Molecular characterization of trichomonads isolated from animal hosts in the Philippines

Development of a single-cell cloning technique for isolation of Pentatrichomonas hominis: a promising tool for diagnosing Trichomonas spp. infections in the pig breeding industry

BACKGROUND

Pig breeding is a crucial sector of the global economy, playing a significant role in meat production. However, the prevalence of Trichomonas spp., a group of parasites known to induce diarrhea in various hosts, presents significant challenges in breeding facilities. These parasites pose a substantial threat to the pig breeding industry. Furthermore, despite its prevalence, diagnosing Trichomonas spp. is often challenging, primarily owing to the presence of mixed infections involving different species within clinical samples. To address this concern, we developed a novel isolation method that combines a single-cell isolation culture technique with an antimicrobial drug susceptibility test.

METHODS

Trichomonas was isolated and cultured by using the established single-worm separation technology combined with antibacterial drug screening method, and it was identified as Pentatrichomonas hominis by molecular biological identification and morphological identification. The in vitro culture conditions of the isolate were optimized to establish a stable in vitro culture system.

RESULTS

The method developed in this study was effective in successfully isolating a pure species of trichomonad from fecal samples obtained from weaned piglets in Guangdong Province. By optimizing important variables such as the culture medium, serum type, and inoculum quantity, we established a stable in vitro culture system utilizing a modified Diamond medium supplemented with 10% Procell fetal bovine serum without the use of antibiotics. Subsequent analysis of the isolate's 18S rRNA gene, ITS1-5.8S rRNA-ITS2 gene, and EF-α gene, through polymerase chain reaction, DNA sequencing, and phylogenetic analysis, revealed its close association to Pentatrichomonas hominis. Light microscopy and scanning electron microscopy demonstrated the presence of various distinct cellular structures, including four anterior flagella, recurrent flagellum, undulating membrane, pelta and axostyle. Additionally, transmission electron microscopy revealed the existence of organelles such as the Golgi complex, rough endoplasmic reticulum, food vacuoles, and hydrogenosomes. This study represents the first successful isolation of monoclonal cells of P. hominis to our knowledge and serves as a valuable baseline for future research focused on the isolation and purification of various other parasites. Additionally, it offers practical guidance for the diagnosis and management of Trichomonas spp. infections in pigs.

CONCLUSIONS

In summary, our findings underscore the efficacy of our novel isolation technique as a valuable tool for the diagnosis and management of Trichomonas spp. infections, which can help mitigate the significant economic losses encountered in the pig breeding industry.

Prevalence of Pentatrichomonas hominis infection in wild rodents

BACKGROUND

Pentatrichomonas hominis is a zoonotic pathogen linked to gastrointestinal diseases in various animal species and humans. However, its prevalence of in wild rodents remains unexplored. Therefore, investigating the prevalence and molecular characteristics of P. hominis in wild rodents is essential.

METHODS

M. Replace the crossed out sentence above with the following version:This study assessed the prevalence of P. hominis in wild rodents by analyzing 510 fecal samples using nested PCR. Statistical analysis of risk factors was performed with SAS (v9.0) and SPSS software.

RESULTS

The infection rates were 18.18% (16/88) in Yunnan, 0.94% (3/319) in Hunan, and 0% (0/103) in Guangxi. Among the species, Rattus rattus sladeni had the highest infection rate at 40% (2/5), followed by R. flavipectus at 23.08% (9/39), while Niviventer lotipes (0%, 0/23) and R. losea (0%, 0/41) showed no infection. Seasonally, the highest prevalence was observed in autumn (18.18%, 16/88) and the lowest in winter (0%, 0/103). Rodents from farmland had significantly higher infection rates than mountain areas (0%, 0/103) and lakeshores (0.32%, 1/312). Although female rodents had a higher infection rate (4.62%, 11/238) compared to males (2.94%, 8/272), the difference was not statistically significant. Phylogenetic analysis revealed that all P. hominis strains identified belonged to the zoonotic CC1 genotype.

CONCLUSIONS

This study is the first to describe the distribution of P. hominis in wild rodents, paving the way for further epidemiological research on this parasite in wild animals. Such research is crucial for developing strategies to protect human health from zoonotic threats from wild rodents.

The Lost Kingdom: commensal protists in the gut microbiota

The gut microbiota critically influences many aspects of host biology, from nutrient acquisition to immunological function, and is integral to metazoan life. While most microbiome research has focused on bacteria, the intestinal microbiota encompasses a diverse constellation of microorganisms, including viruses, fungi, archaea, and protists. Among these microbes, commensal protists have been particularly neglected, to the point that their status as true members of the microbiota remained contentious. However, findings over the past decade revealed that commensal protists, particularly those in the Parabasalia phylum (parabasalids), perform keystone roles within the intestinal ecosystem. Emerging evidence highlights how parabasalids dramatically impact host immunity, gut microbiome ecology, and host susceptibility to both infectious and inflammatory diseases. In this review, we discuss the recent discoveries of the varied and powerful roles of commensal parabasalids in the intestinal microbiota and outline the challenges and opportunities in this burgeoning new area of the microbiome field.

Existence of Pentatrichomonas hominis in Tibetan Antelope (Pantholops hodgsonii)

Introduction

Pentatrichomonas hominis is a conditional pathogen that parasitizes the intestines of vertebrates and has been detected in various wild animals. However, its infection rate in Tibetan antelopes has not been previously studied.

Methods

In this study, 503 fecal samples from Tibetan antelopes were analyzed to determine the prevalence and molecular characteristics of P. hominis.

Results

Results showed that 1.19% (6/503) of the samples tested positive, and although the prevalence was low, this finding underscores the importance of monitoring wild animals population as hosts of zoonotic pathogens. Additionally, the highest prevalence in Nima County (6.25%, 4/64), followed by Shenza County (2.44%, 2/82). No P. hominis was detected in samples from Shuanghu, Ruoqiang, Qiemo, and Qumarlêb Counties. Seasonally, the highest prevalence was recorded in autumn (1.42%, 6/423). Interestingly, P. hominis was only detected in 2020 (2%, 6/300), with no infections found in 2023 (0/50) or 2024 (0/153). Additionally, the phylogenetic analysis indicated that most islolates belonged to the CC1 genotype, with one representing a potential novel genotype.

Discussion

This is the first s to report the presence of P. hominis in Tibetan antelopes, revealing that Tibetan antelopes may be a potential transmitter of zoontic P. hominis. These findings offer new insights into its epidemiology and contribute valuable data for Tibetan antelope conservation efforts.

