Excystation and culture of Giardia spp. from human source.
In this paper, we report the hatching of Giardia spp. trophozoites from purified cysts harvested in Sheather's solution from human feces. Isolated cysts were induced by acidic Hank's Balanced Salt Solution (HBSS), incubated at 37 degrees C for 30 minutes, concentrated by centrifugation and washed with pH 7.5 HBSS. The cysts were placed in 8 ml. culture medium (Pancreatic digest of casein and yeast extracts) supplemented with human serum and bile in borosilicate glass tubes with screw caps. Trophozoite excystation was scanned in a Commandon chamber filled with the suspension, sealed with a cover glass and vaseline. The trophozoite emergence was recorded with phase contrast in a photomicroscope. The excystation began within the first 3 minutes, after inoculation into medium. The trophozoites emerged trough a small hole at one end of the cyst and simultaneously began cellular division, the whole process required 5-30 minutes. The trophozoites attached themselves to the walls of the culture tube, permitting the replacement and removal of contaminants without dislodging them from the tube walls. The isolates MM-INP and MG-INP have been maintained at 37 degrees C for more than six months.
Ponce Macotela
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M
Martínez Gordillo
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MN
Alvarez Chacón
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D000818:Animals; D005243:Feces / Q000469:parasitology; D005872:Giardia / Q000254:growth & development* / Q000302:isolation & purification; D006801:Humans; D010274:Parasitology / Q000379:methods