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. 1997 Mar;35(3):730–733. doi: 10.1128/jcm.35.3.730-733.1997

Uniform staining of Cyclospora oocysts in fecal smears by a modified safranin technique with microwave heating.

G S Visvesvara 1, H Moura 1, E Kovacs-Nace 1, S Wallace 1, M L Eberhard 1
PMCID: PMC229659  PMID: 9041421

Abstract

Cyclospora, a coccidian protist, is increasingly being identified as an important, newly emerging parasite that causes diarrhea, flatulence, fatigue, and abdominal pain leading to weight loss in immunocompetent persons with or without a recent travel history as well as in patients with AIDS. Modified Kinyoun's acid-fast stain is the most commonly used stain to identify the oocyst of this parasite in fecal smears. Oocysts of Cyclospora stain variably by the modified acid-fast procedure, resulting in the possible misidentification of this parasite. We examined fecal smears stained by six different procedures that included Giemsa, trichrome, chromotrope, Gram-chromotrope, acid-fast, and safranin stains. We report on safranin-based stain that uniformly stains oocysts of Cyclospora a brilliant reddish orange, provided that the fecal smears are heated in a microwave oven prior to staining. This staining procedure, besides being superior to acid-fast staining, is fast, reliable, and easy to perform in most clinical laboratories.

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Selected References

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