Tritrichomonas foetus

Bovine neutrophils kill the sexually-transmitted parasite Tritrichomonas foetus using trogocytosis

The protozoan parasite Tritrichomonas foetus (T. foetus) is the causative organism of bovine trichomonosis (also referred to as trichomoniasis), a sexually-transmitted infection that reduces fertility in cattle. Efforts to control trichomonosis on cattle farms are hindered by the discouragement of antibiotic use in agriculture, and the incomplete, short-lived protection conferred by the current vaccines. A more complete mechanistic understanding of what effective immunity to T. foetus entails could enable the development of more robust infection control strategies. While neutrophils, the primary responders to infection, are present in infected tissues and have been shown to kill the parasite in vitro, the mechanism they use for parasite killing has not been established. Here, we show that primary bovine neutrophils isolated from peripheral blood rapidly kill T. foetus in vitro in a dose-dependent manner, and that optimal parasite killing is reduced by inhibitors of trogocytosis. We also use imaging to show that bovine neutrophils surround T. foetus and trogocytose its membrane. These findings are consistent with killing via trogocytosis, a recently described novel neutrophil antimicrobial mechanism.

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.

Time and temperature stability of Tritrichomonas foetus in phosphate-buffered saline as evaluated by a reverse transcription real-time PCR assay and field analysis

Tritrichomonas foetus (TF) is a significant reproductive pathogen of cattle, and sample collection, handling, transport, and testing are significant hurdles to surveillance programs. Recent methods have been developed that allow for the direct detection of TF using a reverse transcription real-time PCR (direct RT-qPCR) approach. To evaluate these methods, a comparative analysis was conducted to assess the technical performance of this assay with a commercially available real-time PCR (qPCR) assay. In addition, the evaluation of two types of collection media (PBS and TF transport tube) was conducted that evaluated sample stability from 0 to 3 days when stored at 4°C or 25°C. Extended incubation times for PBS media were also evaluated (5, 7, and 14 days) at both refrigeration and frozen temperatures to evaluate the effect of extended transport time on samples. Limits of detection (LODs), dynamic range, and RNA stability were assessed using lab-cultured TF spiked into samples of normal bovine smegma collected in PBS or TF transport media, and performance was assessed on field samples collected in parallel. 100% agreement was found between direct RT-qPCR and qPCR at 10 parasites/extraction and a LOD of 1 parasite/extraction. Differences in detection were not observed in either collection media when incubated at either temperatures for up to 3 days of incubation. In addition, the extended incubation experiments indicate that samples containing 10 parasites/extraction can be detected at 4°C for 5 days with a mean Cq 26.34 (95% CI: 23.11–29.58) and detected at −20°C for 7 or 14 days, with a mean Cq 29.55 (95% CI: 27.73–31.37). A significant decrease in detectable RNA was observed in samples containing <10 parasites/extraction at −20°C for 14 days, which should be considered for long-term storage. In summary, direct RT-qPCR was found to be equivalent or superior to qPCR and PBS was not significantly different from TF transport media. The findings of the current study allows for more flexibility during sample collection and transport and ultimately enhancement of TF surveillance programs.

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.

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.

A new inactivated Tritrichomonas foetus vaccine that improves genital clearance of the infection and calving intervals in cattle

Bovine trichomonosis is a sexually transmitted disease that is a primary cause of early reproductive failure in cattle. The aim of the present study was to develop a vaccine formulation based on Tritrichomonas foetus trophozoites inactivated by lyophilization and Quil-A-adjuvanted. The safety, immunogenicity and efficacy of this new vaccine formulation (Trichobovis^®) administered by two routes (subcutaneous: SC, and intravulvar: IVU) were compared with a commercial vaccine (TrichGuard^®) in a well-established experimental bovine model of genital T. foetus infection. The new vaccine was considered safe in cattle because only mild local reactions were found in the vaccination area, which disappeared 3 weeks after administration. Cows immunized with Trichobovis cleared the infection faster than the non-immunized/challenged group (27–28 vs. 60 days; P < 0.05). Not significant differences were observed with the commercial vaccine respect to the positive control group, or between SC and IVU routes. The new vaccine stimulated high serum anti-T. foetus IgG and genital IgA levels and generated an IgG booster effect similar to TrichGuard. IgA levels were associated with significantly earlier genital clearance of T. foetus in cows immunized with Trichobovis by SC route (G1A) or TrichGuard (G2). The strongest association was found in the group G1A on day 14 post-infection (p.i.) (r = −0.74) and in G2 on day 35 p.i. (r = −0.71). The efficacy of vaccination using Trichobovis on the reproductive performance was also investigated under field conditions in a herd where T. foetus was present. The calving intervals were significantly reduced by 45.2 days (P < 0.05), calves were born 28 days earlier (P < 0.05) and an increase of 8.7% in the calving rate (P > 0.05) was observed in the vaccinated group. These results demonstrate that Trichobovis improved the reproductive performance under field conditions in herds where T. foetus infection is present.

