Recovery rates of Eimeria oocysts from cattle feces by Wisconsin sugar flotation method

Abstract

The purpose of this study was to know the recovery rates of Eimeria oocysts through the course of flotation in sugar solution by WSFM. A fecal sample was collected from a calf infected with Eimeria bovis. Stage one of this study involved recovering oocysts from surface of sugar solution in a test tube with cover slips replaced at time points of 10, 20, 30, 40, 50, 60, 90 min, 2, 3, 4, 5, 6, 24, 48 hr., and 5 days. Oocysts were continuously detected up to 48 hr, with a linear increase in recovery counts for the first 2 hr and the average total count was 953 per gram. Recovery rates of oocysts were 8.1%, 13.3% and 16.4% at 10, 20 and 30 min, respectively. Stage 2 involved a set of 3 tubes. Cover slips were put at intervals of 10, 20 and 30 min on the first tube, while one cover slip was kept for 20 min on the second tube and one for 30 min on the third tube. No significant differences were detected in oocyst counts at 20 min between the first and second tubes, and at 30 min between the first and third tubes. Stage 3 involved the comparison of recovery rates at 10 min between sugar solutions with specific gravities of 1.200 and 1.266. There was no significant difference in oocyst counts between the two solutions. These results indicated that it takes time to recover all Eimeria oocysts from cattle fecal samples by WSFM, but total oocyst counts per gram can be estimated by counting oocysts detected at any sampling time points, such as 10, 20 or 30 min using one cover slip. No improvement of recovery rates was seen by using a higher concentrated sugar solution. Keywords: WSFM, Oocyst, Cattle