Activation of murine macrophages by membrane proteins from Tritrichomonas foetus grown on iron- and calcium-rich conditions

Tritrichomonas foetus is a protozoan parasite that causes a venereal disease in cattle limiting reproduction by abortions and sterility. The immune response against this parasite is poorly understood. Since the iron and calcium ions are important regulators of the microenvironment of the urogenital tract in cattle, we decided to evaluate the role of these divalent cations on the antigenicity of membrane proteins of T. foetus on macrophage activation as one of the first inflammatory responses towards this pathogen. Colorimetric methods and ELISA were used to detect the nitric oxide and oxygen peroxide production and expression of cytokines in culture supernatant from macrophage incubated with membrane proteins from T. foetus cultured in iron- and calcium-rich conditions. qRT-PCR assays were used to evaluate the transcript expression of genes involved in the inflammatory response on the macrophages. The membrane proteins used for in vitro stimulation caused the up-regulation of the iNOS and NOX-2 genes as well as the generation of NO and H2 O2 in murine macrophages on a dependent way of the metal concentrations. Additionally, after stimulation, macrophages showed a considerable rise in pro-inflammatory cytokines and a downregulation of anti-inflammatory cytokines, as well as up-regulation in the transcription of the TLR4 and MyD88 genes. These data suggest that membrane proteins of T. foetus induced by iron and calcium can activate an inflammatory specific macrophage response via TLR4/MyD88 signalling pathway.

Prolonged survival of venereal Tritrichomonas foetus parasite in the gastrointestinal tract, bovine fecal extract, and water

IMPORTANCE

Nowadays, the routine herd diagnosis is usually performed exclusively on bulls, as they remain permanently infected, and prevention and control of Tritrichomonas foetus transmission are based on identifying infected animals and culling practices. The existence of other forms of transmission and the possible role of pseudocysts or cyst-like structures as resistant forms requires rethinking the current management and control of this parasitic disease in the future in some livestock regions of the world.

Expansion Microscopy of trichomonads

Light microscopy has significantly advanced in recent decades, especially concerning the increased resolution obtained in fluorescence images. Here we present the Expansion Microscopy (ExM) technique in two parasites, Trichomonas vaginalis and Tritrichomonas foetus, which significantly improved the localization of distinct proteins closely associated with cytoskeleton by immunofluorescence microscopy. The ExM techniques have been used in various cell types, tissues and other protist parasites. It requires the embedment of the samples in a swellable gel that is highly hydrophilic. As a result, cells are expanded 4.5 times in an isotropic manner, offering a spatial resolution of ∼70 nm. We used this new methodology not only to observe the structural organization of protozoa in more detail but also to increase the resolution by immunofluorescence microscopy of two major proteins such as tubulin, found in structures formed by microtubules, and costain 1, the only protein identified until now in the T. foetus's costa, a unique rod-shaped like structure. The individualized microtubules of the axostyle were seen for the first time in fluorescence microscopy and several other details are presented after this technique.

[Prevalence and geographical distribution of bovine sexually transmitted diseases in the province of Formosa, Argentina]

Bovine genital campylobacteriosis (BGC) and bovine trichomonosis (BT) are sexually transmitted diseases (STDs) that affect bovine breeding herds, decreasing their reproductive efficiency. The objective of this work was to estimate the prevalence of these diseases and their temporal-spatial distribution in the province of Formosa, Argentina. The cross-sectional study conducted between 2018 and 2021 included a total of 15,571 bulls, inter-herd prevalence being 29.62% and 17.23% for BGC and BT, respectively. The prevalence of positive animals was 2.05% for BGC and 0.43% for BT. The temporal-spatial analysis of BGC showed two distinct spatial groupings, one group had a low risk of contracting the disease (RR = 0.13; p < 0.001; 2018-2021) while the other group had a high risk (RR = 2.84; p < 0.001; 2020-2021). BT had a high-risk group for the disease (RR = 35.24; p < 0.001; 2019). This study shows that STDs are endemic in the region, providing updated and valuable information as a tool for the health management of these diseases.

Evaluation of the susceptibility of Tritrichomonas foetus to extracts of Lantana camara (Verbenaceae) by flow cytometry

Bovine Trichomonosis (BT), a sexually transmitted disease endemic in countries with extensive cattle farming and natural service, is one of the most common causes of reproductive failure. 5-nitroimidazoles and their derivatives are used for its treatment, mainly metronidazole. The emergence of drug resistance mechanisms and treatment failures raise the need to investigate the effectiveness of new active compounds that contribute to parasite control. In this regard, extracts of Lantana camara (Verbenacea) have shown high biocidal potential against isolates of Trypanosoma cruzi and Leishmania braziliensis in vitro assays, although their effect on Tritrichomonas foetus has not been demonstrated yet. The available information on in vitro susceptibility of trichomonicidal drugs comes from the use of a diversity of methodologies and criteria, especially the observation of parasite motility under the optical microscope to assess their viability. Recently, in our laboratory, the use of flow cytometry has been described for the first time as a rapid and efficient method to evaluate the viability of T. foetus against metronidazole. The present study aimed to evaluate the cytostatic effect of L. camara extracts against T. foetus isolates by flow cytometry. Under aerobic conditions, IC50 values of 22.60 µg/mL were obtained on average. Under anaerobic conditions, the IC50 oscilated around 29.04 µg/mL. The results obtained allowed describing the susceptibility exhibited by these protozoa, being a valuable information for the development of potential BT treatments.

Proteomic analysis of proteins released by Tritrichomonas foetus: Identification of potential targets for the development of new diagnostic methods

Bovine trichomonosis (BT), a disease of the bovine urogenital tract, is caused by the protozoan Tritrichomonas foetus (Tf). Tf causes endometritis, infertility, and premature death of the embryo, which generates considerable economic losses. The proteins released can mediate fundamental interactions between the pathogen and the host, triggering factors associated with the symptomatology, immune evasion and pathogenesis characteristic of the species. However, little is known about the profile of the proteins released by Tf. In order to contribute to their knowledge, we performed an isolation protocol and a proteomic profiling of the supernatant (SN) content of six Tf isolates. A total of 662 proteins present in the SN of Tf were detected, out of which 121 were shared by the six isolates, while the remaining 541 were found in at least one of the isolates studied. The comparative analyses using the databases of Tf strain genome K revealed 32.9% of uncharacterized proteins. The bioinformatic analyses showed that the main molecular functions predicted were binding (47.9%) and catalytic activity (38.2%). Additionally, we performed immunodetection assays to evidence the antigenic potential of SN proteins. Interestingly, we observed great ability to detect SN proteins from all six isolates using serum from immunized mice and infected bulls. A complementary mass spectrometry assay allowed us to determine that the proteins that showed the strongest signal intensity in the immunoassays were Grp78 (A0A1J4IZS3) and Ap65 (A0A1J4JSR1). This work represents the first proteomic characterization of Tf SN proteins and their antigenic potential, which might be interesting for the future design of new diagnosis and treatment methods for BT.

Detection of Tritrichomonas foetus by RT-rtPCR in pooled bovine preputial washings

Trichomonosis is a venereal disease of cattle caused by the protozoan Tritrichomonas foetus. T. foetus infection in cattle herds can be economically costly for cattle producers; therefore, testing is important for detection of the agent. Given that bulls are considered to be subclinical carriers of T. foetus, it is important to detect T. foetus infection prior to movement and/or breeding season. We have described previously the development of an updated set of PCR primers and probes that offer increased sensitivity of T. foetus detection in preputial washings collected in PBS by utilizing reverse-transcription real-time PCR (RT-rtPCR) that targets the 5.8S ribosomal RNA of the T. foetus organism. Here, we report improvements in the updated RT-rtPCR reagents as well as the evaluation of testing of pooled preputial washings. We found that up to 5 preputial washings can be pooled, similar to routine testing practices (InPouch culture), without reducing the sensitivity of detection of T. foetus.

Molecular prevalence and phylogenetic confirmation of bovine trichomoniasis in aborted cows in Iraq

Background and Aim

Bovine trichomoniasis, caused by Tritrichomonas foetus, is a venereal disease that is distributed in many countries, including Iraq. Compared with other abortive infectious diseases, prevalence of T. foetus is expected to be relatively low in the field by veterinarians. This study aimed to estimate the prevalence of T. foetus in aborted cows by conventional polymerase chain reaction (PCR) and phylogenetic analysis of local T. foetus isolates was documented in the National Center for Biotechnology Information as the first sequenced isolates from Iraq.

Materials and Methods

Vaginal fluids were collected from 62 aborted cows and examined by PCR. Data were reported for the following parameters: Vital signs (body temperature and respiratory and pulse rates), age (<4, 4-8, and >8 years), reproductive health status (premature calving, embryonic death, pyometra, and healthy newborn), breed (pure or crossbred), type of breeding (natural or artificial), bull-to-cow ratio (1:<10, 1:10-20, and 1:>20), contact of cow with bull(s) from other farmers (yes or no), and contact with stray animals (dogs and cats).

