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Non-Escherichia coli Enterobacterales (NECE) can colonize the human gut and may present virulence determinants and phenotypes that represent severe heath concerns. Most information is available for virulent NECE strains, isolated from patients with an ongoing infection, while the commensal NECE population of healthy subjects is understudied. In this study, 32 NECE strains were isolated from the feces of 20 healthy adults. 16S rRNA gene sequencing and mass spectrometry attributed the isolates to Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, Enterobacter aerogenes, Enterobacter kobei, Citrobacter freundii, Citrobacter amalonaticus, Cronobacter sp., and Hafnia alvei, Morganella morganii, and Serratia liquefaciens. Multiplex PCR revealed that K. pneumoniae harbored virulence genes for adhesins (mrkD, ycfM, and kpn) and enterobactin (entB) and, in one case, also for yersiniabactin (ybtS, irp1, irp2, and fyuA). Virulence genes were less numerous in the other NECE species. Biofilm formation was spread across all the species, while curli and cellulose were mainly produced by Citrobacter and Enterobacter. Among the most common antibiotics, amoxicillin-clavulanic acid was the sole against which resistance was observed, only Klebsiella strains being susceptible. The NECE inhabiting the intestine of healthy subjects have traits that may pose a health threat, taking into account the possibility of horizontal gene transfer.

Human parvovirus B19 (B19V) commonly induces self-limiting infections but can also cause severe clinical manifestations in patients with underlying hematological disorders or with immune system deficits. Currently, therapeutic options for B19V entirely rely on symptomatic and supportive treatments since a specific antiviral therapy is not yet available. Recently a first step in the research for active compounds inhibiting B19V replication has allowed identifying the acyclic nucleoside phosphonate cidofovir (CDV). Herein, the effect of CDV against B19V replication was characterized in human erythroid progenitor cells (EPCs) cultured and infected following different experimental approaches to replicate in vitro the infection of an expanding erythroid cell population in the bone marrow. B19V replication was selectively inhibited both in infected EPCs extendedly exposed to CDV 500 μM (viral inhibition 82%) and in serially infected EPCs cultures with passages of the viral progeny, constantly under drug pressure (viral inhibition >99%). In addition, a potent inhibitory effect against B19V (>92%) was assessed in a short-term infection of EPCs treated with CDV 500 μM prior to viral infection. This enhanced anti-B19V activity of CDV could be ascribed both to the increased intracellular drug concentration achieved by extended exposure, and to a progressive reduction in efficiency of the replicative process within treated EPCs population.

Parvovirus B19 (B19V) is a human ssDNA virus responsible for a wide range of clinical manifestations, still lacking for a specific antiviral therapy. The identification of compounds active against B19V may add therapeutic options to the treatment of B19V infections. To this purpose, focus was raised to cidofovir (CDV), an acyclic nucleoside phosphonate broadly active against dsDNA viruses. Two model systems were used to assess the inhibitory effect of CDV on B19V replication: 1) the UT7/EpoS1 megakaryoblastoid cell line, able to support B19V DNA replication; 2) the ex vivo expanded CD36+ erythroid progenitor cells (EPCs), a highly permissive system for B19V replication and expression. EPCs were generated from peripheral blood, via culture in a medium containing erythropoietic growth factors (EPO, SCF and Il-3), for up to 18 days. Expression of EPC differentiation markers ranged from a minimum of 10% at 3-day to a 80% at 15-day culturing. Infection at different stages indicated that the EPC system was fully permissive to B19V between days 6 and 15 of EPCs in vitro growth and differentiation. Experiments were carried out at different multiplicity of infection (100 – 104 genomes/cell) and CDV concentrations (0.1 – 500 μM). The effects of CDV were evaluated by its capacity to inhibit viral nucleic acid synthesis, as determined by means of q PCR assays for quantification of viral nucleic acids. CDV showed a dose-dependent inhibiting activity on B19V replication within infected UT7/ EpoS1, allowing for the determination of EC50 and EC90 values (7.45–41.27 μM, and 84.73–360.7 μM, respectively). In EPCs, a significant reduction on B19V DNA amounts was obtained only at 500 μM (68.2–92.8%). However, cell-culture supernatants from B19V-infected, CDV-treated EPCs were used for serial infection of EPCs in the presence of CDV, leading to a progressive inhibition of B19V replication compared to untreated controls. With regard to the host cells, the drug did not interfere with the overall cellular DNA replication and metabolic activity. The effect of CDV on B19V could be likely related to a specific inhibition on the viral replication process, indicating the possibility of developing an antiviral strategy against a relevant human pathogenic virus.

Advances in nanotechnology have opened up new horizons in nanomedicine through the synthesis of new composite nanomaterials able to tackle the growing drug resistance in bacterial strains. Among these, nanosilver antimicrobials sow promise for use in the treatment of bacterial infections. The use of polydopamine (PDA) as a biocompatible carrier for nanosilver is appealing; however, the synthesis and functionalization steps used to obtain Ag-PDA nanoparticles (NPs) are complex and require time-consuming cleanup processes. Post-synthesis treatment can also hinder the stability and applicability of the material, and dry, offline characterization is time-consuming and unrepresentative of real conditions. The optimization of Ag-PDA preparation and purification together with well-defined characterization are fundamental goals for the safe development of these new nanomaterials. In this paper, we show the use of field-flow fractionation with multi-angle light scattering and spectrophotometric detection to improve the synthesis and quality control of the production of Ag-PDA NPs. An ad hoc method was able to monitor particle growth in a TLC-like fashion; characterize the species obtained; and provide purified, isolated Ag-PDA nanoparticles, which proved to be biologically active as antibacterial agents, while achieving a short analysis time and being based on the use of green, cost-effective carriers such as water.

The large amount of cauliflower industry waste represents an unexplored source of bioactive compounds. In this work, peptide hydrolysates from cauliflower leaves were characterized by combined bioanalytical approaches. Twelve peptide fractions were studied to evaluate unexplored biological activities by effect-based cellular bioassays. A potent inhibition of intracellular xanthine oxidase activity was observed in human vascular endothelial cells treated with one fraction, with an IC50 = 8.3±0.6 μg/ml. A different fraction significantly induced the antioxidant enzyme superoxide dismutase 1 and decreased the tumor necrosis factorα-induced VCAM-1 expression, thus leading to a significant improvement in the viability of human vascular endothelial cells. Shotgun peptidomics and bioinformatics were used to retrieve the most probable bioactive peptide sequences. Our study shows that peptides from cauliflower waste should be recycled for producing valuable products useful for the prevention of endothelial dysfunction linked to atherogenesis progression.