The efficiency of MALDI-TOF MS method in detecting Staphylococcus aureus isolated from raw milk and artisanal dairy foods

Abstract

The present study aims to characterize twenty-seven Staphylococcus aureus isolates among a total of forty-four Staphylococci recovered from raw milk and traditional artisanal dairy foods (n = 285) in Central Anatolia and the Mediterranean Regions of Turkey, using MALDI-TOF MS-based phyloproteomic principal component analysis (PCA). The data shown by the spectra were analyzed, followed by composite correlation index (CCI), virtual gel, and cluster analysis for validation. The correlation between standard strain S. aureus 25,923 THL (SA-18) and all strains was significant since protein peak of m/z 5305 ± 2 Da was common in all strains, including SA-18. Twenty-six (9.12%) and fifteen (5.26%) out of all samples were found as contaminated by Staphylococci and S. aureus, respectively. The findings suggest that MALDI-TOF MS-based PCA is a promising fast method to categorize S. aureus in dairy foods, in need of continuous monitoring of foodborne pathogens for public health.

Keywords

• staphylococcus aureus
• raw milk
• matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (maldi-tof ms)
• phyloproteomic principal component analysis (pca)
• artisanal dairy foods