Uniform staining of Cyclospora oocysts in fecal smears by a modified safranin technique with microwave heating.
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.
Visvesvara
G S
GS
Division of Parasitic Diseases, National Cancer for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30341-3724, USA. gsvl@ciddpd2.em.cdc.gov
Moura
H
H
Kovacs-Nace
E
E
Wallace
S
S
Eberhard
M L
ML
D017088:AIDS-Related Opportunistic Infections / Q000175:diagnosis / Q000469:parasitology; D000818:Animals; D003048:Coccidiosis / Q000150:complications / Q000175:diagnosis / Q000469:parasitology; D004396:Coloring Agents; D016783:Eucoccidiida / Q000254:growth & development / Q000302:isolation & purification* / Q000648:ultrastructure; D005069:Evaluation Studies as Topic; D005243:Feces / Q000469:parasitology*; D006358:Hot Temperature; D006801:Humans; D008872:Microwaves; D010274:Parasitology / Q000379:methods*; D010619:Phenazines; D013194:Staining and Labeling / Q000379:methods*
D004396:Coloring Agents; D010619:Phenazines; C009195:safranine T