Antimicrobial activity of MgB2 powders produced via reactive liquid infiltration method

We report for the first time on the antimicrobial activity of MgB2 powders produced via the Reactive Liquid Infiltration (RLI) process. Samples with MgB2 wt.% ranging from 2% to 99% were obtained and characterized, observing different levels of grain aggregation and of impurity phases. Their antimicrobial activity was tested against Staphylococcus aureus ATCC BAA 1026, Enterococcus faecalis ATCC 29212, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10231. A general correlation is observed between the antibacterial activity and the MgB2 wt.%, but the sample microstructure also appears to be very important. RLI-MgB2 powders show better performances compared to commercial powders against microbial strains in the planktonic form, and their activity against biofilms is also very similar

Selection and characterization of the probiotic potential of some lactic acid bacteria isolated from infant feces

Abstrac

Structural and Antimicrobial Evaluation of Silver Doped Hydroxyapatite-Polydimethylsiloxane Thin Layers

An Ag:HAp (xAg = 0.5) powder was deposited by thermal evaporation technique as coating on a silicon substrate previously covered with a polydimethylsiloxane (PDMS) layer. The Ag:HAp-PDMS layers were characterized by Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), and Fourier Transform Infrared Spectroscopy (FT-IR). By infrared spectroscopy analysis, the phase composition of the Ag:HAp-PDMS layers was investigated. The antimicrobial activity of Ag:HAp-PDMS layers was tested against Escherichia coli, Staphylococcus aureus, and Candida albicans microbial strains. The microbial activity decreases significantly for the surveyed time intervals on Ag:HAp-PDMS layers

First report of OXA-72 producing Acinetobacter baumannii in Romania

This is the first report of an OXA-72-producing Acinetobacter baumannii strain in Romania, isolated from chronic leg ulcer samples. Identification of the strain was performed using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Presence of carbapenem resistance genes was investigated by PCR and sequencing. Our data support the spread of the blaOXA-72 gene in Eastern Europe

Fabrication, Characterization, and Antimicrobial Activity, Evaluation of Low Silver Concentrations in Silver-Doped Hydroxyapatite Nanoparticles

The aim of this study was the evaluation of (Ca10-xAgx)(PO4)6(OH)2 nanoparticles (Ag:HAp-NPs) for their antibacterial and antifungal activity. Resistance to antimicrobial agents by pathogenic bacteria has emerged in the recent years as a major public health problem worldwide. In this paper, we report a comparison of the antimicrobial activity of low concentrations silver-doped hydroxyapatite nanoparticles. The silver-doped nanocrystalline hydroxyapatite powder was synthesized at 100°C in deionised water. The as-prepared Ag:Hap nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), FT-IR, and FT-Raman spectroscopy. X-ray diffraction (XRD) studies demonstrate that powders obtained by coprecipitation at 100°C exhibit the apatite characteristics with good crystal structure, without any new phase or impurities found. FT-IR and FT-Raman spectroscopy revealed the presence of the various vibrational modes corresponding to phosphates and hydroxyl groups and the absence of any band characteristic to silver. The specific microbiological assays demonstrated that Ag:HAp-NPs exhibited antimicrobial features, but interacted differently with the Gram-positive, Gram-negative bacterial and fungal tested strains