Abstract
Attempts have been made by many investigators for classifying mycobacteria by the use of mycobacteriophage. However, little attention was paid hitherto to the identification of the phage strains, which were isolated from soil of various places independently. To carry out phage typing of mycobacteria, it seems indispen sable to make classification or identification of the phage strains to be used. In the present paper, studies on the classification of 32 myco phage strains collected from various laboratories of the world are presented.
Anti-phage sera were prepared by the repeated intravenous injections of phage suspension into rabbit. According to the neutralization rates calculated, 32 phage strains examined were classified into following 7 serological types: Y7, Y10, PP, Bl, Li, D29 and X. Here, X type phage strains did not show any sign of neutralization by the 6 kinds of anti-sera used. Further, from the standpoint of the activity to human type tubercle bacilli, these phage strains were classified into 3 lytic types, i. e. a, b and c. Thus, 32 phage strains were clas sified into 10 different types.
Typing phages were selected from these different types and some other strains were additionally selected in consideration of the specificity in the sensitivity to saprophytes and the plaque morphology to make up 14 typing phages. These14 phage strains are thought to be adequate for the phage typing on mycobacteria at the present step of the mycophage studies. However, more effort should be paid, of course, for discovering much more number of adequate phage strains for the typing or adaptive phage like Vi-phage II in Salmonella.