多西环素对大肠埃希氏菌的抗生素后效应试验观察

Observation of Postantibiotic Effect of Doxycycline on E.coil

本试验的目的是观察多西环素对大肠埃希氏菌临床分离株的体外抗菌效果,以及其抗生素后效应(PAE)。试验采用标准肉汤二倍试管稀释法测定体外最小抑菌浓度(MIC),并在MIC的基础上采用菌落计数法分别测定多西环素0.5、1、2、4倍MIC时对细菌的PAE。结果显示,多西环素对临床分离株的MIC为16μg∕m L,在0.5、1、2、4倍MIC时对大肠埃希氏菌临床分离株的PAE分别为0.5 h、1 h、2.5 h和3.5 h。结果表明,多西环素对大肠埃希氏菌临床分离株有明显的PAE,且PAE随药物浓度增大而延长。

The purpose of this study is to observe the antimicrobial effect and the postantibiotic effect (PAE) of doxycycline to the E. coli isolated from clinic case. The double broth dilution method was adopted to detect the minimal inhibitory concentration (MIC) of doxycycline in the experiments. The PAE of 0.5, 1, 2, 4 times of MIC to the bacteria was detected by using colony counting method. The results showed that the MIC of doxycycline was 16μg∕mL and the PAE of doxycycline in the different concentration were 0.5h, 1h, 2.5h and 3.5h respec?tively for E . coli isolated from clinic case. It suggested that the doxycycline to E. coli isolated from clinic case had an obvious PAE. The PAE was able to prolong following the increase of drug concentration.