Abstract
According to our studies of the O [1] antigen of Salmonella bacteria, up to now, we have been explaining that each bacterium of Salmonella which contain O [1] antigen is sure to liberate specified phage and when the prophage of the bacterium is removed from the bacterial body it loses O [1] antigen, but it was found that S. sendai which belongs to Salmonella D group although it contains O [1] antigen, does not liberate phage and is not induced by UV irradiation.
At this point, in order to detect what the factor is that controls O [1] antigen of S. sendai, we experimented by expelling prophage which hides within bacterial body of S. sendai. Namely, s2 phage liberated from S. typhimurium 4066 was used, and phage s2 does not lyse but adsorbs to it. By superinfecting S. sendai with s2 phage, 103-104 of phage can be expelled from S. sendai. These can be considered to be the phages which were expelled from S. sendai. As the natures of these expelled phages are the same with that of s4 phage which were liberated from S. typhimurium var copenhagen 3164, it can be said that S. sendai is the bacteria that obtains s4 phage in the form of “defective prophage” within its bacterial body. But the appearance is different from that of “defective lysogeny” on Appleyard's λ phage, in the case of S. sendai, it may called “abnormal lysogeny”.
Furthermore, by the superinfecting method like this, non-lysogenic S. sendai was experimentally obtained and by inserting s2 or s4 phage to non-lysogenic S. sendai, abnormal lysogenic S. sendai could be artificially manufactured the recovery.
