Rapid Identification of Methicillin-Resistant Staphylococcus aureus (MRSA) by the Vitek MS Saramis system

Abstract

A rapid, sensitive, and accurate Vitek MS assay was developed to distinguish clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) from clinical isolates of methicillin-sensitive Staphylococcus aureus (MSSA) by developing an in-house knowledgebase of SuperSpectra. Three unique peaks, including peaks at 2305.6 and 3007.3 Da specific to MRSA, and 6816.7 Da specific to MSSA, were selected for differentiating MRSA and MSSA. This assay accurately identified 84 and 91% of clinical MRSA and MSSA strains out of the total 142 clinically acquired S. aureus strains that were tested. This method will greatly improve the efficiency of single clinical sample identification of MRSA, thereby facilitating a reduction in the transmission of MRSA in clinical settings.

Characterization of Methicillin Resistance Staphylococcus aureus isolated from chicken and human

“…Susceptibility testing results for all 275 S. aureus isolates were consistent with cefoxitin screening and mecA gene PCR. (Shan et al, 2016). Further S. aureus is Gram positive producing smooth, circular colonies, convex and clustrous; size of the colony may be 0.5-1.5 μm in diameter.…”

Application and Perspectives of MALDI–TOF Mass Spectrometry in Clinical Microbiology Laboratories

“…Moreover, the Vitek MS v3.0 platform offers grouping of spectral data or hierarchical taxonomic analysis [ 10 ], permitting the identification of taxonomic changes in a population of microorganisms. For example, it allows for the successful differentiation between MRSA and MSSA through two MRSA marker peaks of (2305.6 and 3007.3 Da) and a single MSSA marker peak of (6816.7 Da) [ 64 ], or the discrimination between Escherichia coli ST131, with a sensitivity of 86.6% and a specificity of 95.1% [ 65 ].…”