Actinobacillus actinomycetemcomitans proportion of subgingival bacterial flora in relation to its clonal type.
We investigated whether certain Actinobacillus actinomycetemcomitans clones occur in elevated proportions in subgingival flora, and if the proportions relate to other bacteria in the samples. A total of 121 A. actinomycetemcomitans strains from 121 patients with periodontitis were serotyped and 60 strains were also genotyped. The 121 strains were divided into three groups and the 60 strains into two groups according proportion of A. actinomycetemcomitans. The samples from the 60 patients with genotyped strains were cultured for five other species. Among the 121 strains, serotype b occurred significantly more frequently in the high- (n = 14, proportions > 5%, mean = 18.09, SD = 20.07%) than low- (n = 49, proportions < or = 0.1%), mean = 0.04, SD = 0.03%) or intermediate-proportion groups (n = 58, proportions > 0.5%, mean = 1.31, SD = 1.24%). Genotype 3 occurred significantly more frequently in samples with low A. actinomycetemcomitans proportions (n = 28, < or = 0.1%, mean = 0.04, SD = 0.03%) than in those with high proportions (n = 32, > 0.1%, mean = 5.70, SD = 14.60%). No differences were seen in the detection frequencies or proportions of the five bacterial species between the samples with low or high A. actinomycetemcomitans proportions. The results indicate that certain clonotypes of A. actinomycetemcomitans may preferentially occur as low proportions, suggesting their controlled growth. Conversely, some serotype b clones may have a competitive advantage in subgingival flora.
Institute of Dentistry, University of Helsinki, Finland. laura.ukkonen@helsinki.fi
Laura
L
Lakio
Heidi
H
Kuula
Basak
B
Dogan
Sirkka
S
Asikainen
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016976:Aggregatibacter actinomycetemcomitans / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D001439:Bacteroides / Q000145:classification; D002167:Campylobacter / Q000145:classification; D016009:Chi-Square Distribution; D002999:Clone Cells; D015169:Colony Count, Microbial; D004269:DNA, Bacterial / Q000235:genetics; D005260:Female; D005838:Genotype; D005881:Gingiva / Q000382:microbiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010462:Peptostreptococcus / Q000145:classification; D010514:Periodontal Pocket / Q000382:microbiology; D010518:Periodontitis / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000145:classification; D018720:Prevotella / Q000145:classification; D018713:Prevotella intermedia / Q000145:classification; D012703:Serotyping; D013223:Statistics as Topic
D004269:DNA, Bacterial