Bull selection and management in extensive rangeland production systems of California: a producer survey

California's approximately 660,000 head of beef cattle are highly dependent on range bulls used to produce offspring that can perform across the state's diverse ecological regions. Bulls need to be functional on rugged coastal landscapes, rolling foothills, deserts, and in high-elevation terrain. Few data exist that indicate factors related to selection, maintenance, and longevity of bulls used in rangeland landscapes. Objectives herein, were to assess factors influencing bull purchasing, management, and culling decisions of California beef producers. Surveys were mailed to the California Cattlemen's Association membership (N = 1,410) with ~ 16% response rate (N = 227). Mean age and years of bull selection experience of respondents was 61 ± 1 yr and 27 ± 1 yr, respectively. Respondents managed cattle on a total of 694,949 hectare of owned, private leased, and leased public rangelands in California and surrounding states. Cow-calf herd size was 333 ± 92 head and bull battery averaged 18 ± 2 head with average bull longevity of 5 ± 1.3 yr. The average price paid for bulls in the last 2 yr was $5007 ± 163.33, while the highest price paid in the last 5 yr was $7291 ± 335.40. Survey responses were used to define current factors driving management after purchase and for subsequent breeding seasons. After bull purchase, 48% of producers turned bulls out directly with females, while 52% held bulls until the following breeding season. Additionally, most producers (70%) did not manage bulls to reduce condition after purchase. Semen quality analysis, a major component of a breeding soundness exam, was evaluated annually by 45% of respondents, while 20% of respondents never evaluated semen quality. Respondents indicated bull age (35%) and structural soundness (29%) as the most common factors for culling bulls. This research shows that despite the variability in operation demographics, there were similarities in beef bull selection and management across the state. Additionally, these data suggest the need for additional research focused on bull selection and management to maximize producer investment in reproduction.

In-depth comparative analysis of Tritrichomonas foetus transcriptomics reveals novel genes linked with adaptation to feline host

Tritrichomonas foetus is a flagellated parasite able to infect cattle, cats, and pigs. Despite its prevalence, feline tritrichomonosis has received markedly less attention than venereal infection, and little information about the molecular mechanisms that participate in feline host infection is available. Through a bioinformatics approach, we integrated public transcriptomic data for three T. foetus isolates and explored the differences at transcript level with a focus on pathogenesis and adaptation processes, particularly for the feline isolate. Our analysis revealed higher abundance levels of predicted virulence factors, such as proteases and surface antigens. Additionally, by a comparative and expression analysis of T. foetus genes, we proposed putative virulence factors that could be involved in feline infection. Finally, we identified a great proportion of predicted transcription factors of the MYB protein family and, by a promoter analysis, we revealed that MYB-related proteins could participate in the regulation of gene transcription in T. foetus. In conclusion, this integrated approach is a valuable resource for future studies of host–pathogen interactions and identifying new gene targets for improved feline tritrichomonosis diagnosis and treatment.

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.

