Biological and molecular characterization of Streptococcus crista strains isolated from human dental biofilm by means of arbitrary primers - PCR (AP-PCR)

Abstract

Streptococcus ssp are important components of the dental biofilm and Streptococcus crista is considered to be an interesting model of bacterial interactions taking place in this biofilm. In the present work, S. crista strains were isolated from the dental biofilm of Brazilian individuals and studied with respect to their biological characteristics and their molecular profile by means of AP-PCR techniques, using the RR2, 434, OPR2, OPR8, and OPR13 primers. Results allowed us to build a similarity dendrogram. Analysis of the similarity dendrogram allowed the separation of the studied strains into similarity groups. All isolates presented fibril tufts by Transmission Electron Microscopy (TEM). These isolates were able to bind to salivary amylase and to adhere to mouth epithelial cells. Some strains displaying fibril tufts and positive adherence were not able to co-aggregate with Fusobacterium nucleatum, suggesting that different adhesin groups are present in these strains.