Effect of haemoglobin on experimental infections with Pasteurella séptica and Escherichia coli.

BOTH haematin hydrochloride and ferric ammonium citrate can abolish the protective effect of immune serum in experimental infections with Pasteurella septica in mice1. Ferric ammonium citrate has the same effect with Clostridium welchii Type A infections in guinea-pigs2. The importance of these observations depends on the fact that iron can abolish the bacteriostatic effect of sera against Cl. welchii in vitro3. Because iron compounds seem to have such similar effects both in vitro and in vivo, it seems quite likely that the bacteriostatic action of serum may play an important part in resistance to bacterial infections.