Investigation of Tritrichomonas foetus in cryopreserved bovine semen by culture and polymerase chain reaction

ABSTRACT Bovine Trichomoniasis (BT) is an infectious disease caused by Tritrichomonas foetus that can be transmitted either sexually or by fomites. In males, the disease is asymptomatic and permanent. T. foetus has been detected in semen samples where it is able to remain viable even when frozen. The objective of this study was to investigate the presence of T. foetus in 27 samples of commercial frozen bovine semen by culture and Polymerase Chain Reaction (PCR). Samples were thawed in water at 37°C. Part of the samples was inoculated in a test tube containing Diamond’s medium and incubated at 35°C. Growth was evaluated every 24 hours via direct examination under a microscope. The other part was placed in an Eppendorf tube and frozen for later molecular analysis. After 10 days of culture, all samples were negative for T. foetus. The Quick-DNA Miniprep Kit (Zymo Research) without proteinase K was used for DNA extraction. The primers used in PCR were TRF3 and TRF4. PCR results were negative for all samples. In conclusion, bovine semen samples were negative for T. foetus in both diagnostic methods, according to the adopted methodology.

Lactobacilli and other gastrointestinal microbiota of Peromyscus leucopus, reservoir host for agents of Lyme disease and other zoonoses in North America

The cricetine rodent Peromyscus leucopus is an important reservoir for several human zoonoses, including Lyme disease, in North America. Akin to hamsters, the white-footed deermouse has been unevenly characterized in comparison to the murid Mus musculus. To further understanding of P. leucopus' total genomic content, we investigated gut microbiomes of an outbred colony of P. leucopus, inbred M. musculus, and a natural population of P. leucopus. Metagenome and whole genome sequencing were combined with microbiology and microscopy approaches. A focus was the genus Lactobacillus, four diverse species of which were isolated from forestomach and feces of colony P. leucopus. Three of the species-L. animalis, L. reuteri, and provisionally-named species "L. peromysci"-were identified in fecal metagenomes of wild P. leucopus but not discernibly in samples from M. musculus. L. johnsonii, the fourth species, was common in M. musculus but absent or sparse in wild P. leucopus. Also identified in both colony and natural populations were a Helicobacter sp. in feces but not stomach, and a Tritrichomonas sp. protozoan in cecum or feces. The gut metagenomes of colony P. leucopus were similar to those of colony M. musculus at the family or higher level and for major subsystems. But there were multiple differences between species and sexes within each species in their gut metagenomes at orthologous gene level. These findings provide a foundation for hypothesis-testing of functions of individual microbial species and for interventions, such as bait vaccines based on an autochthonous bacterium and targeting P. leucopus for transmission-blocking.

Occlusion of the corpus cavernosum penis in bulls intended for estrus detection: 18 cases (2002-2016)

OBJECTIVE To report surgical and long-term postoperative outcomes of bulls undergoing surgical occlusion of the corpus cavernosum penis (CCP) by acrylic injection and epididymectomy with or without penile fixation as preparation for use in estrus detection. DESIGN Retrospective case series. ANIMALS 18 client-owned bulls. PROCEDURES Medical records of bulls that underwent CCP occlusion between December 2002 and March 2016 were identified. Signalment, surgical data, and reported complications were recorded. Long-term (> 6 months after surgery) follow-up data were obtained from medical records or by telephone interview of bull owners with a questionnaire focused on postoperative outcome, use of the bull for estrus detection, and overall satisfaction with the procedure. RESULTS Intraoperative complications included difficulty isolating the penis, polymerization of the acrylic prior to injection, incomplete anesthesia of the surgical site, and fecal contamination of the site. Deposition of acrylic in an improper location led to urethral obstruction and euthanasia of 1 bull; another developed an abscess that was treated successfully. One bull was euthanized because of orchitis. Most (15/18) bulls were used for estrus detection (mean duration, 17.9 months). Libido was considered good or very good for 14 of 15 bulls; 1 was culled for loss of libido after 14 months. Ten of 12 bulls were reportedly unable to protrude the penis; 2 had or developed partial protrusion ability. Overall client satisfaction was high. CONCLUSIONS AND CLINICAL RELEVANCE In this population of healthy young bulls, CCP occlusion was generally well tolerated. Most bulls that underwent CCP occlusion (and epididymectomy with or without penile fixation) had adequate libido, and none were reported able to achieve intromission.

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.

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.

