Rapid ESBL NP Test for Rapid Detection of Expanded-Spectrum β-Lactamase Producers in Enterobacterales

Objectives: To evaluate the biochemical Rapid ESBL NP ® (Liofilchem, Italy) for the rapid detection of extended-spectrum β-lactamases (ESBLs) in Enterobacterales. Methods: A total of 100 clinical gram-negative strains (40 ESBL producers with or without cephalosporinase, 43 carbapenemase producers with or without additional ESBLs, 8 AmpC-type producers, 6 penicillinase producers, and 3 non-β-lactamase producers) were tested using this colorimetric technique. Results: The overall sensitivity and specificity of the test were found to be 93.9% and 98.5%, respectively. This test is rapid (turn-around-time of 40–45 minutes), easy to perform, and reliable for identification of ESBL producers. Conclusion: The Rapid ESBL NP test allows differentiation between ESBL producers on one hand, and non-ESBL producers or isolates expressing combined mechanisms of resistance on the other hand.