Toxicity of endotoxin to chicks

Area of Science:

• Veterinary immunology
• Pathogen-associated molecular patterns
• Avian disease models

Background:

• Lipopolysaccharide (LPS) from Gram-negative bacteria like Escherichia coli is a potent immune stimulant.
• Understanding LPS toxicity and immune responses in avian species is crucial for poultry health.
• The Shwartzman reaction is a severe inflammatory response often associated with bacterial endotoxins.

Purpose of the Study:

• To investigate the effects of high-dose lipopolysaccharide (LPS) administration in chicks.
• To determine if uric acid can confer protection against LPS-induced toxicity.
• To assess the potential for inducing a generalized Shwartzman-like reaction in chicks using LPS.

Main Methods:

• Purified lipopolysaccharide (LPS) from Escherichia coli was administered in large doses to chicks.
• Survival rates and clinical signs were monitored following LPS exposure.
• Attempts were made to induce a Shwartzman-like reaction through sequential LPS injections.
• The protective effect of prior uric acid injection against LPS was evaluated.

Main Results:

• Large doses of LPS induced clinical signs in chicks, but no mortality was observed.
• Chicks survived mean doses up to 517 mg/kg, with one recovering from 577 mg/kg.
• Sequential LPS injections failed to elicit a generalized Shwartzman-like reaction.
• Pre-treatment with uric acid did not protect chicks from the effects of intravenous LPS.

Conclusions:

• Chicks exhibit significant tolerance to high doses of purified LPS from E. coli.
• The Shwartzman reaction is not readily inducible in chicks via this LPS model.
• Uric acid does not provide protection against acute LPS toxicity in this avian model.