First Molecular Detection and Genetic Characterization of Tetratrichomonas buttreyi and Pentatrichomonas hominis in Donkeys in Shanxi Province, China

Two species of trichomonads, Tetratrichomonas buttreyi and Pentatrichomonas hominis, are common intestinal parasites that can impact animal health and productivity. Severe infection by these parasites can lead to diarrhea and wasting in affected animals. Notably, P. hominis is known to cause diarrhea and has the potential to be transmitted between animals and humans. Donkeys hold significant economic importance in China's agricultural sector. However, whether donkeys are infected with T. buttreyi and P. hominis remains unknown globally. To address this gap in knowledge, 815 fecal samples were collected from donkeys in three representative regions in Shanxi Province, North China. Then, the presence and genetic characteristics of T. buttreyi and P. hominis were examined using species-specific PCR primers amplifying the small subunit ribosomal RNA genes. The overall prevalence was detected to be 25.4% (207/815) for T. buttreyi and 0.7% (6/815) for P. hominis in donkeys in Shanxi Province. All obtained P. hominis sequences were identified as genotype CC1. Genetic analysis revealed that all P. hominis isolates from donkeys were clustered into the same branch with isolates detected in humans, suggesting possible zoonotic transmission. This study is the first to report the occurrence and prevalence of T. buttreyi and P. hominis in donkeys globally. These findings expand the host range of trichomonads and improve our understanding of their genetic diversity and zoonotic potential, providing essential baseline data for the prevention and control of these parasites in donkeys in the region.

The First Report of Tritrichomonas Foetus and Tetratrichomonas Buttreyi in Raccoon Dogs (Nyctereutes Procyonoides) in China

BACKGROUND

In recent years, the trichomonosis in raccoon dogs in China had occurred frequently. Pentatrichomonas hominis had been described in raccoon dogs in China in some previous studies. PURPOSE TO REVEAL: whether raccoon dogs can be infected by other trichomonad species besides P. hominis, and clarify the prevalence and species distribution of trichomonad in raccoon dogs.

METHODS

Herein, the 389 fecal samples were collected from farm-raised raccoon dogs in Hebei Province, all the samples were detected using the microscopic examination and several fecal samples containing trichomonad-like organisms were processed, cultured, stained, and photographed. Meanwhile, all the samples were screened by the species-specific nested PCR based on the small subunit rRNA (SSU rRNA) gene of P. hominis,Tritrichomonas foetus and Tetratrichomonas buttreyi, respectively, and all positive secondary PCR amplications obtained in this study were sequenced, aligned and analysed.

RESULTS

62 fecal samples (15.9%,62/389) were trichomonad-positive under light microscopy, and the trichomonad-like cells were clearly observed in the culture contents. The PCR results showed that 100 samples were trichomonad-positive, including 45 P. hominis-positive samples (11.6%,45/389), 32 T. foetus-positive samples (8.2%,32/389), and 33 T. buttreyi-positive samples (8.5%,33/389), respectively. Double mixed infections were observed in 10 samples. The prevalence of T. foetus and P. hominis were both significantly higher in raccoon dogs with diarrhea (13.9%, and 25.0%) than that in raccoon dogs without diarrhea (7.6%, and 9.3%) (p < 0.05).All samples confirmed as trichomonad-positive under microscopy were also found to be trichomonad-positive by PCR analysis. The sequencing and phylogenetic analysis demonstrated the sequences obtained in this study belonged to P. hominis, T. foetus and T. buttreyi SSU rRNA, respectively. Among them, the T. buttreyi SSU rRNA sequences obtained in this study harbored the new sequence polymorphisms. Based on preliminary morphological and molecular analyses, raccoon dogs are considered as the new host of T. foetus and T. buttreyi.

CONCLUSION

This is the first report about the identifcation and prevalence of T. foetus and T. buttreyi in raccoon dogs in China, and the results increase our knowledge about the host range and prevalence of trichomonad species.

Alleviating Pentatrichomonas hominis-induced damage in IPEC-J2 cells: the beneficial influence of porcine-derived lactobacilli

Pentatrichomonas hominis is a common intestinal parasitic protozoan that causes abdominal pain and diarrhea, and poses a zoonotic risk. Probiotics, known for enhancing immunity and pathogen resistance, hold promise in combating parasitic infections. This study aimed to evaluate two porcine-derived probiotics, Lactobacillus reuteri LR1 and Lactobacillus plantarum LP1, against P. hominis infections in pigs. Taxonomic identity was confirmed through 16 S rRNA gene sequencing, with L. reuteri LR1 belonging to L. reuteri species and L. plantarum LP1 belonging to L. plantarum species. Both probiotics exhibited robust in vitro growth performance. Co-culturing intestinal porcine epithelial cell line (IPEC-J2) with these probiotics significantly improved cell viability compared with the control group. Pre-incubation probiotics significantly enhanced the mRNA expression of anti-oxidative response genes in IPEC-J2 cells compared with the PHGD group, with L. reuteri LR1 and L. plantarum LP1 significantly up-regulating CuZn-SOD、CAT and Mn-SOD genes expression (p < 0.05). The anti-oxidative stress effect of L. reuteri LR1 was significantly better than that of L. plantarum LP1 (p < 0.05). Furthermore, pre-incubation with the probiotics alleviated the P. hominis-induced inflammatory response. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated IL-6、IL-8 and TNF-α gene expression(p < 0.05) compared with the PHGD group. The probiotics also mitigated P. hominis-induced apoptosis. L. reuteri LR1 and L. plantarum LP1 significantly down-regulated Caspase3 and Bax gene expression (p < 0.05), significantly up-regulated Bcl-2 gene expression (p < 0.05) compared with the PHGD group. Among them, L. plantarum LP1 showed better anti-apoptotic effect. These findings highlight the probiotics for mitigating P. hominis infections in pigs. Their ability to enhance anti-oxidative responses, alleviate inflammation, and inhibit apoptosis holds promise for therapeutic applications. Simultaneously, probiotics can actively contribute to inhibiting trichomonal infections, offering a novel approach for preventing and treating diseases such as P. hominis. Further in vivo studies are required to validate these results and explore their potential in animal and human health.

