Human gut microbiota analysis of cystic fibrosis infants using metaproteomics.

We report a metaproteomic analysis of the gut microbiota of eight infants with cystic fibrosis, during the first year of life. This is the first study in this disease that uses metaproteomics to analyze stool samples from patients at such a young age.

Analysis of the leaching and toxicity of new amine activators for the curing of acrylic bone cements and composites.

The comparative reactivity of new tertiary amine activators with the basic chemical structure of N,N-dimethyl-4-toluidine, but reduced toxicity, is analysed. The leaching of the amine compounds from cured cements was studied by analysis of the concentration of the corresponding amine in a physiological saline solution after 3 months of immersion, giving lower values for the new amine compounds as compared to N,N-dimethyl-4-toluidine. The acute toxicity was determined by intravenous injection of saline solutions of the corresponding chlorhydrates in mice and the cytotoxicity by the evolution of specific culture media. The results obtained demonstrate a lower acute toxicity and cytotoxicity of the new activators, even with a noticeable antiseptic action, which makes these materials very interesting from a practical point of view as activators of the curing process of acrylic bone cements for orthopaedic surgery and dentistry.

[Molecular and genetic aspects of resistance to azoles in Candida albicans]. / Aspectos moleculares y genéticos de la resistencia a azoles en Candida albicans.

Fluconazole is one of the most useful drugs in the treatment of fungal systemic infections which frequently affect non immunocompetent individuals. However, the emergence of resistant strains in recent years may severely limit its usefulness in future. Although there are several described mechanisms involved in resistance to azoles, recent genetic studies demonstrate the role of specific genes in clinical resistance. Currently, the best characterized are the MDR1 and CDR1 genes, which code members of the MFS or ABC family of drug transporters, respectively. These proteins respond to the membrane potential (MFS) or hydrolyse ATP (ABC) thus promoting drug efflux and therefore reducing its intracellular accumulation. It has been shown that the mRNA from these genes is frequently increased in some Candida albicans resistant strains from patients receiving long term azole treatment. The development of molecular genetic tools in C. albicans is allowing characterization of their role in this and other important processes in the fungal cell.

Proteomic analysis by two-dimensional differential gel electrophoresis (2D DIGE) of a high-pressure effect in Bacillus cereus.

High hydrostatic pressure (HHP) is a new method used to reduce or eliminate microorganisms that are present in food. Proteins are known to be the most important target of high pressure in living organisms. The main goal of this investigation was focused on the changes that occur on the proteins of Bacillus cereus under HHP stress conditions. The two-dimensional differential gel electrophoresis (2D DIGE) technique allows for a simultaneous resolution of thousands of proteins based on fluorescent prelabeling of the samples with spectrally resolvable fluorescent CyDyes. The results of proteomics profiling show an average of 1300 spots being detected. The analysis revealed 75 spot proteins whose abundance is modified after the application of high pressure, of which 66 were decreased after the HHP treatment. Among them, flagellin was the protein that changed the most. The differential expression of some proteins after HHP treatment at 700 MPa may suggest a reduction of virulence and protective response against oxidative stress in flagellated Bacillus .

Induced expression of the Candida albicans multidrug resistance gene CDR1 in response to fluconazole and other antifungals.

The Candida albicans CDR1 gene encodes a member of the ABC-type family of multidrug transporters which has been shown to be involved in azole resistance. Using an in-frame gene fusion between the CDR1 open reading frame and the green fluorescent protein allele yEGFP3, an optimized derivative for its use in C. albicans, we show here how the CDR1-yEGFP3 gene expression is induced in response to azoles as well as to other structurally unrelated drugs like cycloheximide. Moderate increases were observed for calcofluor, canavanine, 5'-fluorcytosine, cilofungin and caffeine, while no induction was found for the antifungals benomyl and amphotericin B or hydrogen peroxide at subinhibitory concentrations. The use of confocal microscopy enabled us to localize the Cdr1p fusion protein at the cell periphery, thus suggesting a cytoplasmic membrane localization. These results suggest deregulation of CDR1 gene as a putative mechanism for the generation of azole resistance in this clinically important pathogenic fungus.