Survival of Bacteriophage.

Abstract

The interval of time over which bacteriophage filtrates maintain their activity is of general biologic interest. Enzymes demonstrate their activities after many months. Immune substances retain their activities for at least more than 4 years. Ultramicroscopic viruses retain their activity under certain circumstances for several years. Ballantyne 1 has shown the survival of bacteria in water for at least 32 months. Anaerobic organisms have been recovered from old cultures after more than 14 years. The plague bacillus has remained viable for 10 years. Cultures of Leptospira icteroides and L. icterohemorrhagiae may show motility after 2 years and 4 months (Hadley, P.). Pure cultures of molds have yielded active spores after longer periods. The bacteriophage has been demonstrated to retain its activity for more than 5 years.

The present brief note is based on tests of a bacteriophage filtrate originally recovered by d'Herelle. It was sent to Dr. F. G. Novy in 1921, and was rejuvenated by Dr. Philip Hadley against the Shiga dysentery bacillus for which it was said to be specific. The properties were specifically studied 2 during the fall and winter of 1922-23, during which time several filtrates were sealed in tubes and stored in the dark at room temperature. The menstruum was a beef infusion broth, presumably pH 7.2 ± 0.2, used for all of the work performed. Tubes were sealed in a flame (glass seal), allowing about 4 cc. of air space for 10 cc. of filtrate. They have thus been held until the present time, now 8 years. The filtrate used was water clear, although very light granular precipitate appears in several of the ampoules not opened.