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Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

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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.

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Abstract Pentatrichomonas hominis and Tritrichomonas foetus (cat genotype) have been commonly identified as intestinal trichomonads in both dogs and cats. Although P. hominis is considered as non-pathogenic protozoa in many kinds of mammals, it has the potential for zoonotic transmission. T. foetus has been recognized as the emerging causative agent of diarrhea in cats without the risk of zoonotic transmission. As pet shops are the major source of young companion animals, the present study discusses the molecular prevalence of P. hominis and T. foetus from 544 pet shop puppies and 409 kittens. The results suggest that the prevalence of P. hominis (puppies: 7.0%; kittens: 0.5%) and T. foetus (puppies: 0%; kittens: 2.4%) in pet shop young animals are low. In addition, the infections of P. hominis and T. foetus are not always associated with the clinical signs (soft or diarrhea feces).

Resumo Pentatrichomonas hominis e Tritrichomonas foetus (genótipo de gato) têm sido comumente identificados como trichomonas intestinais em cães e gatos. Apesar de P. hominis ser considerado como protozoário não patogênico em muitos tipos de mamíferos, tem potencial para transmissão zoonótica. Enquanto o T. fetus foi reconhecido como o agente causador emergente de diarreia em gatos sem o risco de transmissão zoonótica. Devido às lojas de animais serem as principais fontes de filhotes de animais domésticos, o presente estudo discute a prevalência molecular e/ou o potencial zoonótico de P. hominis e T. foetus em 544 filhotes de cachorro e 409 gatos de "pet shop". Os resultados sugerem que a prevalência de P. hominis (cães: 7,0%; gatos: 0,5%) e T. foetus (cães: 0%; gatos: 2,4%) em animais jovens de "pet shop" é baixa. Além disso, as infecções de P. hominis e T. foetus nem sempre estão associadas aos sinais clínicos (fezes moles ou diarreia).

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The pathological and molecular findings associated with Histomonas meleagridis are described in a leucistic Indian peafowl (Pavo cristatus) from Southern Brazil. The most significant gross findings were multifocal necrotizing hepatitis and diphtheric typhlitis. Histopathologic evaluation of the liver, ceca, kidney, spleen, and small intestine revealed systemic histomoniasis (SH) associated with intralesional and intravascular accumulations of histomonad organisms consistent with H. meleagridis. PCR was used to amplify the DNA of H. meleagridis from the liver, ceca, small intestine, spleen, lungs, and kidneys. Direct sequencing and phylogenetic analyses confirmed that the isolate of the flagellated trichomonad identified from this investigation is more phylogenetically related to H. meleagridis than Tetratrichomonas gallinarum, Tritrichomonas foetus, and Dientamoeba fragilis. These results confirmed the occurrence of SH in this peafowl and add to the diagnosis of this disease in birds from Brazil. This report might represent the first complete identification of spontaneous histomoniasis in a peafowl due to pathological and molecular characteristics and one of the few documented cases of SH in non-commercial birds.

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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.

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This study refutes the accepted dogma that significant pathogenic effects of Trichomonas gallinae are limited to columbiformes and raptors in free ranging bird populations in North America. Trichomonads were associated with morbidity and mortality amongst free ranging house finches (Carpodacus mexicanus), mockingbirds (Mimus polyglottos) and corvids (scrub jay: Aphelocoma californica; crow: Corvus brachyrhynchos; raven: Corvus corax) in northern California. Prevalence of trichomonad infection was 1.7% in house finches, 0-6.3% in corvids, and 0.9% in mockingbirds. Bird case fatality ratio was 95.5% in house finches, 0-100.0% in corvids, and 37.5% in mockingbirds. DNA sequences of parasites in house finches and corvids were identical to T. gallinae strain g7 (GeneBank AY349182.1) for the 5.8s ribosome. DNA sequences of parasites cultured from two mockingbirds were genetically distinct from that of available sequenced trichomonads. These isolates were clearly phylogenetically more closely related to the Trichomonadinae than the Tritrichomonadinae. While molecular techniques were required to differentiate between trichomonad species, wet mount preparations from the oral cavity/crop were a reliable and inexpensive method of screening for trichomonad infections in these species. Positive wet mount tests in house finches and corvids living in northern California were highly likely to indicate infection with T. gallinae, while in mockingbirds positive wet mounts most likely indicated a trichomonad other than T. gallinae.

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The Trichomonads have been the subject of several molecular studies that reported some discrepancies both at the lower and higher taxonomic levels. The purpose of this study was to make an extensive phylogenetic analysis of the Trichomonadidae using ITS-1/5.8S/ITS-2 sequences, to better understand its phylogeny and the usefulness of this marker. ITS-1/5.8S/ITS-2 sequences of 36 strains from 14 species belonging to Trichomonadidae and Monocercomonadidae were analysed, in which 20 were newly determined. Maximum likelihood, maximum parsimony, neighbour joining, and Bayesian phylogenetic methods were employed in order to reconstruct and compare the evolutionary history of this group. Tetratrichomonas gallinarum and four strains of Tetratrichomonas sp. isolated from bull genital organs were found closely related, confirming the classification of the latter, probably as a new species. The monophyly of Tritrichomonadinae and Trichomonadinae subfamilies were corroborated, with the exclusion of Trichomitus batrachorum from the latter since it grouped consistently with Hypotrichomonas acosta. Tritrichomonas foetus, Tritrichomonas suis and potentially also Tritrichomonas mobilensis seemed to correspond to the same species. Monocercomonas sp. and Ditrichomonas honigbergii emerged as independent lineages, with their phylogenetic positions undetermined. Neither Trichomonadidae nor Monocercomonadidae were supported as monophyletic groups. The ITS-1/5.8S/ITS-2 seems to be a reliable locus for phylogenetic studies in the Trichomonadida, mainly at lower taxonomic levels, and at least up to the family level.

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We present observations on an unusual tetratrichomonad species isolated from preputial smegma of virgin bulls. Ultrastructural studies were performed using scanning and electron microscopy techniques. This protozoan presents four anterior flagella of unequal length and a recurrent one forming the undulating membrane. It shows one anterior nucleus, a Golgi complex, an axostyle, and a costa. The hydrogenosomes are rather elongated, seen in groups, and presenting different electron densities. Vacuoles of different sizes containing bacteria and material in process of digestion were frequently found. PCR was also used in order to compare the species herein described with other trichomonad species. The amplification products were seen only with primers TFR1 and TFR2 (specific to trichomonads), but not with TFR3 and TFR4 (specific to Tritrichomonas foetus), suggesting that although collected from the genital tract of the bull, this protist was not T. foetus. We propose that the appearance of these tetratrichomonads were probably due to the sodomy practiced among bulls. Concomitant contamination of preputial cavity with feces could explain the presence of the opportunistic organism. The observations presented here show the importance of the correct diagnostic when investigating samples obtained from the urogenital tract of cattle. We also suggest that this flagellate belongs to the species Tetratrichomonas buttreyi.

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