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[The endotoxin from S-, R- and M-forms of enteropathogenic E. coli O 149: pyrogenicity, Shwartzman-phenomenon and
Abstract:
The authors are interested in elucidation of the role of endotoxin from S, R- and M-forms of E. coli O 149, and of the role of hypersensitivity in pathogenesis of Colibacillosis. It was shown in this experiment that all S, R- and M-form of E. coli O149 possess endotoxin with almost the same pyrogenicity in normal rabbits. The pyrogenicity increases enormously in the hypersensitized rabbit. There were also not observed differences between endotoxins extracted from S, R, M-mutnants. All 3 endotoxins evoke in normal rabbits the skin Shwartzman-Phenomenon, the S-endotoxin was there much stronger. This phenomenon increases in capacity in hypersensitized rabbits. Thus again, the role of hypersensitivity in Colibacillosis was proved to be important.
Insights
This study reveals that endotoxins from E. coli O149 forms are equally pyrogenic in normal rabbits, but significantly more so in hypersensitized rabbits, highlighting hypersensitivity
Area of Science:
- Veterinary Immunology
- Bacterial Pathogenesis
- Microbial Immunology
Background:
- Colibacillosis, a significant disease in livestock, is often caused by Escherichia coli O149.
- Endotoxins are key virulence factors in Gram-negative bacteria, contributing to disease pathogenesis.
- The role of bacterial form (S, R, M) and host hypersensitivity in endotoxin activity is not fully understood.
Purpose of the Study:
- To elucidate the role of endotoxin from different forms (S, R, M) of E. coli O149 in Colibacillosis.
- To investigate the influence of host hypersensitivity on endotoxin-induced pathogenesis.
- To compare the pyrogenicity and Shwartzman Phenomenon induction by endotoxins from various E. coli O149 mutants.
Main Methods:
- Extraction and purification of endotoxins from S, R, and M forms of E. coli O149.
- Assessment of endotoxin pyrogenicity in normal and hypersensitized rabbits via temperature monitoring.
- Induction of the Shwartzman Phenomenon using endotoxins in normal and hypersensitized rabbits.
Main Results:
- All E. coli O149 forms (S, R, M) exhibited similar pyrogenicity in normal rabbits.
- Pyrogenicity of E. coli O149 endotoxins was significantly amplified in hypersensitized rabbits.
- All endotoxins induced the Shwartzman Phenomenon in normal rabbits, with S-endotoxin being more potent; this effect was enhanced in hypersensitized rabbits.
Conclusions:
- Endotoxin from E. coli O149 possesses pyrogenic and Shwartzman Phenomenon-inducing properties.
- Host hypersensitivity plays a crucial role in amplifying the pathogenic effects of E. coli O149 endotoxins.
- These findings underscore the importance of host immune status in the pathogenesis of Colibacillosis.