ABOLITION OF PROTECTIVE EFFECT OF PASTEURELLA SEPTICA ANTISERUM BY IRON COMPOUNDS

Abstract

Ferric ammonium citrate, hematin hydrochloride, soluble hematin, lysed mouse red cells and a variety of purified hemoglobins abolished the protective effect of P. septica antiserum in mice when the iron compounds were injected intraperitoneally with P. septica. Ferric ammonium citrate was less effective than hematin or lysed red cells when the dose of P. septica was reduced to less than 10[degree]. The ability of lysed red cells to abolish protection was greatly reduced if given 4 hr. or more after infection. P. septica grew rapidly in unimmunized normal mice. In passively immunized mice the number of viable bacteria declined rapidly after infection. In passively immunized mice given hematin or lysed red cells the growth of bacteria was identical to that seen in unprotected normal mice. Large numbers of dead P. septica or carbon particles did not interfere with passive protection.