Work

Silent transmission of clonal Pseudomonas aeruginosa via duodenoscopes: microbiological and genomic investigation of a prolonged episode

Year: 2025

Type: article

Abstract: BACKGROUND: Duodenoscope-associated infections are typically linked to multidrug-resistant organisms (MDROs) and detected during outbreak investigations. However, the true burden of transmission involving non-MDRO pathogens remains largely underestimated. This study reports a prolonged episode of silent Pseudomonas aeruginosa transmission through duodenoscopes. METHODS: A retrospective and prospective investigation was conducted at a French tertiary-care hospital from May 2021 to December 2022. Cases were defined as patients who underwent endoscopic retrograde cholangiopancreatography (ERCP) with duodenoscope D2 and developed P. aeruginosa infection or colonisation. Duodenoscope sampling was performed in accordance with national guidelines. Isolates were characterised using antibiotic susceptibility testing, quantitative antibiogram, Fourier transform infrared spectroscopy, and whole genome sequencing (WGS). Longitudinal surveillance of all duodenoscopes was implemented post-incident. RESULTS: Eight patients were infected or colonised with P. aeruginosa after ERCP with D2, despite compliant routine microbiological testing in April and July 2021. D2 was declared non-compliant only in October 2021, revealing persistent contamination. Two patients developed non-biliary infections, suggesting overlooked transmission routes. During prospective surveillance, D4 was found to be contaminated after being used in two additional cases. WGS confirmed a clonal cluster (ST1320) comprising all patient isolates and those from D2 and D4. The similarity of isolates (0-6 single nucleotide polymorphisms) supports device persistence and delayed detection. CONCLUSION: This study demonstrates that clonal P. aeruginosa contamination of duodenoscopes can persist undetected despite routine testing and strict reprocessing. Infections may arise outside typical outbreak settings and involve non-MDRO strains. Enhanced detection strategies, improved endoscope designs, and broader post-procedural surveillance are needed to prevent such silent transmission.

Source: Journal of Hospital Infection

DOI: 10.1016/j.jhin.2025.11.025

Authors: A. Cissé, A. Morin-Le Bihan, M. Pagenault, V. Cattoir, S. Reissier, G. Ménard

Institutions: Centre Hospitalier Universitaire de Rennes, Inserm, Bacterial RNAs & Medicine, Université de Rennes

Language: English

Topic: Medical Device Sterilization and Disinfection

Subfield: Microbiology

Field: Immunology and Microbiology

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: hybrid

Estimated APC paid: $4,000