Rapid visualization and detection of Staphylococcus aureus based on loop-mediated isothermal amplification

In this study, we developed a closed-tube loop-mediated isothermal amplification (LAMP) assay for the visual detection ofS. aureus using the colorimetric indicator hydroxy naphthol blue (HNB). The LAMP reaction was optimized by adjusting the amplification temperature, the concentrations of Mg2+, dNTP, and HNB, and the incubation time. In the optimized reaction system, the specificity of LAMP forS. aureus was 100%. The results established that this method accurately identifiedS. aureus, with no cross-reactivity with 14 non-S. aureus strains. The limit of detection (LOD) of LAMP was 8 copies/reaction of purified plasmid DNA or 400 colony-forming units/reaction ofS. aureus. Compared with conventional PCR, LAMP lowered the LOD by tenfold. Finally, 220 clinically isolated strains ofS. aureus and 149 non-S. aureus strains were used to evaluate the diagnostic efficacy of LAMP (test accuracy, 99.46%). The findings indicated that LAMP is a reliable test forS. aureus and could be a promising tool for the rapid diagnosis ofS. aureus infections.
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research