Abstract
There is a growing demand for rapid and simple molecular point-of-care (POC) diagnostics for use in clinical environments. While more sophisticated molecular diagnostic technologies are well established within dedicated diagnostic laboratories staffed by trained scientists, their utilisation outside of the laboratory environment by non-specialist operators is limited and impractical, particularly in remote locations or in developing countries. One contemporary molecular diagnostic methodology of interest is loop-mediated isothermal DNA amplification (LAMP) which offers fast, convenient, and specific target identification, and is amenable to POC applications. Previous research has identified common human pathogens, such as S. aureus, MRSA, and group A Streptococcus (GAS), using LAMP DNA amplification by targeting highly conserved genes specific to each pathogen. However, these assays have not yet fully been applied to POC settings. In this study, LAMP assays for the detection of the common human pathogens S. aureus, MRSA, and GAS were optimised and then tested in healthy adults. Primer sets for the detection of S. aureus, MRSA and GAS targeted nuc, nuc + mecA, and spy1258, respectively. It was determined that specimens could be inoculated directly into LAMP mastermix, without the need for prior DNA extraction. The performance of the LAMP assays were compared to bacterial culture for the detection of colonisation with S. aureus, MRSA and GAS in 100 healthy volunteers. The efficiency of the LAMP assay compared to culture for the identification of S. aureus and MRSA was 99% and 96%, respectively; the efficiency of the GAS LAMP assay could not be determined due to no positive samples by either the LAMP assay or bacterial culture. Given the simplicity of the optimised LAMP assays, development of simple instrument for POC use should be considered.