First genetic analysis of Cryptosporidium from humans from Tasmania, and identification of a new genotype from a traveller to Bali

Little is known about the molecular composition of Cryptosporidium species from humans living in the insular state of Tasmania, Australia. In the present study, we genetically characterized 82 samples of Cryptosporidium from humans following conventional coproscopic testing in a routine, diagnostic laboratory. Using a PCR-coupled single-strand conformation polymorphism (SSCP) technique, targeting portions of the small subunit rRNA (SSU), and 60 kDa glycoprotein (gp60) loci, we identified two species of Cryptosporidium, including C. hominis (subgenotypes IbA10G2, IdA16, IeA12G3T3, and IfA19G1) and C. parvum (IIaA16G1R1 and IIaA18G3), and a new operational taxonomic unit (OTU) that genetically closely resembled C. wrairi. This OTU was further characterized using markers in the actin, Cryptosporidium oocyst wall protein (COWP), and 70 kDa heat shock protein (hsp70) genes. This study provides the first characterization of species and genotypes of Cryptosporidium from Tasmania, and presents clear genetic evidence, using five independent genetic loci, for a new genotype or species of Cryptosporidium in a Tasmanian person with a recent history of travelling to Bali, Indonesia. It would be interesting to undertake detailed molecular-based studies of Cryptosporidium in Indonesia and neighbouring countries, in conjunction with morphological and experimental investigations of new genotypes.