Rapid detection of the New Delhi metallo-b-lactamase 1 (NDM-1) gene by loop-mediated isothermal amplification (LAMP)

Abstract

Background: New Delhi Metallo-b-lactamase (NDM-1) is an enzyme emerging around the world conferring resistance to a wide range of β-lactams agents and whose early detection is extremely important. We proposed to standardize the detection of the blaNDM-1 gene using the LOOP-mediated isothermal amplification technique (LAMP). Methods: In all, 14 Gram-negative bacterial strains isolated from patients presenting pneumonia associated with mechanical ventilation were used for the blaNDM-1 standardization by LAMP. Klebsiella pneumoniae ATCC BAA-2473 and two clinical strains were used as a positive control. All results were compared to the reaction in polymerase chain reaction (PCR), considered gold standard for this detection. Results: There was an excellent correlation between the two techniques employed, since all measured clinical strains were negative in both employed tests and two clinical, and a reference strains were positive. Conclusions: The lamp technique seems to be an excellent option for the rapid detection of blaNDM-1. The amplification time is much shorter than other molecular techniques, the PCR machine is not necessary, it is easy of implementation and costs is low.