Results

A total of 20.97% of aborted cows were positive for T. foetus. Phylogenetic analysis for 10 positive local T. foetus isolates demonstrated high identity with the Thai (MN560972.2) and Chinese (MH115435.1) isolates, with an identity range of 98.8%-99.5% and 98.6%-99.3%, respectively. Clinical data showed that the vital signs differed insignificantly between cows positive and negative for T. foetus. Prevalence and risk of infection increased significantly in <4-year-old, early calving, embryonic death, crossbred, and naturally inseminated cows that had direct contact with bulls from other farmers, and contact with stray animals. Fetal pneumonia and death of premature calves were significant among positive aborted fetuses.

Conclusion

Tritrichomonas foetus is highly prevalent in aborted cows in Iraq and phylogenetic analysis demonstrated an identity between the local and global isolates, that is, Thai and Chinese, of cats.

Tritrichomonas foetus Cell Division Involves DNA Endoreplication and Multiple Fissions

Tritrichomonas foetus and Trichomonas vaginalis are extracellular flagellated parasites that inhabit animals and humans, respectively. Cell division is a crucial process in most living organisms that leads to the formation of 2 daughter cells from a single mother cell. It has been assumed that T. vaginalis and T. foetus modes of reproduction are exclusively by binary fission. However, here, we showed that multinuclearity is a phenomenon regularly observed in different T. foetus and T. vaginalis strains in standard culture conditions. Additionally, we revealed that nutritional depletion or nutritional deprivation led to different dormant phenotypes. Although multinucleated T. foetus are mostly observed during nutritional depletion, numerous cells with 1 larger nucleus have been observed under nutritional deprivation conditions. In both cases, when the standard culture media conditions are restored, the cytoplasm of these multinucleated cells separates, and numerous parasites are generated in a short period of time by the fission multiple. We also revealed that DNA endoreplication occurs both in large and multiple nuclei of parasites under nutritional deprivation and depletion conditions, suggesting an important function in stress nutritional situations. These results provide valuable data about the cell division process of these extracellular parasites. IMPORTANCE Nowadays, it's known that T. foetus and T. vaginalis generate daughter cells by binary fission. Here, we report that both parasites are also capable of dividing by multiple fission under stress conditions. We also demonstrated, for the first time, that T. foetus can increase its DNA content per parasite without concluding the cytokinesis process (endoreplication) under stress conditions, which represents an efficient strategy for subsequent fast multiplication when the context becomes favorable. Additionally, we revealed the existence of novel dormant forms of resistance (multinucleated or mononucleated polyploid parasites), different than the previously described pseudocysts, that are formed under stress conditions. Thus, it is necessary to evaluate the role of these structures in the parasites' transmission in the future.

Variations in the carbohydrate expression pattern and in lesions of the uterine horns of BALB/c mice infected with different Tritrichomonas foetus isolates

Bovine tritrichomonosis, a sexually transmitted disease caused by the protozoan Tritrichomonas foetus, is characterized by producing reproductive alterations in cattle. Carbohydrates on the surface of the uterine epithelium are involved in the process of adhesion and colonization of the protozoan. The murine model has proved to be an inexpensive, practical and representative alternative to study the lesions produced in the natural host. For this work, during the first stage, 6-8 week old female BALB/c mice were inoculated with 24 different T. foetus isolates in order to classify them according to their pathogenicity. Then, seven isolates were selected and processed with lectin histochemistry to determine if the differences in pathogenicity corresponded to the changes found in the uterine carbohydrate expression pattern. In this work, we demonstrate the differences in the expression of the carbohydrate pattern between infected and uninfected mice. In addition, within the group of infected mice, differences were found in the degree of pathogenicity of the isolates, thus evidencing their biological variability.

Molecular detection of Tritrichomonas foetus in bovine samples: a novel real-time polymerase chain reaction (PCR) assay targeting EF1-alpha-Tf1 and a comparative study of published PCR techniques

The parasite T. foetus causes trichomonosis in cattle but is generally asymptomatic in males. Thus, many bulls carrying the disease go unnoticed, making the detection of T. foetus in bulls an important aspect for its control. Due to drawbacks posed by its cultivation, PCR is a preferred option for diagnostic laboratories. Most published PCR protocols target the genomic region compring the 18S, 5.8S, and 28S rRNA genes and internal transcribed spacers 1 and 2 (rRNA-ITS region), homologous to that of other Tritrichomonas species. There is minimal information on alternative genetic targets and no comparative studies have been published. We compared a protocol based on the microsatellite TfRE (called H94) and five protocols based on the rRNA-ITS region (called M06, M15, G02, G05, and N02). We also designed and evaluated a novel PCR-based assay on the EF1-alpha-Tf1 gene (called V21). The analytical sensitivity and specificity assays for the PCR protocols were performed according to the World Organisation for Animal Health (OIE) directives and the comparative study was performed with a widely used PCR (M06) on clinical samples from 466 breeding bulls. V21 showed a high degree of agreement with our reference M06 (kappa = 0.967), as well as M15 (kappa = 0.958), G05 (kappa = 0.948), and H94 (kappa = 0.986). Protocols H94 and V21 appear to be good approaches for confirming clinical cases in preputial bull samples when genomic regions alternative to rRNA-ITS are required. By contrast, N02 gave false negatives and G02 false positives.

Prevalence of Tritrichomonas foetus in beef bulls slaughtered at two abattoirs in northern Australia

Bovine trichomoniasis, caused by the protozoal parasite Tritrichomonas foetus, is a highly contagious venereal disease characterised by early pregnancy loss, abortion and pyometra. Persistently infected bulls and cows are the primary reservoirs of infection in infected herds. This research investigated the prevalence of T. foetus infection in bulls from properties located across northern Australia and New South Wales. Preputial samples were collected from 606 bulls at slaughter and tested for T. foetus using the VetMAX‐Gold Trich Detection Kit (Thermo Fisher Scientific). The apparent prevalence of T. foetus infection varied between regions, with northern regions in the Northern Territory, Queensland and Western Australia showing a prevalence of 15.4%, 13.8% and 11.4%, respectively. There was some evidence of an association between infection and postcode (P = 0.06) and increasing bull age (P = 0.054). This study confirms that T. foetus infection is likely to be present in many beef breeding herds and contributing to lower than expected reproductive performance, particularly across northern Australia.

Ultrastructural and Functional Analysis of a Novel Extra-Axonemal Structure in Parasitic Trichomonads

Trichomonas vaginalis and Tritrichomonas foetus are extracellular flagellated parasites that inhabit humans and other mammals, respectively. In addition to motility, flagella act in a variety of biological processes in different cell types, and extra-axonemal structures (EASs) have been described as fibrillar structures that provide mechanical support and act as metabolic, homeostatic, and sensory platforms in many organisms. It has been assumed that T. vaginalis and T. foetus do not have EASs. However, here, we used complementary electron microscopy techniques to reveal the ultrastructure of EASs in both parasites. Such EASs are thin filaments (3-5 nm diameter) running longitudinally along the axonemes and surrounded by the flagellar membrane, forming prominent flagellar swellings. We observed that the formation of EAS increases after parasite adhesion on the host cells, fibronectin, and precationized surfaces. A high number of rosettes, clusters of intramembrane particles that have been proposed as sensorial structures, and microvesicles protruding from the membrane were observed in the EASs. Our observations demonstrate that T. vaginalis and T. foetus can connect to themselves by EASs present in flagella. The protein VPS32, a member of the ESCRT-III complex crucial for diverse membrane remodeling events, the pinching off and release of microvesicles, was found in the surface as well as in microvesicles protruding from EASs. Moreover, we demonstrated that the formation of EAS also increases in parasites overexpressing VPS32 and that T. vaginalis-VPS32 parasites showed greater motility in semisolid agar. These results provide valuable data about the role of the flagellar EASs in the cell-to-cell communication and pathogenesis of these extracellular parasites.

The first report of clinical case of intestinal trichomoniasis caused by Tritrichomonas foetus in a cat with chronic diarrhea in Iran

Background

Tritrichomonas foetus is recently found to be one of the causes of chronic diarrhea in domestic cats but there is no report of feline intestinal trichomoniasis in Iran.

Case description

A 9 months female domestic short-haired cat was referred to our hospital with a history of chronic diarrhea over the past two months, and with an unsuccessful previous antibiotic therapy in another clinic.

