Submitted to: Journal of Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 30, 2001
Publication Date: N/A
Interpretive Summary: Parasites of the genus Sarcocystis are single-celled parasites of animals and man. Certain species cause abortion, regard growth and cause mortality in livestock. Sarcocystis falcatula is a pathogenic parasite causing mortality in birds. Scientists at the Beltsville Agricultural Research Center and a zoo in Florida report for the first time fatal sarcocystosis in a bee-eater. The results will be of interest to zoo veterinarians, pathologists, and parasitologists.
An unidentified Sarcocystis falcatula-like infection was diagnosed in a captive bee-eater (Merops nubicus) in a zoo in Florida, USA. The bird died suddenly, probably due to protozoa- associated pneumonia. Protozoal schizonts were found in lungs and heart and immature sarcocysts were seen in skeletal muscles. Ultrastructurally, schizonts were located in capillary endothelium and merozoites lacked rhoptries, consistent with structure of Sarcocystis species. Sarcocysts were immature, microscopic and contained only metrocytes. The sarcocyst wall had finger-like villar protrusions that were up to 0.7 micrometers long and up to 0.2 micrometers wide. The villar protrusions lacked microtubules, characteristically seen in sarcocysts of S. falcatula. Antigenically, parasites in lungs and muscles of the bee-eater reacted to a varying intensity with polyclonal rabbit antisera to S. falcatula and S. neurona. Results indicated that the parasite in the bee-eater was morphologically different from the reported structure for other S. falcatula infections.