Morphological and molecular characterization of parabasilids isolated from ex situ nonhuman primates and their keepers at different institutions in Brazil

Intestinal protozoa, which can be asymptomatic or cause diarrhea, dysentery and even death, are among the main agents that affect nonhuman primates (NHPs) kept under human care. Nevertheless, information on the molecular and morphometric profiles of parabasilids in the Neotropics is still scarce. In this context, the objective of this study was to isolate the Parabasalia protozoa detected in the feces of NHPs and their keepers in Pavlova and TYSGM9 media and to characterize the isolates by molecular biology and morphometry. Fecal samples from NHPs from five Brazilian institutions were analyzed. Direct examination was performed immediately after obtaining the samples. A total of 511 fecal samples from NHPs were collected, and 10.6% contained parabasilids. Regarding the handlers, of the 74 samples analyzed, three were positive. In vitro-generated parabasilid isolates were successfully obtained from all positive samples, as identified via microscopy. Isolates of the parasite were obtained both from New World NHPs, including the genera Leontopithecus, Saguinus, Leontocebus, Aotus, Saimiri, Sapajus, and Alouatta, and from the Old World primate Pan troglodytes. Forty-nine NHP isolates were molecularly identified: Pentatrichomonas hominis (16), Trichomitus batrachorum (14), Tetratrichomonas brumpti (13) and Hypotrichomonas hampli (6). The human isolates were identified as Tetratrichomonas sp. (2) and T. batrachorum (1). Visualization and morphometric analysis revealed trophozoites with piriform or rounded shapes that presented variable measurements. The isolates previously characterized as P. hominis had up to five free flagella, while T. batrachorum and Tetratrichomonas sp. had up to four free flagella, and H. hampli had a maximum of three free flagella. These morphometric characteristics corroborated the molecular identification. In general, a variety of parabasilids were observed to infect NHPs, and T. batrachorum was isolated from biological samples from both NHPs and their keepers, a finding that reinforces the susceptibility of these hosts to infections by parabasilids in Brazil.

Molecular Identification and Survey of Trichomonad Species in Pigs in Shanxi Province, North China

Several trichomonad species have already been identified in pigs, and their pathogenic potential may not be ruled out. To date, however, no information is available regarding the prevalence of trichomonads in pigs in Shanxi Province, North China. In the present study, a total of 362 fecal samples collected from pigs in three representative counties (Qi, Jishan, and Shanyin) in this province were examined for Tetratrichomonas buttreyi, Tritrichomonas foetus, and Pentatrichomonas hominis using a nested polymerase chain reaction (PCR) with primers targeting the small subunit ribosomal RNA (SSU rRNA) gene. The overall prevalence of T. buttreyi was 49.72%, and region and age were found to be significantly associated with T. buttreyi infection, respectively. Only one pig fecal sample from Qi County was found to be positive for T. foetus, and all samples were negative for P. hominis. Molecular evolutionary analysis revealed that some T. buttreyi isolates showed complete genetic identity with those reported previously, and some T. buttreyi isolates and one T. foetus isolate showed minor allelic variations compared with those reported previously. This is the report of the molecular epidemiology of T. foetus and T. buttreyi in pigs in Shanxi Province, North China. These findings not only enrich the knowledge on the distribution of these trichomonad species in pigs in China but also provide baseline information for planning future research and control strategies.

Prevalence of intestinal trichomonads in captive non-human primates in China

Trichomonads are protozoan symbionts with the capacity to infect vertebrates including humans and non-human primates (NHPs), sometimes with pathogenic effects. However, their diversity and prevalence in NHPs in China are poorly understood. A total of 533 fecal samples were collected from captive NHPs in Yunnan Province, China, of which 461 samples from Macaca fascicularis and 72 from Macaca mulatta. Trichomonadidae species were identified using PCR amplification of the ITS-1/5.8S/ITS-2 sequences. The overall prevalence of trichomonads in NHPs was determined to be 11.4% (61/533), with gender, diarrhea, and region identified as potential risk factors for the infections. Sequence alignment and phylogenetic analysis identified three species of trichomonads, i.e., Trichomitopsis minor (n = 45), Pentatrichomonas hominis (n = 11), and Tetratrichomonas sp. (n = 5). To the best of our knowledge, this is the first study to report Trichomitopsis minor infection in NHPs in China. Of note, Pentatrichomonas hominis is generally recognized as a parasitic organism affecting humans. Collectively, our results suggest that NHPs are potential sources of zoonotic trichomonad infections, highlighting the importance of surveillance and control measures to protect human and animal populations.

Unraveling the pathogenic potential of the Pentatrichomonas hominis PHGD strain: impact on IPEC-J2 cell growth, adhesion, and gene expression

Pentatrichomonas hominis, a flagellated parasitic protozoan, predominantly infects the mammalian digestive tract, often causing symptoms such as abdominal pain and diarrhea. However, studies investigating its pathogenicity are limited, and the mechanisms underlying P. hominis-induced diarrhea remain unclear. Establishing an in vitro cell model for P. hominis infection is imperative. This study investigated the interaction between P. hominis and IPEC-J2 cells and its impact on parasite growth, adhesion, morphology, and cell viability. Co-cultivation of P. hominis with IPEC-J2 cells resulted in exponential growth of the parasite, with peak densities reaching approximately 4.8 × 105 cells/mL and 1.2 × 106 cells/mL at 48 h for initial inoculation concentrations of 104 cells/mL and 105 cells/mL, respectively. The adhesion rate of P. hominis to IPEC-J2 cells reached a maximum of 93.82% and 86.57% at 24 h for initial inoculation concentrations of 104 cells/mL and 105 cells/mL, respectively. Morphological changes in IPEC-J2 cells co-cultivated with P. hominis were observed, manifesting as elongated and irregular shapes. The viability of IPEC-J2 cells exhibited a decreasing trend with increasing P. hominis concentration and co-cultivation time. Additionally, the mRNA expression levels of IL-6, IL-8, and TNF-α were upregulated, whereas those of CAT and CuZn-SOD were downregulated. These findings provide quantitative evidence that P. hominis can promote its growth by adhering to IPEC-J2 cells, inducing morphological changes, reducing cell viability, and triggering inflammatory responses. Further in vivo studies are warranted to confirm these results and enhance our understanding of P. hominis infection.

