RESUMO
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.