N-乙酰半胱氨酸与磷霉素联用对几种下呼吸道感染病原菌的体外抑制作用研究

Inhibitory Effect of N-acetylcysteine Combined with Fosfomycin on Several Pathogenic Bacteria of Lower Respiratory Tract Infection in vitro

目的探究N-乙酰半胱氨酸(NAC)与磷霉素联用对下呼吸道感染常见病原菌的体外抑制作用。方法采用纸片扩散法(K-B法)测抑菌圈直径,试管有限稀释法测定最小抑菌浓度(MIC),观察NAC和磷霉素对金黄色葡萄球菌、表皮葡萄球菌、乙型溶血性链球菌、肺炎链球菌、大肠埃希菌、肺炎克雷伯菌、铜绿假单胞菌、鲍曼不动杆菌的抑菌效果。采用纸片扩散法和棋盘法观察两种药物联合应用的效果。结果每片0.5mgNAC对供试菌的抑菌圈直径在7.96mm^12.7mm之间,NAC对供试菌的MIC为2.5mg/mL^5.0mg/mL,表明具有较好的抑菌作用。每片50μg磷霉素钠的抑菌圈直径在12.77mm^48.32mm,磷霉素对供试菌的MIC为0.001mg/mL^0.5mg/mL,结果表明磷霉素对不同的呼吸道感染病原菌抑菌效果存在较大差异。K-B法联合药敏试验结果提示两种药物之间可能存在协同或累加作用。棋盘稀释法结果显示两种药物对供试菌的FIC指数均<0.5,表现为协同作用。结论NAC与磷霉素对常见下呼吸道感染病原菌均具有较好的抑菌效果,NAC与磷霉素联合使用存在协同或累加作用,临床上使用磷霉素一定要根据药敏试验指导性地用药。

Objective To explore the inhibitory effect of N-acetylcysteine (NAC) combined with fosfomycin on common pathogens of lower respiratory tract infection in vitro. Method The diameter of bacteriostatic zone was measured by K-B method, and the minimum inhibitory concentration(MIC) was determined by limited dilution method on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus hemolytic-β,Streptococcus pneumoniae, Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Acinetobacter baumannii.The bacteriostatic effect of NAC and fosfo- mycin was observed. Disk diffusion method and chessboard method were used to observe the effect of combined application of the two drugs. Result 0.5 Mg/film of NAC had a diameter of 7.96~12.70mm, and the MIC of NAC was 2.5~5.0 mg/mL, which indicated that NAC had a good bacteriostasis effect. The antimicrobial circle diameter of 50μg /tablet of fosfomycin sodium was 12.77~48.32 mm. the MIC of osfomycin sodium was 0.001~0.5 mg/mL,MIC results showed thatthe antimicrobial effect of fosfomycin on different pathogenic bacteria of respiratory tract infection was very different. In the joint susceptibility test, the paper diffusion method observed that there may be synergistic or cumulative effects between the two drugs. The results of chessboard dilution showed that the FIC index of the two drugs to the tested bacteria was less than 0.5, showing synergistic effect. Conclusion NAC and fosfomycinhave good bacteriostatic effecton common pathogenic bacteria of lower respiratory tract infection. There is synergistic or cumulative effect between NAC and fosfomycin. The clinical use of fosfomycin must be guided by drug sensitivity test.