Report on a Pseudolysogenic Mycobacterium and a Review of the Literature Concerning Pseudolysogeny

A description is given of a rapidly‐growing mycobacterium (designated C.U.) which produces bacteriophages spontaneously. The strain was isolated from an abscess that occurred 2 months after a BCG vaccination. The phage content was maintained after subculture. Since only some of the colonies produced phages and the content of phages could be eliminated after growth in antiserum against the phage (designated BK 5 ) it is concluded that' C.U. is a pseudolysogenic mycobacterium. No phage‐mediated changes in the characteristics of the bacterium were: demonstrated. The literature and various forms of pseudo‐lysogeny are reported.