Findings/treatment and outcome

Clinical examination revealed 39.8°C rectal temperature. Complete blood count (CBC) showed moderate inflammatory leukogram. By the wet-mount faecal assessment, moving organisms were observed. Rectal scarping dry-mount cytology revealed many inflammatory cells along with huge numbers of trophozoites with typical morphologic characteristics including central axostyle, undulating membrane, flagella, and one laterally located nucleus. Polymerase chain reaction (PCR) was performed and confirmed the diagnosis of T. foetus. After treatment with metronidazole and probiotics, the cat was completely recovered.

Conclusion

This study represents the first case of intestinal trichomoniasis in a cat with chronic diarrhea in Iran.

Costain 1 (ARM19800.1) - The first identified protein of the costa of the pathogenic protozoan Tritrichomonas foetus

Protists members of the Trichomonadidae and Tritrichomonadidae families include agents of trichomoniasis that constitute important parasitic diseases in humans and in animals of veterinary interest. One of the characteristic features of these eukaryotic microorganisms is that they contain a fibrous structure known as the costa as an important cytoskeleton structure, that differs in several aspects from other cytoskeleton structures found in eukaryotic cells. Previous proteomic analysis of an enriched costa fraction revealed the presence of several hypothetical proteins. Here we describe the localization of one of the most prevalent protein found in this previously made proteomic assay to confirm its presence in the costa of Tritrichomonas foetus. A peptide sequence of the hypothetical protein ARM19800.1 was selected for the production of specific polyclonal antibodies and its specificity was confirmed by Western Blotting using an enriched costa fraction. Next, the specific localization of the selected protein was evaluated by immunofluorescence and electron microscopy immunocytochemistry. Our observations clearly showed that the ARM 19800.1 protein is indeed localized in the costa and displays an almost periodic labeling pattern. Since this is the first protein identified in the costa, it was designated as costain 1. A better understanding of a structure as peculiar as the costa is of great biological and evolutionary importance due to the fact that it contains unique proteins, it may represent a possible chemotherapy target and it may correspond to antigens of interest in immunodiagnosis and/or vaccine development.

Control and eradication of bovine trichomonosis in Wyoming, USA by testing and culling positive bulls

Bovine trichomonosis is caused by Tritrichomonas foetus. Thirty-three US states have state rules on this disease and render it reportable due to potential huge economic losses to cattle industry. The various rules of different states generally mandate testing and culling T. foetus-positive bulls as well as prohibiting import of T. foetus-positive animals. Wyoming has enforced these rules for over 20 year beginning in 2000. From 2017 to 2019, 3 years in a row, not even one T. foetus-positive bull has been detected throughout the entire state among over ten thousand bulls tested annually. Wyoming is the first US state to achieve total control and eradication of bovine trichomonosis by testing and culling T. foetus-positive bulls.

Antimicrobial properties of tomato leaves, stems, and fruit and their relationship to chemical composition

BACKGROUND

We previously reported that the tomato glycoalkaloid tomatine inhibited the growth of Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus-like strain C1 that cause disease in humans and farm and domesticated animals. The increasing prevalence of antibiotic resistance requires development of new tools to enhance or replace medicinal antibiotics.

METHODS

Wild tomato plants were harvested and divided into leaves, stems, and fruit of different colors: green, yellow, and red. Samples were freeze dried and ground with a handheld mill. The resulting powders were evaluated for their potential anti-microbial effects on protozoan parasites, bacteria, and fungi. A concentration of 0.02% (w/v) was used for the inhibition of protozoan parasites. A high concentration of 10% (w/v) solution was tested for bacteria and fungi as an initial screen to evaluate potential anti-microbial activity and results using this high concentration limits its clinical relevance.

RESULTS

Natural powders derived from various parts of tomato plants were all effective in inhibiting the growth of the three trichomonads to varying degrees. Test samples from leaves, stems, and immature 'green' tomato peels and fruit, all containing tomatine, were more effective as an inhibitor of the D1 strain than those prepared from yellow and red tomato peels which lack tomatine. Chlorogenic acid and quercetin glycosides were present in all parts of the plant and fruit, while caffeic acid was only found in the fruit peels. Any correlation between plant components and inhibition of the G3 and C1 strains was not apparent, although all the powders were variably effective. Tomato leaf was the most effective powder in all strains, and was also the highest in tomatine. S. enterica showed a minor susceptibility while B. cereus and C. albicans fungi both showed a significant growth inhibition with some of the test powders. The powders inhibited growth of the pathogens without affecting beneficial lactobacilli found in the normal flora of the vagina.

CONCLUSIONS

The results suggest that powders prepared from tomato leaves, stems, and green tomato peels and to a lesser extent from peels from yellow and red tomatoes offer potential multiple health benefits against infections caused by pathogenic protozoa, bacteria, and fungi, without affecting beneficial lactobacilli that also reside in the normal flora of the vagina.

A reassessment of the role of oxygen scavenging enzymes in the emergence of metronidazole resistance in trichomonads

Trichomonads are an order of parasitic protists which infect a wide range of hosts. The human parasite Trichomonas vaginalis and the bovine parasite Tritrichomonas foetus which also infects cats and swine are of considerable medical and veterinary importance, respectively. Since trichomonads are microaerophiles/anaerobes they are susceptible to 5-nitroimidazoles such as metronidazole. 5-nitroimidazoles are exclusively toxic to microaerophilic/anaerobic organisms because reduction, i.e. activation, of the drug can only occur in a highly reductive environment. 5-nitroimidazoles have remained a reliable treatment option throughout the last decades but drug resistance can be a problem. Clinical resistance to 5-nitroimidazoles has been studied in more detail in T. vaginalis and has been ascribed to defective oxygen scavenging mechanisms which lead to higher intracellular oxygen concentrations and, consequently, to less drug being reduced. Two enzymes, flavin reductase (FR) and NADH oxidase have been suggested to be the major oxygen scavenging enzymes in T. vaginalis. The loss, or at least an impairment of FR which reduces oxygen to hydrogen peroxide, has been proposed as the central mechanism that enables the emergence of 5-nitroimidazole resistance. In this study we explored if T. foetus also encodes a homolog of FR and if it is, likewise, involved in resistance. T. foetus was indeed found to express a FR but it was only weakly active as compared to the T. vaginalis homolog. Further, activity of FR in T. foetus was unchanged in metronidazole-resistant cell lines, ruling out that it has a role in metronidazole resistance. Finally, we measured oxygen scavenging rates in metronidazole-sensitive and -resistant cell lines and found that NADH oxidase and FR are not the major oxygen scavenging enzymes in trichomonads and that oxygen scavenging is possibly a consequence, rather than a cause of metronidazole resistance.

Tritrichomonas foetus in cats from Central Italy: Clinical signs and risk factors

Tritrichomonas foetus (Trichomonadida, Tritrichomonadidae) is a parasitic protozoan which causes a diarrheic disease in domestic cats worldwide. The epizootiological and pathogenic impact of this parasite in many geographic locations is still to be unraveled; thus, the present study has investigated the occurrence of T. foetus in cats from central Italy, along with the analysis of risk factors and clinical signs. One hundred and five cats referred to the University Veterinary Teaching Hospital of the University of Teramo were tested with copromicroscopic techniques for common intestinal and extra-intestinal parasites and a specific PCR for T. foetus. A statistical analysis evaluating associations between T. foetus positivity and possible risk factors was performed. One animal scored positive for Giardia (0.95%), 2 for Toxocara cati (1.90%), 1 for Eucoleus aerophilus (syn. Capillaria aerophila) (0.95%), 9 for Aelurostrongylus abstrusus (8.57%) and 1 for Dipylididum caninum (0.95%), while T. foetus was molecularly recorded in 18/105 (17.14%) of the study cats. In two cats, T. foetus was found in association respectively with Giardia and A. abstrusus. Animals with chronic gastrointestinal signs were more significantly infected by T. foetus (40.90% vs 10.84%; p < 0.01; 95% CI = 1.90-17.04; OR = 5.69) in comparison to cats with no gastrointestinal distresses. No other statistically significant associations were found. This study confirms that T. foetus is enzootic in cats in Italy and that it should be included in the differential diagnosis of feline chronic gastrointestinal diseases.

Unexpected Cross-Reaction with Honigbergiella-Like DNA in a PCR for Detection of Bovine Tritrichomonas foetus

The prevalence of bovine Tritrichomonas foetus infection has decreased almost to zero in most European countries, such as Poland, which has been Tritrichomonas foetus-free since 1997. However, trichomonosis is a notifiable disease and there is a duty to examine samples from cattle. In this study, we present an unexpected cross-reaction with Honigbergiella-like DNA in a specimen from a bull. The bovine sample was submitted to the Department of Parasitology National Veterinary Research Institute in Pulawy (NVRI) for confirmatory testing after having been examined at the Regional Veterinary Laboratory, during a routine T. foetus diagnosis. Positive results from microscopic observation and cultures were confirmed. Noteworthily, parasites grew on Diamond’s medium only after seven days of incubation, while optimal growth of trichomonads is generally observed after two to four days for this medium. Moreover, by using PCR we obtained positive results for the presence of T. foetus. However, sequencing of the amplification product revealed 99.62% identity with Honigbergiella sp. Our data suggest that false-positive results may occur in commonly used PCR tests. Thus, unexpected results should be carefully interpreted.

