Using genomic surveillance to detect related Guiana Extended-Spectrum (GES) β-lactamase-producing Carbapenem-Resistant Pseudomonas aeruginosa (CRPA) cases in a clinical setting.

Abstract

Background: Carbapenem-resistant Pseudomonas aeruginosa (CRPA) cause difficult-to-treat infections and can be transmitted in healthcare facilities. CRPA containing Guiana Extended-Spectrum (GES) genes are rare in Los Angeles County and undetectable using commonly used assays. This report describes the detection and transmission of GES-CRPA in a long-term acute care hospital (LTACH).

Methods: Epidemiological investigations and environmental samplings were performed to identify and control a potential source of transmission. Microbiological isolation techniques and whole-genome sequencing (WGS) were used to recover bla_GES isolates and determine relatedness.

Results: Genomic surveillance identified three related clinical cases of GES-CRPA over a three-year span. Environmental sampling of sinks and sink drains identified related GES-CRPA isolates. These isolates were found to contain an uncommon combination of antimicrobial resistance genes present in a class 1 integron. Infection control measures intended to prevent transmission from sinks and adjacent surfaces were implemented.

Conclusions: This work highlights the importance of combining traditional epidemiology and genomic surveillance to detect outbreaks that may have otherwise gone unnoticed, enabling rapid outbreak management.