Detection of oral streptococci with collagen-binding properties in saliva specimens from mothers and their children

Background: Approximately 10-20% of Streptococcus mutans strains have been reported to possess collagen-binding properties, whereas other species in the oral cavity with those properties remain to be elucidated. Aim.: To identify strains with collagen-binding properties and analyse their characteristics in comparison with S. mutans. Design.: A total of 110 expectorated saliva specimens were collected from 55 pairs of mothers and their children. Bacterial strains with collagen-binding properties were isolated and the species specified. In addition, strains with collagen-binding properties isolated from mother-child pairs were analysed using molecular biological approaches. Results.: The detection frequency of strains with collagen-binding properties was shown to be 40.9%, among which S. salivarius was the most frequently detected, followed by S. mutans. The collagen-binding activity of the S. mutans group was the highest, followed by S. salivarius. In addition, S. mutans and S. salivarius strains from 3 and 1 mother-child pairs, respectively, were shown to be the same clones. Conclusions.: Our results indicate that S. mutans and S. salivarius are major species with collagen-binding properties in the oral cavity, and that strains with such properties may be related to mother-child transmission.