| Abstract: | A dose-dependent prophage induction by furazolidone exhibited a gradual rise to a maximum, corresponding to an exposure dose of 1.2 microgram/ml X h and a gradual fall thereafter. A 2-3-fold higher level of induction was achieved when the lysogens were treated with furazolidone in the presence of a metabolizing mixture. A maximum of about 70% efficiency of induction was achieved. Kinetics of prophage induction by any concentration of furazolidone exhibited a common pattern, viz., an initial rise for 15-20 min, then a plateau extending up to about 60 min and a faster rise thereafter. Higher concentrations of the drug (10 micrograms/ml) exhibited a toxic effect. Chloramphenicol at a concentration of 20 micrograms/ml inhibited the furazolidone-induced prophage induction, the plaque-forming units gradually decreasing from several minutes after the chloramphenicol treatment. The burst size of the lysogens was not significantly affected by treatment with 2 micrograms/ml of furazolidone up to a period of about 10 min, but thereafter, decreased faster with the duration of furazolidone treatment. The "latent period' of induction decreased linearly with the duration of furazolidone treatment. |
