Is the bacteriophage of d'Herelle volatile?

Abstract

Following the description of the phenomenon of transmissable lysis of bacteria by d'Herelle in 1917, an enormous amount of evidence has been brought forward in support of his observations.

At the same time, however, there has also been an ever-growing tendency to dispute the parasitic nature of the active principle responsible for the lysis as postulated by d'Herelle.

In this connection, recent findings by Olsen and Yasaki 1 appeared to offer most important evidence which we attempted to corroborate.

Subjecting 18 hour cultures of so-called “bacteriophage” to distillation at 45-50° C. under reduced pressure, Olsen and Yasaki claim to have obtained a product capable of initiating transmissible lysis of cultures of susceptible bacteria. They conclude, therefore, that the “bacteriophage” is a volatile chemical substance and not a living parasite. Following their description of the experiment, we connected three flasks in series. The first, a distilling flask of one liter capacity, received 100 cc. of the filtrate from an 18 hour lysed culture of the colon bacillus (having a titer of 5 × 10^-10 cc.) and was placed in a water bath kept at 45° C. With this was connected a similar distilling flask containing enough sterile distilled water to submerge the opening of the side-arm of the first distilling flask. This second flask was kept cool by means of an ice bath and was connected with a vacuum pump through a wash-bottle containing 25 cc. of sterile broth, also kept under ice.