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

J Clin Microbiol. 1997 Mar;35(3):730-3. doi: 10.1128/jcm.35.3.730-733.1997.

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.

MeSH terms

  • AIDS-Related Opportunistic Infections / diagnosis
  • AIDS-Related Opportunistic Infections / parasitology
  • Animals
  • Coccidiosis / complications
  • Coccidiosis / diagnosis
  • Coccidiosis / parasitology
  • Coloring Agents
  • Eucoccidiida / growth & development
  • Eucoccidiida / isolation & purification*
  • Eucoccidiida / ultrastructure
  • Evaluation Studies as Topic
  • Feces / parasitology*
  • Hot Temperature
  • Humans
  • Microwaves
  • Parasitology / methods*
  • Phenazines
  • Staining and Labeling / methods*

Substances

  • Coloring Agents
  • Phenazines
  • safranine T