Emergence and Characterization of Foodborne Methicillin-Resistant Staphylococcus aureus in Korea

• Published in: Journal of food protection 2010-12, Vol.73 (12), p.2285-2290
• Main Authors: CHAE HONG RHEE, WOO, Gun-Jo
• Format: Article
• Language: English
• Subjects: Annealing; Anti-Bacterial Agents - pharmacology; Antibiotics; Antimicrobial agents; Biological and medical sciences; Colony Count, Microbial; Consumer Product Safety; DNA, Bacterial - analysis; Drug resistance; Electrophoresis; Enterotoxins - genetics; Fish Products - microbiology; Food contamination & poisoning; Food Contamination - analysis; Food industries; Food Microbiology; Food safety; Fundamental and applied biological sciences. Psychology; Genes; Genotype; Humans; Korea; Laboratories; Meat Products - microbiology; Methicillin-Resistant Staphylococcus aureus - genetics; Methicillin-Resistant Staphylococcus aureus - pathogenicity; Microbial Sensitivity Tests; Molecular Epidemiology; Pathogens; Penicillin; Prevalence; Staphylococcal Food Poisoning - epidemiology; Staphylococcal Food Poisoning - microbiology; Staphylococcus infections; Toxins; Virulence
• ISSN: 0362-028X; 1944-9097
• DOI: 10.4315/0362-028X-73.12.2285

A total of 165 Staphylococcus aureus strains, isolated from different food samples between 2003 and 2006, were tested for antimicrobial susceptibility. The mecA-positive methicillin-resistant S. aureus (MRSA) strains were further characterized by testing for various virulence genes and by molecular typing with multilocus sequence typing and pulsed-field gel electrophoresis. Of the 165 S. aureus isolates, 150 strains (90.9%) were resistant to at least one antibiotic while no strain was resistant to vancomycin. Four strains were resistant to both oxacillin and cefoxitin and were mecA positive. The mecA-positive MRSA strains were isolated from raw meat and fish samples (two beef samples and two fish samples) and were resistant to β-lactam antibiotics. Based on multilocus sequence typing analysis, the isolates were assigned to sequence type 1 (ST1), ST72, and an undetermined ST (ST72 slv). All four MRSA isolates were shown to be enterotoxigenic. The ST1 MRSA isolate harbored the sea-seh gene combination and the ST72 and ST72 slv MRSA strains harbored the seg-sei and the sea-seg-sei gene combinations, respectively. However, none of the MRSA isolates had the genes for Panton-Valentine leukocidin, toxic shock syndrome toxin 1, and exfoliative toxins. The pulsed-field gel electrophoresis patterns of the ST72 isolates in our study were highly similar, even though they were isolated from food samples in different years and from different regions of Korea.