The genetic and phenotypic properties of 18 strains which were considered to be Bacteroides oralis or related organisms were examined. These strains were differentiated into several groups on the basis of deoxyribonucleic acid homology, physiological properties, guanine-plus-cytosine content of the deoxyribonucleic acid, and electrophoretic patterns of cell proteins. The groups were considered to constitute separate species. Strains of group I (strains VPI 7570A, WAL 3030, and 1221) belonged to the newly described species Bacteroides denticola. Strain VPI 8906D (group 11) has been designated a new species, Bacteroides bucculis, by Shah and Collins. Strain VPI D27B-24 (group 111) is the type strain of B. oralis. However, the biological properties of none of the three groups described above fit the original description of B. oralis (Loesche et al. 1964). Strain VPI D22A-7= did not belong to any of the three groups but had phenotypic properties that matched the phenotypic properties given in the first description of B. oralis. We propose the name Bacteroides veroralis for this organism and have deposited strain VPI D22A-7 in the American Type Culture Collection (= ATCC 33779) as the type strain.Bacteroides oralis was first described by Loesche et al. (16) as a gram-negative anaerobic bacillus from the oral cavity of humans. The biochemical characteristics of B. oralis reportedly are similar to those of Bacteroides melaninogenicus subsp. melaninogenicus and Bacteroides rurninicola (6, 16, 25), except that B. rnelaninogenicus produces a black pigment (7, 15) and B. ruminicola requires hemin for growth and ferments pentose (1). The type strain of B. oralis designated by Loesche et al. (16) apparently has been lost, and the strain now designated 7CM has been reclassified as Bacteroides vulgatus (23). A second strain deposited by Loesche et al. as representative of B. oralis (strain Loesche 8B [= ATCC 159301) was reclassified as B. melaninogenicus subsp. melaninogenicus (4) and is now the type strain of Bacteroides loescheii (8). B . oralis VPI D27B-24 (= ATCC 33269) has been designated the type strain of B. oralis.The present study was undertaken to clarify the relationships of strains which are similar to B . oralis ( 5 , 23, 27, 29); this was done by examining the physiological and biochemical characteristics, deoxyribonucleic acid (DNA) base compositions, DNA homologies, and protein electrophoretic mobility patterns of these strains.
MATERIALS AND METHODSBacterial strains. We studied the following strains of B. oralis and similar organisms: VPI 7570A, from T.Hofstad; WAL 3030, from S. M. Finegold; 1221, from S. S. Socransky; WPH 179, from J. G. Collee; 5540 and 7880, from H. Werner; VPI 8906D, VPI D22A-7T,