Comparison on In-vitro Induction of Resistance in Methicillin-resistance Staphylococcus Aureus to Vancomycin,Teicoplanin and Linezolid

[Objective]The paper aims to explore the difference of vancomycin,teicoplanin and linezolid in the inducing resistance of MRSA by measuring MIC before and after drug inducing.[Methods]The MIC of Nine MRSA to vancomycin,teicoplanin and linezolid are identified by two-fold agar dilution method,and then two MRSA which are sensitive to the three drugs are found out.The two MRSA are induced separately by vancomycin,teicoplanin and linezolid for 25 generations.At last,the MIC of MRSA which have been induced to vancomycin,teicoplanin and linezolid are identified.The data is analyzed by SPSS 19.0.[Results]After vancomycin,teicoplanin and linezolid inducing MRSA for 25 generations respectively,the MIC of vancomycin and linezolid increased 2 times and teicoplanin increased 2.67 times compared with those before drug induction.However,there was no difference of the change of MIC among the 3 groups.Additionally,no resistant strains were generated.The MIC of 3 drugs to MRSA strains in control groups in drug-free plates did not change after passage.[Conclusions]The comparison of the three drugs at inducing resistance have no significant difference.