产黑色素类杆菌ATCC25845内毒素对小鼠集落刺激因子的诱生活性

产黑色素类杆菌(Bacteroides melaninogenicus)是口腔感染的主要致病菌,由该菌产生的内毒素在致病中具有重要作用。本文采用半固体琼脂培养基培养小鼠骨髓细胞.以形成的集落数作为集落刺激因子(CSF)的水平指标,研究了产黑色素类杆菌内毒察的CSF诱生活性。实验发现,在一定范围内,CSF水平随内毒索剂量增加而上升,但当内毒索剂量大于50μg时。CSF水平不再继续上升。产黑色素类杆菌内毒素的集落形成单位数(CFU-C)为66.6±8.5。     

牙髓类杆菌的分离、培养、鉴定

试验目的是为寻找口腔内产黑色素类杆菌群中新的菌种一牙髓类杆菌(Bacteroides·endodontalis),试验选择牙髓腔感染的成年患者80例,儿童患者(14岁以下)18例,在厌氧环境下用光滑髓针加棉捻方法收集标本,经厌氧培养,对在CDC琼脂培养基(含0.01％Vitk_3及0.05％氯化血红素)上生长的产黑色素的菌落进行生化,直接血凝试验、气相色谱分析、间接荧光免疫(国际参考株     

慢性根尖周炎的细菌学研究

本文对14例慢性根尖周炎患者16个感染根管细菌培养检查的结果发现:以厌氧菌为优势的混合菌感染是慢性根尖周炎感染根管细菌学的主要特点。穿髓根管由于敞开的髓腔,同一根管内4—9种细菌混合感染者占87.5％;未穿髓的感染根管2—3种细菌混合感染的占62.5％,4种以上细菌混合感染的占37.5％。优势的感染菌包括产黑色素类杆菌、口腔类杆菌、口类杆菌、具核梭杆菌、干酪乳杆菌、内氏放线菌等6种厌氧菌;血液链球菌、变链球菌和酿脓链球菌为最常见的兼性厌氧菌。本文指出口腔正常菌群是感染根管的机会病原菌。     

固定矫正器矫正治疗错颌畸形对口腔微生态环境的影响

目的探讨固定矫正器矫正治疗错颌畸形对口腔微生态环境的影响。方法选择51例在口腔科采用固定矫正器进行矫正的错颌畸形患者,分别在矫正前后对口腔微生物进行培养,观察并比较矫正前后口腔微生态环境的变化情况。结果矫正治疗后1个月口腔牙龈卟啉单胞菌、伴放线杆菌、产黑色素类杆菌的检出率较矫正前升高(P均0.05),而口腔核酸杆菌、衣氏放线菌的检出率与矫正前比较差异无统计学意义(P均0.05),矫正后2个月、4个月、6个月口腔牙龈卟啉单胞菌、伴放线杆菌、核酸杆菌、产黑色素类杆菌及衣氏放线菌的检出率均高于矫正前(P0.05或P0.01)。结论采用固定矫正器矫正治疗错颌畸形会造成口腔微生态的改变,破坏口腔内环境的平衡,容易引起口腔疾病的发生,应早期进行预防及干预治疗。     

口源性口臭患者主要厌氧菌的分布

目的分析口臭患者龈下菌斑和舌苔上主要相关厌氧菌的分布情况。方法选择口腔门诊中口臭患者29例,鼻闻法来确定产臭部位和非产臭部位;分别采集龈下菌斑和舌苔标本接种在非选择性培养基和核梭杆菌选择性培养基,厌氧培养5d后记录非选择性培养基上生长的细菌总数、产黑色素细菌总数及核梭杆菌选择性培养基上生长的目的菌总数。结果29例患者中,15例患者的口臭主要来源于龈缘菌斑,10例主要来源于舌苔,4例患者的口臭由龈缘菌斑和舌苔共同产生;产臭部位和非产臭部位相比,细菌总数、产黑色素菌和具核梭杆菌数都明显上升（P〈0．01）。结论口源性口臭患者口气变化与产黑色素细菌、核梭杆菌相关。     

产黑色素拟杆菌群菌株的培养,鉴定及其免疫血清的特异性检测

本文报告了6种产黑色素拟杆菌国际标准菌株、2株参考菌株的培养、鉴定特点。厌氧菌药敏试验发现中间型拟杆菌、牙龈拟杆菌、产黑色素拟杆菌对头孢霉素、利福平、灭滴灵、青霉素、洁霉素、氨苄青霉素、羧苄青霉索敏感,可供临床治疗中参考。对中间型拟杆菌、牙龈拟杆菌、产黑色素拟杆菌、不解糖拟杆菌,牙髓拟杆菌制备的免疫血清进行了特异性鉴定,发现牙龈拟杆菌免疫血清特异性强,可用于临床辅助鉴定该菌,其它免疫血清均具有不同程度的交叉反应。     

