Further Studies of Antigenic Properties of Bacteriophage

Abstract

Although bacteriophage is antigenic, it has not been found possible to induce active anaphylaxis in guinea pigs with bacteriophage, 1 even when employing for the test-injection active purified bacteriophage-protein containing 2.6 × 10¹³ lytic units, (1.79 mg of specific protein, 2 equivalent to 5 liters of crude phage). In seeking another method of demonstrating the interaction of bacteriophage with its antibody in vivo, we attempted to utilize the Shwartzman test.

Four rabbits were sensitized by repeated injections of crude B. coli bacteriophage, and their sera, 10 days after the last (ninth) injection, were found to be capable (in a dilution up to 1:320) of neutralizing an equal volume of undiluted crude phage having a titer of 10⁹ lytic units per cubic centimeter. Two of these rabbits were then prepared by the intracutaneous injection of 0.25 cc of meningo-coccal filtrate, kindly sent us by Dr. Shwartzman, and 24 hours later one of them received intravenously 5 cc of crude phage and the other 9.5 cc of freshly prepared active purified phage containing a total of 5.7 × 10¹³ active lytic units (or 3.42 mg of specific protein equivalent to 11.4 liters of crude phage).

The animal that had received crude phage responded within 3 hours with a typical reaction at the site of the preparatory injection, while the one that had received the purified phage had no reaction. This difference indicated that the reaction in the animal receiving crude phage might have been due not to the bacteriophage itself but rather to other constituents of the crude phage.