AUTHOR=Vestergaard Martin , Cavaco Lina , Sirichote Pantip , Unahalekhakac Aekkawat , Dangsakul Worawat , Svendsen Christina A., Aarestrup Frank M., Hendriksen Rene 

TITLE=SCCmec Type IX Element in Methicillin Resistant Staphylococcusaureusspa Type t337 (CC9) Isolated from Pigs and Pork in Thailand

JOURNAL=Frontiers in Microbiology

VOLUME=3

YEAR=2012

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2012.00103

DOI=10.3389/fmicb.2012.00103

ISSN=1664-302X

ABSTRACT=<p>Methicillin resistant <italic>Staphylococcus</italic><italic>aureus</italic> (MRSA) have emerged among livestock in several countries. In this study, we describe the results of a screening performed in pigs and raw pork samples in Thailand. Ten pork samples and 15 nasal swabs from pigs were collected from 2 markets and 1 pig farm in the Samuth Songkhram province in Thailand. MRSA were isolated using selective isolation procedures and confirmed by <italic>mecA</italic> PCR. The MRSA were characterized by antimicrobial susceptibility testing, pulsed field gel electrophoresis (PFGE), <italic>spa</italic> typing, SCC<italic>mec</italic> typing, and MLST. Resistance and virulence markers were screened using a microarray. Five of the pork samples and six pig nasal swabs were positive for MRSA. All 11 isolates belonged to <italic>spa</italic> type t337 but showed diversity in antimicrobial resistance patterns and PFGE profiles. Additionally, the isolates were sequence-typed; ST9, ST2136, ST2278 belonging to the clonal complex; CC9. All isolates harbored SCC<italic>mec</italic> IX and were resistant to 7 out of 14 tested antimicrobials; additional resistances to all antimicrobials tested were found in some of the pork and pig isolates and 1 pork isolate was resistant to 13 antimicrobials tested. Microarray analysis identified <italic>blaZ</italic>, <italic>aac-aphD</italic>, <italic>vga</italic>(A), <italic>tetM</italic>, and a <italic>tet</italic> efflux marker, in all strains and additionally <italic>ermB</italic> and <italic>aadD</italic>, <italic>cat</italic> and <italic>fex</italic>(A) in the pork isolates. None of the isolates were found PVL-positive, but enterotoxins were identified in all isolates. To our knowledge, only a few descriptions of MRSA in livestock and food products in Thailand have been observed but this is the first observation of MRSA CC9 associated with SCC<italic>mec</italic> IX in pork. This study indicates a likely widespread distribution of MRSA in pig and pork in Thailand and further investigation on the prevalence and importance of livestock associated MRSA in Thailand is needed.</p>