Prevalence and risk factors associated with Tritrichomonas foetus infection in cattle in the state of Paraíba, Brazil

The objective of this study was to determine the prevalence of Tritrichomonas foetus infection and to evaluate risk factors associated with this infection among cattle in the state of Paraíba in northeastern Brazil. Samples of cervicovaginal mucus from 290 females and smegma from 59 males [beef, 31; mixed aptitude (beef and dairy), 10; and dairy, 18] from 31 farms were collected. Modified Diamond's medium and polymerase chain reaction (PCR) were used for the laboratory diagnosis of T. foetus infection. Univariate analysis and logistic regression were performed to test for potential risk factors in addition to prevalence mapping. No sample was positive for T. foetus in culture, and the prevalence of T. foetus infection using PCR was 3.7% (13/349) [confidence interval (CI) 95%, 2.1%-6.4%]. In total, 19.3% (6/31) of the farms had at least one animal positive for T. foetus. The contact of females with males from other farms [Odds ratio, 5.9; 95% CI, 1.5-22.4; p = 0.009] was identified as a risk factor for T. foetus infection. This study demonstrates that T. foetus infection is prevalent among dairy cows in the state of Paraíba, Brazil. Sexual resting, removal of positive females, and avoiding contact of females with males from other farms are recommended to reduce the risk of infection.

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.

Freedom from Tritrichomonas foetus infection in cattle in St. 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.

Trichomonas

The most widely known trichomonad in veterinary medicine is Tritrichomonas foetus. It is the etiologic agent of bovine tritrichomonosis, a sexually transmitted disease in extensively managed herds throughout many geographic regions worldwide. The same trichomonad species is also regarded as the causative agent of chronic diarrhea in the domestic cat, although more recent studies observed molecular differences between bovine- and feline-derived T. foetus. Trichomonosis in cats has a worldwide distribution and is mainly present among cats from high-density housing environments. Other trichomonads are found as inhabitants of the gastrointestinal tract in birds, such as Trichomonas gallinae. Particularly, Columbiformes, Falconiformes, Strigiformes, and wild Passeriformes can be severely affected by avian trichomonads. Diagnosis of trichomonosis is often complicated by the fragility of the parasite. To ensure valid test results, it is essential to collect and handle specimens in the right way prior to analysis. Cultivation tests, the specific amplification of parasites, or a combination of both test methods is the most efficient and most commonly used way to diagnose trichomonosis in animals. Bovine tritrichomonosis is mainly controlled by the identification and withdrawal of infected animals from bovine herds. The control of feline and avian trichomonosis relies mainly on preventive measures.

Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): Trichomonosis

Trichomonosis has been assessed according to the criteria of the Animal Health Law (AHL), in particular criteria of Article 7 on disease profile and impacts, Article 5 on the eligibility of trichomonosis to be listed, Article 9 for the categorisation of trichomonosis according to disease prevention and control rules as in Annex IV and Article 8 on the list of animal species related to trichomonosis. The assessment has been performed following a methodology composed of information collection and compilation, expert judgement on each criterion at individual and, if no consensus was reached before, also at collective level. The output is composed of the categorical answer, and for the questions where no consensus was reached, the different supporting views are reported. Details on the methodology used for this assessment are explained in a separate opinion. According to the assessment performed, trichomonosis can be considered eligible to be listed for Union intervention as laid down in Article 5(3) of the AHL. The disease would comply with the criteria as in sections 3, 4 and 5 of Annex IV of the AHL, for the application of the disease prevention and control rules referred to in points (c), (d) and (e) of Article 9(1). The animal species to be listed for trichomonosis according to Article 8(3) criteria is cattle as susceptible and reservoir.

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.

Iron-modulated pseudocyst formation inTritrichomonas foetus

Iron is an essential element for the survival of trichomonads during host–parasite interaction. The availability of this metal modulates several metabolic pathways of the parasites and regulates the expression of virulence factors such as adhesins and proteolytic enzymes. In this study, we investigated the effect of iron depletion on the morphology and life cycle ofTritrichomonas foetus. Scanning and transmission electron microscopy analyses revealed that depletion of iron from the culture medium (named TYM-DIP inducer medium) induces morphological transformation of typical pear-shaped trophozoites into spherical and non-motile pseudocysts. Remarkably, inoculation of pseudocysts into an iron-rich medium (standard TYM medium), or addition of FeSO4to a TYM-DIP inducer medium reverted the morphological transformation process and typical trophozoites were recovered. These results show that pseudocysts are viable forms of the parasite and highlight the role of iron as a modulator of the parasite phenotype. Although iron is required for the survival ofT. foetus, iron depletion does not cause a cellular collapse of pseudocysts, but instead induces phenotypic alterations, probably in order to allow the parasite to survive conditions of nutritional stress. Together, these findings support previous studies that suggest pseudocysts are a resistance form in the life cycle ofT. foetusand enable new approaches to understanding the multifactorial role of iron in the cell biology of this protozoan parasite.

