Background: Candida auris represents an emerging pathogen that results in nosocomial infections and is considered a serious global health problem. The aim of this work was to evaluate the in vitro antifungal efficacy of Cinnamomum cassia essential oil (CC-EO) pure or formulated in polycaprolactone (PCL) nanoparticles against ten clinical strains of C. auris. Methods: nanoparticles of PCL were produced using CC-EO (nano-CC-EO) and cinnamaldehyde (CIN) through the nanoprecipitation method. The chemical profile of both CC-EO and nano-CC-EO was evaluated using SPME sampling followed by GC-MS analysis. Micro-broth dilution tests were performed to evaluate both fungistatic and fungicidal effectiveness of CC-EO and CIN, pure and nano-formulated. Furthermore, checkerboard tests to evaluate the synergistic action of CC-EO or nano-CC-EO with micafungin or fluconazole were conducted. Finally, the biofilm disrupting activity of both formulations was evaluated. Results: GC-MS analysis shows a different composition between CC-EO and nano-CC-EO. Moreover, the microbiological analyses do not show any variation in antifungal effectiveness either towards the planktonic form (MIC_CC-EO = 0.01 ± 0.01 and MIC_nano-CC-EO = 0.02 ± 0.01) or the biofilm form. No synergistic activity with the antifungal drugs tested was found. Conclusions: both CC-EO and nano-CC-EO show the same antimicrobial effectiveness and are potential assets in the fight against C. auris.

Graphene Quantum Dots (GQDs) have shown the potential for antimicrobial photodynamic treatment, due to their particular physicochemical properties. Here, we investigated the activity of three differently functionalized GQDs—Blue Luminescent GQDs (L-GQDs), Aminated GQDs (NH₂-GQDs), and Carboxylated GQDs (COOH-GQDs)—against E. coli. GQDs were administrated to bacterial suspensions that were treated with blue light. Antibacterial activity was evaluated by measuring colony forming units (CFUs) and metabolic activities, as well as reactive oxygen species stimulation (ROS). GQD cytotoxicity was then assessed on human colorectal adenocarcinoma cells (Caco-2), before setting in an in vitro infection model. Each GQD exhibits antibacterial activity inducing ROS and impairing bacterial metabolism without significantly affecting cell morphology. GQD activity was dependent on time of exposure to blue light. Finally, GQDs were able to reduce E. coli burden in infected Caco-2 cells, acting not only in the extracellular milieu but perturbating the eukaryotic cell membrane, enhancing antibiotic internalization. Our findings demonstrate that GQDs combined with blue light stimulation, due to photodynamic properties, have a promising antibacterial activity against E. coli. Nevertheless, we explored their action mechanism and toxicity on epithelial cells, fixing and standardizing these infection models.

Preserving artworks from the attacks of biodeteriogens is a primary duty of humanity. Nowadays, restorers use chemicals potentially dangerous for both artworks and human health. The purpose of this work was to find a green and safe formulation based on natural substances with fungicidal activity to restore ancient oil paintings, particularly “Il Silenzio” (by Jacopo Zucchi) preserved at the Uffizi Museum in Florence, Italy. The study was divided into two phases. First phase (in vitro study): three essential oils (EOs) and four hydrolates (Hys) were analysed by GC-mass spectrometry and in vitro tested against six ATCC strains of molds. An emulsion based on the more active natural compounds was tested on aged and unaged canvases samples to evaluate both their fungicidal activity and the impact on chemical-physical parameters. Finally, an in vivo toxicity test performed on the Galleria mellonella model assessed the safety for health. Second phase (in situ application): the emulsion was sprayed on the back of the painting and left to act for 24 h. Biodeteriogens present on the “Il Silenzio” painting were microbiologically identified before and after the treatment. The emulsion formulated with C. zeylanicum EO and C. aurantium var. amara Hy showed the best antifungal activity both in vitro and in situ without altering the chemical-physical characteristics of paintings. Furthermore, no in vivo toxicity was shown. For the first time, a green antimicrobial emulsion based on Hy and EO, safe for operators, was used to decontaminate an artwork colonised by fungi before the restoration practices.

