Recent experiences with the Salmonella-O-1-phage in routine diagnostic work.

Sensitivity to the O-1-phage was tested on 5287 Salmonella strains isolated in the course of routine diagnostic work over the period 1971-1973. 3380 (99,2%) strains of the B group, 676 (97,8%) of the C group, 840 (98,8%) of the D group, and 195 (83,0%) of the E group strains were sensitive to the O-1-phage. 92 of the 5 287 strains belonged to other O-groups in the Kauffmann-White scheme; 91,3% of these were phage-positive. 5274 of the strains belonged to subgenus I and only 100 of them were not sensitive to the O-1-phage. A total of 13 strains belonged to subgenera II, III, and IV. The O-1-phage was considered to be suitable for the identification of Salmonella bacteria. It should, however, be observed that monophasic strains belonging to subgenus III and strains belonging to subgenus IV are usually not sensitive to the O-1-phage. Of the total number of strains, 98,0% were sensitive to the O-1-phage.