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Abstract Novel technologies such as complex magnetic fields—CMFs represent an eco-sustainable proposal to counteract the infection associated to resistant microorganisms. The aim of this study was to evaluate the effect of two CMF programs (STRESS, ANTIBACTERIAL) against clinical antifungal resistant C. albicans also evaluating their uneffectiveness on gingival fibroblasts (hGFs). The STRESS program was more efficacious on C. albicans biofilm with up to 64.37% ± 10.80 of biomass and up to 99.19% ± 0.06 CFU/ml reductions in respect to the control also inducing an alteration of lipidic structure of the membrane. The MTT assay showed no CMFs negative effects on the viability of hGFs with a major ROS production with the ANTIBACTERIAL program at 3 and 24 h. For the wound healing assay, STRESS program showed the best effect in terms of the rate migration at 24 h, showing statistical significance of p

The imbalance in skin microbiota is characterized by an increased number of pathogens in respect to commensal microorganisms. Starting from a skin microbiota collection, the aim of this work was to evaluate the possible role of Pomegranate (Punica granatum L.) Peel Extract (PPE) in restoring the skin microbiota balance acting on Staphylococcus spp. PPE was extracted following green methodology by using n-butane and the Dimethyl Ether (DME) solvents and analyzed for phytochemical composition and antimicrobial activity. The PPE antimicrobial action was evaluated against Gram +, Gram - bacteria and yeast reference strains and the most effective extract was tested against the main skin microbiota isolated strains. PPE extracted with DME showed the best antimicrobial action with MICs ranging from 1 to 128 mg/mL; the main active compounds were Catechin, Quercetin, Vanillic acid and Gallic acid. The PPE in DME anti-adhesive effect was examined against S. epidermidis and S. aureus mono and dual-species biofilm formation by biomass quantification and CFU/mL determination. The extract toxicity was evaluated by using Galleria mellonella larvae in vivo model. The extract displayed a significant anti-adhesive activity with a remarkable species-specific action at 4 and 8 mg/mL against S. epidermidis and S. aureus mono and dual-species biofilms. PPE in DME could represent an eco-sustainable non-toxic strategy to affect the Staphylococcal skin colonization in a species-specific way. The innovation of this work is represented by the reuse of food waste to balance skin microbiota.

Resistant wound microorganisms are becoming an extremely serious challenge in the process of treating infected chronic wounds, leading to impaired healing. Thus, additional approaches should be taken into consideration to improve the healing process. The use of natural extracts can represent a valid alternative to treat/control the microbial infections in wounds. This study investigates the antimicrobial/antivirulence effects of Capparis spinose aqueous extract against the main chronic wound pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The extract shows phenolic characterization with rutin (1.8 ± 0.14 μg/mg) as the major compound and antibacterial effect against bacteria (S. aureus PECHA 10 MIC 6.25%; P. aeruginosa PECHA 4 MIC 12.50%) without action against C. albicans (MIC and MFC ≥ 50%). Capparis spinose also shows a significant antivirulence effect in terms of antimotility/antibiofilm actions. In particular, the extract acts (i) on P. aeruginosa both increasing its swimming and swarming motility favoring the planktonic phenotype and reducing its adhesive capability, (ii) on S. aureus and P. aeruginosa biofilm formation reducing both the biomass and CFU/ml. Furthermore, the extract significantly displays the reduction of a dual-species S. aureus and P. aeruginosa Lubbock chronic wound biofilm, a complex model that mimics the realistic in vivo microbial spatial distribution in wounds. The results suggest that C. spinose aqueous extract could represent an innovative eco-friendly strategy to prevent/control the wound microbial infection.

