嫌気性菌の薬剤感受性試験の標準化について

第2報 再現性について

抄録

The agar dilution technique which has been used at our laboratory for several years was converted. Briefly, serial two-fold dilutions of the antibiotic are prepared and incorporated into GAM agar (Nissui). The inoculum is prepared as follows : Almost all strains of anaerobes except slower growing strains is grown in GAM broth (Nissui) for about 6 hours anaerobically. A 6-hour culture in GAM broth has the turbidity of a half of MC FARLAND no. 1 (10⁵ to 10⁶ viables cells/m1). When a 24-hour culture is employed, it is diluted in UENO'S diluent (without agar) or 0. 05% yeast extract solution to the same density above.
The inoculum is applied by means of a multipurpose apparatus for rapid inoculation.
The susceptibility plates are incubated at 37°C in anaerobe jars (Steel-wool copper sulfate method; CO2 10%, N2 90%) for 24 hours.
The MIC of each strain is read as the highest dilution of drug yielding no growth.
This procedure is better at the point of the rapidity, simplicity and reproducibility.