The antimicrobial activity of four different dental gel formulas was evaluated on three microorganisms associated with cariogenesis: Streptococcus mutans, Lactobacillus casei and Actinomyces viscosus. The preliminary antimicrobial activity evaluation was performed using an agar diffusion method. In addition, the formulas were challenged using each microorganism with subsequent determinations of...

The genus Actinomyces is generally regarded as lying between the true bacteria and higher fungi, and contains a few parasitic species but many saprophytic forms. The latter occur mostly in the soil and many of them produce striking pigments. It is quite natural that efforts have been made to utilize these pigments in the identification of species; but the present unsatisfactory nature of the cl...

The influence of Streptococcus mitis BMS biosurfactants on the adhesion of eight pioneer and four cariogenic oral bacterial strains was, for a first screening, examined in a microtiter plate assay. The adhesion to pellicle-coated wells of three cariogenic strains was inhibited >70% by the biosurfactants, while only one pioneer strain showed >70% reduction. The reduction for the other strains di...

Two types of adhesive fimbriae are expressed by Actinomyces; however, the architecture and the mechanism of assembly of these structures remain poorly understood. In this study we characterized two fimbrial gene clusters present in the genome of Actinomyces naeslundii strain MG-1. By using immunoelectron microscopy and biochemical analysis, we showed that the fimQ-fimP-srtC1-fimR gene cluster e...

was developed by using 2'-(4-methylumbelliferyl)oa-D-N-acetylneuraminic acid as substrate in a filter paper spot test. The method was compared to conventional assays that use 2'-(4-methylumbelliferyl)ax-D-N-acetylneuraminic acid and bovine submaxillary mucin and was found to be in excellent agreement. Organisms with >10 U of enzyme activity (in nanomoles per minute per milligram of cell protein...

Open-lung biopsy in a child with chronic pneumonia revealed branched gram-positive acid-fast organisms, later identified as Actinomyces israelii. Like Nocardia asteroides, A israelii can be acid fast by the commonly used Putt stain. The pneumonia was cured with 12 weeks of penicillin treatment.

Here, we present the draft genome sequence of Actinomyces odontolyticus subsp. actinosynbacter strain XH001, isolated from the human oral cavity. Uniquely, it was discovered as a host bacterium to the ultrasmall epibiont TM7x, which is the first cultivated member of "Candidatus Saccharibacteria" (formerly candidate phylum TM7).

An in vitro model of supragingival plaque associated with gingivitis was characterized by traditional culture techniques, comparative 16S rRNA gene sequencing of isolates, and quantitative PCR (QPCR). Actinomyces naeslundii, Prevotella spp., and Porphyromonas gingivalis increased under conditions emulating gingivitis. Gram-negative species and total bacteria were dramatically underestimated by ...

We report the main characteristics of 'Actinomyces provencensis' strain SN12T sp. nov., 'Corynebacterium bouchesdurhonense' strain SN14T sp. nov., 'Corynebacterium provencense' strain SN15T sp. nov. and 'Xanthomonas massiliensis' strain SN8T sp. nov., which were all isolated from stool samples from obese French patients.