Evaluation of the AID ESBL line probe assay for rapid detection of extended-spectrum β-lactamase (ESBL) and KPC carbapenemase genes in Enterobacteriaceae

Objectives: This study aimed at evaluating the AID ESBL line probe assay for the detection of extended-spectrum beta-lactamase (ESBL) and KPC carbapenemase genes in Enterobacteriaceae. Methods: The AID ESBL line probe assay was verified for accuracy of its probes using PCR products from clinical ESBL Enterobacteriaceae strains harbouring TEM, SHV and CTX-M ESBL genes and KPC genes and mutant fusion PCR products generated from Enterobacteriaceae strains containing wild-type (wt) TEM and wt SHV. Sensitivity and specificity was determined testing a set of 424 clinical Enterobacteriaceae strains (including 170 strains negative for TEM, SHV, CTX-M and KPC to evaluate the possibility of false positive signals). Results: The line probe assay was shown to detect with 100% accuracy ESBL genes for which oligonucleotide probes are present in the assay. Testing a set of 424 clinical Enterobacteriaceae strains showed 100% sensitivity and specificity for the detection and differentiation of TEM, SHV and CTX-M ESBL genes present in that group. In addition, the line probe assay detected KPC genes accurately. Conclusions: The AID ESBL line probe assay is an accurate and easy-to-use test for the detection of ESBL and KPC genes, which can readily be implemented in the diagnostic laboratory.