替硝唑体内抗厌氧菌感染作用的研究

本项研究观察了替硝唑对类杆菌,经腹腔感染小鼠的体内保护作用。结果显示替硝唑对脆弱类杆菌和产黑色素类杆菌感染的小鼠,均具有良好的保护作用,两株菌感染的半数有效剂量（ＥＤ５０）分别为１１．１５ｍｇ／ｋｇ和１３．０４ｍｇ／ｋｇ。与甲硝唑相比,两者无显著性差异。     

牙龈紫质单胞菌类胰蛋白酶及其致病机制研究动态

牙龈紫质单胞菌类胰蛋白酶及其致病机制研究动态华西医科大学口腔医学院成都６１００４１黄毅牙周病与产黑色素的革兰氏阴性杆菌尤其是牙龈紫质单胞菌（Ｐｏｒｐｈｏｒｏｍｏｎａｓｇｉｎｇｉ－ｖａｌｉｓ）有密切关系,文献报道该菌为进展性成人牙周炎的优势菌种［１,２...     

感染根管中的产黑色素类杆菌群与临床症状的关系

本文应用免疫荧光法对８０例尖周病变之感柒根管内的产黑色素类杆菌群进行了检测。结果显示慢性尖周炎急性发作产黑色素类杆菌检出率明显高于慢性尖周炎,且根管内产黑菌群与多组临床症状育关。认为产黑菌群为感柒根管的关键性厌氧菌。     

口腔各种产黑色素类杆菌外膜结构的电镜观察

本文对从根管中分离的产黑色素类杆菌群的部分菌株:牙髓类杆菌、牙龈类杆菌、中间型类杆菌、产黑色素类杆菌的表面结构进行了电镜观察。观察发现牙髓类杆菌、牙龈类杆菌表面有放射状排列的菌毛样结构;牙龈类杆菌表面有荚膜;多数细菌的细胞膜外有多个小泡状结构;这些结构可能在细菌吸附于组织的过程中起着重要的作用。     

Isolation and identification of strains of Bacteroides fragilis group from the digestive tract of Callithrix penicillata marmosets

Thirty-five strains of the Bacteroides fragilis group were isolated from oral and intestinal samples from 5 wild caught, captive Callithrix penicillata. Nine oral strains of Bacteroides fragilis (7) and Bacteroides distasonis (2), and 26 intestinal strains of Bacteroides fragilis (14) and Bacteroides distasonis (12) were identified.     

Detection of conjugal transfer systems in oral, black-pigmented Bacteroides spp.

Oral, black-pigmented Bacteroides spp. are important pathogens in oral anaerobic infections and dental disease. We detected conjugation systems in isolates of Bacteroides denticola and Bacteroides intermedius that transferred tetracycline resistance (Tetr) and penicillin resistance to Bacteroides buccae and to Bacteroides fragilis, an intestinal Bacteroides species. A cloned Tetr gene from B. fragilis hybridized to the transferable Tetr locus in the oral strains, indicating that genetic exchange occurs between these two groups of anaerobes.     

Screening for the presence of the insertion sequence IS1 in the genus Bacteroides

Abstract A specific DNA probe, containing a conserved region of the insertion sequence IS1, was hybridised to dot blots of total genomic DNA from 2 oral and 5 intestinal Bacteroides spp. Using Escherichia coli K12 as a positive control and Pseudomonas aeruginosa as a negative control, DNA homologous to the probe could not be detected in Bacteroides corporis, Bacteroides intermedius, Bacteroides ovatus, Bacteroides vulgatus, Bacteroides thetaiotaomicron or 2 strains of Bacteroides fragilis . The total DNA included plasmid DNA of 30.2, 42.7 and 42.7 MDa from B. fragilis, B. intermedius and B. corporis , respectively.
IS1 is commonly found in members of the Enterobacteriaceae, and it was concluded that the 2 groups of bacteria are not closely related.     

High-performance liquid chromatographic analysis of alpha-keto acids produced from amino acid metabolism in oral Bacteroides

Profiles of metabolic alpha-keto acids were determined by a high-performance liquid chromatographic method and applied to characterization of oral black-pigmented Bacteroides. Each bacterial strain was incubated with amino acids in a chemically defined medium. After production alpha-keto acids were purified by hydrazide gel column treatment and converted to u.v.-absorbing derivatives. They were analysed by reversed-phase ion-pair chromatography. Black-pigmented Bacteroides species were differentiated into two groups according to production of aromatic alpha-keto acids. Bacteroides gingivalis, B. endodontalis and B. loescheii produced both p-hydroxyphenylpyruvic and phenylpyruvic acids. However, no such alpha-keto acids were produced by B. levii, B. intermedius and B. denticola. In addition, production profiles of several aliphatic alpha-keto acids (alpha-ketoglutaric, pyruvic, alpha-ketobutyric, alpha-ketoisovaleric, alpha-ketoisocaproic, and alpha-keto-beta-methylvaleric acids) separated each individual species in such groups. The present study offers useful chemotaxonomic information on amino acid metabolic activity of oral black-pigmented Bacteroides species.     