Anti-trichomonad activities of different compounds from foods, marine products, and medicinal plants: a review

Human trichomoniasis, caused by the pathogenic parasitic protozoan Trichomonas vaginalis, is the most common non-viral sexually transmitted disease that contributes to reproductive morbidity in affected women and possibly to prostate cancer in men. Tritrichomonas foetus strains cause the disease trichomoniasis in farm animals (cattle, bulls, pigs) and diarrhea in domestic animals (cats and dogs). Because some T. vaginalis strains have become resistant to the widely used drug metronidazole, there is a need to develop alternative treatments, based on safe natural products that have the potential to replace and/or enhance the activity of lower doses of metronidazole. To help meet this need, this overview collates and interprets worldwide reported studies on the efficacy of structurally different classes of food, marine, and medicinal plant extracts and some of their bioactive pure compounds against T. vaginalis and T. foetus in vitro and in infected mice and women. Active food extracts include potato peels and their glycoalkaloids α-chaconine and α-solanine, caffeic and chlorogenic acids, and quercetin; the tomato glycoalkaloid α-tomatine; theaflavin-rich black tea extracts and bioactive theaflavins; plant essential oils and their compounds (+)-α-bisabolol and eugenol; the grape skin compound resveratrol; the kidney bean lectin, marine extracts from algae, seaweeds, and fungi and compounds that are derived from fungi; medicinal extracts and about 30 isolated pure compounds. Also covered are the inactivation of drug-resistant T. vaginalis and T. foetus strains by sensitized light; anti-trichomonad effects in mice and women; beneficial effects of probiotics in women; and mechanisms that govern cell death. The summarized findings will hopefully stimulate additional research, including molecular-mechanism-guided inactivations and human clinical studies, that will help ameliorate adverse effects of pathogenic protozoa.

A case of "misplaced" Tritrichomonas foetus infection in a dog in Northern Italy

An 8-year-old, spayed female Rottweiler dog, under immunosuppressant treatment for protein-losing enteropathy (PLE) and intestinal lymphangiectasia, was presented for anorexia, poor general conditions and episodes of diarrhea. A subcutaneous mass between the caudal abdominal mammary glands was found. A fine-needle aspiration cytology was performed and revealed the presence of inflammatory cells mixed with pear- or round-shaped microorganisms with cytomorphological features of flagellated protozoan trophozoites, belonging to Trichomonadida order. The final diagnosis of Tritrichomonas foetus infection was achieved with molecular analysis (Real-Time PCR) and sequencing. T. foetus has often been reported as a pathogenic agent in cattle and cats, and rarely reported in dogs, where its pathogenetic role is poorly understood. To the author's knowledge, this is the first case of T. foetus infection described in a location different from the gastrointestinal tract in a dog.

Prevalence of Tritrichomonas foetus infection in cats in Bangkok metropolitan area and in vitro drug sensitivity testing

Tritrichomonas foetus is a causative agent of feline trichomonosis, resulting in large-bowel diarrhea in cats. Feline trichomonosis has been reported in the USA, Europe and some Asian countries but there is limited information for Thailand. This study investigated the prevalence of T. foetus infection in cats in the Bangkok metropolitan area and evaluated the in vitro efficacy of metronidazole (MDZ) and ronidazole (RDZ) against T. foetus Thai isolates. In total, 215 fecal samples were collected from 121 owned cats and 94 stray cats. All fecal samples were cultivated in InPouch™ TF-feline medium. Afterward, polymerase chain reaction (PCR) assays targeting the 5.8S rRNA gene, the ITS regions and DNA sequencing were used for the confirmation of T. foetus. The overall prevalence of T. foetus infection was 4.18% (9/215) based on cultivation and PCR. The sequencing results showed 100% homology to T. foetus sequences from GenBank. The average minimal lethal concentrations (MLCs) of MDZ were 333.33 and 66.67 μg/ml at 24 and 48 h, respectively. The average MLCs of RDZ were 29.16 and 12.5 μg/ml at 24 and 48 h, respectively. The MLC of the MDZ results revealed that T. foetus Thai isolates had a tendency to be MDZ-resistant. To the best of the authors' knowledge, this study was the first using in vitro cultivation and molecular techniques to report and confirm the presence of T. foetus in cats living in the Bangkok metropolitan area. Further studies are needed to determine the genuine infection rate of T. foetus in a greater population sample and the infection status in cats with signs of diarrhea in Thailand.

The Inhibitory Activity of Anthraquinones against Pathogenic Protozoa, Bacteria, and Fungi and the Relationship to Structure

Plant-derived anthraquinones were evaluated in cell assays for their inhibitory activities against the parasitic protozoa Trichomonas vaginalis human strain G3 that causes the sexually transmitted disease trichomoniasis in women, Tritrichomonas foetus bovine strain D1 that causes sexually transmitted diseases in farm animals (bulls, cows, and pigs), Tritrichomonas foetus-like strain C1 that causes diarrhea in domestic animals (cats and dogs), and bacteria and fungi. The anthraquinones assessed for their inhibitory activity were anthraquinone, aloe-emodin (1,8-dihydroxy-3-hydroxymethylanthraquinone), anthrarufin (1,5-dihydroxyanthraquinone), chrysazin (1,8-dihydroxyanthraquinone), emodin (1,3,8-trihydroxy-6-methylanthraquinone), purpurin (1,2,4-trihydroxyanthraquinone), and rhein (1,8-dihydroxy-3-carboxyanthraquinone). Their activities were determined in terms of IC₅₀ values, defined as the concentration that inhibits 50% of the cells under the test conditions and calculated from linear dose response plots for the parasitic protozoa, and zone of inhibition for bacteria and fungi, respectively. The results show that the different substituents on the anthraquinone ring seem to influence the relative potency. Analysis of the structure–activity relationships in protozoa indicates that the aloe-emodin and chrysazin with the highest biological activities merit further study for their potential to help treat the diseases in women and domestic and farm animals. Emodin also exhibited antifungal activity against Candida albicans. The suggested mechanism of action and the additional reported beneficial biological properties of anthraquinones suggest that they have the potential to ameliorate a broad spectrum of human diseases.

Tritrichomonas Foetus: A Study of Prevalence in Animal Hosts in Poland

Tritrichomonas foetus is described as a pathogen of cattle and cats and also exhibits commensalism with pigs. In order to estimate the prevalence and determine the risk factors for parasite infection, specimens from animal hosts (cat, pigs, and cattle) from Poland were investigated. To our best knowledge, this is the first such study to examine samples from wild boars (Sus scrofa) for the presence of T. foetus. Data were collected from 117 cats, 172 pigs, 236 wild boars, and 180 cattle. The sensitivity of T. foetus identification was increased by using two molecular assays: PCR and loop-mediated isothermal amplification (LAMP). The prevalence of feline tritrichomonosis was 20.51%, and statistically significant differences were obtained between groups of animals regarding age, breed, number of cats, diarrhea, and place of living. Positive PCR and LAMP results for T. foetus were estimated for 16.28% of pigs, and the obtained data were significantly correlated with age. Conversely, no significant differences were observed concerning the farm size factor. In our survey, no cases of bovine tritrichomonosis were found, which is consistent with the data from the other countries of the European Union. Similarly, all wild boar samples were also T. foetus-negative according to LAMP and PCR.

Whole genome sequencing of a feline strain of Tritrichomonas foetus reveals massive genetic differences to bovine and porcine isolates

Tritrichomonas foetus is a protozoan parasite that colonizes the reproductive tract of cattle as well as the gastrointestinal tract of cats. Bovine tritrichomonosis is a sexually transmitted disease whereas feline tritrichomonosis is thought to be transmitted by the fecal-oral route. Furthermore, T. foetus is known as an essentially apathogenic commensal located in the nasal cavity of pigs. Transmission of T. foetus between the different hosts has to be considered a realistic scenario that may have important implications for the epidemiology of infections and disease. In our study, we generated whole genome sequencing (WGS) data from bovine, feline and porcine T. foetus strains to investigate the genetic (dis)similarities among these diverse strains. As a reference, we used a previously released draft assembly from a bovine T. foetus strain K isolated from an infected bull in Brazil. In particular, we identified single nucleotide polymorphisms (SNPs) and the insertion-deletion (indel) variations within the genomes of the different strains. Interestingly, only a low degree of polymorphism (68 SNPs and indels) was found between the bovine and the porcine strains in terms of variants with a predicted impact of moderate or high and where one species is homozygous for one allele and the other homozygous for the other allele. Conversely, however, a 964 times higher number of such differences was detected by comparing the feline with either the bovine (65,569) or the porcine (65,615) strain. These data clearly indicated a close phylogenetic relationship between bovine and porcine T. foetus but a remarkable genetic distinctness of these two strains from the feline strain. The latter observation was confirmed by PCR-based sequencing of 20 in silico-selected indel markers and five in silico-selected SNP markers that uniformly demonstrated a relatively distant phylogenetic relationship of three independent feline T. foetus isolates in comparison to the bovine and porcine strains investigated. In summary, our comparative genome sequencing approach provided further insights into the genetic diversity of T. foetus in relation to the different host origins of the parasite. Furthermore, our study identified a large number of SNP- and indel-containing sequences that may be useful molecular markers for future epidemiological studies aimed at the elucidation of the transmission patterns of T. foetus within different host species.