Prevalence of Pentatrichomonas hominis in foxes and raccoon dogs and changes in the gut microbiota of infected female foxes in the Hebei and Henan Provinces in China

Pentatrichomonas hominis (P. hominis) is a zoonotic parasite that affects a wide range of hosts, causing gastrointestinal diseases. The present study aimed to evaluate the prevalence of P. hominis among caged foxes and raccoon dogs and the effect of P. hominis on the gut microbiota in female foxes. A total of 893 fresh fecal samples were collected from the Hebei and Henan Provinces in China. P. hominis was screened based on 18S rRNA gene expression via nested PCR. The difference in the gut microbiota between nine P. hominis-positive and nine P. hominis-negative samples was investigated by 16S rRNA gene sequencing. The total prevalence of P. hominis infection in foxes and raccoon dogs was 31.7% (283/893). The prevalence rates of P. hominis infection were 28.2% (88/312) and 33.6% (195/581) in foxes and raccoon dogs, respectively. Phylogenetic analysis revealed that all P. hominis strains detected in foxes and raccoon dogs in the present study were the zoonotic genotype CC1. Moreover, compared with those in the P. hominis-negative group, the diversity of the gut microbiota in the P. hominis-positive group was lower, and the abundance of Firmicutes and the ratio of Firmicutes/Bacteroidetes (F/B) in the P. hominis-positive group were lower than those in the P. hominis-negative group. We speculate that these differences may be due to indigestion and diarrhea in infected female foxes. Overall, the present study evaluated the prevalence of P. hominis in foxes and raccoon dogs in the Henan and Hebei Provinces and revealed that P. hominis infection interrupted the diversity of the gut microbiota in female foxes.

Commensal protists in reptiles display flexible host range and adaptation to ectothermic hosts

IMPORTANCE

Environmental factors like climate change and captive breeding can impact the gut microbiota and host health. Therefore, conservation efforts for threatened species may benefit from understanding how these factors influence animal microbiomes. Parabasalid protists are members of the mammalian microbiota that can modulate the immune system and impact susceptibility to infections. However, little is known about parabasalids in reptiles. Here, we profile reptile-associated parabasalids in wild and captive reptiles and find that captivity has minimal impact on parabasalid prevalence or diversity. However, because reptiles are cold-blooded (ectothermic), their microbiotas experience wider temperature fluctuation than microbes in warm-blooded animals. To investigate whether extreme weather patterns affect parabasalid-host interactions, we analyzed the gene expression in reptile-associated parabasalids and found that temperature differences significantly alter genes associated with host health. These results expand our understanding of parabasalids in this vulnerable vertebrate group and highlight important factors to be taken into consideration for conservation efforts.

Fine structure and molecular characterization of two new parabasalid species that naturally colonize laboratory mice, Tritrichomonas musculus and Tritrichomonas casperi

Tritrichomonas muris is a common flagellated protist isolated from the cecum of wild rodents. This commensal protist has been shown previously to alter immune phenotypes in laboratory mice. Other trichomonads, referred to as Tritrichomonas musculis and Tritrichomonas rainier, also naturally colonize laboratory mice and cause immune alterations. This report formally describes two new trichomonads, Tritrichomonas musculus n. sp., and Tritrichomonas casperi n. sp., at the ultrastructural and molecular level. These two protists were isolated from laboratory mice and were differentiated by their size and the structure of their undulating membrane and posterior flagellum. Analysis at the 18S rRNA and trans-ITS genetic loci supported their designation as distinct species, related to T. muris. To assess the true extent of parabasalid diversity infecting laboratory mice, 135 mice bred at the National Institutes of Health (NIH) were screened using pan-parabasalid primers that amplify the trans-ITS region. Forty-four percent of mice were positive for parabasalids, encompassing a total of eight distinct sequence types. Tritrichomonas casperi and Trichomitus-like protists were dominant. T. musculus and T. rainier were also detected, but T. muris was not. Our work establishes a previously underappreciated diversity of commensal trichomonad flagellates that naturally colonize the enteric cavity of laboratory mice.

Commensal protists in reptiles display flexible host range and adaptation to ectothermic hosts

Parabasalid protists recently emerged as keystone members of the mammalian microbiota with important effects on their host's health. However, the prevalence and diversity of parabasalids in wild reptiles and the consequences of captivity and other environmental factors on these symbiotic protists are unknown. Reptiles are ectothermic, and their microbiomes are subject to temperature fluctuations, such as those driven by climate change. Thus, conservation efforts for threatened reptile species may benefit from understanding how shifts in temperature and captive breeding influence the microbiota, including parabasalids, to impact host fitness and disease susceptibility. Here, we surveyed intestinal parabasalids in a cohort of wild reptiles across three continents and compared these to captive animals. Reptiles harbor surprisingly few species of parabasalids compared to mammals, but these protists exhibited a flexible host-range, suggesting specific adaptations to reptilian social structures and microbiota transmission. Furthermore, reptile-associated parabasalids are adapted to wide temperature ranges, although colder temperatures significantly altered the protist transcriptomes, with increased expression of genes associated with detrimental interactions with the host. Our findings establish that parabasalids are widely distributed in the microbiota of wild and captive reptiles and highlight how these protists respond to temperature swings encountered in their ectothermic hosts.

Concurrent Infection of Histomonas meleagridis and Pentatrichomonas hominis in a Blackhead Disease Outbreak in Turkeys

Intestinal health plays a major role in profitable and efficient turkey production. Blackhead disease (histomoniasis) is caused by Histomonas meleagridis, an anaerobic protozoan parasite. Histomonas meleagridis disrupts intestinal integrity and may cause systemic infection. Some field outbreaks of blackhead disease are associated with low morbidity and mortality, while in some instances, it may cause severe morbidity and mortality. In the current study, a presumptive diagnosis of blackhead disease was made based on the characteristic gross lesions in the liver and ceca. The cecal culture, PCR, and sequencing confirmed the presence of H. meleagridis and Pentatrichomonas hominis. Pentatrichomonas hominis has been reported in enteritis cases of several other species, such as dogs, cats, and cattle. The impact of P. hominis on intestinal health of turkeys has not previously been studied, and to the best of our knowledge, this is the first case report of concurrent H. meleagridis and P. hominis infection in turkeys.

