Detection of Giardia duodenalis Zoonotic Assemblages AI and BIV in Pet Prairie Dogs (Cynomys ludovicanus) in Bangkok, Thailand

Abstract

Giardia is a flagellate protozoa that can be transmitted via direct contact and by consuming contaminated water. It is pathogenic in humans and various other animals, including exotic pets. Pet prairie dogs are popular in Thailand, but they have not been investigated regarding giardiasis. Giardia infection was measured, and genetic characterization was performed to investigate the zoonotic potential of Giardia carried by pet prairie dogs. In total, 79 fecal samples were examined from prairie dogs visiting the Kasetsart University Veterinary Teaching Hospital during 2017–2021. Simple floatation was conducted. Two Giardia-positive samples were submitted for DNA extraction, PCR targeting the Giardiassu rRNA, tpi and gdh genes was performed, and genetic characterization using sequencing analysis was conducted. Risk factors associated with Giardia infection were analyzed. Giardia infection was found in 11 out of the 79 pet prairie dogs (13.9%). Giardia infection was significantly higher in male prairie dogs (p = 0.0345). Coccidia cysts (12.7%), the eggs of nematodes (6.3%), and amoeba cysts (2.5%) were also detected. Genetic characterization of the two Giardia-positive samples revealed that they were G. duodenalis assemblage A, sub-genotypes AI and assemblage B, and sub-genotype BIV, the zoonotic assemblages. This was the first report of Giardia infection in pet prairie dogs in Bangkok, Thailand. The results revealed that these pet prairie dogs in Thailand were infected with zoonotic assemblages of G. duodenalis sub-genotype AI, which might have been derived from animal contaminants, whereas sub-genotype BIV might have been derived from human contaminants. Owners of prairie dogs might be at risk of giardiasis or be the source of infection to their exotic pets.