Clinical isolates of Tritrichomonas foetus in bulls in Wyoming, South Dakota and Montana, USA

Background

Several Tritrichomonas species have been found in mammalian hosts. Among these trichomonads T. foetus is often found in the urogenital tract of cattle and the gastrointestinal tract of the domestic cat, resulting in sexually transmitted bovine trichomonosis and fecal-orally transmitted feline trichomonosis, respectively. The aims of the current study were to molecularly characterize clinical isolates of T. foetus in cattle populations in Wyoming, South Dakota, and Montana of the United States of America and to phylogenetically analyze Tritrichomonas species of mammalian hosts.

Results

DNA sequencing of rRNA genes showed over 99% identity of the newly described isolates to other bovine isolates. Further, T. foetus isolates of various mammalian hosts originated in different geographic regions worldwide were clustered into two well-defined clades by phylogenetic analysis of rRNA and cysteine protease 2 genes. Clade I consisted of isolates originated from cattle, pig, and human whereas clade II contained isolates of cat and dog.

Conclusion

It is concluded that all mammalian Tritrichomonas spp. apparently belong to T. foetus. Analysis of more sequences is warranted to support this conclusion.

Tritrichomonas Foetus as a Causative Agent of Tritrichomonosis in Different Animal Hosts

Tritrichomonas foetus is a protozoan parasite that has been traditionally identified as a cause of reproductive tract disease in cattle and gastrointestinal tract infection in cats. Moreover, T. foetus is also well known as a commensal of the nasal cavity, intestines, and stomach in swine. In this review we describe T. foetus as a pathogen dangerous to more than one animal host, diagnostic and taxonomic aspects of this infection, and the extent to which isolates from different hosts share genetic identity.

Multilocus analysis reveals further genetic differences between Tritrichomonas foetus from cats and cattle

Tritrichomonas foetus isolates from feline and bovine origin has been previously shown to carry a certain degree of genetic heterogeneity. Here, novel candidate molecular markers were developed by means of multilocus sequence typing of the gap2 gene (encoding for T. foetus glyceraldehyde-3-phosphate dehydrogenase), ITS region, the TR7/TR8 variable-length repeat and microsatellite genotyping. These markers were used to characterize T. foetus field isolates from bulls and domestic cats and to compare phylogenetically with the following ATCC isolates: T. foetus isolated from cattle and pig (syn. Tritrichomonas suis), Tritrichomonas mobilensis, Tetratrichomonas gallinarum and Pentatrichomonas hominis. Among them, TFMS10 and TFMS7 were found to be the most polymorphic markers. Moreover, an 809 bp fragment of the gap2 gene was successfully amplified from all the trichomonads included in this study and the sequence analysis revealed differences between T. foetus porcine and feline genotypes and T. mobilensis in comparison to the bovine T. foetus ATCC isolate. The TR7/TR8 repeat pattern was not reproducible, being only consistent the fragments of approximately 110 and 217 bp. Sequence analysis of the latter revealed the existence of 3 SNPs resulting in 98.6 % homology between bovine and feline isolates. A search for similar sequences was carried out to develop a Restriction Length Fragment Polymorphism analysis. A 503 bp region, named TF1, revealed the existence of two BbvI restriction enzyme sites that were able to generate different length fragments for T. foetus feline and bovine isolates. Finally, the neighbour-joining analyses showed that T. foetus porcine genotype clusters together with bovine genotype, whereas T. mobilensis and the feline genotype form a separate cluster.

Development and comparative evaluation of different LAMP and PCR assays for coprological diagnosis of feline tritrichomonosis

The protozoan parasite Tritrichomonas foetus may cause severe diarrhea in cats all over the world. In order to evaluate the methodology in coprological molecular diagnosis of feline tritrichomonosis, we compared previously published ("old") and newly developed ("novel") loop-mediated isothermal amplification (LAMP) (targeted to the T. foetus β-tubulin and the elf1α 1 gene, respectively) as well as an old conventional and an old and novel real-time PCR (all targeted to overlapping regions of T. foetus rDNA) assays regarding their diagnostic sensitivities and specificities. Here, the novel real-time PCR yielded the best methodical performance in that a sensitivity with a detection limit of <0.1 trophozoites (corresponding to ca.<0.13 trophozoites per mg feces) and a maximal specificity for diagnosis of Tritrichomonas spp. was achieved. The other test systems exhibited either an approximately 10-times lower sensitivity (<1 trophozoite corresponding to ca.<1.3 trophozoites per mg feces) (conventional PCR and both LAMP assays) or a lower specificity (old real-time PCR). Conversely, the diagnostic performance assessed with clinical fecal samples from cats demonstrated identical sensitivities (8 of 20 samples tested were positive) for the novel PCR and both LAMP assays. Diagnostic sensitivities were significantly higher than those found for the old real-time (5 positive samples) and conventional PCR (6 positive samples), respectively. Accordingly, our data suggested the novel PCR and both LAMP assays to be well suited molecular tools for direct (i.e. without including an in vitro cultivation step) coprological diagnosis of tritrichomonosis in cats. Interestingly, relative high (novel LAMP, 7 positive samples) to at least moderate (old LAMP, 6 positive samples and 1 sample with equivocal score) diagnostic sensitivities were also achieved by testing clinical samples upon simple visual inspection of colorimetric changes during the LAMP amplification reactions. Accordingly, both LAMP assays may serve as practical molecular tools to perform epidemiological studies on feline (and bovine as well as porcine) tritrichomonosis under simple laboratory conditions.

Prevalence of Cryptosporidium, Giardia, Blastocystis, and trichomonads in domestic cats in East China

The cat is a reported reservoir for several zoonotic pathogens, including Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. These parasites represent a significant, but often neglected, threat to humans and animals. Furthermore, Tritrichomonas foetus has been described inhabiting the digestive tract of cats, and may be causative agents of gastrointestinal symptoms. However, scant data are available concerning the molecular epidemiology of these parasites in domestic cats in China. This study examined fecal samples from domestic cats in Eastern China to unravel the molecular epidemiology of four protozoans. Of the 346 samples examined, 47 (13.6%) were positive for the detected pathogens, including 8 (2.3%), 5 (1.4%), 2 (0.6%), and 35 (10.1%) samples positive for Cryptosporidium spp., G. duodenalis, Blastocystis sp., and T. foetus, respectively. Co-infection with Cryptosporidium spp. and T. foetus was detected in three cats, no other mixed infections were observed. No age, sex or fecal condition predisposition was observed with any of the four pathogens. The species/assemblages/subtypes/genotypes were C. felis, Assemblage A and F, ST1, and cat genotype for Cryptosporidium spp., G. duodenalis, Blastocystis sp., and T. foetus detected in this study, respectively. The presence of zoonotic species/assemblages/subtypes/genotypes poses a threat to public health. These findings provide useful information for the design of prevention and control strategies to reduce the burden of protozoal infections in cats.

Flow cytometry evaluation of in vitro susceptibility of bovine isolates of Tritrichomonas foetus to metronidazole

Bovine Trichomonosis, an endemic sexually transmitted disease in countries with extensive livestock and natural service, represents one of the most common causes of reproductive failure. 5-nitroimidazoles and their derivatives are used for its treatment, mainly metronidazole (Mz). The emergence of resistance mechanisms adopted by the parasites against the drug and failure of the treatments suggest the need to investigate susceptibility and obtain current values. The available information of in vitro susceptibility of these drugs comes from the use of a diversity of methodologies and criteria, especially observation of the mobility of the parasite under the optical microscope to evaluate its viability. These techniques are arduous and time consuming and lead to a subjective assessment dependent on the operator, the methodology used, and the morphology adopted by the protozoan. In this sense, flow cytometry has proven to be a fast and efficient method to evaluate viability in other protozoa. The aim of this study was to evaluate the in vitro susceptibility of six bovine isolates of Tritrichomonas foetus to Mz in aerobic (AC) and anaerobic (ANC) conditions by means of the calculation of the 50% inhibitory concentration (IC₅₀), by flow cytometry, and also to analyze minimum lethal concentration (MLC) by means of recovery tests post-treatment in vitro. IC₅₀ values ranged from 1.06 to 1.25 μM in ANC and from 1.44 to 3.03 μM in AC, these being the only ones reported at 48 h for these protozoa. With respect to MLC at 48 h, the results were from 3.67 to 7.35 μM in ANC, and from 7.35 to 14.7 μM for AC, where two isolates (Tf0 and Tf2) for AC and one (Tf2) for ANC showed higher values than those described in the literature. Flow cytometry has proven to be an effective, rapid and objective methodology and very useful in susceptibility tests. The data obtained through these tests allow us to describe the susceptibility exhibited by these protozoa, this being valuable information when establishing dosages in Mz treatments.