Molecular prevalence of Tetratrichomonas gallinarum and Trichomonas gallinae in three domestic free-range poultry breeds in Anhui Province, China

Tetratrichomonas gallinarum and Trichomonas gallinae can colonize the alimentary tract of domestic birds. However, little information is available on the epidemiology of the two trichomonad species in domestic free-range poultry in China. In this study, the occurrence and genetic characteristic of T. gallinarum and T. gallinae among free-range chickens, ducks, and geese in Anhui Province, China, were investigated. The 1910 fecal samples collected from 18 free-range poultry farms throughout Anhui Province were examined for the presence of T. gallinarum and T. gallinae by PCR and sequence analysis of the small subunit (SSU) rRNA gene of T. gallinarum and ITS1-5.8S-ITS2 sequence of T. gallinae. The overall occurrence of T. gallinarum in poultry was 1.2% (22/1910), with infection rates of 2.1% (17/829) in chickens, 0.2% (1/487) in ducks, and 0.7% (4/594) in geese. The constructed phylogeny tree using the concatenated ITS1-5.8S-ITS2 region and SSU rRNA indicated the T. gallinarum isolates detected in this study were closely related to previously defined genogroups A, D, and E, respectively. Nine (0.5%) fecal samples were positive for T. gallinae, with infection rates of 0.8% (7/829) in chickens, 0.4% (2/487) in ducks, and 0% (0/594) in geese. Sequence and phylogenetic analysis showed that four T. gallinae ITS1-5.8S-ITS2 sequences obtained from chicken feces and one duck fecal sample belonged to genotype ITS-OBT-Tg-1. This is the first report of the prevalence and genetic characterization of T. gallinarum and T. gallinae in free-range chickens, ducks, and geese in China.

High-Throughput Sequencing of faeces provides evidence for dispersal of parasites and pathogens by migratory waterbirds

Examination of faecal material has demonstrated how a broad range of organisms are distributed by bird movements. Such research has largely focused on dispersal of plant seeds by frugivores and of freshwater organisms by waterbirds. However, with few exceptions (e.g. avian influenza, Ebola virus), there is a dearth of evidence for transport of parasites and pathogens. High-throughput sequencing methods now provide a powerful means of addressing this knowledge gap by elucidating faecal contents in unprecedented detail. We collected faeces excreted by a range of migratory waterbirds in south-west Spain and pooled faecal DNA to create libraries reflective of feeding behavior. We created sets of libraries using high-throughput metagenomic and amplicon sequencing. For the latter we employed two sets of primers to broadly target the V4 region of the 18S rRNA gene (one set amplifying the region across all eukaryotes, the other excluding amplification of metazoans). Libraries revealed a wide diversity of eukaryotes, including parasites of the faecal producers themselves, parasites of food items, or those incidentally ingested. We also detected novel microbial eukaryotic taxa and found that parasite assemblage profiles were relatively distinct. Comparing the performance of the methods used supports their joint use for future studies of diversity and abundance. Because viable stages of many parasites are likely to be present in faeces, our results suggest significant levels of bird-mediated dispersal of parasites (both from avian and other hosts). Our methods revealed much hidden biodiversity, and allowed identification of the individuals who produced the faecal samples to species level, facilitating the study of interaction networks.

Fucose Ameliorates Tritrichomonas sp.-Associated Illness in Antibiotic-Treated Muc2-/- Mice

The mucus layer in the intestine plays a critical role in regulation of host–microbe interactions and maintaining homeostasis. Disruptions of the mucus layer due to genetic, environmental, or immune factors may lead to inflammatory bowel diseases (IBD). IBD frequently are accompanied with infections, and therefore are treated with antibiotics. Hence, it is important to evaluate risks of antibiotic treatment in individuals with vulnerable gut barrier and chronic inflammation. Mice with a knockout of the Muc2 gene, encoding the main glycoprotein component of the mucus, demonstrate a close contact of the microbes with the gut epithelium which leads to chronic inflammation resembling IBD. Here we demonstrate that the Muc2^−/− mice harboring a gut protozoan infection Tritrichomonas sp. are susceptible to an antibiotic-induced depletion of the bacterial microbiota. Suppression of the protozoan infection with efficient metronidazole dosage or L-fucose administration resulted in amelioration of an illness observed in antibiotic-treated Muc2^−/− mice. Fucose is a monosaccharide presented abundantly in gut glycoproteins, including Mucin2, and is known to be involved in host–microbe interactions, in particular in microbe adhesion. We suppose that further investigation of the role of fucose in protozoan adhesion to host cells may be of great value.

Molecular identification of Pentatrichomonas hominis in animals in central and western Thailand

BACKGROUND

Pentatrichomonas hominis inhabits the digestive tracts of several vertebrates, such as humans, monkeys, pigs, dogs, cats and rats. This protozoan was originally considered a commensal of the digestive tract but has subsequently been identified as a potential zoonotic parasite and a causative agent of diarrhoea. Molecular techniques are considered more sensitive and specific to detect P. hominis. This study aimed to determine the presence and genetic diversity of P. hominis in animals in Thailand. A total of 403 faecal samples were collected from 119 cats, 55 dogs, 73 goats, 35 monkeys, 55 cattle and 66 pigs, and the presence of P. hominis was determined using the nested polymerase chain reaction method. Sequence analysis of small-subunit ribosomal RNA genes was used to determine the genotype of the organism.

RESULTS

Twenty-six samples (26/403, 6.45%) were positive for P. hominis. The highest prevalence was found in cats (21/119; 17.65%), followed by cattle (3/55; 5.45%) and dogs (2/55; 3.64%). Seven out of 26 nucleotides demonstrated 100% sequence identity with existing sequences; additionally, 16 novel sequence patterns were identified. All nucleotide sequences of P. hominis-positive samples were shown in the same branch with the previously described P. hominis sequences found in humans, dogs and goat.

CONCLUSION

This is the first study on P. hominis infections in animals in Thailand. Our findings revealed that the prevalence of P. hominis was significantly higher in cats than in cattle and dogs. Cats were the main reservoir host; however, P. hominis can infect several kinds of animals. Therefore, the proper waste management of animals is necessary to reduce and prevent infection in the community.

Lethal infection caused by Tetratrichomonas gallinarum in black swans (Cygnus atratus)

BACKGROUND

Tetratrichomonas gallinarum is parasitic protozoa with a wide host range. However, its lethal infection is rare reported.

CASE PRESENTATION

Here, we described the first lethal cases of T. gallinarum infection in black swans in China. Five black swans died within a week in succession without obvious symptoms except mild diarrhea. At necropsy, severe lesions were observed in caeca with thickened caecal walls and hemorrhages in the mucosa. A large number of moving trophozoites were found in the contents of the cecum by microscopic examination. The livers were enlarged with multiple bleeding spots on the surface. Histopathology of the livers showed mononuclear cell infiltration and moderate hyperplasia of fibrous tissue. The histopathology of the cecum showed that the villi of the cecum were edematous. Finally, the presence of T. gallinarum was determined by specific PCR andin-situ hybridization assay. Additionally, common pathogens that can cause similar symptoms were excluded.

