Evaluation of a DNA microarray (Check-MDR CT102) for rapid detection of TEM, SHV, and CTX-M extended-spectrum β-lactamases and of KPC, OXA-48, VIM, IMP, and NDM-1 carbapenemases

Abstract

The Check-MDR CT102 microarray, aimed at identifying bacteria producing extended-spectrum β-lactamase (ESBL) (SHV, TEM, and CTX-M) and carbapenemase (KPC, OXA-48, VIM, IMP, and NDM-1), was evaluated on a total of 144 Gram-negative strains expressing various β-lactamases. The sensitivity and specificity were 100% for most tested genes, suggesting that this assay allows accurate identification of common ESBL and carbapenemase producers from bacterial cultures.

Fig. 1.

Typical DNA microarray pictures obtained with the Check-MDR CT102 microarray setup. This format uses a DNA microarray fixed at the bottom of a microreaction vial. The microarray consists of unique complementary (cZIP) oligonucleotides targeting individual probes. When hybridization of the PCR-amplified ligation products to the microarray is complete, colorimetric detection of the positive reactions is initiated. Panels in the array are outlined. Each panel defines the typing results of one strain and consists of control spots and specific marker spots, which are numbered from 1 to 96. (A) Theoretical display of the array probes for strain 1 (panel I), strain 2 (panel II), and strain 3 (panel III). (B) Array results for K. pneumoniae HPA-1 ([9]; (OXA-48, SHV-1, TEM-1, CTX-M-15; panel I), K. pneumoniae Afr 2 ([22]; NDM-1, SHV-1, TEM-1, CTX-M-15, CMY-2; panel II), and K. pneumoniae 16 ([10]; KPC-2, SHV-1 CTX-M-15; panel III). HybC, hybridization control; CTR, control; negC, negative control; DNAC, DNA control.