MALDI-TOF mass spectrometry analysis of proteins and lipids in Escherichia coli exposed to copper ions and nanoparticles.

Escherichia coli (E. coli) is one of the most important foodborne pathogens to the food industry responsible for diseases as bloody diarrhea, hemorrhagic colitis and life-threatening hemolytic-uremic syndrome. For controlling and eliminating E. coli, metal nano-antimicrobials (NAMs) are frequently used as bioactive systems for applications in food treatments. Most NAMs provide controlled release of metal ions, eventually slowing down or completely inhibiting the growth of undesired microorganisms. Nonetheless, their antimicrobial action is not totally unraveled and is strongly dependent on metal properties and environmental conditions. In this work, we propose the use of matrix-assisted laser desorption ionization time-of-flight (MALDI TOF) mass spectrometry as a powerful tool for direct, time efficient, plausible identification of the cell membrane damage in bacterial strains exposed to copper-based antimicrobial agents, such as soluble salts (chosen as simplified AM material) and copper nanoparticles. E. coli ATCC 25922 strain was selected as 'training bacterium' to set up some critical experimental parameters (i.e. cell concentration, selection of the MALDI matrix, optimal solvent composition, sample preparation method) for the MS analyses. The resulting procedure was then used to attain both protein and lipid fingerprints from E. coli after exposure to different loadings of Cu salts and NPs. Interestingly, bacteria exposed to copper showed over-expression of copper binding proteins and degradation of lipids when treated with soluble salt. These findings were completed with other investigations, such as microbiological experiments. Copyright © 2016 John Wiley & Sons, Ltd.

Outbreak of Hepatitis A in Italy Associated with Frozen Redcurrants Imported from Poland: A Case Study.

Hepatitis A virus (HAV) was detected in a batch of imported non-packaged frozen redcurrants purchased in a Bari grocery. Sequence and phylogenetic analysis showed the HAV strain clustered tightly with the HAV strain from the 2013 Italian epidemic, providing additional evidence that frozen redcurrants were the main vehicle of the HAV outbreak.

Survey of the presence of patulin in fruit juices.

Patulin is a mycotoxin produced by fungi belonging to the Penicillium and Aspergillus genera. The occurrence of patulin in fruit juices marketed in Italy in 2008 and purchased from supermarkets and retail shops has been measured. The aim of this study was to assess the presence of patulin in order to evaluate the potential risk for the consumer and, at the end of this food chain, to determine the quality of the raw material used. One hundred and five fruit juices (35 apple juice, 35 mixed-taste juices, 35 pear juices), produced by various Italian and European companies, were analysed using a previously published method. The analytical investigation showed that apple juices had a concentration of patulin ranging between 6 and 30 µg l(-1), with a mean of 18 µg l(-1); mixed fruit juices had a concentration ranging between 1 and 45 µg l(-1), with a mean of 23 µg l(-1). Instead, pear juices had a concentration ranging between 5 and 92 µg l(-1), with a mean of 43 µg l(-1), and 14 samples of the 35 analysed juices showed a patulin level above the highest regulated limit of 50 µg l(-1), imposed by European Commission Regulation 1881/06.