Prevalence of bovine trichomonosis and associated risk factors in bulls from Spanish beef herds

Bovine trichomonosis is a sexually transmitted disease considered as an important cause of early reproductive failure in beef cattle. To investigate the occurrence of the infection in different Spanish beef cattle-producing areas, retrospective data from the SALUVET veterinary diagnostic laboratory (Veterinary Faculty, Madrid, Spain) derived from the analysis of samples from beef bulls that were routinely tested for Tritrichomonas foetus infection, were compiled from 2011 to 2015. In addition, a number of potential risk factors were assessed. T. foetus was detected in 12.7% (385/3016; 95% CI: 11.5%-13.9%) of samples from bulls and in 20.7% (195/941; 95% CI: 18.1%-23.3%) of the herds tested. "Bull age" and "reproductive disorders in the herd" were the risk factors identified in the multivariable analysis. Bulls older than 3 years (19.7%) were more likely to be infected than young bulls (8.2%) and T. foetus was more often detected in herds with reproductive problems (27.9%) than in those without reproductive disorders (9.4%). The prevalence in bulls originating in mountain systems (13.9%, 267/1922) was significantly higher than that in "dehesa" (Mediterranean holm-oak pasture) areas (10.8%; 118/1094) (P ˂ 0.05), which might be attributable to the use of communal pastures and specific management practices in mountain systems. The results reported here indicate that T. foetus infection is substantially spread among beef cattle herds, suggesting that BT could be having a significant negative impact on the reproduction and productivity of Spanish beef herds managed under extensive conditions.

Highly Potent 1H-1,2,3-Triazole-Tethered Isatin-Metronidazole Conjugates Against Anaerobic Foodborne, Waterborne, and Sexually-Transmitted Protozoal Parasites

Parasitic infections like amebiasis, trichomoniasis, and giardiasis are major health threats in tropical and subtropical regions of the world. Metronidazole (MTZ) is the current drug of choice for amebiasis, giardiasis, and trichomoniasis but it has several adverse effects and potential resistance is a concern. In order to develop alternative antimicrobials, a library of 1H-1,2,3-triazole-tethered metronidazole-isatin conjugates was synthesized using Huisgen's azide-alkyne cycloaddition reaction and evaluated for their amebicidal, anti-trichomonal, and anti-giardial potential. Most of the synthesized conjugates exhibited activities against Trichomonas vaginalis, Tritrichomonas foetus, Entamoeba histolytica, and Giardia lamblia. While activities against T. vaginalis and T. foetus were comparable to that of the standard drug MTZ, better activities were observed against E. histolytica and G. lamblia. Conjugates 9d and 10a were found to be 2–3-folds more potent than MTZ against E. histolytica and 8–16-folds more potent than MTZ against G. lamblia. Further analysis of these compounds on fungi and bacteria did not show inhibitory activity, demonstrating their specific anti-protozoal properties.

Improvements in Tritrichomonas foetus molecular testing

Bovine trichomoniasis is a sexually transmitted disease that results in infertility, abortion, and calf age variability. To date, management strategies include testing for Tritrichomonas foetus and culling of infected males. Challenges associated with testing include cost of culture medium, time and labor burden of sample incubation and processing, and adverse effects of bacterial growth on detection sensitivity. To overcome these challenges, we developed a direct reverse-transcription quantitative real-time PCR (direct RT-qPCR) utilizing smegma, eliminating the use of culture medium. In an analysis of 166 field samples (56 positives and 110 negatives as determined using microscopic reading of cultures as the reference test), the direct RT-qPCR exhibited 100% diagnostic sensitivity and 100% specificity, whereas the currently employed qPCR (culture qPCR), which utilizes cultured samples, exhibited 95% diagnostic sensitivity and 100% specificity. Agreement between direct RT-qPCR and culture qPCR was 98%. Moreover, direct RT-qPCR identified 3 more positive samples and exhibited lower quantification cycle (Cq) values among positives by culture reading than did culture qPCR (direct RT-qPCR Cq range = 14.6-32.3 vs. culture qPCR Cq range = 18.7-37.4). The direct RT-qPCR enables simplified sample collection, elimination of culture medium, faster results, applicability in cows, and lower cost than culture qPCR.

Systemic humoral immunity in beef bulls following therapeutic vaccination against Tritrichomonas foetus

The utility of therapeutic vaccination of bulls against Tritrichomonas foetus has been advocated in previous studies, but anecdotal reports suggest this practice does not clear infections and may additionally confound diagnostic testing by reducing parasite burdens below detectable limits. The objective of this study was to characterize the systemic humoral immune response to therapeutic vaccination in T. foetus-infected bulls over a period of four months using an indirect ELISA and to compare the dynamics of this response to culture and PCR results to establish the existence of a relationship (or lack thereof) between immunization and infection status. A study population of 4- to 6-year-old T. foetus-infected beef bulls (n = 20) was divided equally into a treatment group and a control group. The treatment group received two doses of commercially prepared whole cell killed vaccine 2 weeks apart while the control group received injections of vaccine diluent. Blood samples were collected at each injection and at 4 subsequent dates every 4 weeks thereafter (i.e. 0, 2, 6, 10, 14, and 18 wks) to measure IgG₁ and IgG₂ antibody subisotype response via an indirect ELISA. Preputial smegma samples were collected at the four monthly intervals following vaccination for diagnosis of infection via InPouch™ culture, Modified Diamond's Medium (MDM) culture, and PCR. Humoral response for both IgG isotypes from week 2 through week 18 were significantly increased in vaccinates compared to controls. No significant decrease in infection prevalence was detected in the treatment group for any of the diagnostic methods used. The apparent lack of pathogen clearance during a stimulated immune response suggests that therapeutic vaccination may not be a useful T. foetus management practice.

Kitts

Trichomonosis is an endemic disease in cattle that are reared under extensive conditions and bred by natural mating. It causes profound economic losses to the producers by increasing calving interval, increasing embryo losses, and decreasing pregnancy rates. The aim of this study was to determine whether Tritrichomonas foetus infections were absent from cattle in St. Kitts. Using the modified hypergeometric method, preputial samples from bulls (n = 78) were tested using the InPouch™ culture for presence of T. foetus. Results highlighted an absence of trichomoniasis in bulls on St. Kitts with a 95% confidence.

Failure to detect Tritrichomonas foetus in a cross-sectional survey in the populations of feral cats and owned outpatient cats on St Kitts, West Indies

OBJECTIVES

For over two decades, feline trichomonosis caused by Tritrichomonas foetus has been recognized as a large-bowel protozoan disease of the domestic cat. It has a wide distribution, but no reports exist in the Caribbean. The objectives of this study were to detect the presence of T foetus and its prevalence in the domestic cat on St Kitts, West Indies.

METHODS

A cross-sectional study was performed between September 2014 and December 2015. This study recruited 115 feral cats from a trap-neuter-return program and 37 owned cats treated as outpatients at the university veterinary clinic. Fresh feces were inoculated in InPouch culture medium, as per the manufacturer's instructions. In addition, PCR was performed using primers for T foetus. DNA extraction with amplification using primers of a Feliscatus NADH dehydrogenase subunit 6 was used as a housekeeping gene for quality control.

RESULTS

Only two owned cats had reported diarrhea in the preceding 6 months. None of the 152 samples were positive on InPouch culture microscopic examination. Only 35/69 feral cat fecal DNA samples were positive for the housekeeping gene, of which none tested PCR positive for T foetus.

CONCLUSIONS AND RELEVANCE

T foetus was not detected by culture and PCR in feral cats and owned cats on St Kitts. A high proportion of PCR inhibitors in the DNA samples using a commercial fecal DNA kit can lead to underestimating the prevalence, which should be taken into consideration when a survey on gastrointestinal pathogens depends exclusively on molecular detection.

