In vitro inhibition of Clostridium difficile by commercial probiotics: A microcalorimetric study

The aim of the study was to investigate the influence of some commercial probiotics on the growth of Clostridium difficile using isothermal microcalorimetry, a technique which can monitor the real time growth of bacteria. Commercial probiotic strains and products, Lactobacillus acidophilus LA-5(®), Bifidobacterium lactis BB-12(®), Probio 7(®) and Symprove™ were co-cultured with C. difficile in Brain Heart Infusion (BHI) broth supplemented with 0.1% (w/v) l-cysteine hydrochloride and 0.1% (w/v) sodium taurocholate and monitored in the microcalorimeter. Pseudomonas aeruginosa NCIMB 8628 was also co-cultured with C. difficile and studied. The results indicated inhibition of C. difficile by the probiotics. The inhibition of C. difficile was shown to be pH-dependent using neutralized and unmodified cell free supernatant (CFS) produced by the probiotic strains. However, concentrated CFS of the probiotics also inhibited the intestinal pathogen in a non pH-dependent manner, likely due to specific antimicrobial substances produced. The results also indicated that C. difficile growth was greatly influenced by the presence of sodium taurocholate and by the pH of the medium. A medium pH of between 6.45 and 6.9 demonstrated maximum growth of the organism in the microcalorimeter

Review of: Assignment Problems by Rainer Burkard, Mauro Dell\u27Amico, and Silvano Martello

The article reviews the book Assignment Problems, by Rainer Burkard, Mauro Dell\u27Amico and Silvano Martello

Review of: A Java Library of Graph Algorithms and Optimization by Hang T. Lau

The article reviews the book A Java Library of Graph Algorithms and Optimization, by Hang T. Lau

Review of: Graph Theory by J. A. Bondy and U. S. R. Murty

The article reviews the book Graph Theory, by J. A. Bondy and U. S. R. Murty

Sage (version 3.4); The Princeton Companion To Mathematics

The article reviews the mathematics software Sage Version 3.4 from Sage Group

Review of: Pearls Of Discrete Mathematics by Martin Erickson

This article reviews the book Pearls of Discrete Mathematics, by Martin Erickson

Review of: Graph Theory by Reinhard Diestel

This article reviews the book Graph Theory, by Reinhard Diestel

Review of: Vector Calculus by Michael Corral

The article reviews the book Vector Calculus, by Michael Corral

Real-time monitoring of the heat of transfer of a homologous series of m-alkoxy phenols from isotonic aqueous solution to bacterial cells

Heats of dissolution of a homologous series of m-alkoxy phenols in an osmotically stable isotonic solution and in the same media containing a suspension of Escherichia coli cells were obtained by a differential heat conduction batch calorimeter at 298 K. The calorimetric curves show an initial rapid endothermic dissolution of the solute, followed by an exothermic process. From the heats of solution, the heat of transfer (Qtrs) of these compounds from the aqueous solution to the cells was calculated. The heat of transfer is exothermic and increases with the hydrophobicity of the compounds due to the biological consequences of the interaction process with the lipidic phase.O calor de dissolução de uma série homóloga de m-alcoxifenóis numa solução isotônica osmoticamente estável e no mesmo meio contendo em suspensão células de Escherichia coli foi obtido à 298 K usando um calorímetro de batelada diferencial de condução de calor. As curvas calorimétricas mostram uma dissolução inicial rápida do soluto, seguida por um processo exotérmico. A partir dos calores de solução, o calor de transferência (Qtrs) destes compostos da solução aquosa para as células, foi calculado. Qtrs é exotérmico e aumenta com a hidrofobicidade dos compostos, devido às conseqüências biológicas do processo de interação com a fase lipídica.12341237Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq