Fusobacterium nucleatum involvement in adult periodontitis and possible modification of strain classification.
BACKGROUND
This investigation was designed to evaluate the involvement of Fusobacterium nucleatum clinical strains in adult periodontitis by subspecies and expression of hemagglutination activity.


METHODS
Forty-nine Fusobacterium strains were isolated from 40 sites in 40 subjects presenting with adult periodontitis. F. nucleatum subspecies identification was based on the electrophoretic migration of glutamate dehydrogenase and 2-oxoglutarate reductase. Hemagglutination activity and inhibition by galactose were tested on sheep erythrocytes.


RESULTS
The 49 isolates belonged to the F. nucleatum species with a predominance of the nucleatum (34.7%) followed by the vincentii (26.5%) subspecies. In parallel, 71% of the strains belonging to the nucleatum subspecies were preferentially associated with Porphyromonas gingivalis. Prevotella intermedia/nigrescens detection was essentially correlated with identification of Fusobacterium nucleatum subspecies vincentii. No correlation was established between any particular subspecies and the pathogenicity factors tested (hemagglutination and production of short-chain fatty acids). On the other hand, significant predominance (65%, P= 0.017) of strongly hemagglutinating strains (titre > or =8 U) was observed in the sites where Porphyromonas gingivalis, Prevotella intermedia/nigrescens and/or Campylobacter rectus were not detected. These strains also showed higher butyric acid production.


CONCLUSIONS
The importance of the adherence factors for Fusobacterium nucleatum strains and their multimodal aspect may indicate a higher pathogenicity or a higher involvement of certain strains and could lead to a classification of these strains, which is more closely related to their implication in the development of periodontal disease.
Roques
C G
CG
Laboratoire de Bacteriologie, Virologie et Microbiologie Industrielle, Faculté des Sciences Pharmaceutiques, Université Paul Sabatier, Toulouse, France. CH.Roques@wanadoo.fr
El kaddouri
S
S
Barthet
P
P
Duffort
J F
JF
Arellano
M
M
D000328:Adult; D000368:Aged; D000429:Alcohol Oxidoreductases / Q000032:analysis; D001422:Bacterial Adhesion; D015373:Bacterial Typing Techniques; D005232:Fatty Acids, Volatile / Q000096:biosynthesis; D016967:Fusobacterium nucleatum / Q000145:classification / Q000378:metabolism / Q000472:pathogenicity*; D005969:Glutamate Dehydrogenase / Q000032:analysis; D006384:Hemagglutination; D006385:Hemagglutination Inhibition Tests; D006801:Humans; D008875:Middle Aged; D010518:Periodontitis / Q000382:microbiology*; D013045:Species Specificity; D014774:Virulence
D005232:Fatty Acids, Volatile; D000429:Alcohol Oxidoreductases; C023858:2-hydroxyglutarate dehydrogenase; D005969:Glutamate Dehydrogenase