Chronic wound infections represent an important health problem due to the reduced response to antimicrobial treatment of the pathogens organized in structured biofilms. This study investigated the effects of the previously described antifungal peptide L18R against three representative wound pathogens: Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The antimicrobial activity of L18R was evaluated (i) against single planktonic microbial populations; (ii) on single, dual, and triadic species of biofilms in both the early stage and mature stage; and (iii) in the polymicrobial Lubbock chronic wound biofilm (LCWB) model, mimicking spatial microbial colonization. This study used the evaluation of CFUs, biofilm biomass detection, and confocal and scanning electron microscopy analysis. L18R showed a significant antimicrobial activity against planktonic microorganisms and was able to differentially reduce the biomass of monomicrobial biofilms. No reduction of biomass was observed against the polymicrobial biofilm. In mature LCWB, L18R caused a moderate reduction in total CFU number, with a variable effect on the different microorganisms. Microscopy images confirmed a predominant presence of P.aeruginosa and a lower percentage of C. albicans cells. These findings suggest a modulating action of L18R and recommend further studies on its potential role in chronic wound management in association with conventional antibiotics or alternative treatments.

The drug-resistance phenomenon in Helicobacter pylori underlines the need of novel strategies to improve the eradication rate including alternative treatments combining antibiotic and non-antibiotic compounds with synergistic action. In this study, the antibacterial (MIC/MBC) and anti-virulence effects (biofilm reduction and swarming motility inhibition) of resveratrol-RSV and new synthetized RSV-phenol derivatives, with a higher bioavailability, alone and combined with levofloxacin-LVX were evaluated against resistant H. pylori clinical strains. The experiments were confirmed in vivo using the Galleria mellonella model. Among the studied RSV derivatives, RSV-3 and RSV-4 possessed higher antibacterial activity with respect to RSV (MICs from 6.25 to 200 µg/mL and from 3.12 to 200 µg/mL, respectively). RSV, RSV-3, and RSV-4 were able to synergize with LVX restoring its effect in two out of seven clinical resistant strains tested for the study. RSV, RSV-3, and RSV-4, alone and with LVX at sub-MIC and sub-synergistic concentrations, significantly reduced the biofilm formation. Moreover, RSV-3 and RSV-4 reduced the H. pylori swarming motility on soft agar. RSV, RSV-3, and RSV-4 were non-toxic for G. mellonella larvae and displayed a protective effect against H. pylori infection. Overall, RSV–phenol derivatives should be considered interesting candidates for innovative therapeutic schemes to tackle the H. pylori antibiotic resistance.

Background: An unbalanced skin microbiota due to an increase in pathogenic vs. commensal bacteria can be efficiently tackled by using prebiotics. The aim of this work was to identify novel prebiotic combinations by exerting species-specific action between S. aureus and S. epidermidis strains. Methods: First, the antimicrobial/antibiofilm effect of Xylitol-XYL and Galacto-OligoSaccharides–GOS combined with each other at different concentrations (1, 2.5, 5%) against S. aureus and S. epidermidis clinical strains was evaluated in time. Second, the most species-specific concentration was used to combine XYL with Fructo-OligoSaccharides–FOS, IsoMalto-Oligosaccharides–IMO, ArabinoGaLactan–LAG, inulin, dextran. Experiments were performed by OD600 detection, biomass quantification and LIVE/DEAD staining. Results: 1% XYL + 1% GOS showed the best species-specific action with an immediate antibacterial/antibiofilm action against S. aureus strains (up to 34.54% ± 5.35/64.68% ± 4.77) without a relevant effect on S. epidermidis. Among the other prebiotic formulations, 1% XYL plus 1% FOS (up to 49.17% ± 21.46/37.59% ± 6.34) or 1% IMO (up to 41.28% ± 4.88/36.70% ± 10.03) or 1% LAG (up to 38.21% ± 5.31/83.06% ± 5.11) showed antimicrobial/antibiofilm effects similar to 1% XYL+1% GOS. For all tested formulations, a prevalent bacteriostatic effect in the planktonic phase and a general reduction of S. aureus biofilm formation without loss of viability were recorded. Conclusion: The combinations of 1% XYL with 1% GOS or 1% FOS or 1% IMO or 1% LAG may help to control the balance of skin microbiota, representing good candidates for topic formulations.