Search results for "Streptococcus"
showing 10 items of 169 documents
Development of an Efficient In Vivo System (P-junc-TpaseIS(1223)) for Random Transposon Mutagenesis of Lactobacillus casei
2012
ABSTRACT The random transposon mutagenesis system P junc -TpaseIS 1223 is composed of plasmids pVI129, expressing IS 1223 transposase, and pVI110, a suicide transposon plasmid carrying the P junc sequence, the substrate of the IS 1223 transposase. This system is particularly efficient in Lactobacillus casei , as more than 10,000 stable, random mutants were routinely obtained via electroporation.
Neumonía adquirida en la comunidad: tratamiento ambulatorio y prevención
2015
Resumen: La neumonía adquirida en la comunidad (NAC) en la edad pediátrica ha sufrido, en la última década, una serie de cambios epidemiológicos, clínicos, etiológicos y de resistencias a antibióticos, que obligan a replantear su abordaje terapéutico. En este documento, dos de las principales sociedades de especialidades pediátricas involucradas en el diagnóstico y tratamiento de esta entidad, como son la Sociedad Española de Infectología Pediátrica y la Sociedad Española de Neumología Pediátrica, así como el Comité Asesor de Vacunas de la AEP, proponen unas pautas consensuadas de tratamiento y prevención, con el fin de proporcionar a todos los pediatras una guía actualizada. En esta primer…
Ex vivo study of bacterial coronal leakage in indirect pulp treatment
2012
Objective: The aim of this study was to evaluate, ex vivo, bacterial coronal leakage with different antimicrobial agents applied to the dentine for indirect pulp treatment (IPT). Study Design: Sixty extracted teeth were prepared and randomly distributed into 5 groups (n=10): Group 1: no antimicrobial dentine treatment; group 2: 1% chlorhexidine (CHX)+1% thymol varnish (Cervitec®); group 3: 2 % CHX solution; group 4: 40% CHX varnish (EC40™) and group 5: Clearfil™ Protect Bond (CPB). Ten teeth served as controls. The teeth were restored using a resin-modified glass ionomer cement (GIC) and then mounted in a two-chamber device. The coronal access was exposed to Streptococcus mutans for 45 days…
Effect of oxidoreduction potential on aroma biosynthesis by lactic acid bacteria in nonfat yogurt
2011
; The aim of this study was to investigate the effect of oxidoreduction potential (Eh) on the biosynthesis of aroma compounds by lactic acid bacteria in non-fat yogurt. The study was done with yogurts fermented by Lactobacillus bulgaricus and Streptococcus thermophilus. The Eh was modified by the application of different gaseous conditions (air, nitrogen, and nitrogen/hydrogen). Acetaldehyde, dimethyl sulfide, diacetyl, and pentane-2,3-dione, as the major endogenous odorant compounds of yogurt, were chosen as tracers for the biosynthesis of aroma compounds by lactic acid bacteria. Oxidative conditions favored the production of acetaldehyde, dimethyl sulfide, and diketones (diacetyl and pen…
Discovering lactic acid bacteria by genomics
2002
International audience; This review summarizes a collection of lactic acid bacteria that are now undergoing genomic sequencing and analysis. Summaries are presented on twenty different species, with each overview discussing the organisms fundamental and practical significance, environmental habitat, and its role in fermentation, bioprocessing, or probiotics. For those projects where genome sequence data were available by March 2002, summaries include a listing of key statistics and interesting genomic features. These efforts will revolutionize our molecular view of Gram-positive bacteria, as up to 15 genomes from the low GC content lactic acid bacteria are expected to be available in the pu…
Streptococcus pneumoniae sortāzes A inhibitoru atlase multirezistentu patogēnu izraisīto infekcijas slimību terapijai
2019
Darba mērķis ir atrast jaunas novatoriskas vielas, kas inhibē Grampozitīvās baktērijas Streptococcus pneumoniae transpeptidāzi sortāzi A. Šo inhibitoru atlasei tika izmantota rekombinanta S.pneumoniae sortāzes A katalītisko domēnu kodējoša konstrukcija bez N terminālā reģiona. Šāda rekombinanta transpeptidāze tika ekspresēta E.coli ekspresijas sistēmā un sintezētais proteīns izrādījās šķīstošs. Pēc attīrīšanas sortāze tika izmantota inhibitoru atlasei, izmantojot skrīningu, kas balstās uz fluorescences rezonanses enerģijas pārnesi (FRET). Pavisam tika pārbaudīti 966 potenciāli inhibitori savienojumi, no kuriem tālākām pārbaudēm tika atlasīti trīs labākie, kuri inhibēja IC50 testā izmantotās…
Pneumococcal HxxHxH triad – Copper(II) interactions – How important is the ‘x’?
2019
Abstract PhtA, a Streptococcus pneumoniae polyhistidine triad protein, which contributes to virulence by interacting with components of the immune system, by being involved in adherence of bacteria and in Zn(II) uptake, contains five copies of the HxxHxH sequence. Since this motif is also present in numerous Cu(II) binding proteins, we decided to focus on the bioinorganic chemistry of copper(II) with three of such PhtA repeats, in order to understand which of the PhtA triads binds Cu(II) with the highest affinity and explain if Cu(II) would be able to outcompete Zn(II) from its native binding site under physiological metal concentrations.
ChemInform Abstract: One-Step Synthesis, Crystallographic Studies and Antimicrobial Activity of New 4-Diazopyrazole Derivatives.
2010
Summary A number of new 4-diazopyrazole derivatives were prepared by the reaction of 1- R -3-methyl-5(R 1 -substituted)benzamidopyrazoles with a sevenfold excess of nitrous acid in acetic medium. The compounds were tested for activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus faecalis, Listeria monocytogenes, Candida albicans, Candida tropicalis and Paecilomyces varioti . The highest microbial susceptibility was shown by Gram-positive bacteria, with minimum inhibitory concentrations (MIC) in the range 0.5–12.5 μg/mL. For S aureus the R 1 substituents were screened utilizing the Topliss operational scheme. The 4-nitro g…
Antimicrobial efficacy of the supernatant of <i>Streptococcus dentisani</i> against microorganisms implicated in root canal infections
2019
The present study aimed to test the antimicrobial activity of Streptococcus dentisani (S. dentisani) supernatant against a collection of microorganisms implicated in dental root infections, and to analyze morphological changes induced in a selection of the tested microorganisms. A total of 22 microbial species were selected, and their growth was monitored by spectrophotometry in the presence and absence of the supernatant of S. dentisani at different assay concentrations (0.2×, 1×, 2×). The generation time and maximum growth rates were evaluated under every tested condition. Scanning electron microscope (SEM) images were obtained to assess the effect on the cell surface following incubation…
The tongue biofilm metatranscriptome identifies metabolic pathways associated with halitosis and its prevention
2021
AbstractHalitosis is an oral condition caused by an increase in the concentration of volatile sulfur compounds (VSCs), such as methyl mercaptan and hydrogen sulfide, generated as a consequence of bacterial metabolism on the tongue biofilm. Microbial communities on the tongue of halitosis patients have been studied by bacterial culture, 16S rRNA taxonomic studies and metagenomics. However, there are currently no reports on the microbial gene-expression profiles. In this study, we performed RNAseq of tongue coating samples from control individuals and halitosis patients with different levels and composition of VSCs, as determined by gas chromatography. In this metatranscriptomic study, the ac…