浊度法在金黄色葡萄球菌体外药物敏感性试验及耐药性分析中的应用

Application of Turbidimetric Method in Antimicrobial Susceptibility Test and Drug Resistance Analysis of Staphylococcus aureus

目的:探讨不同药物浓度下药物与金黄色葡萄球菌之间的作用关系,为解决细菌耐药性及指导临床合理使用抗生素提供数据和试验参考。方法:采用浊度法对庆大霉素、红霉素、氧氟沙星3个药物浓度进行试验,测定其MIC值;另取1/2MIC、1/4MIC、1/8MIC浓度进行试验,并绘制抑菌生长曲线。结论:金黄色葡萄球菌在亚抑菌浓度(1/2 MIC)的压力下,可能并非是细菌抑制或杀死其生长量绝对值的一半;不同药物浓度下金黄色葡萄球菌进入对数生长期的时间有显著差异,高浓度药物下的金黄色葡萄球菌进入对数生长期较低浓度药物有一定的延迟;耐药金黄色葡萄球菌的生长曲线呈现增长后减小的趋势;随着时间的延长,不同药物浓度的红霉素抑菌时间均比庆大霉素、氧氟沙星长。

Objective:To explore the relationship between drug and Staphylococcus aureus in different concentrations to solve bacterial drug resistance and guide clinical rational use of antibiotics.Methods:Turbidimetric method was used to test the concentrations of gentamicin,erythromycin and ofloxacin.In addition,the concentrations of 1/2 MIC,1/4 MIC and 1/8MIC were selected for the test,and the antibacterial growth curve was drawn.Conclusion:By analyzing the time inhibition growth curve of 3 drugs of erythromycin,gentamicin and ofloxacin,we found that the growth trend of Staphylococcus aureus is different from the theoretical assumption under the pressure of subinhibitory concentration(1/2 MIC).It may not be the inhibition or killing of the absolute value of the growth of the Staphylococcus aureus.The time of the entry of Staphylococcus aureus at the logarithmic growth period was significantly different in different drug concentrations.The growth curve of Staphylococcus aureus under the high concentration of Staphylococcus aureus was delayed,and the growth curve of Staphylococcus aureus showed a tendency to decrease after growth.