Cryptosporidium parvum sporozoite staining by propidium iodide.
Modified Ziehl-Neelsen (ZN) acid-fast stain is the usual method for detection of Cryptosporidium oocysts in feces. Propidium iodide permitted us to stain free or intra-oocyst sporozoites. With the ZN method only 3-5% of the oocysts purified from three human and one experimentally infected lamb dichromate-preserved feces were stained by carbol fuchsin. These fuchsin-stained oocysts were free of intact sporozoites as identified by propidium iodide staining. Treatment with 10% formalin or 0.5% sodium hypochlorite increased the percentage of acid-fast stained oocysts and thus the sensitivity of acid-fast staining. Treatment with sodium hypochlorite induced intra-oocyst sporozoite alterations as demonstrated by flow cytometric analysis of the oocysts' DNA content. Propidium iodide staining of fixed oocysts is a simple and rapid method to visualize sporozoites and to assess oocyst preservation after different treatments.
Cozon
G
G
INSERM U80 CNRS URA 1177 UCBL, Hôpital E. Herriot, Lyon, France.
Cannella
D
D
Biron
F
F
Piens
M A
MA
Jeannin
M
M
Revillard
J P
JP
D000818:Animals; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology*; D005434:Flow Cytometry; D006801:Humans; D011419:Propidium; D013194:Staining and Labeling
D011419:Propidium