CONCLUSIONS

The death of the black swan was caused by T. gallinarum, suggesting that the parasite might be a new threat to the Cygnus birds.

Occurrence of Tetratrichomonas gallinarum (Trichomonadida: Trichomonadidae) in chicken feces from Lorestan Province, Western Iran

Species of Tetratrichomonas gallinarum and Trichomonas gallinae, are found in the digestive tract of birds. To investigate trichomonads of a lower intestinal tract of native chickens, we examined 72 feces samples from the different life stages of fowl species in Khorramabad County, Lorestan Province, Western Iran. Using microscopical examination, out of 72 collected samples, 26 (31.6%) bird feces samples were found infected with a trichomonad similar to T. gallinarum. A 527-bp fragment of 18S rRNA gene of T. gallinarum was amplified by PCR. The 18S constructed phylogeny indicates two different clades within T. gallinarum, suggesting that commensal T. gallinarum-like of the bird hosts may be the reason for the genetic divergence in T. gallinarum species complex.

Prevalence of Tetratrichomonas buttreyi and Pentatrichomonas hominis in yellow cattle, dairy cattle, and water buffalo in China

The trichomonad species Tetratrichomonas buttreyi and Pentatrichomonas hominis have been reported in the bovine digestive tract in only a few studies, and the prevalence and pathogenicity of these two protists in cattle herds remain unknown. In this study, the prevalence of T. buttreyi and P. hominis in yellow cattle, dairy cattle, and water buffalo in Anhui Province, China, was determined with a PCR analysis of the small subunit ribosomal RNA genes. The overall infection rates for T. buttreyi and P. hominis were 8.1% and 5.4%, respectively. Double infections were found in 15 (1.6%) samples from four farms. The prevalence of P. hominis in cattle with abnormal feces was significantly higher than that in cattle with normal feces (χ² = 13.0, p < 0.01), and the prevalence of T. buttreyi in the northern region of Anhui Province was also significantly higher than that in the mid region (χ² = 16.6, p < 0.01). Minor allelic variations were detected in the T. buttreyi isolates from cattle in this study, as in other hosts in previous studies. Morphological observations, together with the PCR analysis, demonstrated that the trichomonads isolated in this study were P. hominis. The presence of T. buttreyi and P. hominis indicated that cattle are natural hosts of these two trichomonads and could be a potential source of P. hominis infections in humans and other animal hosts.

A survey of gastrointestinal parasites of goats in a goat market in Kathmandu, Nepal

Gastrointestinal (GI) parasites in goats are predominant around the world. They may be the underlying cause of the pathological and immunological consequences leading to significant economic losses of the goat industry. The main aim of the current research was to reveal the prevalence of gastrointestinal parasites, including protozoa, trematodes, and nematodes in the fecal samples of goats in the goat market in Kathmandu, Nepal. A total of 400 goat fecal specimens were purposively collected from the goat market, and they were processed by direct wet mount, sedimentation, floatation techniques, and acid-fast staining, and were observed under the compound microscope. Out of a total 400 fecal samples, 349 (87.25%) were found to be infected with GI parasites among which Eimeria (80.75%), Strongyle (59.25%), Trichuris (29.75%), Strongyloides (28.75%), Moniezia (21.75%), Entamoeba (20%), Fasciola (10.25%), Balantidium (7.75%), Cryptosporidium (4%), Capillaria (1.75%), Trichomonas (1.25%), Ascaris (1.0%), Cyclospora (1%), Blastocystis (0.75%), Giardia (0.5%), and Paramphistomum (0.5%) were reported. GI parasites like protozoa and helminthes were widely distributed in the goats brought for the meat purposes in Kathmandu Valley, showing a high proportion of the goats were having higher risks of morbidity and mortality around the country.

Occurrence of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats in China

Background

Global data regarding the molecular epidemiology of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats are sparse. China has one of the largest sheep and goat populations in the world. In this study we investigated the occurrence of Blastocystis sp. and P. hominis in domestic sheep and goats in China, and analyzed the genetic characterization of these two parasite species.

Methods

In total, we collected fresh fecal samples from 832 sheep and 781 goats located on seven and ten farms, respectively, in the central eastern region of China. The corresponding sequences obtained in this study were subject to molecular analysis for subtype and allele identification of Blastocystis sp., and species and genotype confirmation of P. hominis.

Results

The occurrence of Blastocystis sp. was 6.0% (50/832) in sheep and 0.3% (2/781) in goats. The most predominant subtype (ST) of Blastocystis sp. in sheep was ST10 (50.0%), followed by ST14 (20%), ST5 (16%), novel sequence 1 (6%), novel sequence 4 (4%), novel sequence 2 (2%) and novel sequence 3 (2%). However, only ST1 was observed in goats. No mixed infections with different subtypes were found in this study. The 18S alleles showed allele 2 (100%) for ST1; allele 115 (75%) for ST5; and no match allele for ST5 (25%), ST10 (100%), ST14 (100%), novel sequence 1 (100%), novel sequence 2 (100%), novel sequence 3 (100%), and novel sequence 4 (100%) on the Blastocystis subtype (18S) and Sequence Typing (MLST) database. For P. hominis, two goats (0.3%) and zero sheep (0%) were identified as positive in this study. The 18S rRNA gene sequences of two P. hominis isolates from goats displayed 100% identity to type CC1, found previously in dogs, monkeys and humans.

Conclusions

These results provide the detailed data on the occurrence and molecular epidemiology of Blastocystis sp. and P. hominis in sheep and goats in China. They also contribute to and expand our knowledge of the Blastocystis sp. and P. hominis epidemiology around the world.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2671-5) contains supplementary material, which is available to authorized users.

Responding to a Zoonotic Emergency with Multi-omics Research: Pentatrichomonas hominis Hydrogenosomal Protein Characterization with Use of RNA Sequencing and Proteomics

Pentatrichomonas hominis is an anaerobic flagellated protist that colonizes the large intestine of a number of mammals, including cats, dogs, nonhuman primates, and humans. The wide host range of this organism is alarming and suggests a rising zoonotic emergency. However, knowledge on in-depth biology of this protist is still limited. Similar to the human pathogen, Trichomonas vaginalis, P. hominis possesses hydrogenosomes instead of mitochondria. Studies in T. vaginalis indicated that hydrogenosome is essential for cell survival and associated with numerous pivotal biological functions, including drug resistance. To further decipher the biology of this important organelle, we undertook proteomic research in P. hominis hydrogenosomes. Lacking a decoded P. hominis genome, we utilized an RNA sequencing (RNA-seq) data set generated from P. hominis axenic culture as the reference for proteome analysis. Using this in-house reference data set and mass spectrometry (MS), we identified 442 putative hydrogenosomal proteins. Interestingly, the composition of the P. hominis hydrogenosomal proteins is very similar to that of T. vaginalis, but proteins such as Hmp36, Pam16, Pam18, and Isd11 are absent based on both MS and the RNA-seq. Our data underscore that P. hominis expresses different homologs of multiple gene families from T. vaginalis. To the best of our knowledge, we present here the first hydrogenosome proteome in a protist other than T. vaginalis that offers crucial new scholarship for global health, therapeutics, diagnostics, and veterinary medicine research. In addition, the research strategy used here using RNA sequencing and proteomics might inform future multi-omics research in other understudied organisms without decoded genomes.

