FACTORS IN PLASMA CONCERNED IN NATURAL RESISTANCE TO AN AVIAN MALARIA PARASITE (PLASMODIUM LOPHURAE)

Area of Science:

• Immunology
• Parasitology
• Avian Biology

Background:

• Plasmodium lophurae is a significant parasite affecting avian species.
• Understanding natural immunity factors in birds is crucial for developing treatments.

Purpose of the Study:

• To investigate the anti-parasitic properties of adult chicken and duck plasma against Plasmodium lophurae.
• To identify the nature and characteristics of the active substances within the plasma.

Main Methods:

• Infection of young chicks and ducklings with Plasmodium lophurae.
• Injection of plasma from adult chickens and ducks into infected young birds.
• Fractionation of plasma and heat treatments to isolate active components.

Main Results:

• Adult chicken plasma significantly reduced parasitemia in infected chicks and embryos.
• Active substances in chicken plasma were heat-labile above 56°C and located in the euglobulin fraction.
• Duck plasma effectiveness correlated positively with the adult duck's resistance to infection.
• Female ducks with active ovaries predominantly produced effective plasma and showed higher resistance.

Conclusions:

• Avian plasma contains factors that confer resistance to Plasmodium lophurae infection.
• These factors are linked to the host's natural immune status and potentially sex-linked.
• Further research into these plasma components could lead to novel anti-parasitic strategies.