Tritrichomonas foetus Prevention and Control in Cattle

Bovine trichomoniasis has been recognized as a pathogen of the bovine reproductive tract for nearly 100 years. Although characteristics of the causative organism, Tritrichomonas foetus lend to control and there are examples of disease eradication, cattle producers are still faced with this disease. This article highlights the clinical presentation, magnitude of effect, risk factors, epidemiology, and sample collection and suggests applications in developing herd-level control measures for beef cattle producers including testing strategies for control, testing strategies for surveillance, strategies to eliminate trichomoniasis from infected herds, and strategies for prevention in uninfected herds.

Prevalence and risk factors associated with bovine genital campylobacteriosis and bovine trichomonosis in the state of Pernambuco, Brazil

The aim of the present study was to determine the prevalence and risk factors associated with Campylobacter fetus subsp. venerealis and Tritrichomonas foetus infection in cows from dairy herds in the state of Pernambuco, Brazil. In total, 383 samples of cervico-vaginal mucus were collected from cows on 21 herds in 19 districts. Genomic DNA was extracted from the samples and submitted for polymerase chain reaction analysis. An investigative questionnaire was used to analyze the risk factors, using questions related to reproductive and hygiene/sanitation management. A prevalence of 1.8% (0.8-3.9%; confidence interval (CI) 95%) and 33.4% (28.7-38.4%; CI 95%) was found for C. fetus subsp. venerealis and T. foetus, respectively. In terms of the number of foci, 28.6% of the herds contained at least one animal that was positive for C. fetus subsp. venerealis and 90.5% for T. foetus. The present study identified herds larger than 100 animals as a risk factor for bovine genital campylobacteriosis (OR = 7.2; CI 1.3-38.4%; p = 0.020) and the use of natural breeding as a risk factor for bovine trichomonosis (OR = 2.4; CI 1.1-5.9%; p = 0.041). In conclusion, C. fetus subsp. venerealis and T. foetus infections occurred in the region studied and high numbers of foci were found. Thus, prophylaxis and control measures, such as diagnosis, separation, and sexual rest for infected females, are suggested. An artificial insemination program with early rigorous sanitary care should be implemented on the properties in order to avoid the spread of agents in the herds.

Revisiting bovine pyometra--new insights into the disease using a culture-independent deep sequencing approach

The bacteria present in the uterus during pyometra have previously been studied using bacteriological culturing. These studies identified Fusobacterium necrophorum and Trueperella pyogenes as the major contributors to the pathogenesis of pyometra. However, an increasing number of culture-independent studies have demonstrated that the bacterial diversity in most environments is underestimated in culture-based studies. Consequently, fastidious pyometra-associated pathogens may have been overlooked. Therefore, the primary purpose of this study was to investigate the diversity of bacteria in the uterus of cows with pyometra by using culture-independent 16S rRNA PCR combined with next generation sequencing. We investigated the microbial composition in the uterus of 21 cows with pyometra, which were obtained from a Danish slaughterhouse. Similar to the observations from the culture studies, Fusobacteriaceae, the family that F. necrophorum belongs to, was the operational taxonomic unit (OTU) observed in the largest quantities. By contrast, the Actinomycetaceae family, which includes T. pyogenes, constituted only 1% of the total number of reads. Thus we cannot confirm the previously reported role of species from this family in the pathogenesis of pyometra. Finally, we identified a large number of sequences representing three families of Gram-negative bacteria in the pyometra samples: Porphyromonadaceae, Mycoplasmataceae, and Pasteurellaceae. It is likely that these families comprise potential pathogenic species of a fastidious nature, which have been overlooked in previous studies. Our results increase the knowledge of the complexity of the pyometra microbiota and suggest that pathogens in addition to F. necrophorum may be involved in the pathogenesis of pyometra.

