title: Influence of hydrogen peroxide on acid-fast staining of Cryptosporidium parvum oocysts.
abstract: Infections by the protozoan parasite Cryptosporidium parvum are routinely diagnosed by modified Ziehl-Neelsen (acid-fast) staining of faecal preparations despite the counterstaining and ghost-like appearance of some oocysts. Quantitative studies demonstrated that only a small percentage of oocysts excreted by naturally infected newborn calves displayed acid-fast characteristics, but that percentage increased when the time between excretion and sample staining was increased. The treatment of faecal samples with hydrogen peroxide (10 min, 5 vol. final concentration) caused all oocysts to become acid-fast, with up to 40-fold increases in test sensitivity in samples treated and stained within 3 h of excretion. Flow-cytometry analysis of hydrogen peroxide-treated oocysts also demonstrated increased labelling of oocysts by a commercial monoclonal antibody preparation commonly used for diagnosis.
authors.affiliation: Instituto de Biotecnología, Departmento de Parasitologia, Facultad de Ciencias, Polígono Universitario de Fuentenueva s/n, Granada, Spain.
authors.forename: E
authors.initials: E
authors.lastname: Entrala
authors.forename: M
authors.initials: M
authors.lastname: Rueda-Rubio
authors.forename: D
authors.initials: D
authors.lastname: Janssen
authors.forename: C
authors.initials: C
authors.lastname: Mascaró
mesh_terms: D000143:Acids; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis / Q000473:pathology; D004396:Coloring Agents; D003457:Cryptosporidiosis / Q000175:diagnosis / Q000469:parasitology / Q000662:veterinary; D016785:Cryptosporidium parvum / Q000166:cytology* / Q000302:isolation & purification; D005243:Feces / Q000469:parasitology; D005434:Flow Cytometry; D006801:Humans; D006861:Hydrogen Peroxide; D007202:Indicators and Reagents; D013194:Staining and Labeling / Q000379:methods*
chemical_list: D000143:Acids; D004396:Coloring Agents; D007202:Indicators and Reagents; D006861:Hydrogen Peroxide