Comparison of the action of different proteases on virulence properties related to the staphylococcal surface.

AIMS: The purpose of this study was to evaluate the antimicrobial efficacy of five different proteases belonging to two different families on Staphylococcus aureus and Staphylococcus epidermidis strains. METHODS AND RESULTS: We used three serine proteases and two metalloproteases in single species biofilm formation assays and in human cell invasion processes. Following each protease incubation with bacterial cells, surface protein patterns were analysed by SDS-PAGE and zymography. Some differently expressed proteins were identified by mass spectrometry. CONCLUSIONS: The effect of tested proteases on biofilm formation was not related to the protease category but was strain-dependent and was related to the biofilm formation capacity of each staphylococcal strain. Some proteases showed a nonspecific and indiscriminate effect on surface proteins, while others induced a discrete and reproducible action on protein profiles. SIGNIFICANCE AND IMPACT OF THE STUDY: The inhibition of the surface-related virulence factors is a promising avenue to overcome persistent infections caused by bacterial biofilms. To this end, we show here that proteases, in particular the metalloprotease serratiopeptidase, can interfere with adhesion and invasion of eukaryotic cells and biofilm formation in staphylococci and their use could represent a viable treatment for the development of novel combination therapies.

Correction: Selenium effects on the metabolism of a Se-metabolizing Lactobacillus reuteri: analysis of envelope-enriched and extracellular proteomes.

Correction for 'Selenium effects on the metabolism of a Se-metabolizing Lactobacillus reuteri: analysis of envelope-enriched and extracellular proteomes' by E. Mangiapane et al., Mol. BioSyst., 2014, 10, 1272-1280.

Selenium effects on the metabolism of a Se-metabolizing Lactobacillus reuteri: analysis of envelope-enriched and extracellular proteomes.

Selenium (Se) has received great attention in the last few years, as it is considered to be essential for human health (prevention of viral infections, heart diseases and ageing-related diseases). Se deficiency can be counteracted by the administration of selenium-enriched probiotics that are able to convert inorganic selenium into less toxic and more bio-available organic forms. This study was performed on Lactobacillus reuteri Lb2 BM DSM 16143, a probiotic LAB previously demonstrated to be able to fix Se into selenocysteines. The aim was to assess Se influence on its metabolism, by a 2-DE proteomic approach, on two different cellular districts: envelope-enriched and extracellular proteomes. While in the envelope-enriched fraction 15 differentially expressed proteins were identified, in the extracellular proteome no quantitative difference was detected. However, at a molecular level, we observed the insertion of Se into selenocysteine, exclusively under the stimulated conditions. The obtained results confirmed the possibility to use L. reuteri Lb2 BM DSM 16143 as a carrier of organic Se that can be easily released in the gut becoming available for the human host.

Qualitative screening in doping control by MALDI-TOF/TOF mass spectrometry: a proof-of-evidence.

The analysis of doping agents in biological fluids is of top significance in clinical and forensic toxicology. Herein we describe the study of a screening method for the detection of a mixture of drugs of potential abuse including cocaine and its metabolites. By using matrix-assisted laser desorption/ionization MALDI-TOF/TOF mass spectrometry. This screening procedure to detect the presence of different drugs, avoiding time consuming procedures could be useful in different fields of forensic analytical toxicology, including antidoping analysis.

An atypical ballistic traumatic cauda equina syndrome with a positive outcome. Focus on prognostic factors.

INTRODUCTION: Traumatic cauda equina syndromes due to projectile wounds often have a poor prognosis. We report on an unusual ballistic cauda equina traumatism with a good functional outcome. CLINICAL CASE: A 44-year-old man was admitted to emergency room for an incomplete cauda equina syndrome after trying to kill himself by means of a pneumatic nail gun. The nail had gone right through the third lumbar vertebra. Because of the stability of the fracture, orthopaedic surgery was not indicated. Neurological recovery was progressive. At 6 months, there was still a partial L5-S1 motor deficit on the left side but the patient could walk without crutches, and within an unlimited walking distance. DISCUSSION: Initial imaging displayed a projectile trajectory focused on the spinal canal on level L3, which could have been considered as bad prognosis. The positive analytic and functional outcome correlates with the limited neurological tissue damage, probably explained by the ballistic properties of the projectile. CONCLUSION: Apart from the influence of a possible surgical act, the neurological and functional prognosis of a traumatic cauda equina syndrome caused by a projectile also depends on its physical characteristics.