In vitro manganese-dependent cross-talk between Streptococcus mutans VicK and GcrR: implications for overlapping stress response pathways.

Streptococcus mutans, a major acidogenic component of the dental plaque biofilm, has a key role in caries etiology. Previously, we demonstrated that the VicRK two-component signal transduction system modulates biofilm formation, oxidative stress and acid tolerance responses in S. mutans.

A biochemical characterization of the DNA binding activity of the response regulator VicR from Streptococcus mutans.

Two-component systems (TCSs) are ubiquitous among bacteria and are among the most elegant and effective sensing systems in nature. They allow for efficient adaptive responses to rapidly changing environmental conditions. In this study, we investigated the biochemical characteristics of the Streptococcus mutans protein VicR, an essential response regulator that is part of the VicRK TCS.

[Assessment of dot blot tests and latex agglutination for cysticercosis diagnostic in Peru].

In order to evaluate dot blot tests and latex agglutination for the detection of human cysticercosis with liquid antigen of Taenia solium cysticerci, 125 human sera were used, of which 60 were from people with cysticercosis confirmed by Western Blot, 45 with other parasitic diseases and 20 apparently healthy. The optimal concentration of antigen to impregnate dot blot strips was 0.01 ug/uL, and to impregnate the latex particles was 0.

Characterization of DNA binding sites of the ComE response regulator from Streptococcus mutans.

In Streptococcus mutans, both competence and bacteriocin production are controlled by ComC and the ComED two-component signal transduction system. Recent studies of S. mutans suggested that purified ComE binds to two 11-bp direct repeats in the nlmC-comC promoter region, where ComE activates nlmC and represses comC.

[Evaluation of two immunoblot tests with goat and sheep hydatid antigen for human echinococcosis diagnosis].

To estimate the diagnosis value of goat and ovine antigen for echinococcosis immunoblot test, 135 serums were used, of which 70 were coming from patients with hydatid disease confirmed by the finding of proto scolex and membrane in the pathology study of surgical piece, 45 from patients with other parasitic diseases and 20 apparently healthy people. The sensitivity, the specificity, positive and negative predictive value of immunoblot test, with hidatyd antigen of goat was of 92.8%, 100%, 100%, 92.

Regulation of ciaXRH operon expression and identification of the CiaR regulon in Streptococcus mutans.

The ciaRH operon in Streptococcus mutans contains 3 contiguous genes, ciaXRH. Unlike the CiaRH system in other streptococci, only the ciaH-null mutant displays defective phenotypes, while the ciaR-null mutant behaves like the wild type. The objective of this study was to determine the mechanism of this unusual property.