Li R C, Nix D E, Schentag J J
Department of Pharmaceutics, State University of New York, Buffalo 14260.
Antimicrob Agents Chemother. 1993 Feb;37(2):371-4. doi: 10.1128/AAC.37.2.371.
A turbidimetric assay was developed and validated against Escherichia coli for the quantitation of viable bacterial densities. The Abbott MS-2 research system was employed for continuous 5-min measurements of optical density. A linear standard curve was obtained by regressing the initial bacterial density (log CFU per milliliter) against the time required for bacterial growth causing a 5% decrease in optical transmittance. Slope and intercept values obtained from eight standard curves showed excellent assay reproducibility. Results obtained by the turbidimetric assay compared favorably to those obtained by the conventional pour plate assay. Prior to the application of the new assay, possible interferences of postantibiotic effect induced by the test antibiotics were excluded. The turbidimetric assay, which is presumably more efficient and less expensive, was implemented for the time-kill studies of three different beta-lactams against E. coli.
开发了一种比浊法，并针对大肠杆菌进行了验证，用于定量活菌密度。采用雅培MS-2研究系统连续5分钟测量光密度。通过将初始细菌密度（每毫升对数CFU）与导致光透射率降低5%的细菌生长所需时间进行回归，获得了线性标准曲线。从八条标准曲线获得的斜率和截距值显示出良好的测定重现性。比浊法获得的结果与传统倾注平板法获得的结果相比具有优势。在应用新方法之前，排除了受试抗生素诱导的抗生素后效应的可能干扰。比浊法可能更高效且成本更低，被用于三种不同β-内酰胺类药物对大肠杆菌的杀菌时间研究。
