Nowadays, thanks to nanotechnological progress, which itself guides us more and more closely toward not only the efficient design of innovative nanomaterials or nanostructures, but to the improvement of their functionality, we benefit from an important asset in the battle against pathogenic illnesses. Herein, we report a versatile biocompatible plasmonic nanoplatform based on a Whatman paper incorporating positively-charged gold nanospherical particles via the immersion approach. The morphological characterization of the as-engineered-plasmonic paper was examined by SEM (scanning electron microscopy) and HRTEM (high-resolution transmission electron microscopy) investigations, while its surface chemical modification with a synthetic polypeptide, specifically RRWHRWWRR-NH2 (P2), was proved by monitoring the plasmonic response of loaded gold nanospheres and the emission signal of P2 via fluorescence spectroscopy. The as-functionalized plasmonic paper is non-cytotoxic towards BJ fibroblast human cells at bactericidal concentrations. Finally, the antimicrobial activity of the P2-functionalized plasmonic paper on both planktonic bacteria and biofilms was tested against two reference strains: Gram-positive Bacteria, i.e., Staphylococcus aureus and the Gram-negative Bacteria, i.e., Escherichia coli, determining microbial inhibition of up to 100% for planktonic bacteria. In line with the above presented nanoplatform’s proper design, followed by their functionalization with active antimicrobial peptides, new roads can be open for determining antibiotic-free treatments against different relevant pathogens.

The increasing burden of invasive biofilm-related staphylococcal infections led to a dire need for new agents to prevent biofilm formation. Bacteriophages may hypothetically alter biofilm through several mechanisms, including induction of depolymerizing enzymes, and lysis of persistent bacteria. We have assessed the influence of commercially-available bacteriophage cocktails on Staphylococcus spp. clinical strains viability and biofilm formation. We analyzed 83 staphylococcal strains from patients consecutively admitted to a Romanian infection reference center from October 2014 through May 2015; the strains were characterized by phenotypic and genetic tools for their resistance and virulence features and for their phyliation. Experiments were performed in triplicate. Methicillin-susceptible strains were significantly more susceptible to all tested phages – 1.7-fold higher susceptibility for PYO, 1.4-fold for INTESTI, 2.9-fold for PHAGYO, 2.7-fold for PHAGESTI and 3.9 for STAPHYLOCOCCAL, respectively; t030 strains were significantly more susceptible to PYO and INTESTI compared with t127 strains. We identified a significant decrease in biofilm formation in the presence of both low and high PYO and INTESTI concentrations (P < 0.001). In conclusion, Staphylococcus strains from Romania displayed fairly good susceptibility to commercially-available bacteriophages. We have also ascertained the phages-driven in vitro inhibition of biofilm formation, the results potentially impacting prevention of prosthetic infections.

In March 2012, a food poisoning outbreak was reported in a Romanian county, with a total number of 30 children affected. The symptoms (vomiting, diarrhea and abdominal pain), with onset within 1-2 hours after the ingestion of a particular food (milk), suggested a possible staphylococcal aetiology. An outbreak investigation was carried out, in accordance with the national surveillance methodology and 25 samples: stool (n=9), vomit (n=5), nasal swabs (n=9), and milk (n=2) were collected from the affected children, food handlers and suspected food. All isolated strains were sent to the Reference Centre for Staphylococci within the “Cantacuzino” National Institute of Research-Development for Microbiology and Immunology, Bucharest, Romania, for confirmation and further analysis. The aim of this study was to increase the reference laboratory capacity to confirm staphylococcal food poisoning (SFP) outbreak by defining the molecular basis of toxicity of Staphylococcus aureus (S. aureus) isolates and assessing their genetic relatedness. PCR methods have been used to detect 14 enterotoxin genes and the expression of some of these genes was proved by using a reverse transcription real-time PCR. Pulsed-field gel electrophoresis (PFGE) and Staphylococcus protein A coding gene sequence typing (spa typing) have been used to track the origin of the S. aureus contamination and to confirm the food poisoning outbreak. Two enterotoxigenic S. aureus strains isolated from milk, twelve isolated from patients and two from food handlers were of the same spa- type (t902) and revealed an indistinguishable SmaI macrorestriction pattern after a PFGE analysis. All these strains harboured the same toxin genes profile, namely the enterotoxin gene cluster (egc), which strongly supports the evidence that the milk was the incriminated food vehicle of the outbreak and a food-handler was the most likely source of the staphylococcal food poisoning (SFP) incident.