A report on the preparation of pneumococcic antitoxin.

Abstract

In the present paper I wish to make a brief report of results obtained in an effort to produce a pneumococcic antitoxin. This work is the outgrowth of our observation that bacterial toxins are rendered non-toxic by soaps of some of the unsaturated fatty acids, particularly sodium ricinoleate, and that the antigenic properties of such detoxified toxins remain unimpaired. We have further called attention to the fact that pneumococci, streptococci and certain other micro-organisms are either killed in a short time in aqueous solutions of sodium ricinoleate, or lose their powers to infect. Larson and Nelson 1 showed further that there is a rapid development of agglutinins in rabbits against both pneumococci and streptococci following the injection of soaped cultures of these organisms.

Ten cc. or more of a virulent broth culture of soaped pneumococci may be injected intraperitoneally into rabbits without causing an infection. Agglutinins appear in the blood stream as early as 24 hours following such injections. This observation led us to attempt to produce an antipneumococcic serum by this method. Pneumococci of various types were passed through a series of mice in order to increase their virulence as much as possible. They were then grown in veal infusion broth which contained 1 to 2 per cent peptone. Parke-Davis'and Witte's peptones were used, since these products have been found by others to be best for toxin production. The whole cultures were treated with sodium ricinoleate solutions of a pH of 7.8, so the final concentration of the soap was 1 per cent. The pH of the cultures was adjusted to 7.4 before the soap was added.

Rabbits and sheep were then immunized with these soaped cultures. Sheep were given as much as 200 cc. at one time.