Genotype And Epidemic Status Of Methicillin Resistant Staphylococcus Aureus In Hangzhou

Objcetives:Methicillin-resistant Staphylococcus aureus (Methicilin-resistant Staphylococcus aureus, MRSA) is a common and critical pathogen in clinic. It is widely spread in the world and causes outbreak of infection. Furthermore, strong resistance of MRSA leads to difficulty of clinical treatment. Therefore, Understanding the polymorphism of MRSA in hospitals may be helpful for selecting effective antibiotics to restrict the spread of MRSA.The purpose of this study is to define the distribution of genotypes of MRSA, discover the epidemiology and evolutionary pattern of MRSA and provide a scientific basis for prevention and. control of MRSA in this in Hangzhou.Methods:Based VITEK-Compact automated bacterial identification/susceptibility meter for177drug-sensitive Staphylococcus aureus results of the initial screening of MRSA, then specific gene PCR method MRSA (methicillin-resistant gene) mecA testing to confirmed MRSA. PCR was then performed on MRSA staphylococcal cassette chromosome mec gene, staphylococcal protein A gene, luk Virulence genes, and conduct multi-point sequence typing, and results were compared to prevalent genotypes of MRSA reported worldwide to analyze the evolutionary relationships.Results:1. MRSA confirmed:90strains of MRSA of cefoxitin, oxacillin were resistant, and Meca gene (MecA147, MecAP4-P7) after all positive, confirmed the90strains of MRSA.2. MRSA genotyping:successful classification of86strains, results are as follows: 2.1Staphylococcal protein A (spa) gene polymorphisms:86MRSA were found in13spa type to T311model-based,42; followed T6418type10.2.286strains of MRSA were found nine ST type, give priority to with ST5,51strains,followed by ST239,14strains; T59,10strains; ST1,3strains; ST88,4strains; ST630, ST573, ST965, ST19211strains.The eBURST software analysis they belong to four group (group1, group6, group8, group12) and eight kinds of cloning complex (CC1, CC5, CC630, CC20, CC59, CC88, CC239, CC573.)2.3SCCmec genotyping:MRSA isolated SCCmec Ⅱ type is given priority to,53strains (61.6%). Followed by SCCmec Ⅲ type,19(22%);7of SCCmecI;5of SCCmec IV (CA-MRSA),2have no types.86strains of mainly group1(71strains,82.6%), the first line of cloning for SCCmec-，-ST5-spa t311-CC5(41strains,47.7%), the second pop cloning for SCCmec、-ST239-spa t030/t037-CC239(11strains,12.8%).3. Panton-Valentine leucocidin.(PVL):90MRSA which has six, all SCCmec-、-S759-spa t6418-CC59clone; the positive rate of6.67%. Conclusion:Between2009and2012in sterile humoral specimens of staphylococcus aureus isolated from MRSA detection rate was50.9%, SCCmec-Ⅱ-ST5-t311was the most prevalent strain of MRSA in Hangzhou,The emergence of CA-MRSA strains suggested that MRSA has spread trends from hospitals to community in Hangzhou;In addition, the strains(SCCmec-Ⅰ-ST1921-t164-CC20and SCCmec-N-ST965-t062-CC5) which had developed a new variant strain should be pay more attention.