Detection and molecular characterization of methicillin-resistant Staphylococcus aureus isolated from raw meat at the retail market

J Glob Antimicrob Resist. 2021 Jul 13:S2213-7165(21)00168-5. doi: 10.1016/j.jgar.2021.06.012. Online ahead of print.


OBJECTIVE: This study aimed to detect and characterize methicillin-resistant Staphylococcus aureus (MRSA) from meat retailed in the Czech Republic.

METHODS: Isolates were identified using PCR detection of the Staphylococcus aureus-specific fragment SA442 and mecA gene. Spa typing, MLST, detection of genes encoding enterotoxins (SEs), Panton-Valentine leukocidin (pvl), exfoliative toxins A, B (eta, etb), toxic shock syndrome toxin (tst), staphylokinase (sak), φSa3 prophage and antimicrobial susceptibility testing were performed.

RESULT: Out of 65 raw meat samples examined (poultry, beef, pork and rabbit), 23 (35.4%) were MRSA positive. Twelve positive samples originated from poultry (12/33, 36.4%), while the remaining eleven came from pork (9/9, 100%) and mix of pork and beef minced meat (2/5, 40%). Eight spa types belonging to five different sequence types (STs) were identified. ST398 was the most frequent one (28/36, 77.8%), presenting spa types t011, t034, t2576, t4132, t588 and t899. Other LA-MRSA STs (ST9/t899, ST5/t002, ST692/t8646 or the newly described ST4034/t899) were also sporadically identified. In seven isolates (19.4%), one or more SEs genes were detected, sea, seg, sei prevailed. Three isolates from turkey (ST398/t899 (n=2), ST398/t011) harboured the sak gene, the latter harboured also the sea gene. Seven isolates from poultry harboured the φSa3 prophage as well as tetracycline resistance.

CONCLUSION: Specific kinds of meat appear to be a possible source of MRSA, though the risk for humans is hard to define. Therefore, surveillance of MRSA in meat and hygienic practices should be improved.

PMID:34271219 | DOI:10.1016/j.jgar.2021.06.012