Production of the Shwartzman reaction with microbial L forms.

Study of potential pathogenicity of microbial L forms was done by the localized Shwartzman reaction. Stable L forms of Proteus mirabilis served as skin preparation in rabbits for induction of Shwartzman reaction by subsequent intravenous injection of either P. mirabilis L forms or Escherichia coli endotoxin. The intensity of the reaction was positively correlated to numbers of L forms in the skin. L forms also served as the intravenous challenge. In vivo multiplication of L forms was not a prerequisite for the reaction, as it could be produced with nonviable, osmotically lysed L forms. The reaction produced with L forms in the skin was more intense than that produced with the parent bacterial form. These latter observations, coupled with the demonstration that L forms disappeared from the skin (lysed?) after 4 hr, in contrast to bacteria which were recoverable for 72 hr (duration of study), suggest release of endotoxin by L forms as a pathogenic mechanism.