S. Caccio et al., Large sequence variation at two microsatellite loci among zoonotic (genotype C) isolates of Cryptosporidium parvum, INT J PARAS, 31(10), 2001, pp. 1082-1086
The genetic polymorphism among 57 Cryptosporidium parvum isolates belonging
to genotype 'C' was studied by PCR amplification and the sequencing of two
microsatellite loci (ML1 and ML2). A comparative analysis of DNA sequences
showed the presence of three (ML1-238, ML1-226, and ML1-220) and seven (ML
2-231, ML2-229, ML2-227, ML2-213. ML2-193, ML2-191, and ML2-187) different
alleles at these two loci. Alleles differed by expansions/contractions of t
he microsatellite repeats that generated length polymorphisms. Some alleles
were found to be associated with infections of all examined hosts (calf, k
id, lamb, and human), whereas others were either associated with a single h
ost, or were geographically restricted. When considering the information fr
om both loci, some preferential associations between alleles are apparent.
These data confirm the utility of microsatellite markers for the molecular
identification of C. parvum, which is of particular relevance in the invest
igation of the source of infection of outbreaks and single cases, its well
as for genetic studies. (C) 2001 Australian Society for Parasitology Inc. P
ublished by Elsevier Science Ltd. All rights reserved.