Comparison of conventional staining methods and monoclonal antibody-based methods for Cryptosporidium oocyst detection.
The sensitivity and specificity of seven microscopy-based Cryptosporidium oocyst detection methods were compared after application to unconcentrated fecal smears. The seven methods were as follows: (i) a commercial acid-fast (AF) stain (VOLU-SOL) method, (ii) Truant auramine-rhodamine (AR) stain method, (iii) fluorescein-conjugated C1B3 monoclonal antibody (MAb) direct fluorescence method, (iv) OW3 MAb indirect fluorescence method, (v) biotinylated OW3 indirect fluorescence method, (vi) biotinylated OW3-indirect diaminobenzidine (DAB) method, and (vii) biotinylated OW3-aminoethylcarbazole (AEC) method. A total of 281 randomly collected Formalin-fixed fecal samples (submitted to the Maricopa County Health Department, Phoenix, Ariz.) and 30 known positives (Formalin-fixed and K2Cr2O7-preserved stools from our laboratory) were examined in a blind test; 32 of 311 samples (10.3%) were confirmed positive. Of the confirmed positives, 40.6% were identified by the AF method, 93.8% were identified by the AR method, 93.8% were identified by the C1B3 method, 81.3% were identified by the OW3-DAB method, 71.9% were identified by the OW3-AEC method, 100% were identified by the OW3 indirect fluorescence method, and 100% were identified by the biotinylated OW3 indirect fluorescence method. False-positives were encountered by the AF and AR methods (52.0 and 85.7% specificity, respectively), while no false-positives encountered by the MAb-based methods. Oocysts in infected tissue sections were easily detected by the MAb-based methods.
Arrowood
M J
MJ
Department of Veterinary Science, University of Arizona, Tucson 85721.
Sterling
C R
CR
D000818:Animals; D000911:Antibodies, Monoclonal; D001710:Biotin; D015153:Blotting, Western; D002417:Cattle; D003044:Coccidia / Q000302:isolation & purification*; D003457:Cryptosporidiosis / Q000175:diagnosis*; D003458:Cryptosporidium / Q000276:immunology / Q000302:isolation & purification*; D005189:False Positive Reactions; D005243:Feces / Q000469:parasitology*; D005455:Fluorescent Antibody Technique; D006801:Humans; D006825:Hybridomas; D007124:Immunoenzyme Techniques; D051379:Mice; D011237:Predictive Value of Tests; D013194:Staining and Labeling
D000911:Antibodies, Monoclonal; D001710:Biotin