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

ABSTRACT

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.