English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

A new species, Bacteroides endodontalis, is proposed for black-pigmented asaccharolytic Bacteroides strains that have negligible deoxyribonucleic acid homology with either Bacteroides gingivalis or Bacte- roides asaccharolyticus. Strain HG370 (= ATCC 35406) is the type strain. Unlike B. gingivalis, B. endodontalis does not agglutinate sheep erythrocytes or produce phenylacetic acid. B. endodontalis resembles B. asaccharolyticus physiologically but can be distinguished by its lower deoxyribonucleic acid guanine-plus-cytosine content (50 versus 53 to 54 mol%), by its serological reactions, by its electrophoretic patterns of proteins, and possibly by its menadione requirement. The classification of black-pigmented Bacteroides strains, which were formerly classified as Bacteroides rnelaninogeni- cus, has been much improved recently, and many new species have been proposed, mainly on the basis of deoxyri- bonucleic acid (DNA) homology studies (1, 2, 5-7, 13, 19, 20). The following two asaccharolytic species have been described previously: Bacteroides asaccharolyticus (2) and Racteroides gingivalis (1). Strains of B. asaccharolyticus are mostly from nonoral sources, whereas strains of B. gingival- is are mainly from periodontal pockets. B. gingivalis can be easily distinguished from B. asaccharolyticus by its ability to agglutinate erythrocytes (15), to produce phenylacetic acid (8), and to demonstrate a strong trypsin-like activity (14). Previously, we reported (19) that two asaccharolytic black-pigmented Bacteroides strains that were isolated by Sundqvist (G. Sundqvist, Ph.D. thesis, University of Umea, Umea, Sweden, 1976) from dental root canals had negligible DNA homology with either B. gingivalis or B. asaccharolyti- cus. In this paper we describe DNA hybridization studies which showed that these strains and another isolate from an infected dental root canal form a distinct DNA homology group. We propose a new species for these strains, Bacte- roides endodontalis; strain HG370 (= ATCC 35406) is the type strain of this species. MATERIALS AND METHODS Bacterial strains. The strains which we used are listed in Table 1. Strain HG370T (T = type strain) was isolated along with anaerobic streptococci from an infected root canal with a very large area of periapical destruction. The strains were maintained on sheep blood agar plates (Oxoid no. 2 agar supplemented with 0.05% hemin and 0.01% menadione) in an atmosphere containing 80% N2, 10% C02, and 10% H2. Physiological characteristics. The fermentation and bio- chemical tests, as well as the procedures for extraction and methylation of volatile and nonvolatile fatty acids, were done according to the methods outlined in the Anaerobe Laboratory Manual (4) and by the Minitek anaerobic system (BBL Microbiology Systems, Cockeysville, Md.). The com- pounds used in the fermentation assays were glucose, su- crose, lactose, cellobiose, mannose, arabinose, maltose, rhamnose, trehalose, xylose, raffinose, sorbitol, salicin, mannitol, and glycerol. Menadione requirement was deter- mined by using BM agar plates (18) without menadione for

Bacteroides endodontalis sp. nov., an Asaccharolytic Black-Pigmented Bacteroides Species from Infected Dental Root Canals