Performance of the modified CLSI extended-spectrum β-lactamase (ESBL) confirmatory test for detecting ESBLs in Pseudomonas aeruginosa

- Phenotypic detection of extended-spectrum β-lactamases (ESBLs) in P. aeruginosa remains challenging since overexpression of intrinsic AmpC cephalosporinases and/or coproduction of carbapenemases may mask their detection.
- No standardized phenotypic method for ESBL detection exists and the proposed methods may underestimate prevalence of ESBLs
- A modification of the CLSI ESBL confirmatory test, recently proposed for ESBL detection in Enterobacteriaceae, was evaluated for ESBL detection in P. aeruginosa.