| Cryptosporidiosis is an important zoonotic parasitosis. In order to investigate the prevalence of intestinal parasites in sheep in Hennan province, we spent one year to detect sheep faecal samples from 5 farms in 4 counties from July 2006 to July 2007. The samples were identificated by microscope, nested PCR detection and nested PCR-RFLP analysis; genotypic analysis of the Small-Subunit rRNA (SSU rRNA) gene were carried out to indentify species/ genotype, infered molecular phylogenetic relationship between sheep cryptosporidium and other Cryptosporidium.spp. In order to analyze dynamic variation rule of sheep Cryptosporidium.spp with host age and seasons, a trace investigate was carried out in one sheep farm where Cryptosporidium.spp were found in sheep, so that established necessary control rationale of Cryptosporidiosis.For understanding the prevalence of intestinal parasites in sheep in Hennan province, 1265 sheep faecal samples from 5 farms were detected with the convention methods. The results showed that 5 types parasites were detected in stool specimens, 2 types were protozoon (Coccidian, Cryptosporidium), 2 types were nematode (Trichuris ovis, Strongyloides stercoralis), and 1 type was cestode. As a result,the average infection rate was 93.12%(1178/1265), Thereinto, the infection rate of Cryptosporidium sp. was 3.10%, Eimeria sp. was 88.94%, Trichuris sp was 10.83%, Strongyloides sp was 59.11%, cestode was 43.96%, respectively. The results showed that sheep parasites mixed infections are more serious; In addition, the mixed infection of Eimeria sp, tapeworm and Strongyloides stercoralis took up 60.10% of the total infections rate. The results showed that sheep infection rate was decreased with the age increased.An epidemiologic survey was carried out to investigate the prevalence of and to identify factors associated with the risk of Cryptosporidium infection in sheep in Henan province. 1701 sheep faecal samples from 5 farms in 4 regions were detected by the Sheather's sugar flotation and modified acid-fast staining method. The results showed that oocysts of Cryptosporidium were found in 80 samples, the total infection rate was 4.70%(80/1701), and the percentage of animals shedding oocysts peaked in 3-week-old lambs and in ewes on three week postpartum was 41.18% and 6.29%, respectively. According to the morphometrical values, the Cryptosporidium oocysts were identified as C. parvum and C. andersoni. At the same time, the results showed that there were difference in the infection rates of Cryptosporidium among different ages of sheep, but with no significant difference among seasons.The Small-Subunit rRNA (SSU rRNA) gene fragments of 80 sheep postitive samples were amplified by nested PCR. The PCR products were digested by Sspâ… restriction enzyme and Vspâ… restriction enzyme respevtively to determine species and genotype. After 39 samples sequencing, homological sequences were alignmented. Phylogenetic tree and homological analysis were made by some biological softwares such as ClustalX 1.81, and DNAStar 4.0. Based on the phylogenetic analysis of 18S rRNA gene and PCR-RFLP analysis, 39 isolates were idenfied as cervine genotype(35/39),C. bovis (2/39),C. andersoni (2/39), and cervine genotype may be an important zoonotic Cryptosporidium.spp.To analyze variation rule of sheep Cryptosporidium.spp with age and season, on the basis of epidemiological survey. We investigated pregnant ewes and lamb in positive sheep farm to study and analyze sheep Cryptosporidium species and genotypes variation rule with different age groups, different seasons, to infer animals infection source and transmission mechanism in sheep farm.The result showed: Cryptosporidium cervine genotype could infect differenct age groups sheep and was dominance species in all sheep Cryptosporidium.spp in Henan, variation rule with age and seasons was not significant.The present research PCR- RFLP and molecular phylogenetic relationship analysed were employed to identity sheep Cryptosporidium.spp in Henan, China. The result showed that sheep Cryptosporidium.spp included cervine genotype,C. bovis,C. andersoni, and cervine genotype was dominance species in all Cryptosporidium. spp. |
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