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There is evidence that in infected cells in vitro the meningococcal HrpA/HrpB twopartner secretion system (TPS) mediates the exit of bacteria from the internalization vacuole and the docking of bacteria to the dynein motor resulting in the induction of pyroptosis. In this study we set out to study the role of the HrpA/HrpB TPS in establishing meningitis and activating pyroptotic pathways in an animal model of meningitis using a reference serogroup C meningococcal strain, 93/4286, and an isogenic hrpB knockout mutant, 93/4286WhrpB. Survival experiments confirmed the role of HrpA/HrpB TPS in the invasivemeningococcal disease. In fact, the ability of the hrpB mutant to replicate in brain and spread systemically was impaired in mice infected with hrpBmutant. Furthermore, western blot analysis of brain samples during the infection demonstrated that: i. N. meningitidis activated canonical and noncanonical inflammasome pyroptosis pathways in themouse brain; ii. the activation of caspase-11, caspase-1, and gasdermin-D was markedly reduced in the hrpB mutant; iii. the increase in the amount of IL-1b and IL-18, which are an important end point of pyroptosis, occurs in the brains of mice infected with the wild-type strain 93/4286 and is strongly reduced in those infected with 93/4286WhrpB. In particular, the activation of caspase 11, which is triggered by cytosolic lipopolysaccharide, indicates that during meningococcal infection pyroptosis is induced by intracellular infection after the exit of the bacteria from the internalizing vacuole, a process that is hindered in the hrpBmutant. Overall, these results confirm, in an animal model, that theHrpA/HrpB TPS plays a role in the induction of pyroptosis and suggest a pivotal involvement of pyroptosis in invasive meningococcal disease, paving the way for the use of pyroptosis inhibitors in the adjuvant therapy of the disease. [ABSTRACT FROM AUTHOR]

This study investigates airborne bacterial and fungal communities in south-eastern Italy and Albania using advanced DNA-based techniques and compositional data analysis (CoDa). We assess the significance of airborne microbial communities, detailing our methodologies for site selection, sample collection, DNA extraction, and data analysis. Our results reveal distinct differences in microbial composition between the two regions, driven by local environmental factors. Specifically, Albanian samples showed higher abundances of bacterial species such as Rubellimicrobium roseum and Sphingomonas cynarae, while Italian samples were characterized by a prevalence of Truepera radiovictrix and Rubrobacter radiotolerans. In terms of fungi, Albanian sites exhibited greater abundance of Mycosphaerella tassiana, Aureobasidium pullulans, and Ascochyta herbicola. Aitchison distance-based dendrograms and principal component analysis (PCA) biplots, utilizing singular value decomposition, clearly delineated a geographical separation of microbial communities, underscoring the impact of regional atmospheric conditions on microbial composition. In the discussion, we interpret these findings in the context of regional environmental factors, highlighting their implications for understanding regional differences in airborne microbial communities. The conclusion emphasizes the effectiveness of advanced DNA techniques and CoDa in environmental microbiology, offering insights into how local environmental conditions shape microbial communities and suggesting directions for future research and public health considerations. [ABSTRACT FROM AUTHOR]

Herein, a study on the photocatalysis and antibacterial performances of Cu‐doped titania films as a function of the dopant concentration is presented. The TiO2 films are produced by sol–gel spin‐coating technique, and the doping is performed by adding different quantities of copper in the form of salt (CuSO4) during the preparation of sol. The obtained films are characterized by Raman and X‐ray diffraction spectroscopies, atomic force microscopy, and Rutherford backscattering spectrometry, to investigate on the chemical–physical properties, the quality, the composition, and the thickness. The photocatalytic activity of the films is studied by measuring the degradation of methylene blue (MB) under UV light, while Staphylococcus aureus is chosen for microbiological testing. The results show a correlation between photocatalysis and antibactericity with a rise of these two activities with increasing dopant concentrations in the films up to a given point, beyond which structural defects are introduced, promoting electron–hole recombination. [ABSTRACT FROM AUTHOR]

Lindane is an organochlorine pesticide belonging to persistent organic pollutants (POPs) that has been widely used to treat agricultural pests. It is of particular concern because of its toxicity, persistence and tendency to bioaccumulate in terrestrial and aquatic ecosystems. In this context, we assessed the role of bacteria associated with the sponge Hymeniacidon perlevis in lindane degradation. Seven bacteria isolates were characterized and identified. These isolates showed a remarkable capacity to utilize lindane as a sole carbon source leading to a percentage of residual lindane ranging from 3% to 13% after 12 days of incubation with the pesticide. The lindane metabolite, 1,3–6-pentachloro-cyclohexene, was identified as result of lindane degradation and determined by gas chromatography–mass spectrometry (GC–MS). The bacteria capable of lindane degradation were identified on the basis of the phenotypic characterization by morphological, biochemical and cultural tests, completed with 16S rDNA sequence analysis, and assigned to Mameliella phaeodactyli, Pseudovibrio ascidiaceicola, Oceanicaulis stylophorae, Ruegeria atlantica and to three new uncharacterized species. The results obtained are a prelude to the development of future strategies for the in situ bioremediation of lindane.