Genotype and epidemic status of Methicillin resistant Staphylococcus aureus in Hangzhou area

Abstract:

[Objective] To analyze the genotype of Methicillin-resistant Staphylococcus aureus (MRSA), discover the epidemiology and evolutionary pattern of MRSA and provide a scientific basis for prevention and control of MRSA in Hangzhou area. [Methods] In total 86 MRSA strains were characterized by spa typing, multi-locus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing. Results were compared with prevalent genotypes of MRSA reported worldwide to analyze the evolutionary relationships. [Results] The 86 MRSA isolates were classified into 13 spa types and 9 STs, which were further categorized into 4 groups and 8 clonal complex. The SCCmecⅡwas the predominant genotype (61.6%), followed by SCCmec-III (22%), 5 strains of CA-MRSA (SCCmecⅣ). SCCmec-II-ST5-t311-CC5 and SCCmec-III-ST239-t030/t037-CC239 were the main clones, representing for 47.7% and 12.8%, respectively. [Conclusion] SCCmec-Ⅱ-ST5-t311 was the most prevalent strain of MRSA in Hangzhou area. The emergence of CA-MRSA strains suggested that MRSA has spread from hospitals to community in Hangzhou. In addition, the strains (SCCmec-Ⅰ-ST1921-t164-CC20 and SCCmec-Ⅳ-ST965- t062-CC5) developed a new variant strain that needs more attention.

Key words:MRSA, SCCmec, MLST, spa