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Newborns admitted to neonatal intensive care units (NICU) are at increased risk of health care-associated infections. Serratia marcescens represent the third most common pathogen in NICU outbreaks. Here we present an outbreak investigation performed using Whole Genome Sequencing (WGS) analyses and the control measures implemented to limit the spread of S. marcescens in the NICU of an Italian hospital. In February 2023 S. marcescens was isolated from six newborns, when in 2022 this pathogen was isolated only from two samples in the same ward. Measures for infection prevention were adopted. Routinary surveillance screening, performed with rectal swabs collected at admission and weekly thereafter, was implemented to search for S. marcescens presence. Environmental samples were collected. All the isolates, obtained from the conjunctival swab of six newborns, from rectal swab of two newborns who did not develop infections, as well as from the aerators of two faucets, were sequenced. WGS analyses showed no correlation between the isolates from newborns and environmental isolates. The implementation of the measures for infection prevention and control had enabled us to successfully control the outbreak within a short period. WGS analyses proved to be crucial in outbreak investigation to limit the spreading of the pathogens., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

The dissemination of carbapenemase-producing Escherichia coli, although still at low level, should be continuously monitored. OXA-244 is emerging in Europe, mainly in E. coli . In Italy, this carbapenemase was reported from an environmental river sample in 2019. We report clinical isolates of OXA-244-producing ST131 E. coli in four patients admitted to an acute care hospital in Pavia, Italy. The association of this difficult-to-detect determinant with a globally circulating high-risk clone, ST131 E. coli, is of clinical relevance.

New Delhi metallo-beta-lactamase (NDM)-producing Klebsiella pneumoniae ( Kp ) ST147 caused a large multi-hospital outbreak in Italy from 2018 to 2021. We describe a new ST6668 NDM-producing Kp clone, belonging to CC147, which rapidly spread across hospitals in the Pavia province (Northern Italy) from February to August 2023. Genomic analyses revealed that ST6668 is different from ST147 and fast evolving. As shown here, genomic surveillance programmes are useful for tracking the spread of new clones with reduced susceptibility to most antibiotics.

Several studies have strengthened the link between the gut microbiota (GM) and the response to immunotherapy in patients with tumors, highlighting the potential role of GM as a biomarker of response. Targeted therapies including B-cell receptor (BCR) inhibitors (BCRi) represent the newest approach to the treatment of chronic lymphocytic leukemia (CLL); however, not all patients achieve a satisfactory response, and immune-related adverse events (irAEs) can also impact the efficacy. The aim of the study was to compare GM biodiversity in patients with CLL, treated with BCRi for at least 12 months. Twelve patients were enrolled: 10 patients in the responder group (R) and 2 patients in the non-responder group (NR). We identified seven patients (58.3%) who experienced adverse reactions (AE). Although we did not observe a significant difference across the study population in terms of relative abundance and alpha and beta diversity, we found a differing distribution of bacterial taxa between the analyzed groups. We noted a higher level of the class Bacteroidia and the order Bacteroidales in the R group, and an inversion in the Firmicutes and Bacteroidetes ratio in the AE group. No prior studies have focused on linking GM and response to BCRi in these patients. Although the analyses are preliminary, they provide suggestions to guide future research.