Comparison of sensitivity of immunofluorescent microscopy to that of a combination of immunofluorescent microscopy and immunomagnetic separation for detection of Cryptosporidium parvum oocysts in adult bovine feces.
A direct immunofluorescence assay (DFA) (Merifluor; Meridian Diagnostics, Inc., Cincinnati, Ohio) was compared to an immunomagnetic separation (IMS) assay (Dynabeads; Dynal, Inc., Lake Success, N.Y.) coupled with immunofluorescent microscopy (Waterborne, Inc., New Orleans, La.) for their ability to detect low concentrations of Cryptosporidium parvum oocysts in adult bovine fecal material. IMS-DFA resulted in a 2-log-unit increase in sensitivity (10 oocysts/g) compared to DFA alone (1,000 oocysts/g). The higher sensitivity obtained with IMS-DFA resulted from testing 2 g of fecal material instead of the 13 to 19 mg of fecal material tested in the DFA; the increased sensitivity was not attributable to a higher percent recovery.
Pereira
M D
MD
Veterinary Medicine Teaching and Research Center, School of Veterinary Medicine, University of California, Davis, Tulare, California 93274, USA.
Atwill
E R
ER
Jones
T
T
D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000469:parasitology*; D003457:Cryptosporidiosis / Q000469:parasitology / Q000662:veterinary*; D016785:Cryptosporidium parvum / Q000302:isolation & purification*; D005243:Feces / Q000469:parasitology*; D019085:Fluorescent Antibody Technique, Direct; D018189:Immunomagnetic Separation; D008856:Microscopy, Fluorescence; D012680:Sensitivity and Specificity