RESUMO
Objective To analyze the inhibition effect of antimicrobial peptide human βdefensin 3 (hBD3 )against methicillin resistant Staphylococcus aureus (MRSA)N31 5.Methods Antimicrobial peptide hBD3 was synthesized.The direct inhibition on N31 5 was detected by the MIC (minimal inhibitory concentration,MIC)test,antibacterial activity test and the analysis on some important functional genes.The peptide was combined with penicillin,tetracycline,cephradine, rifampin,vancomycin,cefuroxime and chloramphenicol to evaluate the effects on antibiotic MIC values.Results The MIC of hBD3 against N31 5 was 8 μg/mL and the bactericidal activity was observed while the hBD3 concentration reached 2 μg/mL.The peptide hBD3 could improve the expression of agr and reduce the expression of icaA.With 5 μg/mL peptide hBD3,the MIC values against N31 5 of penicillin,cephradine,vancomycin,cefuroxime and chloramphenicol were dropped down.Conclusion There is considerable bactericidal activity of antimicrobial peptide hBD3 against MRSA N31 5. Antibiotic peptide hBD3 could be used to prevent the spread of antibiotic resistant bacteria in the future.