Differentiation of Community-Associated and Livestock-Associated Methicillin-Resistant Staphylococcus aureus Isolates and Identification of <i>spa</i> Types by Use of PCR and High-Resolution Melt Curve Analysis

Abstract

Infections due to methicillin-resistant <i>Staphylococcus aureus</i> (MRSA) are present worldwide and represent a major public health concern. The capability of PCR followed by high-resolution melt (HRM) curve analysis for the detection of community-associated and livestock-associated MRSA strains and the identification of staphylococcal protein A (<i>spa</i>) locus was evaluated in 74 MRSA samples which were isolated from the environment, humans, and pigs on a single piggery. PCR-HRM curve analysis identified four <i>spa</i> types among MRSA samples and differentiated MRSA strains accordingly. A nonsubjective differentiation model was developed according to genetic confidence percentage values produced by tested samples, which did not require visual interpretation of HRM curve results. The test was carried out at different settings, and result data were reanalyzed and confirmed with DNA sequencing. PCR-HRM curve analysis proved to be a robust and reliable test for <i>spa</i> typing and can be used as a tool in epidemiological studies.