Isolation of a Vibrio parahaemolyticus pandemic strain from a marine water sample obtained in the northern Adriatic

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Antimicrobial properties of chitosan from different developmental stages of the bioconverter insect Hermetia illucens

Growing antimicrobial resistance has prompted researchers to identify new natural molecules with antimicrobial potential. In this perspective, attention has been focused on biopolymers that could also be functional in the medical field. Chitin is the second most abundant biopolymer on Earth and with its deacetylated derivative, chitosan, has several applications in biomedical and pharmaceutical fields. Currently, the main source of chitin is the crustacean exoskeleton, but the growing demand for these polymers on the market has led to search for alternative sources. Among these, insects, and in particular the bioconverter Hermetia illucens, is one of the most bred. Chitin can be extracted from larvae, pupal exuviae and dead adults of H. illucens, by applying chemical methods, and converted into chitosan. Fourier-transformed infrared spectroscopy confirmed the identity of the chitosan produced from H. illucens and its structural similarity to commercial polymer. Recently, studies showed that chitosan has intrinsic antimicrobial activity. This is the first research that investigated the antibacterial activity of chitosan produced from the three developmental stages of H. illucens through qualitative and quantitative analysis, agar diffusion tests and microdilution assays, respectively. Our results showed the antimicrobial capacity of chitosan of H. illucens, opening new perspectives for its use in the biological area

Characterization of chitin and chitosan derived from Hermetia illucens, a further step in a circular economy process

Due to their properties and applications, the growing demand for chitin and chitosan has stimulated the market to find more sustainable alternatives to the current commercial source (crustaceans). Bioconverter insects, such as Hermetia illucens, are the appropriate candidates, as chitin is a side stream of insect farms for feed applications. This is the first report on production and characterization of chitin and chitosan from different biomasses derived from H. illucens, valorizing the overproduced larvae in feed applications, the pupal exuviae and the dead adults. Pupal exuviae are the best biomass, both for chitin and chitosan yields and for their abundance and easy supply from insect farms. Fourier-transform infrared spectroscopy, X-ray diffraction and scanning electron microscope analysis revealed the similarity of insect-derived polymers to commercial ones in terms of purity and structural morphology, and therefore their suitability for industrial and biomedical applications. Its fibrillary nature makes H. illucens chitin suitable for producing fibrous manufacts after conversion to chitin nanofibrils, particularly adults-derived chitin, because of its high crystallinity. A great versatility emerged from the evaluation of the physicochemical properties of chitosan obtained from H. illucens, which presented a lower viscosity-average molecular weight and a high deacetylation degree, fostering its putative antimicrobial properties

Adherence to growth hormone (GH) therapy in na\uefve to treatment GH-deficient children: data of the Italian Cohort from the Easypod Connect Observational Study (ECOS)

Background: With the use of non-objective measurement, adherence to growth hormone (GH) therapy has been reported suboptimal in a large proportion of patients, and poor adherence has been shown to affect short-term growth response in patients receiving GH treatment. Objective: The Easypod\u2122 electronic device allows objective measurement of adherence. In this study, we report 3-year prospective adherence data of the Italian cohort of na\uefve GH deficient (GHD) children extrapolated from the Easypod Connect Observational Study (ECOS) database. Patients and methods: Seventy-three GHD children na\uefve to GH treatment were included in the analysis. 22 Italian centers participated in the study. Results: Mean adherence rate was consistently above 85% across the 3-year observation period. Particularly, mean adherence was 88.5%, 86.6%, and 85.7% after 1, 2 and 3\ua0years, respectively. Mean (\ub1 SD) height-SDS increase after the first year was 0.41 (\ub1 0.38). Conclusions: The majority of na\uefve GHD children starting GH treatment with Easypod maintained an adherence rate > 85% up to 3\ua0years. Easypod is a useful tool to follow-up patients\u2019 adherence allowing timely intervention to improve optimal treatment for these patients

Permeation through the Cell Membrane of a Boron-Based β-Lactamase Inhibitor

Bacteria express beta-lactamases to counteract the beneficial action of antibiotics. Benzo[b]-thiophene-2-boronic acid (BZB) derivatives are β-lactamase inhibitors and, as such, promising compounds to be associated with β-lactam antibacterial therapies. The uncharged form of BZB, in particular, is suggested to diffuse through the outer membrane of Gram negative bacteria. In this study, through the combination of electrophysiological experiments across reconstituted PC/n-decane bilayers and metadynamics-based free energy calculations, we investigate the permeation mechanism of boronic compounds. Our experimental data establish that BZB passes through the membrane, while computer simulations provide hints for the existence of an aqueous, water-filled monomolecular channel. These findings provide new perspectives for the design of boronic acid derivatives with high membrane permeability

AMBER force field implementation of the boronate function to simulate the inhibition of B-lactamases by alkyl and aryl boronic acids

Boronic acids are a very appealing class of serine proteases inhibitors whose rational design suffers, in spite of their therapeutic potential, from the lack of boron-related parameters in force fields commonly used for proteins. We introduced bonded, non-bonded and point charges in the MacroModel/Amber force field, as well as GB/SA solvation parameters, to model boronic acids as tetrahedral adducts formed after protease's serine Ogamma coordination. With the aim to check the implemented force field, flexible docking studies were performed on three crystallographic complexes of beta-lactamases with boronic acids that output the crystallographic conformation of the complexes as the global minimum energy structure. Although the used approach was basic, nevertheless the resultant force field seems to be efficient and suitable for the structure-based design of new boronic inhibitors of beta-lactamases