REVERSION OF 3A TYPE L FORMS OF PROTEUS MIRABILIS

Abstract

Reversion of 3A type L particles of Proteus mirabilis to the bacillary state is a function of the number of colonies on the plate and incubation time and temperature. The frequency of reversion on soft serum agar varied from 7.7 x 10-6 at 37 C to 1.5 x 10-8 at 23 C. The generation time of 3A type L units was approximately 8 hr. at 37 and 30 C and approximately 22 hr. at 23 C. Bacterial cells obtained from reversion of 3A type L particles are no more efficient than the original cells in forming 3A type L colonies, and 3A L units so obtained revert to bacteria with the same frequency as 3A L units obtained from parent bacilli. Reversion frequency may be altered by medium modifications which do not change the generation time of the 3A L bodies.