Ultrastructure of Babesia equi in ponies treated with imidocarb.

This research article investigates the effect of the drug imidocarb on the ultrastructure of Babesia equi, a parasitic protozoan that infects the red blood cells of ponies. Imidocarb treatment resulted in significant degeneration and morphological changes in the parasites.

Objective and Methodology

• The research involved infecting four splenectomized ponies with Babesia equi. Two ponies were not treated and used as controls, while the other two were treated with imidocarb.
• The imidocarb was administered when 20% of the ponies’ erythrocytes were infested by the parasite.
• Scientists analyzed the morphology of the parasites in both treated and untreated ponies by observing blood smears under a microscope.

Findings in Unhandled Ponies

• In non-treated ponies, the parasite’s nucleus within the erythrocyte was round, deeply red staining, and typically made up two-thirds of the organism’s size.
• Advanced diagnostic tools such as electron microscopy revealed that the Babesia equi in untreated ponies had food vacuoles, a distinct nucleus, smooth and rough endoplasmic reticulums, and ribosomes.

Effects of Imidocarb Treatment on Parasite Structure

• In imidocarb-treated ponies, the parasite exhibited swelling and the formation of empty spaces known as vacuoles, except for an area beneath the plasma membrane, where the nucleus was compressed, elongated and clumped.
• Scientists identified four stages of degeneration of Babesia equi in ponies treated with imidocarb.
• Stage 1: The parasite’s nuclear cistern (an envelope structure within the nucleus) dilated and the chromatin (the material that makes up chromosomes) clumped together.
• Stage 2: The nuclear envelope dissolved, allowing nuclear substance to seep into the cytoplasm.
• Stage 3: The cytoplasm became filled with vacuoles and chromatin was pushed to the cell periphery.
• Stage 4: The organism was mostly filled with a vacuole, and the chromatin had condensed into an irregular and clumped mass.
• These changes indicate significant degeneration and destruction of the parasite due to the imidocarb treatment.