Functional profiling in Streptococcus mutans: construction and examination of a genomic collection of gene deletion mutants.

A collection of tagged deletion mutant strains was created in Streptococcus mutans UA159 to facilitate investigation of the aciduric capability of this oral pathogen. Gene-specific barcoded deletions were attempted in 1432 open reading frames (representing 73% of the genome), and resulted in the isolation of 1112 strains (56% coverage) carrying deletions in distinct non-essential genes. As S.

Alkali production associated with malolactic fermentation by oral streptococci and protection against acid, oxidative, or starvation damage.

Alkali production by oral streptococci is considered important for dental plaque ecology and caries moderation. Recently, malolactic fermentation (MLF) was identified as a major system for alkali production by oral streptococci, including Streptococcus mutans. Our major objectives in the work described in this paper were to further define the physiology and genetics of MLF of oral streptococci and its roles in protection against metabolic stress damage.

Targets for hydrogen-peroxide-induced damage to suspension and biofilm cells of Streptococcus mutans.

Hydrogen peroxide (H2O2) is considered a major endogenous source of oxidative stress to oral bacteria and also is widely used in oral care products. Our study objectives were to identify specific targets for H2O2-induced damage to cells of Streptococcus mutans in suspensions and monospecies biofilms and to differentiate bacteriostatic and bactericidal actions of the peroxide. Streptococcus mutans was grown in suspension cultures and fed-batch biofilms for assessing relative sensitivities of viability, glycolysis, and protein synthesis to H2O2 damage.

Antimicrobial actions of benzimidazoles against the oral anaerobes Fusobacterium nucleatum and Prevotella intermedia.

Background/objective: Benzimidazoles are widely used as proton-pump inhibitors to control stomach hyperacidity and have been found also to have antimicrobial actions against Helicobacter pylori and oral streptococci. Our primary aim was to determine if they are active also against oral anaerobes associated with gingivitis. Our major focus was on catabolism because it leads to production of inflammatory metabolites such as butyrate and ammonia.

Pimecrolimus: absorption, distribution, metabolism, and excretion in healthy volunteers after a single oral dose and supplementary investigations in vitro.

The absorption and disposition of pimecrolimus, a calcineurin inhibitor developed for the treatment of inflammatory skin diseases, was investigated in four healthy volunteers after a single oral dose of 15 mg of [(3)H]pimecrolimus. Supplementary information was obtained from in vitro experiments. Pimecrolimus was rapidly absorbed.