Expression and characterization of a β-fructofuranosidase from the parasitic protist Trichomonas vaginalis

BACKGROUND

Trichomonas vaginalis, a flagellated protozoan, is the agent responsible for trichomoniasis, the most common nonviral sexually transmitted infection worldwide. A reported 200 million cases are documented each year with far more cases going unreported. However, T. vaginalis is disproportionality under studied, especially considering its basic metabolism. It has been reported that T. vaginalis does not grow on sucrose. Nevertheless, the T. vaginalis genome contains some 11 putative sucrose transporters and a putative β-fructofuranosidase (invertase). Thus, the machinery for both uptake and cleavage of sucrose appears to be present.

RESULTS

We amplified the β-fructofuranosidase from T. vaginalis cDNA and cloned it into an Escherichia coli expression system. The expressed, purified protein was found to behave similarly to other known β-fructofuranosidases. The enzyme exhibited maximum activity at pH close to 5.0, with activity falling off rapidly at increased or decreased pH. It had a similar K(m) and V(max) to previously characterized enzymes using sucrose as a substrate, was also active towards raffinose, but had no detectable activity towards inulin.

CONCLUSIONS

T. vaginalis has the coding capacity to produce an active β-fructofuranosidase capable of hydrolyzing di- and trisaccharides containing a terminal, non-reducing fructose residue. Since we cloned this enzyme from cDNA, we know that the gene in question is transcribed. Furthermore, we could detect β-fructofuranosidase activity in T. vaginalis cell lysates. Therefore, the inability of the organism to utilize sucrose as a carbon source cannot be explained by an inability to degrade sucrose.

N-Propargylated isatin-Mannich mono- and bis-adducts: synthesis and preliminary analysis of in vitro activity against Tritrichomonas foetus

Cu(I)Cl promoted synthesis of N-propargylated-isatin Mannich mono- and bis-adducts with an extension towards the synthesis of N-propargylated-isatin-7-chloroquinoline conjugates was described. The synthesized scaffolds were evaluated for their in vitro activity against the veterinary protozoal pathogen Tritrichomonas foetus and cytotoxicity against human prostate (PC-3) cancer cell line. The preliminary evaluation data revealed the enhancement in the activity profiles with the introduction of 7-chloroquinoline ring with the most active conjugates 7a, 7c and 7d exhibiting an IC₅₀ of 22.2, 11.3 and 24.5 μM respectively against T. foetus and minimal toxicity against human prostate (PC-3) cell lines.

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Cu(I)Cl promoted synthesis of N-propargylated-isatin Mannich mono- and bis-adducts.

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Introduction of 7-chloro-quinoline moiety remarkably enhanced the activity against Tritrichomonas foetus.

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The most active and non-cytotoxic compound exhibited an IC₅₀ value 11.3 μM.

New insights on the Golgi complex of Tritrichomonas foetus

Tritrichomonas foetus is a protist that causes bovine trichomoniasis and presents a well-developed Golgi. There are very few studies concerning the Golgi in trichomonads. In this work, monoclonal antibodies were raised against Golgi of T. foetus and used as a tool on morphologic and biochemical studies of this organelle. Among the antibodies produced, one was named mAb anti-Golgi 20.3, which recognized specifically the Golgi complex by fluorescence and electron microscopy. By immunoblotting this antibody recognized two proteins with 60 and 66 kDa that were identified as putative beta-tubulin and adenosine triphosphatase, respectively. The mAb 20.3 also recognized the Golgi complex of the Trichomonas vaginalis, a human parasite. In addition, the nucleotide coding sequences of these proteins were identified and included in the T. foetus database, and the 3D structure of the proteins was predicted. In conclusion, this study indicated: (1) adenosine triphosphatase is present in the Golgi, (2) ATPase is conserved between T. foetus and T. vaginalis, (3) there is new information concerning the nucleic acid sequences and protein structures of adenosine triphosphatase and beta-tubulin from T. foetus and (4) the mAb anti-Golgi 20.3 is a good Golgi marker and can be used in future studies.