A diverse and well-functioning gut microbiota normally serves as a protective shield against the invasion of harmful bacteria or the proliferation of opportunistic pathogens. Clostridioides difficile infection (CDI) is predominantly associated with the overuse of antibiotics, resulting in a significant alteration in the gut’s microbial balance. Unfortunately, the lack of global standardization does not allow for the identification of a set of biomarkers associated with the onset and progression of this disease. In this study, we examined the composition of the gut microbiota in patients at the time of the initial detection of CDI compared to a control group of CDI-negative individuals, with a focus on identifying potential CDI biomarkers for diagnosis. While no significant differences in the alpha and beta diversity between CDI-negative and CDI-positive individuals were found, we found that certain genera (such as Clostridium XIVa and Clostridium XVIII) showed different abundance patterns in the two groups, indicating potential differences in gut microbiota balance. In conclusion, am enrichment in Clostridium XI and a decrease in Faecalibacterium emerged in the CDI-positive patients and following antibiotic treatment, indicating that changes in the Clostridium/Faecalibacterium ratio may be a promising biomarker that warrants further investigation for CDI diagnosis.

MXenes, a family of two‐dimensional transition metal carbides, carbonitrides and nitrides, have emerged as highly interesting antimicrobial nanomaterials. While mostly Ti‐based MXenes have been explored in this field, our work aims at characterizing and investigating the antibacterial and biocompatibility profiles of two vanadium‐based MXenes (V₂CT ₓ and V₄C₃T ₓ ) against Escherichia coli and Staphylococcus aureus , two clinically relevant pathobionts. First, the as‐synthesized nanomaterials were chemically and structurally characterized to confirm their morphology and structural integrity. After setting up two distinct experimental models (static and dynamic), the antibacterial activity was evaluated by colony‐forming units (CFUs) counting and scansion electron microscopy (SEM). Cellular cytotoxicity was assessed by lactate dehydrogenase (LDH) release and crystal violet characterization (CV). To further evaluate the MXenes' properties, the antimicrobial activity was tested in in‐vitro infection models using both epithelial (Caco‐2) and macrophage (J774) cells measuring CFUs. To assess the oxidative stress contributing to MXenes' antibacterial activity, reactive oxygen species (ROS) production was valued in infected cells after treatment. V₂CT ₓ and V₄C₃T ₓ showed an antibacterial activity concentration and condition dependent. The dynamic incubation improved the bacterial reduction, supporting a “nano‐knife” mechanism linked to the physical disruption of the membrane. Finally, V₂CT ₓ and V₄C₃T ₓ significantly reduced the intracellular bacterial burden in infected Caco‐2 epithelial cells in comparison with macrophages. Importantly, MXenes' treatment did not result in marked ROS stimulation, suggesting that their antibacterial activity mainly arose from physical interactions. Our findings highlight that vanadium‐based MXenes have good biocompatibility and are moderately effective antimicrobial nanomaterials, emphasizing the need to use commonly recognized and standardized experimental models to elucidate their potential antimicrobial applications.

Background/Objectives: Antimicrobial resistance (AMR) represents a major global health challenge, driving the need for rapid and accurate diagnostic tools. Novel molecular assays, including multiplex PCR and DNA microarray-based systems, have emerged to detect antimicrobial resistance genes (ARGs) alongside bacterial identification. Methods: In this study, we evaluated the performance of the HybriSpot12 PCR AUTO (HS12a) system and the MDR Direct Flow Chip (MDR-FC) Kit—an automatic microarray assay based on reverse hybridization—for the detection of ARGs directly from positive blood culture (PBC) samples. A total of 111 Gram-negative bacterial isolates (92 Enterobacterales, 14 Acinetobacter baumannii, and 6 Pseudomonas spp.), previously characterized by whole-genome sequencing (WGS), were each used to generate a PBC, which was then analyzed with the HS12a/MDR-FC assay. Results: We demonstrated perfect agreement for the detection of macrolide resistance genes across all bacterial species and high agreement for genes conferring resistance to sulfonamides and β-lactams. In contrast, aminoglycoside resistance genes showed only moderate agreement, with minor discrepancies observed in Klebsiella pneumoniae and Escherichia coli, largely attributable to specific SNP variations. Conclusions: The HS12a/MDR-FC assay includes 51 ARGs, though not all were represented in our isolate set, and some false negatives were observed. Despite these limitations, its broad coverage and rapid turnaround remain advantageous compared to other rapid assays with fewer targets. Future refinements should aim at broader gene coverage, inclusion of key mutations, and detection of emerging variants, making this approach a promising tool for rapid AMR surveillance and antimicrobial stewardship.