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Objective To investigate the prevalence, accessory gene regulator (agr) and staphylococcal cassette chromosome mec (SCCmec, only for methicillin resistantS. aureus, MRSA) types of theS. aureus strains carrying toxic shock syndrome toxin-1 (tst) and/or panton-valentine leukocidin (pvl) genes.Methods Nine hundred and sixteen isolates ofS. aureus were collected from seven hospitals in Shanghai and Zhejiang Province and subjected to detection oftst,pvl,mecA andmecC genes by polymerase chain reaction (PCR). Theagr and SCCmec (only for MRSA) types were determined in thetst orpvl gene positive isolates.Results Of the 916 isolates, 208 carriedtst gene (22.7%), 35 harboredpvl gene (3.8%), and 665 weremecA positive (MRSA). No isolate was mecC positive. Out of the 665 MRSA isolates, 198 hosted thetst gene (29.8%). The most commonagr and SCCmec types were agr 2 (97.0%) and SCCmec II (94.4%), respectively. For thepvl gene, only 14 isolates were positive (2.1%). Theagr 1 (85.7%), SCCmecIII (42.9%) and SCCmec IVa (28.6%) were the most commonagr type and SCCmec type. In the 251 methicillin-sensitiveS. aureus (MSSA) isolates, 10 carriedtst gene (4.0%) and 21 carriedpvl gene (8.4%). The prevalence oftst gene in MRSA was higher than that in MSSA, while the prevalence ofpvlgene was just the opposite. However, the prevalence ofpvlgene in MRSA isolates from Zhejiang Province was higher than that in the MRSA isolates from Shanghai (P severeS. aureus infections.
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Objective To detect the mecA gene and tst gene of toxic shock syndrome toxin 1 (TSST-1)of Staphylococcus aureus by using PCR and to learn the carrier condition of tst gene.Methods The mecA gene and tst gene of Staphylococcus aureus strains that isolated from clinical sources in our hospital during August 2006 to May 2007 were amplified in vitro using PCR,and to establish the rapid,specific,and sensitive method of detecting tst gene of methicillin resistant Staphylococcus aureus(MRSA).Results The mecA gene and tst gene were detected,and were made the gene sequencing successfully.Forty-one of 84 strains had mecA gene(48.81%),16 of 84 strains had tst gene(19.05%),10 of 84 strains had both of them,and the positive rate was 24.39%(10/41).Conclusion The proportion of tst gene positive strains of MRSA iS high in clinic,and it must be paid more attention.