磷霉素与9种抗菌药物分别联用对不动杆菌的体外抗菌活性研究

In vitro antibacterial activity of fosfomycin combined with nine antimicrobial agents against acinetobacter

[目的]研究磷霉素与其它9种临床常用抗菌药物分别联合应用对47株不动杆菌的体外抗菌活性。[方法]收集痰标本中分离出的不动杆菌47株,将磷霉素与其它9种抗菌药物在体外单独以及联合应用,采用琼脂二倍稀释法,测定最低抑菌浓度(M IC)、计算部分抑菌浓度(FIC)指数,评价磷霉素与其它9种抗菌药物分别联合应用的体外抗菌活性。[结果]磷霉素、左氧氟沙星、环丙沙星、头孢呋辛、头孢他啶、头孢吡肟、头孢哌酮/舒巴坦、阿米卡星单独应用时对47株不动杆菌的M IC50值均显示耐药,磷霉素分别与这9种抗菌药物在体外按1∶1联合应用后,M IC值均比单独应用时有所下降,FIC指数均≤2,协同及相加作用的比例大于无关作用的比例,未见拮抗作用,磷霉素与阿米卡星联用后,使后者由耐药变成敏感。[结论]磷霉素与左氧氟沙星、环丙沙星、头孢呋辛、头孢他啶、头孢吡肟、头孢哌酮/舒巴坦、美罗培南、亚胺培南/西司他丁、阿米卡星在体外分别联合应用对不动杆菌有协同及相加作用,增强了这9种抗菌药物的抗菌活性。

[Objective] To study the antibacterial activity of fosfomycin combined with other 9 antimicrobial agents against 47 strains of Acinetobacter in vitro,in order to provide laboratory data for clinical combination application.[Methods] The 47 strains of acinetobacter isolated from sputum samples were treated by 10 antimicrobial agents alone and by fosfomycin combined with other 9 antimicrobial agents.Through the minimal inhibitory concentration（MIC） and fractional inhibitory concentration（FIC） index,using a two-fold agar dilution method,we could evaluate the antibacterial activity of fosfomycin combined with other 9 antimicrobial agents in vitro.[Results] All the 47 strains of acinetobacter were resistant to fosfomycin,levofloxacin,ciprofloxacin,cefuroxime,ceftazidime,cefepime,cefoperazone/ sulbactam,amikacin,and were intermedium to meropenem and imipenem/cilastatin.The ratio of antimicrobial agents was 1∶ 1.The MICs of fosfomycin combined with other 9 antimicrobial agents were lower than those of 10 antimicrobial agents alone and FIC index≤2.The primary action was synergistic/additional effect.There was no antagonistic effect observed.[Conclusion] Synergistic/additional effect was observed in fosfomycin combined with levofloxacin,ciprofloxacin,cefuroxime,ceftazidime,cefepime,cefoperazone/sulbactam,amikacin,meropenem and imipenem/cilastatin against acinetobacter in vitro.The antimicrobial activities of combination were increased.