Fast and Accurate Large-Scale Detection of β-Lactamase Genes Conferring Antibiotic Resistance

Abstract

ABSTRACTFast detection of β-lactamase (bla) genes allows improved surveillance studies and infection control measures, which can minimize the spread of antibiotic resistance. Although several molecular diagnostic methods have been developed to detect limitedblagene types, these methods have significant limitations, such as their failure to detect almost all clinically availableblagenes. We developed a fast and accurate molecular method to overcome these limitations using 62 primer pairs, which were designed through elaborate optimization processes. To verify the ability of this large-scalebladetection method (large-scaleblaFinder), assays were performed on previously reported bacterial control isolates/strains. To confirm the applicability of thelarge-scaleblaFinder, the assays were performed on unreported clinical isolates. With perfect specificity and sensitivity in 189 control isolates/strains and 403 clinical isolates, thelarge-scaleblaFinder detected almost all clinically availableblagenes. Notably, thelarge-scaleblaFinder detected 24 additional unreportedblagenes in the isolates/strains that were previously studied, suggesting that previous methods detecting only limited types ofblagenes can miss unexpectedblagenes existing in pathogenic bacteria, and our method has the ability to detect almost allblagenes existing in a clinical isolate. The ability oflarge-scaleblaFinder to detectblagenes on a large scale enables prompt application to the detection of almost allblagenes present in bacterial pathogens. The widespread use of thelarge-scaleblaFinder in the future will provide an important aid for monitoring the emergence and dissemination ofblagenes and minimizing the spread of resistant bacteria.