Related Experiment Videos
Characterization of the dermal lesions induced by a purified protein from toxigenic Pasteurella multocida
F Elling1, K B Pedersen, P Høgh
1University Institute of Pathological Anatomy, Copenhagen, Denmark.
Abstract:
The dermonecrotic effect of purified Pasteurella multocida toxin (PMT) was studied sequentially in guinea pigs and rats. The skin reaction was initially an acute inflammatory reaction, with edema and emigration of neutrophils and a few eosinophils and diapedesis of some erythrocytes. Four hours after intracutaneous injection the vessels were congested and thrombocytes were focally attached to the endothelial wall. Twenty-four h after the injection the inflammatory reaction appeared more severe and venules and arterioles were thrombosed. Necrotic changes were seen in hair follicles and in striated muscle fibers. Crude extracts from P. multocida and Clostridium perfringens injected intracutaneously into guinea pigs induced skin lesions qualitatively similar to the lesions induced by the purified PMT, indicating that dermonecrotic bacterial toxins may share similar biochemical properties.
Insights
Pasteurella multocida toxin (PMT) causes acute inflammation, thrombosis, and necrosis in animal skin. Dermonecrotic bacterial toxins may share similar biochemical properties, affecting skin tissue.
Area of Science:
- Veterinary Pathology
- Microbiology
- Dermatology
Background:
- Pasteurella multocida toxin (PMT) is a key virulence factor.
- Understanding PMT's dermonecrotic effects is crucial for animal health.
- Bacterial toxins can induce significant tissue damage.
Purpose of the Study:
- To investigate the sequential dermonecrotic effects of purified PMT in vivo.
- To compare the skin lesions induced by PMT with those from crude bacterial extracts.
Main Methods:
- Intracutaneous injection of purified PMT into guinea pigs and rats.
- Histopathological examination of skin tissues at various time points post-injection.
- Injection of crude extracts from P. multocida and Clostridium perfringens into guinea pigs.
Main Results:
- PMT induced acute inflammation, edema, and neutrophil emigration.
- Vascular congestion, thrombosis, and erythrocyte diapedesis were observed.
- Necrotic changes in hair follicles and muscle fibers occurred 24 hours post-injection.
- Crude extracts induced qualitatively similar skin lesions.
Conclusions:
- Purified PMT elicits a severe inflammatory and necrotizing skin response.
- Dermonecrotic bacterial toxins may possess shared biochemical characteristics.
- PMT's pathological effects highlight its role in disease pathogenesis.