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

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 blaGES 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.