MOLECULAR CHARACTERIZATION OF CRYPTOSPORIDIUM FROM VARIOUS HOSTS

A 298 bp region of the Cryptosporidium parvum 18S rDNA and a 390 bp re gion of the acetyl-CoA synthetase gene were sequenced for a range of h uman and animal isolates of Cryptosporidium from different geographica l areas. A distinct genotype is common to isolates from cattle, sheep and goats and also an alpaca from Peru and is referred to here as the 'calf'-derived Cryptosporidium genotype. Another genotype of 'human'-d erived isolates also appears to be conserved amongst human isolates al though humans are also susceptible to infection-with the 'calf' Crypto sporidium genotype. Mice and pigs carry genetically distinct genotypes of Cryptosporidium. Three snake isolates were also analysed, 2 of whi ch exhibited C. muris genotypes and the third snake isolate carried a distinct 'mouse' genotype.