Morphological and molecular characterization of a species of Tetratrichomonas present in feces of Brazilian sheep (Ovis aries) and goats (Capra hircus).

The trichomonads form part of the phylum Parabasalia, a complex assemblage of diverse species of flagellated protists, with some members recognized as pathogens of men and/or animals. Associations, probably as commensals, between the species Tetratrichomonas ovis and sheep were reported in North America during the 1960s based on morphological and cultural characteristics. Intriguingly, no subsequent studies of this topic have been published. Feces, collected from sheep (n = 55) and goats (n = 14), reared on small-scale, production facilities in Southeastern Brazil, were examined for parabasalids. Protozoa, demonstrating morphologies and motility characteristic of trichomonads, were detected by direct microscopy in 64% of sheep and 43% of goat samples. In contrast to T. ovis, none of the samples could be cultured in Diamond's medium; however, cultures were obtained for three goat and seventeen sheep samples in peptonized broth. Based on morphological analyses, all isolates were classified as members of the genus Tetratrichomonas. Sequencing of the ITS1-5.8S rRNA gene-ITS2 region revealed three highly similar genotypes that were essentially identical to sequences reported for Tetratrichomonas spp. isolated from the preputial cavity of cattle in the USA and Southern Brazil. The findings of this study extend and enhance our knowledge of parasitism in small ruminants by parabasalids.

Morphological, ultrastructural, and molecular characterization of intestinal tetratrichomonads isolated from non-human primates in southeastern Brazil.

Non-human primates are our closest relatives and represent an interesting model for comparative parasitological studies. However, research on this topic particularly in relation to intestinal parasites has been fragmentary and limited mainly to animals held in captivity. Thus, our knowledge of host-parasite relationships in this species-rich group of mammals could be considered rudimentary. The current study combined morphological, ultrastructural, and molecular analyses to characterize isolates of intestinal tetratrichomonads recovered from the feces of three species of South American, non-human primates. Fecal samples were collected from 16 animals, representing 12 distinct species. Parabasalid-like organisms were evident in five samples (31%) of feces: two from Alouatta sara, two from Callithrix penicillata, and one from Sapajus apella. The five samples presented morphologies consistent with the description of Tetratrichomonas sp., with four anterior flagella of unequal length, a well-developed undulating membrane, and a long recurrent flagellum. Sequencing of the ITS1-5.8S rRNA-ITS2 region demonstrated that the isolates from A. sara, and C. penicillata were closely related and highly similar to isolates of Tetratrichomonas brumpti, recovered previously from tortoises (Geochelone sp.). The flagellate recovered from S. apella demonstrated a similar morphology to those of the other isolates, however, sequence analysis showed it to be identical to an isolate of Tetratrichomonas sp. recovered from white-lipped peccaries (Tayassu pecari). The findings of this study extend and enhance our knowledge of parasitism of non-human primates by members of the genus Tetratrichomonas and indicate that the host range of these parasites is broader than previously believed.