The aim of this study was to develop and evaluate a padlock probe based on the Rolling Circle Amplification (RCA), which targeted to 16S-23S rDNA region of S. mutans. The specificity of developed padlock probe was tested for DNA within a panel strains, including S. mutans isolated from the saliva and reference strains of the genus Streptococcus, as well as total DNA samples of biofilm and saliva. The results were positive either for DNA samples of S. mutans or DNA samples recovered from the biofilm and saliva revealing the specificity of designed padlock probe. The padlock probe based on the RCA was proved to be an effective, reproducible method for S. mutansdetection and demonstrated the possibility of a rapid detection and accurate identification of S. mutans infection.

O objetivo deste trabalho foi investigar a capacidade de aderência in vitro de Streptococcus mutans e Candida albicans. Ensaios de aderência foram realizados in vitro na superfície dentária, com posterior análise por Microscopia Eletrônica de Varredura (M.E.V.). Dentes humanos extraídos foram inoculados com Streptococcus mutans e Candida albicans, além de ambas espécies em conjunto, e foram incubados a 37ºC por 21 dias. Os inóculos eram provenientes de amostras salivares de crianças colonizadas por ambos microrganismos. Como controles foram utilizadas linhagens de referência ATCC dos dois microrganismos. A análise por M.E.V. mostrou a formação de um biofilme que cobriu toda a superfície dentária analisada de forma mais homogênea quando incubados juntos do que separadamente. Um segundo experimento foi desenvolvido utilizando isolados mostrando maior aderência dos experimentos anteriores e cortes de polietileno de alta densidade como substrato. A potencialização da capacidade de aderência de Streptococcus mutans e Candida albicans em associação foi confirmada.

The objective of the present study was to investigate the in vitro adherence capacity of Streptococcus mutans and Candida albicans. Adherence assays were conducted on dental surfaces and analyzed by scanning electron microscopy (SEM). Extracted human teeth were inoculated with Streptococcus mutans or Candida albicans and with both species simultaneously, and incubated at 37ºC for 21 days. Bacterial inocula had been obtained from saliva samples of children that had been colonized by both organisms. ATCC reference strains were used as controls. SEM analyses showed that the biofilm that covered the entire analyzed dental surface was more homogeneous inoculated with the two microorganisms simultaneously than with each species separately. In a second experiment, carried out with isolates that had shown the highest adherence the isolates were tested for adherence to high-density polyethylene substrates. The potentialization of the adherence capacity of Streptococcus mutans and Candida albicans when in association was confirmed.