Genotype and phenotype of Cryptosporidium parvum and C. muris

The study of genotype and phenotype variation was conducted on two species of intestinal parasites (Cryptosporidium parvum and C. muris) via experimental infection involving 10 successive passages in calves (Bos taurus). Infection with C. parvum worked well, whereas no clinical signs were observed in this study with C. muris. For the genotype, we studied two genes (HSP70 and GP60) that we amplified by double PCR and then sequenced. The results seem to indicate that these genes are not modified after 10 passages in calves. This could indicate a low level of genetic evolution in the parasite when it passes from the environment to a host animal, thus facilitating epidemiological studies during cryptosporidiosis outbreaks. However, it should be noted that the parasites used did not come from the environment. An attempt was made to study phenotype variation using dot blot immunoassay with serum from infected calves, but this was unsuccessful. Problems related to the concentration of C. parvum oocysts placed on the dot blot immunoassay membrane are suspected.