Isolation of Cyclospora oocysts from fruits and vegetables using lectin-coated paramagnetic beads

Published techniques for recovering parasites from fruit and vegetables are generally inadequate, with low and variable recovery efficiencies. Herein, we describe an improved method for analyzing fruit and vegetables for Cycl ospora oocysts. The technique includes washing procedures, sonication, and separation using lectin-coated paramagnetic beads. Identification is by mic roscopy (differential interference contrast and fluorescence). Oocyst recov ery efficiencies from mushrooms, lettuce, and raspberries were approximatel y 12%. Recovery efficiencies from bean sprouts were approximately 4%. Altho ugh no significant difference in recovery efficiency could be detected betw een samples processed using the lectin-coated beads and samples processed w ithout this procedure, distinct advantages were apparent when the lectin-co ated beads were used. A considerably smaller, cleaner final volume remained for microscopy, which increases the sensitivity of the technique and reduc es operator time.