ABSTRACT
The genotyping of cryptosporidium clinical isolates obtained from 36 gastrointestinal symptomatic patients were identified by nested PCR for amplification of 18S rRNA followed by RFLP analysis using Ssp1 and Vsp1, and then pathological changes between different cryptosporidium genotypes were evaluated in experimentally infected mice. Cryptosporidium genotypes [C. parvum, C. hominis and C. melegridies] were detected [66.7%, 27.7% and 5.6%] respectively in human isolates. Different degrees of pathological changes were found among infected mice by different Cryptosporidium genotypes. Moderate and severe degrees of pathological changes with infection score ranging from 2 to 4 were found in all infected mice with C. parvum [except one isolate], while mild degree of pathological changes with infection score of 2 was found in all mice with C. melegridies. The results showed statistically significant relation between genotype and pathological degrees. There were no differences in the average number of oocysts per smear in Group II and Group III while in Group I, there was no oocysts shedding