Prevalence and Multilocus Genotyping Analysis of Cryptosporidium and Giardia Isolates from Dogs in Chiang Mai, Thailand.

The occurrence and zoonotic potential of spp. and isolated from dogs in Chiang Mai, Thailand were determined. Fecal samples were collected from 109 dogs between July and August 2008. spp. infection was determined by immunofluorescent assay (IFA), PCR assays that amplify heat-shock protein 70 kDa (hsp70), and two PCR assays that amplify a small subunit-ribosomal RNA (SSU-rRNA). infection was identified using zinc sulfate centrifugal flotation, IFA, and four PCR assays that amplify the glutamate dehydrogenase (gdh), beta-giardin (bg), and generic and dog-specific assays of triosephosphate isomerase (tpi) genes. Overall prevalence of spp. and was 31.2% and 45.9%, respectively. Sequence analysis of 22 -positive samples and 21 -positive samples revealed the presence of in 15, and in 7, Assemblage C in 8, D in 11, and mixed of C and D in 2 dogs. Dogs in Chiang Mai were commonly exposed to spp. and . can be isolated from the feces of dogs, and all assemblages were dog-specific. Dogs could be a reservoir for a zoonotic infection in humans, but further studies will be required to determine the clinical and zoonotic importance.