Kanazawa Y, Kuramata T, Matsumoto K
Jpn J Antibiot. 1986 Jan;39(1):79-86.
Susceptibilities of 175 strains of 27 bacterial species to ceftizoxime (CZX) were determined by the 2-fold agar dilution method in parallel with the diameter of inhibition zones by the single-disc method under the experimental conditions established by Kanazawa. The experiments demonstrated a significant correlation between MIC by the dilution method and diameter of inhibition zone in each of the conventional assay of over-night (about 16 hours) incubation, the delayed assay (about 24 hours incubation), and the rapid assay (about 3 approximately 4 or 5 approximately 6 hours incubation), thus confirming the applicability of the single-disc assay for CZX. Analysis of the data obtained by using CZX disc containing 30 micrograms revealed the primary regression equation to be: D (diameter, mm) = 27.3-9.7 log MIC (micrograms/ml) in conventional assay, D = 32.5-12.3 log MIC (micrograms/ml) in delayed assay, D = 22.8-7.5 log MIC (micrograms/ml) in 5 approximately 6 hours rapid assay, and D = 17.9-5.1 log MIC (micrograms/ml) in 3 approximately 4 hours rapid assay, respectively. The range of variations in MICs estimated from the diameter of inhibition zone by the disc test was then calculated in comparison with that in MIC determined by the 2-fold agar dilution test, as a reference for the experimental errors which may be involved in the estimation of MIC of CZX by the single-disc assay.
采用2倍琼脂稀释法，在金泽建立的实验条件下，平行于单纸片法测定抑菌圈直径，对27种细菌的175株菌株对头孢唑肟（CZX）的敏感性进行了测定。实验表明，在过夜（约16小时）培养的传统试验、延迟试验（约24小时培养）和快速试验（约3至4或5至6小时培养）的每种试验中，稀释法测得的最低抑菌浓度（MIC）与抑菌圈直径之间均存在显著相关性，从而证实了单纸片法对CZX的适用性。对含30微克CZX纸片所得数据的分析表明，传统试验中的一级回归方程为：D（直径，mm）=27.3 - 9.7 log MIC（微克/毫升），延迟试验中为D = 32.5 - 12.3 log MIC（微克/毫升），5至6小时快速试验中为D = 22.8 - 7.5 log MIC（微克/毫升），3至4小时快速试验中为D = 17.9 - 5.1 log MIC（微克/毫升）。然后，通过纸片试验从抑菌圈直径估算的MIC变化范围与通过2倍琼脂稀释试验测定的MIC变化范围进行比较，作为单纸片法估算CZX MIC时可能涉及的实验误差的参考。
