Identification of zoonotic Cryptosporidium and Giardia genotypes infecting animals in Sydney's water catchments

To identify the animal sources for Cryptosporidium and Giardia contamination, we genotyped Cryptosporidium and Giardia spp. in wildlife from Sydney's water catchments using sequence analysis at the 18S rRNA locus for Cryptosporidium and 18S rRNA and glutamate dehydrogenase (gdh) for Giardia. A total of 564 faecal samples from 16 different host species were analysed. Cryptosporidium was identified in 8.5% (48/564) samples from eight host species and Giardia was identified in 13.8% (78/564) from seven host species. Eight species/genotypes of Cryptosporidium were identified. Five G. duodenalis assemblages were detected including the zoonotic assemblages A and B.

Research highlights► Identification of zoonotic Cryptosporidium species in kangaroos, a wallaby, a cow and a dog. ►First report of C. hominis in kangaroos. ► Identification of zoonotic Giardia in kangaroos and novel A1 variants in cattle and deer. ► First report of Giardia assemblage D in kangaroos and foxes and assemblage C in cattle and marsupials. ► Novel Giardia assemblage C & D variants identified in kangaroos, a deer and a dog.