Nosocomial outbreak due to a novel sequence type of carbapenem-resistant Acinetobacter seifertii.

Background: Acinetobacter seifertii, a member of A baumannii-calcoaceticus complex, can be considered a pathogen of concern due to the presence of resistance genes. The aim of the study was to describe an outbreak of carbapenem-resistant A seifertii among neonates admitted to the neonatal intensive care unit (NICU) at a tertiary care hospital.

Methods: All patients with carbapenem-resistant A seifertii diagnosed and admitted to the NICU from June 2023 to October 2023 were included.

Rapid colorimetric polymyxin B microelution directly from positive blood bottles: because patients with serious infections should not have to wait for results of culture-based methodologies.

Purpose: To evaluate the performance of the rapid colorimetric polymyxin B microelution (RCPEm) in determining polymyxin B resistance directly from Enterobacterales-positive blood cultures.

Methods: A set volume of positive blood culture bottles (diluted 1:10) was inoculated into a glucose-broth-phenol red solution (NP solution), where a polymyxin B disk was previously eluted (final concentration of 3 µg/mL). Test was read each 1 h for up to 4 h.

Detection of polymyxins resistance among Enterobacterales: evaluation of available methods and proposal of a new rapid and feasible methodology.

Background: Fast and accurate detection of polymyxins resistance is necessary as they remain the last resources to treat infections caused by Carbapenem-resistant Enterobacterales in many regions. We evaluated the rapid colorimetric polymyxin B elution (RCPE) and developed its miniaturized version, RCPE microelution (RCPEm), aiming to detect polymyxins resistance among Enterobacterales.

Methods: The methodologies consist of exposing the bacterial population in a solution (NP solution) where polymyxin B disks were previously eluted to obtain a concentration of 2 µg/mL for RCPE and 3 µg/mL for RCPEm.

Otopathogens in the middle ear and nasopharynx of children with recurrent acute otitis media.

Objective: This study aimed to describe the microbiology of the middle ear and nasopharynx, determining the prevalence of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis in a group of children vaccinated with pneumococcal conjugate vaccine (PCV) who underwent ventilation tube insertion for recurrent acute otitis media.

Methods: We analyzed 278 middle ear effusion and 139 nasopharyngeal samples obtained from 139 children who underwent myringotomy and ventilation tube insertion for recurrent acute otitis media between June 2017 and June 2021. The children's ages ranged from 9 months to 9 years, 10 months, with a median of 21 months.

Streptococcus pneumoniae serotype 19A from carriers and invasive disease: virulence gene profile and pathogenicity in a Galleria mellonella model.

Purpose: This study aimed to evaluate and compare the presence of genes related to surface proteins between isolates of Streptococcus pneumoniae from healthy carriers (HC) and invasive pneumococcal disease (IPD) with a particular focus on serotype 19A.

Methods: The presence of these genes was identified by real-time PCR. Subsequently, we employed the Galleria mellonella larval infection model to study their effect on pathogenicity in vivo.