Oribaculum catoniae gen. nov., sp. nov.; Catonella morbi gen. nov., sp. nov.; Hallella seregens gen. nov., sp. nov.; Johnsonella ignava gen. nov., sp. nov.; and Dialister pneumosintes gen. nov., comb. nov., nom. rev., Anaerobic Gram-Negative Bacilli from the Human Gingival Crevice

Abstract

Many undescribed species of bacteria occur among the floras of the human gingival crevice and periodontal pockets (6,(8)(9)(10)(11)(12)(13)(14). Among these are organisms previously referred to as "Bacteroides D19" (9,11,12), "Bacteroides D26" (9, 14), and "Bacteroides D42" (9, 13), as well as one additional species ("Bacteroides D12") that we have not reported previously. We have found that "Bacteroides D19" is associated with gingivitis (11, 12) and periodontitis (9) and that "Bacteroides D42" is associated with periodontitis (9, 13), whereas "Bacteroides D26" is associated principally with oral health (9,14). One purpose of this study was to describe these four species.In addition, we propose reclassification of Bacteroides pneumosintes, a relatively common oral species that has been associated with gingivitis (1, 11, 12) and various infections above the diaphragm (3). This species is a small, non-fermentative, gram-negative, anaerobic rod, originally isolated from nasopharyngeal secretions of patients with influenza during the epidemics of 1918 through 1921 (15). In 1970 the species was reclassified in the genus Bacteroides by Holdeman and Moore (4). This nonfermentative species was excluded from the genus Bacteroides as redefined by Shah and Collins (16), and its taxonomic position currently is incertae sedis. MATERIALS AND METHODSBacterial strains. Unless otherwise stated, all strains were from our Virginia Polytechnic Institute and State University Anaerobe Laboratory Culture Collection and were isolated from the gingival crevices of clinically healthy persons or persons with gingivitis or periodontitis.Characterization of strains. Tests to determine fermentation, enzymatic properties, fermentation products, and antimicrobial susceptibility in prereduced media and polyacrylamide gel electrophoresis of soluble proteins were performed as described previously (2, 7).To determine cellular fatty acids, unless indicated otherwise, actively growing cultures were inoculated into tubes containing 10 ml of prereduced anaerobically sterilized peptone-yeast extract-glucose (PYG) broth (2). Cultures were inoculated under an oxygen-free carbon dioxide atmosphere or under an atmosphere containing an oxygen-free 10% carbon dioxide-90% nitrogen gas mixture. Tubes were stoppered with neoprene stoppers and were incubated at 37°C. All subsequent steps in sample preparation, including centrifugation, were done in the same tubes closed with Teflon-lined screw caps under an aerobic atmosphere.Sedimented cells from cultures that had been incubated at 37°C for 18 to 24 h were used immediately or were frozen and later thawed. Cells were lysed and saponified and the acids were extracted as described previously (5). A 2-bl portion of washed extract was chromatographed on a fused-silica capillary column with a model HP-5890A chromatograph (HewlettPackard Co., Palo Alto, Calif.) equipped with a flame ionization detector and a model HP-3392A integrator (HewlettPackard). The gas flow rates were ca. 400 ml/min for air, 30 ml/min for hydr...

Dialister pneumosintes Associated with Human Brain Abscesses

“…By using the CLUSTAL method (9), the DNA sequences obtained were compared with those from other D. pneumosintes strains and other members of the Sporomusa, a subbranch of the Clostridium subphylum cluster IX, which contains closely interrelated bacteria that belong to the genera Dialister, Megasphaera, and Veillonella (20), sequences which are available from GenBank ( Table 1). The two isolated strains, IBS 708/99 and IBS 18607/00, displayed exactly the same 16S rRNA partial gene sequences, which were very similar to those of D. pneumosintes strain SC3D (99.3% similarity) and D. pneumosintes ATCC 33048 (99.8%) (14). These data indicate that the two isolates are very closely related or identical to the D. pneumosintes species, in accordance with previously established criteria (18).…”

“…D. pneumosintes is a small, nonfermentative, gram-negative anaerobic rod which was first described by Olisky and Gates as Bacterium pneumosintes and obtained from the nasopharyngeal secretions of patients with influenza during the epidemics of 1918 through 1921 (17). After several phylogenetic reclassifications over the last several years, it was reclassified as D. pneumosintes (10,14,20). Precise identification of the bacterium cannot be performed by morphological and traditional biochemical means and therefore requires nucleotide sequencing of the 16S rRNA gene (20).…”

hsp60 and 16S rRNA gene sequence relationships among species of the genus Bacteroides with the finding that Bacteroides suis and Bacteroides tectus are heterotypic synonyms of Bacteroides pyogenes

“…In the past, because of poor definition of the genus, more than 50 species of the genus Bacteroides have been included in this group. The taxonomy of the genus Bacteroides has undergone significant changes in the last two decades (Dewhirst et al, 1990;Moore & Moore, 1994;Rautio et al, 2003;Sakamoto et al, 2002Sakamoto et al, , 2007Sakamoto & Benno, 2006;Shah & Collins, 1988. It has also been reported that 16S rRNA gene sequencing is useful for the identification of isolates of clinically significant species of the genus Bacteroides (Song et al, 2005).…”

Phylogenetic Placement of Dialister pneumosintes (formerly Bacteroides pneumosintes) within the Sporomusa Subbranch of the Clostridium Subphylum of the Gram-Positive Bacteria

“…B. pneumosintes differs markedly from this genus as defined by Shah and Collins (14), and its true taxonomic affiliations remained uncertain. On the basis of phenotypic criteria, Moore and Moore (11) have recently resurrected the genus Dialister, to accommodate B. pneumosintes. In this study, we have sequenced the 16s rRNA gene of the type strain of Dialister pneumosintes to determine its phylogenetic proximity to the genus Bacteroides and other members of the family Ba cteroidaceae.…”