Assessment of peripheral venous catheters microbiota and its association with phlebitis.

BACKGROUND: Peripheral venous catheters (PVCs) remain the primary mode of short-term venous access for managing intravenous fluid, obtaining blood samples, and peripheral parenteral nutrition. They may get contaminated and require regular monitoring to prevent complications. This study evaluated the occurrence of phlebitis and its associated-clinical and microbiological indicators. METHODS: The frequency of phlebitis was evaluated in hospitalized patients of both medical and surgical fields. Subsequently, the dichotomous association between the presence of phlebitis and the clinical aspects was investigated. In parallel, the bacterial contamination of PVCs was assessed through culture-based methods, microscopy observation, and 16S rRNA gene sequencing. RESULTS: Approximately one in four patients presented phlebitis (28.4%). The most frequent symptom was erythema at access site, with or without pain, corresponding to Score 1 on the phlebitis scale (17.9%). Colonization of both lumen and external surface of PVC was observed in 31.3% of the samples. Staphylococcus and Pseudomonas were the most isolated bacterial genera on the PVC surface. No significant association was observed between the presence of phlebitis and the clinical aspects, as well as the presence of microorganisms. CONCLUSION: Microorganism were present on both internal and external PVC surface, without being associated to phlebitis.

Deacetylation by sirtuins is important for Aspergillus fumigatus pathogenesis and virulence.

Protein acetylation is a crucial post-translational modification that controls gene expression and a variety of biological processes. Sirtuins, a prominent class of NAD + -dependent lysine deacetylases, serve as key regulators of protein acetylation and gene expression in eukaryotes. In this study, six single knockout strains of fungal pathogen Aspergillus fumigatus were constructed, in addition to a strain lacking all predicted sirtuins (SIRTKO). Phenotypic assays suggest that sirtuins are involved in cell wall integrity, secondary metabolite production, thermotolerance, and virulence. AfsirE deletion resulted in attenuation of virulence, as demonstrated in murine and Galleria infection models. The absence of AfSirE leads to altered acetylation status of proteins, including histones and non-histones, resulting in significant changes in the expression of genes associated with secondary metabolism, cell wall biosynthesis, and virulence factors. These findings encourage testing sirtuin inhibitors as potential therapeutic strategies to combat A. fumigatus infections or in combination therapy with available antifungals.