Transmission of Peptostreptococcaceae within Families

Objectives: The purpose of this study was to investigate the transmission within multi-generation families, of three members of the gram-positive anaerobic Peptostreptococcaceae family. This group of bacteria has been strongly linked to chronic periodontitis by recent studies using DNA-based detection methods. The presence of Peptostreptococcus micros, Peptostreptococcus CK035 (an uncultivated phylotype), and Filifactor alocis was examined within extended families. Methods: Plaque samples were collected from 565 members of 104 multi-generation families. PCR was used for detection of CK035, P. micros, and F. alocis in 3 separate assays. A universal amplification was followed by a species-specific amplification targeting the intergenic spacer region between the 16S and 23S ribosomal genes. The samples were analyzed for presence of the three bacteria using gel electrophoresis. Results: Entire families were much more likely to have similar colonization status (P<0.0000 by chisquare) for all 3 Peptrostreptoccoccacea examined. Intrafamilial pairs were also examined. Married couples were highly likely to be similarly colonized (P<0.005 by chisquare for all species). Children whose mothers were colonized were more likely to be colonized (P<0.01 by chisquare for all species), but not if their fathers were colonized. Adults were also likely to match the colonization status of their mothers (P<0.05 by chisquare for all species), but not their fathers. Siblings did not show significant similarity in colonization status by chisquare analysis. Conclusion: All 3 members of the Peptostreptococcaceae examined, P. micros, the uncultivated phylotype CK035, and F. alocis, showed similar transmission patterns within families. Transmission was highly significantly likely to occur within families. The most common route of transmission appears to be between spouses. Transmission also occurs from mother to child, and this vertical transmission appears to persist into adulthood. Transmission from father to child was less common, and child-to-child transmission appears unlikely. Supported by NIH Grant DE10467