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.

Prevalence and Molecular Characterization of Intestinal Trichomonads in Pet Dogs in East China

The trichomonad species Tritrichomonas foetus and Pentatrichomonas hominis were recently detected in the feces of dogs with diarrhea. However, little information is available on the prevalence and pathogenicity of these parasites in the canine population. Therefore, the aim of this study was to determine the prevalence and molecular characterization of trichomonads infecting pet dogs in Anhui and Zhejiang provinces, east China. In total, 315 pet dogs, with or without diarrhea, from 7 pet hospitals were included in this epidemiological survey. Microscopy and PCR detected P. hominis in 19.7% (62/315) and 31.4% (99/315) of fecal samples, respectively. T. foetus infection was detected in 0% (0/315) of samples with microscopy and in 0.6% (2/315) with PCR. The prevalence of P. hominis was significantly higher in young dogs (≤12 months) than in adult dogs (>12 months), and was significantly higher in diarrheic dogs (50.6%) than in non-diarrheic dogs (24.3%; P<0.05). Infection with T. foetus did not correlate with any risk factors evaluated in this study. A sequence analysis of the P. hominis PCR products showed minor allelic variations between our sequences and those of P. hominis strains from other hosts in different parts of the world. Type CC1 was the most common strain in dogs in east China. The internal transcribed spacer 1 (ITS1)-5.8S rRNA gene sequences from the 2 T. foetus isolates detected in this study displayed 100% identity and were homologous to the sequences of other strains isolated from domestic cats in other countries.

Pentatrichomonas hominis: prevalence and molecular characterization in humans, dogs, and monkeys in Northern China

Pentatrichomonas hominis is an anaerobic amitochondrial flagellated protist that primarily colonizes the large intestines of a number of species, including cats, dogs, nonhuman primates, and humans. The prevalence of this parasite in dogs, monkeys, and humans is, however, poorly understood. In this study, a total of 362 fecal samples including 252 dogs, 60 monkeys, and 50 humans from northern China were collected for an epidemiological survey of P. hominis infection.The average prevalence of P. hominis infection determined by nested PCR was 27.38% (69/252), 4.00% (2/50), and 46.67% (28/60) in dogs, humans, and monkeys, respectively. The prevalence was significantly higher in 6-month-old dogs (41.53%) and children (7.69%) than in older dogs (14.39%) and adults (0%) (P < 0.05). Sequencing of amplicons revealed that four variable positions separated sequences into three types, called CC1-3. CC1 was the most prevalent in the study population. This study determined that P. hominis infection is common in dogs, monkeys, and humans, especially in children and young dogs. Given the infection prevalence, P. hominis may pose a risk of zoonotic and anthroponotic transmission.

Genetic diversity of Trichomonas vaginalis clinical isolates from Henan province in central China

Trichomonas vaginalis is a flagellated protozoan parasite that infects the human urogenital tract, causing the most common non-viral, sexually transmitted disease worldwide. In this study, genetic variants of T. vaginalis were identified in Henan Province, China. Fragments of the small subunit of nuclear ribosomal RNA (18S rRNA) were amplified from 32 T. vaginalis isolates obtained from seven regions of Henan Province. Overall, 18 haplotypes were determined from the 18S rRNA sequences. Each sampled population and the total population displayed high haplotype diversity (Hd), accompanied by very low nucleotide diversity (Pi). In these molecular genetic variants, 91.58% genetic variation was derived from intra-regions. Phylogenetic analysis revealed no correlation between phylogeny and geographic distribution. Demographic analysis supported population expansion of T. vaginalis isolates from central China. Our findings showing moderate-to-high genetic variations in the 32 isolates of T. vaginalis provide useful knowledge for monitoring changes in parasite populations for the development of future control strategies.

The prevalence of intestinal trichomonads in Chinese pigs

Intestinal infection of pigs with trichomonads, (Tritrichomonas suis, Tetratrichomonas buttreyi, and Pentatrichomonas hominis) has been reported in many countries, such as the Philippines, Belgium, and the Czech Republic. However, the prevalence of trichomonads infection of swine in China has not yet been investigated. In this study, we used small subunit ribosomal RNA genes to detect the prevalence of T. suis, T. buttreyi and P. hominis among 158 fecal specimens from healthy pigs. Infection rates were 12.03%(19/158), 14.57% (23/158), and 24.05% (38/158) for T. suis, T. buttreyi and P. hominis, respectively. Molecular evolutionary analysis showed minor allelic variation in T. buttreyi from China compared to T. buttreyi isolated from other hosts in different parts of the world.

A single strain of Tetratrichomonas gallinarum causes fatal typhlohepatitis in red-legged partridges (Alectoris rufa) to be distinguished from histomonosis

Typhlohepatitis was observed in a flock of 2500 red-legged partridges in Great Britain, characterized by the sudden deaths of 15 birds within 2 days. Necropsy of five dead birds revealed severe lesions in the caeca with thickened caecal walls, a reddened lining and bloody contents. The livers contained multiple miliary lesions and similar pathological changes were found in the spleens of some birds. Microscopic examination of intestinal contents showed the occurrence of coccidial oocysts in two partridges. Different methods for the detection of bacteria from liver and intestine samples were conducted without positive results. Histopathological examination revealed the presence of protozoan parasites in the caecum, liver and spleen of the affected birds. In situ hybridization (ISH) for the detection of trichomonads resulted in positive findings and polymerase chain reaction (PCR) confirmed the presence of Tetratrichomonas gallinarum in the lesions. Additionally, archived tissues of red-legged partridges from different flocks suffering from severe typhlohepatitis in Great Britain in 2008 and 2009 were re-investigated by ISH and PCR. Beside the sporadic occurrence of histomonosis, in most of the cases trichomonads were detected by ISH in the caecum and liver of affected birds. Furthermore, dissemination of the flagellate into the lung and bursa of Fabricius could be demonstrated. Analyses of T. gallinarum DNA obtained from the different cases resulted in homologous nucleotide sequences. Altogether, the results demonstrate the circulation of a virulent strain of T. gallinarum in reared red-legged partridges.

