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 β-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.