Immunological specificity of oral Eubacterium species

Abstract

~Antigens of Eubacterium species including E. alactolyticum, E. brachy, E. nodatum, E. saburreum, E. timidum, E. yurii subsp. yurii and E. yurii subsp. margavetiae, which have been isolated frequently from periodontal pockets and associated with periodontal diseases, were extracted by ultrasonication from whole bacterial cells. Antigens were also prepared from E. aerofaciens, E. lentum and E. rectale, which have been found in intestinal tracts and infected abscesses in human oral cavities. The antigens of the oral Eubacterium species were compared with antigens from E. Zimosum, the type species of the genus Eubacterium, by using SDS-PAGE and Western immunoblot assays. SDS-PAGE gels stained with Coomassie brilliant blue indicated that no major peptide bands were common among the Eubacterium species examined. The protein profile patterns were distinctly different from each other. Western immunoblotting reactions with rabbit antisera showed that the Eubacterium species could be clearly distinguished serologically, and that the species-specific antigens were peptide components of ultrasonic extracts from the whole bacterial cells. The present study demonstrates that these Eubacterium species show great heterogeneity in their peptide components and immunological reactions, which may be useful for identification of the Eubacterium species from human oral specimens.

Genetic Relationships among Eubacterium Species

“…We have found that the oral Eubacterium species are clearly distinguished by serological reactions (24), and this immunological heterogeneity suggests that they are a genetically heterogeneous group of microorganisms. There is no comprehensive study of relationships among Eubacterium species by DNA reassociation, although the limited data on the G + C content of DNA suggests heterogeneity and the need for research.…”

Description of Mogibacterium pumilum gen. nov., sp. nov. and Mogibacterium vescum gen. nov., sp. nov., and reclassification of Eubacterium timidum (Holdeman et al. 1980) as Mogibacterium timidum gen. nov., comb. nov.

“…Proteins were transferred from SDS-PAGE gels to a nitrocellulose membrane (pore size 0n45 µm ; Bio-Rad) by using the transfer buffer system described by Burnette (1981), in conjunction with the trans blot system (Marysol) at a constant current of 350 mA for 4 h with cooling. Membranes were processed with slight modification as described previously (Nakazawa & Hoshino, 1993). Briefly, a rabbit immune antiserum (1 : 1000) was used as first antibody, goat anti-rabbit IgG conjugated with peroxidase (1 : 1000) was used as the second antibody and the colour was then developed.…”

“…Because of its broad definition, the genus has historically acted as a repository for a large number of phenotypically diverse organisms (Cheeseman et al, 1996 ;Nakazawa & Hoshino, 1993). In addition to their phenotypic heterogeneity, it is reported that the bacterial species belonging to the genus are not phylogenetically homogeneous and several species may be closely related to members of the genus Clostridium (Collins et al, 1994 ;Willems et al, 1996).…”

Treponema medium sp. nov., Isolated from Human Subgingival Dental Plaque

“…After electrophoresis, the gel was stained with Coomassie brilliant blue R-250 or used for Western transfer. Western transfer of the antigens from the gel to a nitrocellulose membrane was performed as described previously (19,34). An immunoblotting analysis was carried out by using goat anti-rabbit immunoglobulin G conjugated with peroxidase as the second antibody as described previously (19).…”

“…Western transfer of the antigens from the gel to a nitrocellulose membrane was performed as described previously (19,34). An immunoblotting analysis was carried out by using goat anti-rabbit immunoglobulin G conjugated with peroxidase as the second antibody as described previously (19). It has been reported that a polypeptide is a main antigen of strain G7201T (17).…”