硝酸银与传统抗生素对常见细菌和真菌的杀菌能力比较

Comparison of Sterilization Effect of Silver Nitrate with Conventional Antibiotics on Bacteria and Fungi

目的比较硝酸银与传统抗生素对常见细菌和真菌的杀菌能力。方法实验采用平板稀释法,即用3种药物分别制成含不同梯度浓度药物的培养基,然后在其上涂布相应的细菌、真菌,根据菌落生长被抑制的状态,判断最小抑菌浓度。结果硝酸银对细菌和真菌都有抑菌作用,且无显著差异(P>0.05),最小抑菌浓度3—7μg/mL;金黄色葡萄球菌和肺炎克雷伯菌对新霉素较敏感,最小抑菌浓度在0.1—1μg/mL之间;庆大霉素对金黄色葡萄球菌和大肠杆菌的最小抑菌浓度分别为0.1μg/mL和1.25μg/mL;庆大霉素对绿脓杆菌无抑菌作用,而新霉素对绿脓杆菌的抑菌作用较差,其最小抑菌浓度为16μg/mL。结论硝酸银对细菌和真菌的抑菌作用无选择性,而抗生素却表现出了抑菌的高度选择性。随着银粒子及银离子在医疗上的作用被重新认识,我们认为,在临床上可以复合使用硝酸银和抗生素以达到更好的杀菌和抑菌效果。

Objective To investigate whether the silver nitrate has the advantages over conventional antibiotics in sterilization of common bacteria and fungi. Method Plate dilution method was performed, that is, three drugs were dissolved in the culture medium at different concentrations, and then the bacteria and fungi were plated. The minimum inhibitory concentration was determined by growth situation of the bacteria and fungi. Result Silver nitrate had similar inhibitory function to both bacteria and fungi （P 〉 0.05 ）and the minimum inhibitory concentration was between 3 -7 μg/mL. For antibiotics, the minimum inhibitory concentration of neomycin to S. aureus and K. pneumoniae was between 0. 1 - 1.0μg/mL and that of gentamicin to S. aureus and E. coli were 0. 1 μg/mL and 1.25 μg/mL, respectively. However, there was no inhibitory function was found for gentamicin against P. aeruginosa, and the inhibitory function of neomycin against P. aeruginosa was 16μg/mL. Conclusion There is no selectivity of inhibitory effect for silver nitrate against bacteria and fungi. Comparatively, the antibiotics prefer to inhibit the bacteria, but not fungi. With the bactericidal and baeteriostatic effects of the silver particles and silver ions are re-realized in the modern medicine, the combination of silver nitrate and antibiotics may be an effective therapy strategy in clinical.