Diamine derivative anti-Trichomonas vaginalis and anti-Tritrichomonas foetus activities by effect on polyamine metabolism

Human and bovine trichomoniasis are sexually transmitted diseases (STD) caused by Trichomonas vaginalis and Tritrichomonas foetus, respectively. Human trichomoniasis is the most common non-viral STD in the world and bovine trichomoniasis causes significant economic losses to breeders. Considering the significant impact of the infections caused by these protozoa and the treatment failures, the search for new therapeutic alternatives becomes crucial. In this study the effect of diamines and amino alcohols in the in vitro viability of trichomonads was evaluated. Screening demonstrated the high activity of diamine 4 against these protozoa. Although cytotoxicity against HMVII cell line and slight hemolysis were observed in vitro, the compound showed no toxic effect on the Galleria mellonella in vivo model. Importantly, diamine 4 was active against both trichomonads species at 6h and 24h of incubation, and these effects was reverted by putrescine, a polyamine, suggesting competition for the same metabolic pathway. These findings indicate that the mechanism of action of diamine 4 is through the polyamine metabolism, a pathway distinct from that presented by metronidazole, the drug usually used to treat trichomoniasis and to which resistance is widely reported. These data demonstrate the importance of diamines as potential novel candidates as anti-T. vaginalis and anti-T. foetus agents.

Phytochemical-rich foods inhibit the growth of pathogenic trichomonads

Background

Plants produce secondary metabolites that often possess widespread bioactivity, and are then known as phytochemicals. We previously determined that several phytochemical-rich food-derived preparations were active against pathogenic foodborne bacteria. Trichomonads produce disease (trichomoniasis) in humans and in certain animals. Trichomonads are increasingly becoming resistant to conventional modes of treatment. It is of interest to test bioactive, natural compounds for efficacy against these pathogens.

Methods

Using a cell assay, black tea, green tea, grape, pomegranate, and jujube extracts, as well as whole dried jujube were tested against three trichomonads: Trichomonas vaginalis strain G3 (found in humans), Tritrichomonas foetus strain D1 (found in cattle), and Tritrichomonas foetus-like organism strain C1 (found in cats). The most effective of the test substances was subsequently tested against two metronidazole-resistant Trichomonas vaginalis strains, and on normal mucosal flora.

Results

Black tea extract inhibited all the tested trichomonads, but was most effective against the T. vaginalis organisms. Inhibition by black tea was correlated with the total and individual theaflavin content of the two tea extracts determined by HPLC. Metronidazole-resistant Trichomonas vaginalis strains were also inhibited by the black tea extract. The response of the organisms to the remaining preparations was variable and unique. We observed no effect of the black tea extract on common normal flora bacteria.

Conclusions

The results suggest that the black tea, and to a lesser degree green tea, grape seed, and pomegranate extracts might present possible natural alternative therapeutic agents to treat Trichomonas vaginalis infections in humans and the related trichomonad infections in animals, without negatively affecting the normal flora.

Prevalence of Tritrichomonas foetus in tennessee bulls

The prevalence of bovine trichomonosis (BT) in TN bulls was estimated through both active screening of bulls and review of previous laboratory records. During the active bull screening, preputial smegma specimens were collected from 458 TN beef bulls at 2 cattle slaughterhouses and 2 stockyards, which serve most beef bulls in TN, between March 2014 and June 2015. Each specimen was cultured for Tritrichomonas foetus (T. foetus) as well as evaluated microscopically every other day for seven days for any protozoa resembling T. foetus. An aliquot of the culture media from each specimen was used for DNA extraction and subsequent qPCR testing. Two specimens were considered suspect on microscopic evaluation, but all specimens were negative for T. foetus on qPCR. This suggests that the 2 specimens were most likely contaminated by fecal trichomonads. Retrospectively, 1979 T. foetus test records from 2 major TN diagnostic laboratories were reviewed between October 2013 and September 2016. True prevalence of BT in TN beef bulls was estimated at <0.01% from the laboratory records, although the county prevalence differed in 2 TN counties (Marshal: 0.09% and Bedford: 0.5%). Overall, the prevalence of BT in TN is low, and the current screening efforts to help control BT disease in TN are acceptable. Future efforts should focus on educating cattle stakeholders on the importance of optimal specimen collection and handling as well as routine testing for BT before cattle movement. In addition, cattle producers should be reminded of leading risk factors associated with BT in cattle.

Evaluation of surface antigen TF1.17 in feline Tritrichomonas foetus isolates

Tritrichomonas foetus (T. foetus) is a flagellated protozoa that infects the distal ileum and proximal colon of domestic cats, as well as the urogenital tract of cattle. Feline trichomonosis is recognized as a prevalent cause of chronic diarrhea in cats worldwide. The suspected route of transmission is fecal-oral, with cats in densely crowded environments at highest risk for infection. Thus, the recommended strategy for minimizing spread of infection is to identify and isolate T. foetus-positive cats from the general population. Rapid identification of infected cats can be challenging due to the inability to accurately and quickly detect the organism in samples at point of care facilities. Thus, identification of targets for use in development of a novel diagnostic test, as well as a vaccine or therapy for T. foetus infection is a significant area of research. Despite a difference in organ tropism between T. foetus genotypes, evidence exists for conserved virulence factors between feline and bovine T. foetus. The bovine T. foetus surface antigen, TF1.17, is an adhesin that is conserved across isolates. Vaccination with the purified antigen results in amelioration of cytopathogenicity and more rapid clearance of infection in cattle. We previously showed that three feline isolates of T. foetus were positive for TF1.17 antigen so we further hypothesized that TF1.17 is conserved across feline T. foetus isolates and that this antigen would represent an attractive target for development of a novel diagnostic test or therapy for feline trichomonosis. In these studies, we used monoclonal antibodies previously generated against 1.15 and 1.17 epitopes of the bovine T. foetus TF1.17 antigen, to evaluate for the presence and role of TF1.17 in the cytopathogenicity of feline T. foetus. A previously validated in vitro co-culture approach was used to model feline T. foetus infection. Immunoblotting, immunofluorescence assays, and flow cytometric analysis confirmed the presence and surface localization of antigen TF1.17 across all feline T. foetus isolates tested. Antigen TF1.17 was notably absent in the presumably nonpathogenic intestinal trichomonad, Pentatrichomonas hominis, a parasite that can be confused microscopically with T. foetus. Similar to bovine trichomoniasis, TF1.17 was found to promote T. foetus adhesion to the intestinal epithelium. These results support further characterization and development of the TF1.17 antigen as a possible target for the diagnosis and prevention of feline T. foetus infection.

The costa of trichomonads: A complex macromolecular cytoskeleton structure made of uncommon proteins

BACKGROUND INFORMATION

The costa is a prominent striated fibre that is found in protozoa of the Trichomonadidae family that present an undulating membrane. It is composed primarily of proteins that have not yet been explored. In this study, we used cell fractionation to obtain a highly enriched costa fraction whose structure and composition was further analysed by electron microscopy and mass spectrometry.

RESULTS

Electron microscopy of negatively stained samples revealed that the costa, which is a periodic structure with alternating electron-dense and electron-lucent bands, displays three distinct regions, named the head, neck and body. Fourier transform analysis showed that the electron-lucent bands present sub-bands with a regular pattern. An analysis of the costa fraction via one- and two-dimensional electrophoresis and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) allowed the identification of 54 hypothetical proteins. Fourteen of those proteins were considered to be major components of the fraction.

CONCLUSIONS

The costa of T. foetus is a complex and organised cytoskeleton structure made of a large number of proteins which is assembled into filamentous structures. Some of these proteins exhibit uncharacterised domains and no function related according to gene ontology, suggesting that the costa structure may be formed by a new class of proteins that differ from those previously described in other organisms. Seven of these proteins contain prefoldin domains displaying coiled-coil regions. This propriety is shared with proteins of the striated fibres of other protozoan as well as in intermediate filaments.

SIGNIFICANCE

Our observations suggest the presence of a new class of the cytoskeleton filaments in T. foetus. We believe that our data could auxiliate in determining the specific locations of these proteins in the distinct regions that compose the costa, as well as to define the functional roles of each component. Therefore, our study will help in the better understanding of the organisation and function of this structure in unicellular organisms.

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.

Cross-sectional survey on Tritrichomonas foetus infection in Italian cats

The feline genotype of Tritrichomonas foetus is a widespread cause of large-bowel diarrhoea in cats. The aim of this study was to determine the prevalence of the T. foetus infection in cat populations across Italy. Fresh, individual faecal samples were collected from 267 cats, kept in different environments (i.e., private households, breeding structures, municipal catteries and colonies) in three different sites across Italy. The faecal samples were tested by PCR to detect T. foetus. Moreover, the same samples were subjected to a concentration-flotation technique and a commercial direct fluorescent-antibody (DFA) test to detect additional enteric parasites, including Giardia duodenalis. The overall prevalence of T. foetus infection was 5.2%. All the infected cats showed diarrhoea at the time of sampling: 9 out of 14 positive cats were co-infected with G. duodenalis, 1 with Toxocara cati and 3 with Dipylidium caninum. The risk factor analysis showed that not only the breed, but also co-infections with G. duodenalis and Dipylidium caninum were significantly associated with the presence of T. foetus. This study confirms the presence of T. foetus in cats living in Italy, suggesting that this protozoan parasite should always be included in the differential diagnosis of patients referred with large-bowel disease symptoms, especially if they were purebred animals, or affected by other enteric protozoa, such as G. duodenalis.

