ABSTRACT
Objective To investigate infection status and antimicrobial resistance mechanism of methicillin-resistant Staphylococcusaureus(MRSA),and provide reference for the rational antimicrobial use in clinic. Methods Staphylococcusaureus (SA)isolated from various specimens in Xuzhou area in 2012-2015 were collected,MR-SA strains were preliminarily screened by cefoxitin disk diffusion method,and confirmed by amplification of mecA gene,antimicrobial resistance of MRSA was determined by Kirby-Bauer method,minimal inhibitory concentration (MIC)was measured by E-test method,genotypes of staphylococcal chromosomal cassette mec(SCCmec)were de-termined by multiplex PCR. Results A total of 116 strains of MRSA were identified among 210 SA strains in 2012-2015,114 of which were positive for mecA gene,the total detection rate of MRSA was 55.24% . Susceptibility rates of MRSA to vancomycin,quinupristin/dalfopristin,and linezolid were all 100% ,resistance rates of MRSA to chloramphenicol and furantoin were both low,which were 15.52% and 1.72% respectively,resistance rates of MR-SA to 10 kinds of antimicrobial agents were all>80% ;resistance rates of MRSA to penicillins,aminoglycosides, macrolides,quinolones,sulfanilamide,rifampicin,tetracycline,and clindamycin were all higher than methicillin-sensitive Staphylococcusaureus(MSSA). MICs of vancomycin to MRSA in 2012-2015 were all 1.0μg/mL,MIC90 were all 1.5μg/mL,one MRSA isolate was with a vancomycin MIC of 2.0μg/mL in 2015. MRSA typing results of 116 MRSA isolates showed that SCCmec II,SCCmec III,and SCCmec IV accounted for 9.48% (n= 11),73.28% (n= 85),and 1.72% (Iva,n= 2;IVb,n= 2)respectively,13.79% (n= 16)of MRSA isolates were nontypeable, SCCmec I and SCCmec V type strains were not found. Conclusion MRSA is seriously multidrug-resistant,the drift has not been discovered in MIC value of vancomycin against MRSA,the major SCCmec genotype of MRSA is SCCmec III,infection control measures should be taken to control MRSA infection.