Detection of Methicillin-Resistant Staphylococcus aureus (MRSA) Using Loop Mediated Isothermal Amplification (LAMP)

Abstract

Staphylococcus aureus is one of the most common pathogens that cause a wide range of infections ranging from skin and soft tissue infections to invasive, life threatening infections. The emergence of methicillin-resistant Staphylococcus aureus (MRSA) substantially increased healthcare burdens associated with Staphylococcal infections because of high morbidity and mortality and increasing the need for efficient and cost-effective screening methods, for high-risk patients. The objective of this study is to develop two molecular methods, real-time PCR and loop-mediated isothermal amplification (LAMP), and validate them following Clinical Laboratory Improvement Amendments (CLIA) and College of American Pathologists (CAP) standards. The real time PCR assay was developed targeting mecA, mecC, nuc, and coa to detect S. aureus and methicillin-resistance. The assay had high precision, a linear range of 104-108 CFU/ml, and 95% accuracy. The assay detects MRSA, MSSA, MR-CoNS, and MS CoNS. The LAMP assay was developed targeting the same genes; however, its lower limit of detection was 106 CFU/ml, which was much higher than that of the real-time PCR assay. Additional studies are required to optimize the performance characteristics of the LAMP assay further. Nevertheless, the real-time PCR assay developed in this study will be useful for the detection of MRSA in a cost-effective manner.