High-performance liquid chromatographic analysis of α-keto acids produced from amino acid metabolism in oral Bacteroides

Profiles of metabolic α-keto acids were determined by a high-performance liquid chromatographic method and applied to characterization of oral black-pigmented Bacteroides . Each bacterial strain was incubated with amino acids in a chemically defined medium. After production α-keto acids were purified by hydrazide gel column treatment and converted to u.v.-absorbing derivatives. They were analysed by reversed-phase ion-pair chromatography. Black-pigmented Bacteroides species were differentiated into two groups according to production of aromatic α-keto acids. Bacteroides gingivalis, B. endodontalis and B. loescheii produced both ρ-hydroxyphenylpyruvic and phenylpyruvic acids. However, no such α-keto acids were produced by B. levii, B. intermedius and B. denticola . In addition, production profiles of several aliphatic α-keto acids (α-ketoglutaric, pyruvic, α-ketobutyric, α-ketoisovaleric, α-ketoisocaproic, and α-keto-β-methylvaleric acids) separated each individual species in such groups. The present study offers useful chemotaxonomic information on amino acid metabolic activity of oral black-pigmented Bacteroides species.     

An Electron Microscope Study of Bacteroides nodusus: Ultrastructure of Organisms from Primary Isolates and Different Colony Types

Examination of the ultrastructure of strains of Bacteroides nodosus isolated from cases of ovine foot-rot shows the organism to be highly piliated on primary culture. On subculture in the laboratory two colony types characterized by a high and low degree of piliation can be demonstrated. In agglutination tests the interaction of pili with antibody is responsible for high titre homologous agglutination. Low titre heterologous agglutination appears to be due to other surface antigens. These findings are discussed in relation to the pathogenicity of the organism.     

Ultrastructural Studies on a Model Tintinnid – Schmidingerella meunieri (Kofoid & Campbell, 1929) Agatha & Strüder‐Kypke, 2012 (Ciliophora). II. The Oral Apparatus

The ultrastructure of the oral apparatus is supposed to be significant for elucidating more recent common ancestry and might thus provide support for particular groupings of oligotrichean ciliates. The transmission electron microscopical study on mainly cryofixed Schmidingerella meunieri specimens provides the first detailed data for tintinnids and Oligotrichea in general. Ten new characters are included into the cladistic analysis. These features together with the very limited body of literature suggest that substantial changes in the oral ultrastructure correlate only with the formation of a circular adoral zone in choreotrichids. Despite homoplasious morphological and ontogenetic adaptations to the planktonic lifestyle in halteriid hypotrichs and oligotrichids, their oral apparatuses generally retain the plesiomorphic ultrastructure of the Perilemmaphora. The highly complex ultrastructure of the adoral zone is thus able to accomplish an extension in the zone's functionality without obvious changes; only the position of the adoral zone at the apical cell portion together with a globular to obconical cell shape are apparently crucial. Merely, minute apomorphies characterise the Oligotrichea and tintinnids, respectively. Tintinnids with derived somatic ciliary patterns possess distinct microtubular bundles connecting the oral apparatus with the myoneme in the peduncle.     

Description of an unusual gram-negative anaerobic rod isolated from periodontal pockets

A Gram-negative rod which grew with an unusual colonial "water-drop" form was isolated from periodontal pocket samples from 12 patients. Six strains were characterized by biochemical tests, cell wall analyses, malate dehydrogenase mobilities, protein profiles, and serology. By these criteria, the organisms formed a group of similar strains which were anaerobic, nonmotile, nonsporing, Gram-negative rods resembling Bacteroides. Comparison of the isolates to American Type Culture Collection strains of Bacteroides showed that they represented a closely related group, distinct from the described species of oral Bacteroides. Initial results on the DNA of the isolates suggested a base ratio of 54-57% G + C. Despite the DNA G + C base ratios currently accepted for the Bacteroides (28-61 mol% G + C), many species fall into a narrower range of 40-52 mol% G + C. This range would exclude the organisms described here and suggests that placing them into the genus Bacteroides may be inappropriate.     

Infant gut microbiota is protective against cow's milk allergy in mice despite immature ileal T-cell response

Faecal microbiota of healthy infant displays a large abundance of Bifidobacterium spp. and Bacteroides spp. Although some studies have reported an association between these two genera and allergy, these findings remain a subject of debate. Using a gnotobiotic mouse model of cow's milk allergy, we investigated the impact of an infant gut microbiota – mainly composed of Bifidobacterium and Bacteroides spp. – on immune activation and allergic manifestations. The transplanted microbiota failed to restore an ileal T-cell response similar to the one observed in conventional mice. This may be due to the low bacterial translocation into Peyer's patches in gnotobiotic mice. The allergic response was then monitored in germ-free, gnotobiotic, and conventional mice after repeated oral sensitization with whey proteins and cholera toxin. Colonized mice displayed a lower drop of rectal temperature upon oral challenge with b-lactoglobulin, lower plasma mMCP-1, and lower anti-BLG IgG1 than germ-free mice. The foxp3 gene was highly expressed in the ileum of both colonized mice that were protected against allergy. This study is the first demonstration that a transplanted healthy infant microbiota mainly composed of Bifidobacterium and Bacteroides had a protective impact on sensitization and food allergy in mice despite altered T-cell response in the ileum.