The procedure described is based on the fact that polymyxin B is added in a corresponding concentration to a synthetic medium which permits the growth of E. coli but inhibits the germination of anthrax spores. The antibiotic kills the multiplying E. coli but does not affect the anthrax spores. Polymyxin B was chosen because vegetative forms of the anthrax bacilli -- especially the spores -- are quite resistent to this substance. Anthrax bacilli can be detected very easily in a culture treated in this manner.
Trans. of Zentralblatt fuer Bakteriologie, Parasitenkunde und Infektionskrankheiten. Abt. 1. Originale (West Germany) v182 p232-237 1961.