spa typing and resistance profile of Staphylococcus aureus isolated from clinical specimens / 中国感染与化疗杂志

Objective To study the resistance and molecular profiles of Staphylococcus aureus strains isolated from the clinical specimens.Methods Antimicrobial susceptibility was tested with 56 strains of Staphylococcus aureus isolated from a hospital from May to November 2011.The mecA and pvl genes were detected.The spa genetic types were analyzed.Results A total of 21 (37.5%)Staphylococcus aureus strains were resistant to methicillin (MRSA)and 35 (62.5%)were sensitive to methicillin (MSSA).Nineteen of the 21 (90.5%)MRSA strains carried mecA gene.Compared with MSSA,MRSA were much less sen-sitive to rifampin,fluoroqunolones,tetracycline and gentamicin (P <0.05).All the MRSA isolates were susceptible to vanco-mycin,linezolid,tigecycline,quinupristin-dalfopristin and nitrofurantoin.Six spa types were identified among the MRSA strains.Type t030 was the most prevalent,accounting for 66.7% (14/21)of all the MRSA strains.MRSA-t030 and MRSA-t002 were resistant to multiple antibiotics.Eighteen spa types were identified among the MSSA strains.Type t189,t377 and t034 were the top three spa types of MSSA,accounting for 14.3%,14.3% and 11.4%,respectively.A new MSSA spa typ-ing strain new1 was isolated from pus.There were five Panton-Valentine leukocidin (PVL)-positive isolates,3 of which was MSSA-t189 type. Conclusions Type t030 is the most prevalent spa type among clinical MRSA strains,which is resistant to many kinds of antibiotics and widely spreads in the hospital setting.There are many different spa types a-mong the MSSA strains.Type t389,t377 and t034 are the top three spa types of MSSA.

Role of preconditioning to oxidative stress in HepG2 cells / 中国病理生理杂志

AIM: To induce preconditioning and oxidative stress by H_2O_2 in HepG2 cells. METHODS: The different doses of H_2O_2 were used to induce apoptosis in HepG2 cells, which was estimated by AO/EB staining, MTT assay and flow cytometry. RESULTS: The different group of HepG2 cells stained with AO/EB showed different staining state. The high dose of H_2O_2 resulted in the increase in apoptosis rate of HepG2 cells and made MTT activity decreased. However, after pretreated with low dose of H_2O_2, the apoptosis rate was decreased and MTT activity was increased. CONCLUSION: The high dose H_2O_2 induced apoptosis in HepG2 cells and the low dose H_2O_2 protected HepG2 cells against the oxidative stress.