Joint study on oral asaccharolytic Eubacterium species.

厌氧真细菌是严格意义上的厌氧、革兰氏阳性杆菌，经常从不同的口腔样本中分离出优势菌种。口腔无糖真细菌的生长缓慢和对氧的敏感性阻碍了它们在各种口腔感染性疾病中的意义的确定。通过采用有效的厌氧分离程序，我们分离到了几株不同于已建立的真细菌种的未分类真细菌菌株，即短毛真细菌E.brachy，真细菌E.lentum，真细菌E.nodatum和真细菌E.timium.多相方法被用来检查这些生物的分类位置。这些未命名的菌株在常规生化试验中是惰性的，但经SDS-PAGE蛋白图谱分析和氨基肽酶活性(Rapid ID 32A)的结果表明，这些菌株与已建立的阿糖分解菌有很大的区别，并被划分为4个类群。在免疫印迹反应和DNA-DNA杂交分析的基础上，提出了两组产丁酸革兰氏阳性短杆菌的新种，分别为隐形艾美耳球虫和微小艾美耳球虫；第三组为苯乙酸乙酯产生菌，通过全细胞蛋白谱和氨基肽酶活性的差异来区分它们。第四组的菌株产生了微量的苯乙酸酯(如果有的话)。厌氧培养和鉴定技术的不断发展和改进导致了真细菌生长缓慢和培养困难的阿糖分解菌的分离。进一步的研究正在进行中，以提供关于未分类菌株和其他真细菌物种在口腔疾病中的作用的信息。

Asaccharolytic Eubacterium species are strictly anaerobic, gram-positive rods and are frequently isolated and predominant bacterial species from different oral samples. The slow growth and oxygen sensitivity of the oral asaccharolytic Eubacterium species has hindered the determination of their significance in various oral infectious diseases. By adopting efficient anaerobic isolation procedures, we isolated several unclassified strains of Eubacterium that were distinct from the established Eubacterium species namely, E.brachy, E.lentum, E.nodatum and E.timidum. A polyphasic approach was used to examine the taxonomic positions of these organisms. These un-named strains were inert in conventional biochemical tests, however, the results of SDS-PAGE protein profile analysis and aminopeptidase activty (Rapid ID 32A) revealed that these strains were quite distinct compared from the established asaccharolytic species and assigned to four groups. Two groups of strains, is butyrate producing gram-positive short rods, have been proposed new species namely, E.saphenum and E.minutum, established on the additional basis of western immunoblotting reactions and DNA-DNA hybridization analysis.The third group were phenylacetate producing strains, which can be distinguished from E.timidum by the differences in whole-cell protein profile and aminopeptidase activity. The strains in the fourth group produced a trace (if any) of phenylacetate. The continuos development and improvement of anaerobic incubation and identification techniques resulted in the isolation of slow growing and culture-difficult asaccharolytic species of Eubacterium. Further studies are in progress to provide information on the roles of the unclassified strains and other Eubacterium species in oral disease.