[PFGE profiles and antimicrobial susceptibilities of Staphylococcus aureus in quick-frozen prepared foods].

OBJECTIVE

To analyze the contamination situation, resistance characteristics and PFGE profiles of Staphylococcus aureus from quick-frozen prepared foods in Beijing.

METHODS

Staphylococcus aureus were separated according to GB4789. 10-2010, the identification and drug susceptibility was tested by the phoenixTM-100 automated microbiology system, and PFGE method was used for molecular classification.

RESULTS

A total of 92 samples were examined and 31 of which( 33. 70%)were positive for Staphylococcus aureus. All strains were divided into 23 kinds of PFGE type, PFGE patterns were obviously spread. 31 strains were antibiotic resistant, the positive β-lactams and MRSA were 70. 97%( 22/31) and 12. 90%( 4/31), respectively, and all 4 MRSA isolates carried the mec A gene. Moreover, one strain was erythromy cininduced by clindamycin resistant bacteria strain( STAMLS). Those isolates showed different antibiotic resistance resistant phenotype and multidrug resistantce. Antibiotics resistant phenotype has no apparent consistence with PFGE patterns.

CONCLUSION

The contamination and serious antimicrobial resistance phenomenon of the Staphylococcus aureus isolates in quick-frozen prepared foods in Beijing was severe.