The presence of methicillin-resistant Staphylococcus aureus (MRSA) strains in the food chain has been confirmed by several studies in the European Union, but there are only limited data available in Hungary. The objective of the present study was to investigate the antibiotic resistance of Staphylococcus strains isolated from foods, using classical microbiological, molecular biological methods and the MALDI-TOF-MS technique, as well as the multi-locus sequence typing (MLST) of antibiotic resistant strains. During the study, 47 coagulase-positive (CPS) and 30 coagulase-negative (CNS) Staphylococcus isolates were collected. In the course of the MALDI-TOF-MS investigations, all CPS isolates (n=47) were found to be S. aureus species, while 8 different species were identified in the case of the CNS strains. Methicillin resistance was confirmed in two S. aureus strains, one of which had a sequence type not yet known, while the other MRSA strain was type ST398, which is the most common type of MRSA strain isolated from farm animals in the EU/EEA. (The abbreviation “MRSA” is often used in common parlance, but occasionally in the literature to denote “multidrug-resistant Staphylococcus aureus”. In the authors’ manuscript - the methicillin-resistant pathogen is correctly designated as such. Ed.)
The presence of a single MALDI-TOF mass spectral peak predicts methicillin resistance in staphylococci