Molecular and morphological diversity of the genus Hypotrichomonas (Parabasalia: Hypotrichomonadida), with descriptions of six new species

The genus HypotrichomonasLee, 1960 belongs to the small parabasalian class Hypotrichomonadea. Although five Hypotrichomonas species have been described from intestines of lizards and birds, some descriptions were brief and incomplete. Only the type species H. acosta has been observed repeatedly. We have established 23 strains of the genus Hypotrichomonas in culture. Phylogenetic and morphological analyses showed that these isolates represent eight distinct species, six of which are novel. Three of the species showed unusual morphology, such as a reduced undulating membrane, absence of the free part of the recurrent flagellum or a costa-like fiber. Our strains were isolated from a wide range of hosts including cockroaches, frogs, tortoises, lizards, snakes, marsupials, pigs, rodents, and primates. The genus Hypotrichomonas thus contains a relatively large number of species that differ in morphology, phylogenetic position and host range. It is remarkable that such diversity of hypotrichomonads was previously undetected, although a number of studies dealt with intestinal trichomonads of vertebrates and invertebrates. Our results indicate that the diversity of the genus Hypotrichomonas as well as of the whole Parabasalia is still only poorly understood, and the lineages described so far likely represent only a small fraction of the true diversity of parabasalids.

Molecular characterization of various trichomonad species isolated from humans and related mammals in Indonesia

Trichomonad species inhabit a variety of vertebrate hosts; however, their potential zoonotic transmission has not been clearly addressed, especially with regard to human infection. Twenty-one strains of trichomonads isolated from humans (5 isolates), pigs (6 isolates), rodents (6 isolates), a water buffalo (1 isolate), a cow (1 isolate), a goat (1 isolate), and a dog (1 isolate) were collected in Indonesia and molecularly characterized. The DNA sequences of the partial 18S small subunit ribosomal RNA (rRNA) gene or 5.8S rRNA gene locus with its flanking regions (internal transcribed spacer region, ITS1 and ITS2) were identified in various trichomonads; Simplicimonas sp., Hexamastix mitis, and Hypotrichomonas sp. from rodents, and Tetratrichomonas sp. and Trichomonas sp. from pigs. All of these species were not detected in humans, whereas Pentatrichomonas hominis was identified in humans, pigs, the dog, the water buffalo, the cow, and the goat. Even when using the high-resolution gene locus of the ITS regions, all P. hominis strains were genetically identical; thus zoonotic transmission between humans and these closely related mammals may be occurring in the area investigated. The detection of Simplicimonas sp. in rodents (Rattus exulans) and P. hominis in water buffalo in this study revealed newly recognized host adaptations and suggested the existence of remaining unrevealed ranges of hosts in the trichomonad species.

Pentatrichomonas hominis: first isolation from the feces of a dog with diarrhea in China

A trichomonad-like parasite isolated from canine fecal samples in Changchun, China was successfully cultivated in vitro using RPMI1640 medium supplemented with 10% heat-inactivated calf serum and antibiotics. These were then subjected to scanning and transmission electron microscopy for ultrastructural study. This parasite has four anterior flagella of unequal length, one independent flagellum, and one recurrent flagellum. It exhibits an anterior nucleus, a Golgi complex, an axostyle, food vacuoles, and hydrogenosomes. These features are consistent with the ultrastructural characteristics of previously described Pentatrichomonas hominis. Polymerase chain reaction and sequence analysis of three genetic loci, including ITS1-5.8S rRNA-ITS2, 18S rRNA, and EF-1α, were also used to compare these samples with other trichomonad species. Molecular identification was also consistent with P. hominis. This is the first time that isolation of P. hominis has been isolated from dog in China, although several other strains of P. hominis have been isolated from human samples.

First report of Trichomonas tenax infections in the Philippines

Recent studies have reported Trichomonas tenax as a cause of pleuropulmonary infections in humans. In this study, sputum and vaginal swab samples were collected from patients suffering from respiratory ailments in Rodriguez, Rizal and sex workers attending the social hygiene clinics in Angeles City in Pampanga, Mandaluyong City and Pasay City in Metro Manila, Philippines, respectively. DNA was extracted from samples and the 18S rRNA gene was amplified and sequenced. Phylogenetic trees were constructed using neighbor-joining, maximum-likelihood, maximum parsimony, and Bayesian inference analyses. Results showed that the new primer sets successfully amplified T. tenax from 14 sputum samples and Trichomonas vaginalis from 19 vaginal swab samples. Consequently, all isolates clustered with high bootstrap support and posterior probability values to their respective reference strains in the phylogenetic tree. Thus, the genus Trichomonas formed a highly supported clade with T. vaginalis in the first clade and T. tenax in the second clade. These findings conclude that T. vaginalis is solely present in the genito-urinary tract of females and that T. tenax can be found in the respiratory tract of humans. To our knowledge, this is the first report of detection and identification of T. tenax from sputum samples in the Philippines. However, further studies are still needed to determine the pathogenicity of this organism in humans.

New Hosts of Simplicimonas similis and Trichomitus batrachorum Identified by 18S Ribosomal RNA Gene Sequences

Trichomonads are obligate anaerobes generally found in the digestive and genitourinary tract of domestic animals. In this study, four trichomonad isolates were obtained from carabao, dog, and pig hosts using rectal swab. Genomic DNA was extracted using Chelex method and the 18S rRNA gene was successfully amplified through novel sets of primers and undergone DNA sequencing. Aligned isolate sequences together with retrieved 18S rRNA gene sequences of known trichomonads were utilized to generate phylogenetic trees using maximum likelihood and neighbor-joining analyses. Two isolates from carabao were identified as Simplicimonas similis while each isolate from dog and pig was identified as Pentatrichomonas hominis and Trichomitus batrachorum, respectively. This is the first report of S. similis in carabao and the identification of T. batrachorum in pig using 18S rRNA gene sequence analysis. The generated phylogenetic tree yielded three distinct groups mostly with relatively moderate to high bootstrap support and in agreement with the most recent classification. Pathogenic potential of the trichomonads in these hosts still needs further investigation.