonaphthalene were employed to calculate surface free energies of various oral bacteria. Differences of 30 to 40 erg cm-2 were obtained for four different bacterial species isolated from the human oral cavity, if the concept of dispersion and polar surface free energies is applied. The free energies obtained were used to calculate interfacial free energies of adhesion of these bacteria from saliva onto tooth surfaces. Bacterial adhesion is energetically unfavorable, if the enamel surface free energy is less than 50 erg cm-2.     

Measurement of the surface free energy of bacterial cell surfaces and its relevance for adhesion.

An experimental technique is described to determine contact angles on bacterial layers deposited on cellulose triacetate filters. Measurements with water, water-n-propanol mixtures, and alpha-bromonaphthalene were employed to calculate surface free energies of various oral bacteria. Differences of 30 to 40 erg cm-2 were obtained for four different bacterial species isolated from the human oral cavity, if the concept of dispersion and polar surface free energies is applied. The free energies obtained were used to calculate interfacial free energies of adhesion of these bacteria from saliva onto tooth surfaces. Bacterial adhesion is energetically unfavorable, if the enamel surface free energy is less than 50 erg cm-2.     

健康青少年口腔优势菌的分离、培养和鉴定

目的 寻找健康青少年口腔优势菌,为口腔微生态调节剂的研究提供基础资料。方法 通过需氧及厌氧培养法,随意引物聚合酶链反应法来得到健康青少年口腔的优势菌。结果 实验发现,在健康青少年口腔中可以分离出1种构成比较大的细菌,经鉴定为1种血链球菌。结论 血链球菌是健康青少年口腔优势菌。     

Human oral cavity as a model for the study of genome-genome interactions

The enormous diversity of culturable bacteria within the oral microbial community coupled with experimental accessibility renders the human oral cavity a valuable model to investigate genome-genome interactions. The complex interactions of oral bacteria result in the formation of biofilms on the surfaces of the oral cavity. One mechanism thought to be important in biofilm formation is the coaggregation of bacterial partners. In this paper, we examine the role of coaggregation in oral biofilms and develop protocols to elucidate the spatial organization of bacterial species retained within oral biofilms. To explore these issues, we have employed two experimental systems: the saliva-coated flowcell and the retrievable enamel chip. From flowcell studies, we have determined that coaggregation can greatly influence the ability of an oral bacterial species to grow and be retained within the developing biofilm. To examine the spatial architecture of oral biofilms, fluorescent in situ hybridization protocols were developed that successfully target specific members of the oral microbial community. Together, these approaches provide insight into the development of oral biofilms and expand our understanding of genome-genome interactions.     

具核梭杆菌对结直肠癌诊疗作用的研究进展

口腔菌群作为人体的第二大微生物群,对人体健康具有非常重要的作用。具核梭杆菌是口腔中的常驻菌之一,与其他菌共同维持机体的稳态,现已被证实是结直肠癌最相关的菌属之一,参与结直肠癌的发生、发展以及预后。很多学者根据具核梭杆菌在结直肠癌中的致病机制,寻找以具核梭杆菌为靶点的对结直肠癌进行早期诊断和治疗的新方法。本文阐述了具核梭杆菌在结直肠癌中的致病机制,着重探讨其在结直肠癌的诊断和治疗中的潜在作用,以期为临床诊疗提供参考。

     

The effect of selected factors on the course of wound healing after surgery for laryngeal neoplasms

Finding of the a etiologic factors and participation of bacteria flora in wound healing in laryngeal cancer treatment was the purpose of our study. Investigations were performed in 27 patients. Swabs were taken from the postoperative wounds. Detailed identifications of the bacteria flora and antibiotic susceptibility of bacteria were performed. Wound healing was estimated according to extension of the carcinoma, applied antibiotics, state of the oral cavity, the kind of bacteriological flora isolated after surgical treatment from postoperative wounds. It was found that wound healing depended on the extension of carcinoma, as well as, type of isolated bacteria and antibiotic therapy used. The proper healing of postoperative wounds was not dependent on the state of the oral cavity and the dentition. The main cause of postoperative complication of wounds was methicillin-resistant Staphylococcus aureus (MRSA).