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Production of the Shwartzman reaction with microbial L forms
Abstract:
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.
Insights
Microbial L-forms, a variant of bacteria, can cause a potent inflammatory reaction in rabbits, even when not alive. This suggests L-forms release endotoxins, contributing to their pathogenicity.
Area of Science:
- Microbiology
- Immunology
- Pathology
Background:
- Microbial L-forms are cell wall-deficient variants of bacteria.
- Their pathogenic potential, particularly concerning endotoxin release, requires further investigation.
Purpose of the Study:
- To investigate the pathogenicity of microbial L-forms using the localized Shwartzman reaction.
- To determine if L-forms can induce the Shwartzman reaction and elucidate the underlying mechanisms.
Main Methods:
- The localized Shwartzman reaction was induced in rabbits using stable L-forms of Proteus mirabilis as the skin preparation.
- Subsequent intravenous injections included either P. mirabilis L-forms or Escherichia coli endotoxin.
- The intensity of the Shwartzman reaction was correlated with the number of L-forms in the skin.
Main Results:
- The Shwartzman reaction intensity correlated positively with the number of L-forms in the skin.
- Nonviable, osmotically lysed L-forms could also induce the reaction, indicating multiplication was not required.
- L-forms induced a more intense reaction than the parent bacterial form.
- L-forms disappeared from the skin within 4 hours, unlike parent bacteria.
Conclusions:
- Microbial L-forms possess pathogenic potential, capable of inducing the Shwartzman reaction.
- The rapid disappearance and intense reaction suggest L-forms release endotoxin as a key pathogenic mechanism.
- This study highlights a novel pathway for bacterial pathogenicity mediated by L-forms.