Identification of zoonotic Giardia genotypes in marsupials in Australia
Division of Veterinary and Biomedical Sciences, Murdoch University, Murdoch Drive, Perth, Murdoch, WA 6150, Australia Department of Biological Sciences, Macquarie University, North Ryde, Sydney, NSW 2109, Australia Faculty of Veterinary Science, University of Melbourne, Werribee, Vic. 3030, Australia, Division of Health Sciences, School of Nursing, Murdoch University, Murdoch, WA 6150, Australia
A total of 421 fecal samples from a variety of captive and wild marsupial hosts in Western Australia, Victoria and South Australia were screened for the presence of Giardia species/genotypes using PCR and sequence analysis of a fragment of the 18S rRNA gene. Giardia spp. were identified in 13.4% (28/209) of samples from captive marsupials and 13.7% (29/212) of samples from wild marsupials. Sequence analysis at the 18S locus identified the zoonotic Giardia duodenalis Genotypes A and B in both captive and wild marsupials. Eight isolates were typed as genotype B3 and B4 at the gdh locus, although 7/8 were typed as genotype A at the 18S rRNA locus. The possible reasons for this discordance are discussed. This is the first report of genotype B and only the second report of genotype A in marsupials. As some of the genotype B isolates were identical to human-derived Giardia gdh sequences, these results suggest that marsupials in catchments may pose a public health risk and therefore warrant further investigation.