抄録
The most reliable method for the phage sensitivity test of bacteria seems to be the comparison of EOP (efficiency of plating) according to the plaque counting results by the agar layer method. However, this method is relatively complicated from the technical view point, and therefore, a method of spotting a certain amount of phage suspension on the lawn of bacilli to be tested has been established and adopted routinely on Salmonella and Staphylococci, etc. In the techniques of the spotting method in these bacteria, it was known that the use of the“routine test dilution”of the typing phage is an important principle. However, in the case of Mycobacteria, very little has been hitherto reported on the methodology of the phage sensitivity test; no investigator has used the routine test dilution except Penso (1951) who applied it to saprophytic Mycobacteria.
In the present paper a routine procedure for the phage sensitivity test of Mycobacteria, the growth of which are remarkably slower than the non-acid-fast bacilli, was studied, especially the availability of a routine test dilution (RTD) of phage suspension. In addition, the following factors affecting the test results were studied: the inoculum amount of bacteria to be tested, time intervals from bacterial inoculation to phage spotting and from phage spotting to reading results.