Prevalence of bovine genital campylobacteriosis and trichomonosis of bulls in northern Nigeria

BACKGROUND

A survey was conducted to determine the prevalence of campylobacteriosis and trichomonosis, and their concurrence with brucellosis, in cattle in three states of northern Nigeria.

METHODS

A total of 602 preputial samples was collected from bulls in 250 herds and tested using culture and identification. Various indigenous and exotic breeds were studied and four major management systems were encountered. Age of the cattle was estimated using dentition, farm records or cornual rings.

RESULTS

The estimated true animal-level prevalence of Campylobacter fetus infection was 16.4% (95% CI: 13.0-20.7), of which 18.5% was C. f. fetus and 81.5% was C. f. venerealis. Of the latter, 92% were C. f. venerealis biovar intermedius strains. Animal-level prevalences in Adamawa, Kano and Kaduna states were 31.8%, 11.6% and 8.3% respectively, and were highest in bulls>7 years old (33.4%) and in the Gudali breed (28.8%). Of the 250 herds, 78 (25.5%, 95% CI: 19.4-32.7) had at least one infected bull, and herd prevalence was highest in the pastoral management system (43.5%). After adjustment for confounding using multivariable analysis, the odds of C. fetus infection were highest in Adamawa state (P<0.01), in the pastoral management system (P<0.01), and in bulls>7 years old (P=0.01), and tended to be higher in Bos taurus breeds (P=0.06). There was a strong positive association between the presence of campylobacteriosis and brucellosis (P<0.01), both within bulls (OR=8.3) and within herds (OR=16.0). Trichomonosis was not detected in any herds.

CONCLUSION

Bovine genital campylobacteriosis is prevalent particularly in the pastoral management system in northern Nigeria, with C. f. venerealis biovar intermedius as the major aetiology. There was a strong positive correlation between the occurrence of campylobacteriosis and brucellosis. No evidence of trichomonosis was found in herds in this study.

Determination of presence of Tritrichomonas foetus in uterine lavages from cows with reproductive problems

The aim of this study was to determine the presence of Tritrichomonasfoetus in two dairy herds on the Altiplano Cundiboyacense. Twenty-one low-volume uterine lavages from cows with a history of reproductive problems in two dairy herds located in the municipality of Sibaté (Cundinamarca) and Ventaquemada (Boyacá) were evaluated. In the first herd, 10 cows were sampled and in the second, 11 cows, based on three inclusion criteria. The uterine lavages were obtained through infusion of physiological saline solution into the uterine body. The samples were centrifuged and seeded in Tritrichomonas basal medium for 10-15 days at 37 ºC. The protozoa were evaluated on the day of sampling and 10 and 15 days after incubation by means of direct viewing under a dark-field microscope. Positive samples were stained with Wright and Lugol to identify the morphological characteristics. This study showed that T. foetus was present in 61.8% of the animals sampled. The determination that T. foetus was present in 61.8% of the samples analyzed is a significant finding given that in the herds evaluated, this agent had not previously been diagnosed.

Campilobacteriose genital bovina e tricomonose genital bovina: epidemiologia, diagnóstico e controle

A presente atualização trata de duas das mais importantes doenças sexualmente transmitidas de bovinos, a campilobacteriose genital bovina e a tricomonose genital bovina. São abordados aspectos relacionados à epidemiologia destas doenças, principalmente em relação a sua distribuição no Brasil. Também são revisados aspectos importantes de diagnóstico, incluindo as técnicas e interpretação dos resultados, além de medidas de controle para ambas as doenças.

The ambiguous life of Dientamoeba fragilis: the need to investigate current hypotheses on transmission

Dientamoeba fragilis is an inhabitant of the human bowel and is associated with gastrointestinal illness. Despite its discovery over a century ago, the details of Dientamoeba's life cycle are unclear and its mode of transmission is unknown. Several theories exist which attempt to explain how Dientamoeba may be transmitted. One theory suggests that animals are responsible for the transmission of Dientamoeba. However, reports of Dientamoeba in animals are sporadic and most are not supported by molecular evidence. Another theory suggests that Dientamoeba may be transmitted via the ova of a helminth. Given that the closest relative of Dientamoeba is transmitted via the ova of a helminth, this theory seems plausible. It has also been suggested that Dientamoeba could be transmitted directly between humans. This theory also seems plausible given that other relatives of Dientamoeba are transmitted in this way. Despite numerous investigations, Dientamoeba's mode of transmission remains unknown. This review discusses the strengths and weaknesses of theories relating to Dientamoeba's mode of transmission and, by doing so, indicates where gaps in current knowledge exist. Where information is lacking, suggestions are made as to how future research could improve our knowledge on the life cycle of Dientamoeba.

