Abstract
Reliable and rapid identification of Staphylococcus aureus constitutes a critical issue in food safety. A total of 180 meat samples were analysed, and 30 isolates that phenotypically matched S. aureus were obtained. All 30 isolates generated positive results in agglutination with the SlidexStaph test. The results of agglutination were verified with the matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) method, S. aureus-specific PCR and sequencing of the 16 S rRNA genes. Among 30 isolates positive in the SlidexStaph test, 17 were finally identified as S. aureus, eight as Macrococcus caseolyticus, four as Mammaliicoccus fleurettii (previously Staphylococcus fleurettii), and one single isolate as Staphylococcus pseudintermedius. In this study, we have demonstrated for the first time false-positive results of the rapid identification based on S. aureus-specific agglutination obtained for M. fleurettii. Antimicrobial resistance testing revealed a considerable prevalence of multidrug resistance among M. caseolyticus (100%) and M. fleurettii (50%). This study highlights the possibility of obtaining false-positive results in agglutination tests with M. caseolyticus and M. fleurettii. Furthermore, the presence of multidrug-resistant M. caseolyticus and M. fleurettii in meat samples may contribute to the spread of microbial drug resistance and requires further investigation.