State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China.
Sci China Life Sci. 2010 Nov;53(11):1346-55. doi: 10.1007/s11427-010-4087-0. Epub 2010 Nov 3.
The dynamic growth process of Escherichia coli CVCC249 under different concentrations of antibiotics was analyzed. The results suggested that the main reason that definitive results cannot be obtained by antibiotic susceptibility testing (AST) is that the ratio of drug concentration to the population of bacteria and the combined effect of drug concentration and action time cannot be completely determined with the methods used. Based on the analysis of the growth process with a series of concentrations of gentamicin acting for a certain time, and according to the forward difference method, a novel method for AST was proposed. The net increase in turbidity of the bacterial population was used to eliminate the existing effects of resting cells, and then the recurrent coefficient for a growing sequence was used to characterize the effect of antibiotics on bacterial division, and the contour plot was used to display and analyze the combined effect of drug concentration and action time. The inhibition rate of the antibiotics can be characterized as the dynamic change in the composite function of the antibiotic concentration and action time, which indicated that the inhibition rate was dependent on the combined effect of time and concentration of antibiotics. The effectiveness of this new method has been verified with different kinds of antibiotics, such as enrofloxacin, levofloxacin, and ceftriaxone, having different antibacterial mechanisms.
分析了不同浓度抗生素作用下大肠杆菌 CVCC249 的动态生长过程。结果表明，抗生素药敏试验（AST）无法得出明确结果的主要原因是，采用的方法不能完全确定药物浓度与细菌数量的比值以及药物浓度和作用时间的综合效应。根据一系列浓度的庆大霉素作用一定时间的生长过程分析，采用前向差分法，提出了一种新的 AST 方法。利用细菌群体浊度的净增加来消除休眠细胞的现有影响，然后用生长序列的递归系数来描述抗生素对细菌分裂的影响，并利用等高线图来显示和分析药物浓度和作用时间的综合效应。抗生素的抑制率可以表示为抗生素浓度和作用时间的复合函数的动态变化，这表明抑制率取决于抗生素时间和浓度的综合效应。该新方法已通过具有不同抗菌机制的不同类型抗生素（如恩诺沙星、左氧氟沙星和头孢曲松）得到验证。
