Table 5 Diagnostic features of enteric pathogens previously classified as coccidians
From: Inflammatory and infectious manifestations of immunodeficiency in the gastrointestinal tract
Feature | Microsporidia spp.a [105] | Cryptosporidia parvumb [106] | Cystoisospora belli [107] | Cyclospora cayetanensis [99] |
|---|---|---|---|---|
Size | 2–3 µm spores, or slightly larger plasmodia | 2–5 µm spherical sporozoites | 15–20 µm | 2–3 µm schizonts. 5–6 µm merozoites |
Location | Luminal aspects of epithelial cells | Vacuoles at apical surface | Epithelial cells. Macrophages | Luminal aspects of epithelial cells |
Morphologic features | Multiple tiny round organisms in supranuclear vacuole impart bubbly appearance to cytoplasm | “Blue beads on a string” at luminal surface | Large, elliptoid asexual forms. Round sexual forms with prominent nucleoli | Multiple stages of life cycle: round schizonts and crescentic merozoites |
Positive ancillary stains | Modified trichrome. Giemsa, Gram, PAS Warthin-Starry | Giemsa. Gram | Giemsa, Gram, PAS, | Acid fast. Giemsa |