Identification of Tritrichomonas foetus pseudocysts in fresh preputial secretion samples from bulls

Tritrichomonas foetus is a serious veterinary pathogen that causes bovine trichomonosis, a sexually transmitted disease that eventually leads to abortion and infertility. T. foetus has a simple life cycle that consists of only a trophozoitic form. During unfavorable environmental conditions, the trophozoites, which are polar and flagellated, can adopt a spherical shape and internalize their flagella. These rounded organisms are known as pseudocysts. Although it is currently assumed that T. foetus pseudocyst formation is reversible and that it represents a response to stressful conditions, there are no reports showing the presence of this form in vivo. For this reason, the aim of this study was to verify whether T. foetus pseudocysts are encountered in naturally infected bulls. Towards this goal, fresh preputial samples obtained from seven mature bulls that were naturally infected with T. foetus were analyzed using complementary techniques, such as video microscopy, fluorescence microscopy, scanning and transmission electron microscopy. The analyses revealed that approximately 55% of the parasites were in pseudocyst form in each preputial sample, whereas approximately 25% of T. foetus displayed pear-shaped bodies. Previous research demonstrated that in vitro T. foetus pseudocysts are able to divide by a budding process. Here, this division mode was observed in approximately 20% of fresh T. foetus obtained from preputial bovine samples. Thus, this study shows that in infected bulls, pseudocysts are present and occur more frequently than the pear-shaped parasites.

Infectious causes of reproductive disorders in cattle

The incidences of reproductive disorders in bovine are increasing over years. This scenario is further aggravating due to more emphasis on selection and rearing of animal for specific commercial purposes which compromises livestock reproduction. Reproductive disorders like infertility and abortions in cattle are major problems in the bovine industry. The reproductive disorders might be caused by several different agents such as physical agents, chemical agents, biological agents, etc. Also, the causative agent and pathogenesis of reproductive disorders are influenced by various factors including environmental factor. The exact causes may not be evident and are often complicated with multiple causative agents. Thus, there is a need for multi-faceted approach to understand correlation of various factors with reproductive performance. Of the agents, infectious biological agents are significant cause of reproductive disorder and are of high priority in the bovine industry. These factors are not only related to the prosperity of bovine industry but are also important from public health point of view because of their zoonotic potentials. Several infectious agents like bacterial, viral, protozoon, chlamydial and fungal agents are known to have direct impact on reproductive health of cattle. These diseases can be arranged and discussed in different groups based on the causative agents.

Pooled polymerase chain reaction to detect Tritrichomonas foetus in beef bulls

Preputial scraping samples from 305 mixed breed beef bulls were examined for the detection of Tritrichomonas foetus infection. All samples were collected by veterinarians and transported in commercial media to an accredited lab. Upon arrival samples underwent microscopic examination for the presence of Tritrichomonas foetus and were then incubated until 5 days postcollection before final microscopic examination. Culture detected 14 samples with Trichomonad spp.; all were confirmed to be Tritrichomonas foetus by polymerase chain reaction (PCR). After final examination samples were randomly placed in groups of 5 samples; technicians were blinded as to culture results of the individual samples constituting each pool. From each sample within a group, a portion of the fluid sediment was removed and pooled with the other samples of the group to form 61 pools. From each of the formed pools an aliquot was removed for PCR. PCR detected 16 positive pools; an additional 2 positive samples were then identified on individual PCR on samples previously diagnosed as culture negative. Relative to culture, the 95% confidence intervals for sensitivity and specificity of PCR pools to detect Tritrichomonas foetus were 76.8% to 100% (mean value: 100%) and 85.5 to 99.5% (mean value: 93.4%), respectively.