Detection of Plasmodium sp. in capybara

Area of Science:

• Veterinary Parasitology
• Molecular Biology
• Wildlife Health

Background:

• Plasmodium parasites are known to infect a wide range of vertebrate hosts.
• Capybaras (Hydrochaeris hydrochaeris) are large South American rodents with limited documented parasitic infections.
• Understanding Plasmodium prevalence in captive wildlife is crucial for disease management and conservation.

Purpose of the Study:

• To investigate the presence of Plasmodium sp. infection in captive capybaras.
• To characterize any detected Plasmodium isolates molecularly.
• To determine the phylogenetic relationship of capybara Plasmodium to known species.

Main Methods:

• Microscopic examination of blood smears using light microscopy.
• Molecular detection via nested genus-specific Polymerase Chain Reaction (PCR) targeting the small subunit ribosomal RNA (ssrRNA) gene.
• Sequencing and phylogenetic analysis of PCR products.

Main Results:

• One out of 11 capybaras was initially positive by microscopy.
• PCR detected Plasmodium in three out of 11 animals.
• Sequencing revealed low divergence between capybara isolates and suggested a novel species with 73-77.2% similarity to known Plasmodium ssrRNAs, and 78% to Plasmodium mexicanum.

Conclusions:

• This study reports the first evidence of Plasmodium infection in capybaras.
• The molecular data suggest the existence of a new Plasmodium species, proposed as "Plasmodium hydrochaeri".
• Further research is warranted to fully characterize this novel parasite and its host-parasite interactions.