PHAGE INACTIVATING AGENT CLOSELY RELATED WITH SALMONELLA O (XII) ANTIGEN

Abstract

1) It can be recognized that Pc and Pv, the mutants from S. sendai (71) phage Krh strain, produce the so-called pin hole plaque on the original indicator Sg (S. gallinarum Akita strain). 2) Analysing the agent concerning the pin hole plaque formation of these P-mutants, the authors could detect specific agent inactivating the P-mutant particles in the bouillon culture filtrate of Sg, which is presumed to play at the same time the most important role in the formation of pin hole plaque of these mutants. 3) While the indicator Sg/z, which is one of the phage resistant strains obta-ined from the original indicator Sg, and on which Pc and Pv produce an ordinal large plaque similar to that of the original phage strain Krh does not elute such a specific agent in its bouillon culture filtrate. 4) This agent is not only eluted in bouillon culture but also into the mere saline washings or somatic extracts of Sg, thermostable and can be specifically neu-tralized by anti-Sg serum. 5) This agent is closely related with the salmonella O antigen (XII) and also exists in various strains of A, B and D group of salmonella besides in indicator Sg. Phage particles Pc and Pv can be specifically adsorbed onto the bacterial bodies of these strains, and on the other hand, the specific inactivating agent can be de-tected in their bouillon culture filtrate or their somatic extracts. 6) However, a series of B group salmonella provided with antigen (XXVII) besides (XII) for example S. abortus bovis and all strains of C group lacking in (XII) are not quite concerned with this agent. 7) On the other hand, the O antisera against the representative strains of salmonella group A, B and D have a specific neutralizing ability to the function of this agent, while the antisera against S. paratyphi C or S. abortus bovis have no such ability. Although these evidences are those recognized in very distinctive phage samples, they are considered to provide very interesting and important materials to the pro-blem of phage-host relationship. Ultimately, they can be presumed to reveal a specific role as phage receptor of bacterial antigen which is played in the adsorption of some type phages to their host bacteria. Also they report one of the most remarkable cases in which the strict correla-tion can be seen between the specific phage inactivating agent and the bacterial antigen, and this specific agent is concerned in pin hole plaque formation and ex-tremely low efficiency of plating. On the other hand, they can be important in providing a very suggestive da-tum concerning the essential nature of salmonella antigen (XII) or antigen complex (XII: XXVII).