Advance in fibronectin binding Streptococcus mutans from patients with high (HR) and low risk (LR) of dental caries
Streptococcus mutans – fibronectin - binding The aim of this study is found possible relation of caries dental risk and fibronectin binding capacity. We study 6 salivary samples from 3 patient (HR) CPO > 5 with 3 or more active caries and 3 (LR) CPO < 3 without active caries. 20 colony from each sample were typified by “de la Higuera et al” method: S. mutans 53 strain: 37 S. mutans (HR: 15, LR: 22), 1 S. sobrinus (HR), 10 S. rattus (HR: 4, BR: 6) y 5 (HR) no typified, the others were eliminated because were β hemolytic. Binding assay: 1º Immobilization of 100 μl of fibronectin solution (50 μg/ml) with 100 μl of coupling buffer in microtiterplates. The plates were sealed and incubated on a orbital platform rocker for 18 h at 4º C. 2º The plates were washed three times in PO43- buffer and blocked in 2% BSA- PO43- buffer for 2 h at 25ºC followed by three times wash in PO43- buffer. 3º 100 μl of a bacteria suspension were applied to each well and the plates were sealed and incubated on a orbital platform rocker for 2 h at 37ºC. The plates were washed 3 times in PO43- buffer and the bound bacteria were heat fixed by warm air in an oven at 60ºC for 20 min. A crystal violet solution were applied to each plate. The plates were sealed and incubated for 45 min. without shaking, washing 6 times with PO43- buffer. 4º 100 μl/well of developer solution were applied to each plate. The plates were sealed and incubated for 45 min. without shaking. The seals were removed and the plates analyzed in a ELISA reader at 550 nm. In all the strain evaluated we had obtained an absorbance > 800UA at 550nm, in LR patients the values were about 844-1022 and in HR patients were about 811-1138 Conclusions: We typified 1 strain of S sobrinus and 10 strains of S rattus, data discordant with international literature. In binding assay results not shown difference in the adherence capacity among HR and LR patients. We must continue the study with more strains quantity. Este cuadro de texto mide 11,25 x 17,7 cm. La letra debe ser Arial 10 pts. Interlineado simple ( borrar todo este texto)