Clonal persistence of oral Fusobacterium nucleatum in infancy.
Once established, early-colonizing bacterial species tend to persist in the mouth. To obtain detailed information on the population dynamics of early-colonizing oral anaerobes, we examined the clonal diversity and persistence of clones among oral Fusobacterium nucleatum populations during the first 2 yrs of life. Consecutive salivary samples from 12 infants, collected at 2, 6, 12, 18, and 24 mos of age, yielded a total of 546 F. nucleatum isolates for clonal typing with arbitrarily primed PCR (AP-PCR). Up to 7 AP-PCR types were simultaneously detected in each sample. In 11 out of the 12 infants examined, AP-PCR types persisted for up to 1 yr. Strain turnover rate was high during the first year of life, but then the occurrence of persistent clones increased. This study indicates a wide genetic diversity within the species and provides evidence for the increasing persistence of F. nucleatum clones in the oral cavity with age.
Haraldsson
G
G
Anaerobe Reference Laboratory, National Public Health Institute, Helsinki, Finland. gah@hi.is
Holbrook
W P
WP
Könönen
E
E
D016009:Chi-Square Distribution; D002675:Child, Preschool; D002999:Clone Cells; D005500:Follow-Up Studies; D016967:Fusobacterium nucleatum / Q000166:cytology / Q000235:genetics*; D014644:Genetic Variation; D006801:Humans; D007223:Infant; D009055:Mouth / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D012463:Saliva / Q000382:microbiology; D013997:Time Factors