Asaccharolytic anaerobic gram-negative coccobacilli (AAGNC) isolated from infected root canals and periodontal pockets.
OBJECTIVE
Culture-difficult bacteria, including asaccharolytic anaerobic gram-negative coccobacilli (AAGNC), may constitute a predominant group of organisms in oral sites. This study aimed to characterize phylogenetically 10 AAGNC isolated from endodontic lesions and periodontal pockets.


METHODS
16S rDNA sequence and G + C content were determined. Strains sharing more than 98% sequence similarities and similar G + C content were considered the same bacterial species.


RESULTS
One isolate resembled Dialister pneumosintes (the type species of the genus Dialister) with 35 mol% G + C content and 97% sequence similarity. Of eight isolates having 45-47 mol% G + C content, seven were identified as D. invisus and one resembled Dialister invisus with 97% sequence similarity. However the 16S rDNA sequence similarities with D. pneumosintes were relatively low, indicating the strains may belong to a new genus. The last isolate revealed 35 mol% G + C content, but had higher 16S rDNA sequence similarity with D. invisus than with D. pneumosintes.


CONCLUSIONS
The group of oral AAGNC isolates need to be reclassified.
Djais
A
A
Oral Ecology in Health and Infection, Niigata University Graduate School of Medical and Dental Sciences, Japan.
Nakazawa
F
F
Sato
M
M
Sato
N
N
Sundqvist
G
G
Hoshino
E
E
D001482:Base Composition / Q000235:genetics; D003596:Cytosine / Q000032:analysis; D004269:DNA, Bacterial / Q000032:analysis; D004275:DNA, Ribosomal / Q000032:analysis; D003786:Dental Pulp Cavity / Q000382:microbiology*; D003788:Dental Pulp Diseases / Q000382:microbiology*; D006089:Gram-Negative Anaerobic Bacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D006147:Guanine / Q000032:analysis; D006801:Humans; D010514:Periodontal Pocket / Q000382:microbiology*; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000032:analysis
D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D006147:Guanine; D003596:Cytosine