Stenotrophomonas maltophilia Outbreak in an ICU: Investigation of Possible Routes of Transmission and Implementation of Infection Control Measures.

Stenotrophomonas maltophilia, a non-fermentative, ubiquitous, gram-negative aerobic bacterium, is associated with high mortality rates, particularly in immunocompromised or debilitated patients. The prevalence rate of ICU-acquired pneumonia episodes caused by this microorganism has been found to be 2%. S. maltophilia has been identified as one of the top 10 microorganisms responsible for such infections in EU/EEA countries. This study describes an outbreak of S. maltophilia in an intensive care unit of a hospital in northern Italy. This includes an epidemiological investigation of the cases, the environmental microbiological controls carried out, a comparison of the strains by multilocus sequence typing (MLST), and the measures taken to prevent and control the outbreak. Among the seven clinical isolates of S. maltophilia analyzed herein, six demonstrated susceptibilities to trimethoprim-sulfamethoxazole. Conversely, one isolate of S. maltophilia exhibited resistance to first-line antibiotics. ST was found to be identical for six patients (ST 4), as well as in the environmental feedback on the trolley of Box 2. The analysis of the temporal and spatial progression of the outbreak has suggested that the transmission of S. maltophilia may have occurred through cross-transmission during care practices.

Impact of the COVID-19 Pandemic on Epidemiology of Antibiotic Resistance in an Intensive Care Unit (ICU): The Experience of a North-West Italian Center.

The SARS-CoV-2 pandemic caused an increase in intensive care unit (ICU) hospitalizations with a rise in morbidity and mortality; nevertheless, there is still little evidence on the impact of the pandemic on antibiotic resistance in ICUs. This is a retrospective, monocentric epidemiological study. The aim of the study was to describe and analyze the impact of the SARS-CoV-2 pandemic on ICU bacterial resistance patterns. All bacteria isolated from all patients admitted to the E.O. Galliera ICU from January 2018 to December 2022 were included. Antibiotic resistance (AR) profiles were evaluated. A total of 1021 microorganisms were identified, of which 221 (12.47%) had a resistance pattern (resistant organisms; ROs). In this time, there were 1679 patients with a total of 12,030 hospitalization days. The majority of microorganisms were Gram-negative (79.66% in 2018, 77.29% in 2019, 61.83% in 2020, 62.56% in 2021, and 60.75% in 2022), but an increase in Gram-positive microorganisms was observed (20.34 to 39.25% between 2018 and 2022). The prevalence of AR was 19.44% in 2018, 11.54% in 2019, 38.04% in 2020, 34.15% in 2021, and 39.29% in 2022 for Gram-positive microorganisms and 19.86% in 2018, 13.56% in 2019, 18.12% in 2020, 12.41% in 2021, and 12.31% in 2012 for Gram-negative microorganisms. The incidence of ROs showed a COVID-19-related increase in 2020-2021, followed by a lowering trend since 2021, and a new increase in 2022. Possible explanations are antibiotic overtreatment and a decrease in containment measures. An interesting finding was the cumulative lowering trend of carbapenem-resistant K. pneumoniae and P. aeruginosa, probably due to different patient features.

Erysipelothrix rhusiopathiae septicaemia in systemic lupus erythematosus.

Erysipelothrix rhusiopathiae is a Gram-positive bacillus that is rarely reported as a causative agent of infections in humans. Human cases in most instances present as localized or generalized skin infections. Invasive infections are exceptionally described and septic forms are usually associated with endocarditis. We report a case of invasive infection caused by Erysipelothrix rhusiopathiae without skin or endocardium involvement in a patient with systemic lupus erythematosus (SLE). To our knowledge, this is the first report of an isolated bacteraemia due to this pathogen in a patient with SLE without skin or endocardium involvement.

An unexpected Streptococcus pneumoniae strain.

This clinical driven report describes the unexpected detection of a multidrug resistant (MDR) Streptococcus pneumoniae strain. Italy is usually considered a country characterized by a low prevalence of MDR S. pneumoniae. We describe the occurrence of bacterial meningitis sustained by a MDR S. pneumoniae strain in Italy. The first-line treatment was started with ceftriaxone and dexamethasone, but after the identification of such a resistant strain a second-line regimen was needed. The new regimen was chosen on both susceptibility and pharmacokinetic criteria. Linezolid and levofloxacin were started and a dramatic improvement was observed. A more sensitive anamnesis revealed some elements known to be associated to a MDR S. pneumoniae occurrence (immunesuppression, former antibiotic therapy). So this case should pinpoint our attention on risk factors of MDR for a careful choice of antibiotic therapy in serious pneumococcal infections.

Erysipelothrix rhusiopathiae intra-abdominal abscess.

Erysipelothrix rhusiopathiae is a Gram-positive bacillus that is infrequently responsible for infections in humans. Most human cases present as localized or generalized cutaneous infections. An invasive septic form, usually associated with endocarditis, has rarely been described. We report here an invasive infection caused by E. rhusiopathiae without endocardium involvement. To our knowledge, this is the first report of an intra-abdominal abscess due to this pathogen.

Imported typhoid fever with hepatitis from Bangladesh: a case of delayed response to ceftriaxone?

Typhoid fever due to multidrug-resistant (MDR) Salmonella typhi has been extensively reported. We present an imported case (from Bangladesh) of typhoid fever with typhoid hepatitis due to an MDR S typhi strain with clinically delayed response or reduced susceptibility to ceftriaxone. The relevant clinical and public health implications are discussed.