First identification of zoonotic assemblages A and B of Giardia duodenalis in mules and donkeys in Brazil

Research on Giardia duodenalis in mules and donkeys is scarce in Brazil, especially in molecular epidemiology. Therefore, we performed molecular detection and genotyping of G. duodenalis in mules and donkeys from São Paulo, Brazil. Through diagnostic techniques, we compared the agreement between the parasitological examination and the Polymerase Chain Reaction (PCR), through diagnostic techniques. A total of 110 animals, 46 mules, and 64 donkeys were investigated in this study. Fecal samples were collected directly from the rectal ampulla of the animals and submitted to the parasitological investigation of Giardia spp. cysts using the Faust technique. An aliquot of the sample was also subjected to DNA extraction and molecular detection of Giardia spp. was performed by nested PCR of the 18S rRNA gene. Positive samples were subjected to amplification of the additional genes β-giardin (βg), Triose Phosphate Isomerase (Tpi), and Glutamate Dehydrogenase (Gdh) for genotyping. In our study, we identified 4.35 % (2/46) and 1.56 % (1/64) of G. duodenalis in mules and donkeys, respectively. Through microscopic examination, we detected the parasite in 0.9 % (1/110) of the combined samples. Amplifying and sequencing the Gdh revealed that two samples presented 100 % genetic similarity with assemblage B (sub-assemblage BIV) and one with assemblage A (sub-assemblage AII). In this research, through molecular characterization, we identified, for the first time in the world, the potentially zoonotic assemblages A and B in mules and, for the first time, assemblage B in donkeys in Brazil.