[Lysis of the cells of Propionibacterium acnes by the culture supernatant of Actinomyces viscosus].

Abstract

Ecologically there seemed to be antagonistic relations between Actinomyces viscosus and Propionibacterium acnes. The Supernatant of A. viscosus was shown to possess a lytic activity on the growing cells of P. acnes. The results obtained were as follows: 1. Only a small number of P. acnes was isolated in samples from which numerous A. viscosus were isolated. On the other hand, P. acnes were frequently isolated in samples from which few cells of A. viscosus were isolated. 2. The concentrate with ammonium sulfate of the anaerobic culture supernatant of A. viscosus was used as a lytic factor. When P. acnes was grown in broth with the lytic factor, for a short time optical density of the culture increased and then decreased. Release of 3H-thymidine was observed from the radio-labeled cells of P. acnes, suggesting the release of DNA due to the disruption of the cells. 3. Gram positive staining during early stage of cell lysis began to turn to Gram negative and disrupted cells were observed at later stages. Using an electronic microscope it was observed that cell poles were broken with cytoplasm flowing out. 4. The lytic factor lysed the growing cells, but did not lyse either the resting cells or the dead cells. 5. Radio-labeled high molecular substances were released into the supernatant from the growing cells of P. acnes which were radio-labeled by 3H-glycerol or 14C-alanine. This suggested the release of lipoteichoic acid or peptidoglycan. 6. The lytic factor did not release radio-labeled substances from the isolated peptidoglycan which was radio-labeled by both 3H-glucosamine and 14C-alanine. 7. Lysis of P. acnes by the lytic factor was inhibited by adding chloramphenicol which was assumed to inhibit the release of lipoteichoic acid. 8. From the results mentioned above, the lytic factor seemed to cause the cellular lysis of P. acnes by the release of lipoteichoic acid followed by activation of the autolytic enzyme. This mode of action is similar to that of penicillin, but the molecule of the lytic factor seemed to have the nature of protein.