| Three valid Cryptosporidium species C. meleagridis, C. baileyi and C. galli are found in bird, in which, C. meleagridis is the third species infected humans and have made extensive concerntration worldwide. Based on it, we conducted an investigation on the prevalence of Cryptosporidium spp. in birds (ostrich, duck, chicken and quail) in Henan province, and the results made us understand the prevalence characterization of Cryptosporidium spp. Moreover, the product of egg yolk antibodies was also performed using C. baileyi from chicken. The results provides a basic research for diagnosing and curing cryptosporidiosis by specific IgY antibodies against Cryptosporidium.From June 2006 to July 2007, six ostrich farms, eight duck farms, eight scale and 37 moderate chicken farms, and 47 quail farms were checked to understand the prevalence of Cryptosporidium spp. The fecal samples were examined using the Sheather's sugar flotation technique and the modified acid-fast stain method. The results showed that the infection rate of ostrich was 1.7% (14/829), 16.31% (92/564) for the duck, the prevalence of laying hens was 10.57%(163/1542)and the broilers was 3.17%(15/473), and 13.15%(239/1818) for the quail. The statistical data showed that the young ostrich and duck are more susceptible to Cryptosporidium. To chicken, with a more higher infection rate for the 0-30d, 31-60d and 121-180d chicken, however, 60-120d and >180d chichen had a lower prevalence. According to the shape of oocysts, the parasites found in ostrich, duck and chichen was C. baileyi,. However, C. baileyi and C. meleagridis were also discovered in quail.The oocysts of C. baileyi were purified by amelioration discontinuous sucrose gradients, then eliminated bacterium by filtration and low speed centrifugation, and after several freeze-thawed cycles and treatment by ultrasonic wave, the antigen of whole oocysts were mixed with Freund compiete and incompiete adjuvant to obtain the immune-antigen. Four immune procedure were designed to immunize the five-month-old laying hens, so to choice the best procedure. The results confirmed that the best immunity procedure was gradually augment the dosage of antigen: the dosage of antigen in the 1st time and the 2nd time are all 1×107 oocysts per hen, 3×107 oocysts per hen in the 3rd time and the 4th time, 5×107 oocysts per hen in the 5th time and the 6th time,and 15～20 days arfter the next immunity injection. The egg yolk antibody were examined with indirect immunofluorescence assay and indirect ELISA assay that has been set up, and testified it was against Cryptosporidium. The egg yolk antibodies were purified with water dilution method, and passed through SDS- PAGE electrophoresis:the result shown that egg yolk show more than twelve protein codes,there were 136KDa,74KDa,62KDa,49KDa and 33KDa,and the purified egg yolk show heavy chains were approximately 62 kDa and light chains was about 33 kDa. The reaction between IgY antibody and oocyst was located by immunofluorescence test. The results showed that the reaction intension was the highest in the top of oocysts, and the intension with sporozoite was higher than that of oocyst wall. |
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