Mechanisms of interaction between Candida albicans and Streptococcus mutans: an experimental and mathematical modelling study

M. I. BRUSCA; R. M. IRASTORZA; D. I. CATTONI; M. OZU; O. CHARA

ACTA ODONTOLOGICA SCANDINAVICA

TAYLOR & FRANCIS AS

Lugar: Stockholm; Año: 2013 vol. 71 p. 416 - 423

0001-6357

Objective: To evaluate the mechanisms of microbial interaction between the oral pathogens Candida albicans and Streptococcus mutans. Material and Methods: Growth kinetics for the two microorganisms, cultured individually or together, were followed experimentally for 36 hours. The different growth curves were analyzed by means of mathematical modelling. Results: Under our experimental conditions, S. mutans final concentration, when growing individually, was five times that of C. albicans. Contrarily, when both microorganisms grew together, this ratio was inversed and C. albicans final concentration was even higher than that of S. mutans. When both microorganisms share the niche, a model including linear competition among one another was best suited to reproduce our experimental observations. The results of our model show that the initial growth rates of both species are positively influenced by their mutual interaction. However, at longer incubation times, C. albicans prevents bacterial growth and achieves concentrations four times higher than when growing individually. Conclusions: Our results suggest that C. albicans biofilm formation could be potentiated by the presence of S. mutans by two mechanisms: synergically at short times and by competition at longer periods.