Antiprotozoal Effects of the Tomato Tetrasaccharide Glycoalkaloid Tomatine and the Aglycone Tomatidine on Mucosal Trichomonads

The present study investigated the inhibitory effects of the commercial tetrasaccharide tomato glycoalkaloid tomatine and the aglycone tomatidine on three mucosal pathogenic protozoa that are reported to infect humans, cattle, and cats, respectively: Trichomonas vaginalis strain G3, Tritrichomonas foetus strain D1, and Tritrichomonas foetus strain C1. A preliminary screen showed that tomatine at 100 μM concentration completely inhibited the growth of all three trichomonads. In contrast, the inhibition of all three pathogens by tomatidine was much lower, suggesting the involvement of the lycotetraose carbohydrate side chain in the mechanism of inhibition. Midpoints of concentration-response sigmoid plots of tomatine on the three strains correspond to IC₅₀ values, the concentration that inhibits 50% of growth of the pathogenic protozoa. The concentration data were used to calculate the IC₅₀ values for G3, D1, and C1 of 7.9, 1.9, and 2.2 μM, respectively. The results show an approximately 4-fold variation from the lowest to the highest value (lowest activity). Although the inhibition by tomatine was not as effective as that of the medicinal drug metronidazole, the relatively low IC₅₀ values for both T. vaginalis and T. foetus indicated tomatine as a possible natural alternative therapeutic for trichomoniasis in humans and food-producing (cattle and pigs) and domestic (cats) animals. Because tomatine has the potential to serve as a new antiprotozoan functional (medical) food, the distribution of this glycoalkaloid in tomatoes and suggestions for further research are discussed.

Impact of a killed Tritrichomonas foetus vaccine on clearance of the organism and subsequent fertility of heifers following experimental inoculation

Tritrichomonas foetus is a sexually transmitted reproductive pathogen of cattle that causes transient infertility, early embryonic death, metritis, pyometra, and sporadic abortions. The objective of this research was to assess the impact on reproductive health of vaccinating naïve heifers with a killed T. foetus vaccine (TrichGuard) before experimental exposure followed by breeding. A total of 40 beef heifers were randomly assigned into two treatment groups. Heifers where then vaccinated with two doses of TrichGuard or sham vaccinated with 0.9% sterile saline according to their respective groups. Sixty days following vaccination or sham vaccination, heifers were intravaginally inoculated with 2 × 10⁶ organisms of a cloned isolate of T. foetus of bovine origin (CDTf-4) during synchronized estrus. Three days following inoculation of T. foetus, bulls free of T. foetus were introduced for natural breeding. Three bulls were maintained with the 40 heifers (20 vaccinated; 20 sham vaccinated) for a 49-day breeding season. Cervical mucous samples were obtained from each heifer at Day 0 and at 29 additional time points throughout the study for T. foetus culture. Pregnancy assessments were performed routinely by using transrectal palpation and ultrasonography. Pregnancies were detected in 19/20 (95%) vaccinated heifers and 14/20 (70%) sham-vaccinated heifers (P = 0.046). Only 4/20 (20%) of the sham-vaccinated heifers gave birth to a live calf compared with 10/20 (50%) of the vaccinated heifers (P = 0.048). Thus, embryonic or fetal loss was detected in 9/19 (47%) vaccinated heifers and 10/14 (71%) sham-vaccinated heifers (P = 0.153). The interval of time between inoculations with T. foetus and conceptions of pregnancies that were maintained until birth did not differ significantly between groups (vaccinated = 18.7 days; sham-vaccinated = 17.3 days; P = 0.716). The infectious challenge in this study proved to be very rigorous as a positive culture was detected from all heifers. The culture-positive results on the last culture day did not differ significantly (P = 0.115) between vaccinated heifers (63.9 days) and sham-vaccinated heifers (79.2 days). All uterine culture samples collected from the 26 nonpregnant heifers on Day 207 postinoculation did not result in the detection of T. foetus. These findings indicate that the killed, whole cell vaccine used in this study (TrichGuard) was effective in improving reproductive health evidenced by significantly reducing losses associated with T. foetus infections.

Novel genotype of Tritrichomonas foetus from cattle in Southern Africa

Bovine trichomonosis caused by Tritrichomonas foetus is a significant reproductive disease of cattle. Preputial samples were collected using sheath washing technique in bulls in Namibia. Thirty-six trichomonad cultures were characterized using the TaqMan-probe commercial real-time polymerase chain reaction (PCR) diagnostic assay (VetMAX™-Gold Trich Detection Kit) and CYBR real-time PCR assay based on TFR3/4 primers. Diagnostic real-time PCRs and DNA sequencing of the internal transcribed region confirmed presence of T. foetus in 35 out of 36 samples. Multilocus genotyping using cysteine proteases (CP1, CP2, CP4, CP5, CP6, CP7, CP8, CP9) and malate dehydrogenase (MDH1) gene sequences demonstrate that the T. foetus in Namibia are genetically distinct from those characterized elsewhere. We report the discovery of a novel genotype of T. foetus in Namibian cattle, distinct from other T. foetus genotypes in Europe, South and North America and Australia. We suggest recognition of a 'Southern African' genotype of T. foetus. Identification of the new genotype of T. foetus demonstrates the need for wider global sampling to fully understand the diversity and origin of T. foetus causing disease in cattle or cats.

Validation of a gauze sponge sampling methodology to detect Tritrichomonas foetus by real-time PCR

Bovine trichomoniasis is a concern for the cattle industry. Advances in testing systems have increased the ability to detect the disease in bulls. However, the greatest limitation is proper collection of an adequate sample. The low repeatability observed with most sample collection techniques can cause false-negative results. The aim of our study was to validate a sample collection technique that increases diagnostic sensitivity and is easier and safer to collect than preputial scraping. Commercial bulls (n = 111) of unknown infection status were sampled for detection of Tritrichomonas foetus using 2 different collection methods: 1) preputial scraping with a dry insemination pipette and 2) penile sponging with a 16-ply gauze sponge. Preputial scraping samples were collected by vigorously scraping preputial and penile mucosa using a rigid insemination pipette while applying negative pressure with a syringe. Penile sponge samples were obtained by swabbing the penile and preputial mucosa with a gauze sponge during full extension of the penis. All samples were processed using a commercial medium and submitted under similar conditions for PCR testing. Positive PCR results were detected in 37 of 111 (33%) bulls using the preputial scraping technique; however, 39 of 111 (35%) were positive using the penile sponging technique. The Newton-Raphson algorithm predicted that the sensitivity of the preputial scraping method was 0.919 (95% CI: 0.689-0.983) and the sensitivity of the penile sponging was 0.949 (95% CI: 0.818-0.987). These data indicate that the penile sponging technique is a reliable alternative to the preputial scraping method.

Infectious reproductive disease pathogens in dairy herd bulls

OBJECTIVE

Investigate the presence of infectious reproductive disease pathogens in dairy herd bulls in south-west Victoria, Australia, using a cross-sectional study.

METHODS

Dairy herd bulls from 32 herds were sampled for bovine viral diarrhoea virus (BVDV: 256 bulls, 32 herds) prior to the natural mating period, bovine herpes virus-1 prior to (10 bulls, 5 herds) and after (118 bulls, 19 herds) the natural mating period, and for Campylobacter fetus spp. and Tritrichomonas foetus after the natural mating period (61 bulls, 7 herds). BVDV was detected from an ear-notch sample using a commercially available rapid assay ELISA, bovine herpes virus-1 and T. foetus were screened for by PCR from a penile swab and preputial sample respectively, and C. fetus spp. were screened for by culture of preputial samples.

RESULTS

None of the bulls tested positive for BVDV antigen. Campylobacter fetus venerealis (or C. fetus fetus) was cultured in 6.6% (4/61) of bulls, representing 2 of the 7 (28.6%) farms that were not vaccinating bulls against bovine genital campylobacteriosis. Bovine herpes virus-1 was identified in 7.8% (10/128) bulls sampled; T. foetus was not identified in any samples.

CONCLUSION

Bovine genital campylobacteriosis is present in south-western Victoria, despite longstanding recommendations to vaccinate bulls. Screening bulls for persistent infection with BVDV is probably justified, despite the absence of persistently infected bulls in this study. Further research is warranted to investigate the potential reproductive implications of BHV-1, and the presence of T. foetus.