Abstract:Objective To investigate the staphylococcal chromosome cassette mec (SCCmec) typing and drug susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) clinically isolated in Hefei, so as to understand the drug resistance phenotypic and genotypic characteristics of MRSA epidemic strains in this region. Methods Totally 264 non-replicated MRSA strains were randomly selected from 5 teaching hospitals from Jan. 2016 to Dec. 2021. MRSA was screened by cefoxitin disk diffusion method, mecA gene was amplified by polymerase chain reaction (PCR), and SCCmec typing of MRSA was performed by multiplex PCR. Software WHONET 5.6 was used to analyze the antimicrobial susceptibility of MRSA strains of different SCCmec types. Results Among the 264 MRSA strains, 156 strains (59.1%) were SCCmec type Ⅱ, 92 strains (34.8%) were type Ⅳa, 4 strains (1.5%) were type Ⅲ, and 12 strains (4.5%) were untyped. The sensitivities of SCCmec type Ⅱ and type Ⅳa MRSA to daptomycin, tigecycline, linezolid and vancomycin were all 100.0%. The resistance of SCCmec type Ⅱ MRSA to ciprofloxacin, levofloxacin, moxifloxacin and gentamicin was significantly higher than that of SCCmec type Ⅳa MRSA (all P<0.05). There was no significant difference in the resistance of different types of MRSA strains to erythromycin, clindamycin, tetracycline, sulfamethoxazole, or rifampicin (all P>0.05). Conclusion The SCCmec typing of MRSA strains in Hefei is dominated by types Ⅱ and Ⅳa. There is some variation in the resistance of MRSA to certain antimicrobial drugs by genotype, and dynamic monitoring of the typing and drug susceptibility of this group of bacteria is of clinical interest.