Analysis on drug-resistance of 128 strains of Staphylococcus aureus

Objective To investigate the resistance of Staphylococcus aureus to commonly used antimicrobial agents,so as to guide the rational antimicrobial application in clinic.Methods One hundred and twenty-eight strains of Staphylococcus aureus were performed antimicrobial susceptibility test with disc agar diffusion method;methicillin-resistant Staphylococcus aureus(MRSA) were screened with oxacillin and cefoxitin disc agar diffusion methods;D-test was performed with clindamycin and erythromycin disc.Results Sixty-seven(52.34%) strains of MRSA were detected,MRSA had high resistant rate to β-lactamase antibiotics,the resistant rate to penicillin,oxacillin and ampicillin were all up to 100%;MRSA and methicillin-sensitive Staphylococcus aureus(MSSA) had different resistant levels to aminoglycosides;rifampicin had high resistance against Staphylococcus aureus,the sensitive rate of MRSA and MSSA to rifampicin was 85.07% and 96.72% respectively;MRSA had high resistance to ofloxacin,which was 70.15%;the sensitive rates of MRSA and MSSA to vancomycin were all 100%.The detection rate of MRSA with cefoxitin was 53.03%,which was higher than detection rate(42.42%) of MRSA with oxacillin(χ2=4.00,P0.05).The positive rate of D-test was 53.85%.Conclusion Staphylococcus aureus isolated from clinic has multiple resistance to commonly used antimicrobial resistance,different treatment protocols should be chosen according to the drug-resistant characteristics of isolated strains;cefoxitin disc diffusion method is superior to oxacillin.