抗菌药物联用对耐甲氧西林金黄色葡萄球菌体外抗菌活性研究

In vitro antibacterial activity of combined antimicrobial agents against methicillin-resistant Staphylococcus aureus

目的了解万古霉素与头孢哌酮/舒巴坦、亚胺培南、左氧氟沙星联用对MRSA的体外抗菌活性,指导临床合理用药。方法常规方法培养分离细菌,用VITEK微生物自动分析仪或API系统鉴定到种。MRSA鉴定应用乳胶凝集试剂盒,药敏试验采用肉汤倍比稀释法和琼脂平板稀释法。结果万古霉素对40株MRSA的MIC90为4mg/L,而与头孢哌酮/舒巴坦、亚胺培南、左氧氟沙星联用MIC90降为0.25～1mg/L。结论万古霉素与上述三种药物联用以协同作用为主,抗菌活性提高4倍以上。临床上治疗由MRSA引起的重症感染应根据药敏试验结果采用万古霉素与亚胺培南或头孢哌酮/舒巴坦或其它抗菌药物联合应用。

Objective To investigate in vitro activity of vancomycin combined with cefoperazone/sulbactam, imipenem, levofloxacin against methicillin-resistant Staphylococcus aureus (MRSA) and propose the rational use of antibiotics. Methods MRSA were identified by VITEK and API identification system and ~latex agglutination method. Drug susceptibility test was performed by broth-double dilution method and agar dilution method. Results The MIC_~90 of vancomycin was 4mg/L to 40 strains of MRSA, while those of vancomycin combined with imipenem, cefoperazone/sulbactam, levofloxacin lowered by 0.25~1mg/L. Conclusion The main mechanism of combination of vancomycin and above 3 drugs were synergism, and antibacterial activity increased by more than four times. It suggested that vancomycin combined with cefoperazone/sulbactam or imipenem or other antimicrobial agents should be adopted for the treatment of severe infections with MRSA in clinic.