Rapid Detection of Genes Encoding Extended-Spectrum Beta-Lactamase and Carbapenemase in Clinical Escherichia coli Isolates with eazyplex SuperBug CRE System.

Objectives

This study evaluated the diagnostic performance of the eazyplex® SuperBug CRE (eSBCRE) system, based on a loop-mediated isothermal amplification (LAMP), for the detection of the most common extended-spectrum beta-lactamases (ESBL) and carbapenemase genes in 140 clinical isolates of Escherichia coli. Materials and

Methods

ESBL (blaCTX-M-1group and blaCTX-M-9group) and carbapenemase (blaKPC, blaVIM, blaNDM, blaOXA-48, and blaOXA-181) genes were detected using the eSBCRE test and compared with the results obtained by PCR, real-time PCR, and phenotypic methods.

Results

Concordant results of 100% between PCR/real-time PCR and eSBCRE assays were observed. Two of 140 E. coli isolates were positive for both ESBL and carbapenemase genes according to eSBCRE, PCR, and real-time PCR assays, whereas they were negative in double-disk synergy test. Of 16 E. coli isolates suspected of producing carbapenemase, 9 were positive for 48-oxacillinases (OXA-48) by 30 μg temocillin test, whereas the blaOXA-48 was found only in 1 E. coli isolate by all molecular methods. Maximum threshold time values (minutes:seconds) in the eSBCRE test were 6:00, 11:15, 11:00, and 9:00 for the blaCTX-M-1group, blaCTX-M-9group, blaVIM, and blaOXA-48 genes, respectively.

Conclusions

The eSBCRE test based on LAMP method is a reliable, easy-to-use, and timesaving molecular system, which can be successfully used in the routine diagnostic for the rapid detection of the most common ESBL and carbapenemase genes among clinical E. coli isolates.