Antibiotic Resistance and Molecular typing of Staphylococcus aureus Isolated from Intensive Care Unit

Objective:To investigate the antibiotic resistance and the characteristic of the molecular epidemiology of Staphylococcus aureus.Methods:Disc diffusion method and Pulsed-field gel electrophoresis(PFGE)was used to analyze the resistance and the homology of 30 strains of Staphylococcus aureus,isolated from clinic specimen in intensive care unit(ICU)of our hospital during January to December,2004.Results:Thirty strains of Staphylococcus aureus were all susceptible to vancomycin and nitrofurantoin,and resistance to penicillin.To ampicillin/sulbactam,amoxicillin/clavulanic acid,clindamycin,erythromycin,ciprofloxacin,cefazolin,gentamicin,the resistance rates of methicillin-resistant Staphylococcus aureus(MRSA)were all 100%,and those of methicillin-susceptible Staphylococcus aureus(MSSA)were 50.0%,64.3%,57.2%,71.7%,50.0%,50.0%and 28.6%,respectively;To levofloxacin,tetracycline,rifampin,trimethoprim/sulfamethoxazole and flomosef,the resistance rates of MRSA were 93.8%,81.3%,50.0%,6.3% and 31.3%,respectively;those of MSSA strains were 57.2%,28.6%,7.2%,42.9%,21.4%,respectively.Thirteen different PFGE types(A~M)were found among 30 strains of Staphylococcus aureus and most of Staphylococcus aureus were type A(10 strains),type B(6 strains)and type C(3 strains).Conclusion:The resistance to antibiotics was a serious problem in Staphylococcus aureus isolated from the patients of our ICU.Results of PFGE showed that there was a prevalent trend of homologous Staphylococcus aureus in ICU,and the trend was relative with nosocomial infection.ICU should take a multidisciplinary approach for a decrease of nosocomial infection caused by Staphylococcus aureus,the achievement of therapy and the prevention of prevalence.