Molecular Phylogenetic Analysis of Cyclospora, the Human Intestinal Pathogen, Suggests that It Is Closely Related to Eimeria Species

• Published in: The Journal of infectious diseases Vol. 173; no. 2; pp. 440 - 445
• Main Authors: Reiman, David A., Schmidt, Thomas M., Gajadhar, Alvin, Sogin, Mitchell, Cross, John, Yoder, Kristine, Sethabutr, Orntipa, Echeverria, Peter
• Format: Journal Article
• Language: English
• Published: Chicago, IL The University of Chicago Press 01.02.1996; University of Chicago Press
• Subjects: Animals; Base Sequence; Biological and medical sciences; Coccidiosis - parasitology; Cyclospora; Diarrhea - parasitology; DNA; DNA Primers - chemistry; DNA, Protozoan - analysis; DNA, Ribosomal - analysis; Eimeria; Eimeria - classification; Eimeria - genetics; Eucoccidiida - classification; Eucoccidiida - genetics; Eucoccidiida - isolation & purification; Evolution; Feces - parasitology; Fundamental and applied biological sciences. Psychology; Humans; Intestinal Diseases, Parasitic - parasitology; Molecular Biology; Molecular Sequence Data; Oocysts; Parasites; Parasitism; Pathogens; Phylogenetics; Phylogeny; Polymerase Chain Reaction; Protozoa; Ribosomal DNA; RNA, Protozoan - analysis; RNA, Ribosomal - analysis; Systematics. Geographical distribution. Morphology. Cytology; Human; Protozoa; Eimeria; Taxonomy; Phylogenetic tree; Classification; Gut; Molecular biology; Sporozoa
• ISSN: 0022-1899; 1537-6613
• DOI: 10.1093/infdis/173.2.440

A coccidian organism assigned to the genus Cyclospora has been increasingly recognized in association with prolonged diarrhea in humans throughout the world. Confusion surrounds the taxonomy of this fastidious organism, despite the availability of morphology and sporulation characteristics. The small subunit rRNA coding region from cyclosporan oocysts purified from a human fecal specimen was amplified and sequenced. The same sequence was present in specimens from 8 other patients with cyclosporan oocysts but absent in specimens from asymptomatic subjects and from cryptosporidiosis patients. Phylogenetic analysis of rDNA sequences reveals that the human-associated Cyclospora is closely related to members of the Eimeria genus. These results allow predictions concerning Cyclospora host specificity, lifecycle, and epidemiology as well as the development of a specific polymerase chain reaction-based diagnostic assay.