Phenomenon of Local Skin Reactivity to Culture Filtrates of Various Microorganisms.

In previous communications a new phenomenon of local skin reactivity to B. typhosus culture filtrates in rabbits was described. 1 The local skin reactivity was induced by skin injections of the filtrate. If 24 hours later the filtrate was injected intravenously into the locally prepared rabbits there appeared extremely severe hemorrhagic necrosis at the site of previous skin injections 4 to 5 hours after the intravenous injection. There were observed certain features which considered together distinguished this phenomenon from the known manifestations of bacterial hypersusceptibility and the Arthus phenomenon. These features were: the local reactivity, the short incubation period necessary to induce the local reactivity, the short duration of the state of reactivity, the ability to induce local reactivity by a single skin injection, the severity of the reaction and the necessity to make the second injection of the toxic agent by the intravenous route.

The factors inducing the local skin reactivity were termed skin preparatory factors and those injected intravenously were called skin reaction factors.

The B. typhosus skin preparatory factors were specifically neutralized by immune anti-typhoid sera. Normal and non-related heterologous sera failed to neutralize these factors.

Further studies representing attempts to reproduce the described phenomenon with culture filtrates of microorganisms other than B. typhosus are reported here.