Loop mediated isothermal amplification of 5.8S rDNA for specific detection of Tritrichomonas foetus

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.

Field detection of Tritrichomonas foetus through loop mediated isothermal amplification with CELDA

An affordable, portable, and easy-to-build instrument was implemented to perform loop-mediated isothermal amplification (LAMP) in the field. Controlled by Arduino, CELDA heats the reaction tubes, reads the intensity of green fluorescent light and stores data in a computer. In the laboratory and in the field, CELDA was successfully used for the detection of Tritrichomonas foetus DNA in less than 60 min and helped distinguish positives with less difficulty than visual inspection.

Sporadic isolation of Tetratrichomonas species from the cattle urogenital tract

Tritrichomonas foetus is a venereal trichomonad parasite which causes reproductive issues in cattle. No other trichomonads are known to be urogenital pathogens in cattle, but there are several reports of Tetratrichomonas and Pentatrichomonas isolates of unclear origin from the cattle urogenital tract (UGT) in the Americas. This study reports the first case of a non-T. foetus cattle urogenital trichomonad isolate in Europe. Molecular analysis of the internal transcribed spacer (ITS) 1-5.8S ribosomal RNA-ITS 2 and 18S ribosomal RNA loci suggest that the isolate is a Tetratrichomonas species from a lineage containing other previously described bull preputial isolates. We identified close sequence similarity between published urogenital and gastrointestinal Tetratrichomonas spp., and this is reviewed alongside further evidence regarding the gastrointestinal origin of non-T. foetus isolates. Routine screening for T. foetus is based on culture and identification by microscopy, and so considering other trichomonad parasites of the bovine UGT is important to avoid misdiagnosis.

Taguchi method for the optimization of three loop mediated isothermal amplification procedures for Tritrichomonas foetus detection

Taguchi method was used to optimize loop mediated isothermal amplification tests aimed to amplify segments of the elongation factor 1a1 (tf-ef1a1), the 5,8 ribosomal gene (tf-5,8 r) or the beta tubulin 2 (tf-btub2) from the protozoan parasite Tritrichomonas foetus. L9 orthogonal array and quadratic loss functions that penalize deviations from prediction values revealed the effect of amplification reaction components. Analysis of variance (ANOVA) decomposed the contribution of individual factors to a small Ct. Confirmation experiments established that optimum conditions were predictable, verifiable and reproducible. Primers concentration conditioned the non-specific amplification of tf-ef1a1 while betaine and magnesium concentration contributed to accelerate the time to reach a positive threshold in tf-ef1a1, tf-5,8 r and tf-btub2. The general strategy of simple and robust experimental design holds potential as a general optimization protocol for LAMP tests in every diagnostic laboratory.

An innovative and user-friendly smartphone-assisted molecular diagnostic approach for rapid detection of canine vector-borne diseases

Present-day diagnostic tools and technologies for canine diseases and other vector-borne parasitic diseases hardly meet the requirements of an efficient and rapid diagnostic tool, which can be suitable for use at the point-of-care in resource-limited settings. Loop-mediated isothermal amplification (LAMP) technique has been always a method of choice in the development and validation of quick, precise, and sensitive diagnostic assays for pathogen detection and to reorganize point-of-care (POC) molecular diagnostics. In this study, we have demonstrated an efficient detection system for parasitic vector-borne pathogens like Ehrlichia canis and Hepatozoon canis by linking the LAMP assay to a smartphone via a simple, inexpensive, and a portable “LAMP box,” All the components of the LAMP box were connected to each other wirelessly. This LAMP box was made up of an isothermal heating pad mounted below an aluminum base which served as a platform for the reaction tubes and LAMP assay. The entire setup could be connected to a smartphone via an inbuilt Wi-Fi that allowed the user to establish the connection to control the LAMP box. A 5 V USB power source was used as a power supply. The sensitivity of the LAMP assay was estimated to be up to 10⁻⁶ dilution limit using the amplified, purified, and quantified specific DNA templates. It can also serve as an efficient diagnostic platform for many other veterinary infectious or parasitic diseases of zoonotic origin majorly towards field-based diagnostics.

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.

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.

Aberrant and accidental trichomonad flagellate infections: rare or underdiagnosed?

The clinical significance and frequency of human infections with trichomonad flagellates in aberrant locations (locations other than the predilection sites) and accidental infections (infections with non-human trichomonads) are unclear. The total number of case reports in the literature is low, with the identification of the infection largely the outcome of investigations for the cause of clinical signs. At least seven species have been identified in either aberrant or accidental infections, with these infections occurring worldwide. Results of prospective and retrospective surveys of adults with respiratory disease suggest that aberrant and accidental trichomonad infections are less rare than the number of case reports suggest, with Trichomonas tenax being the most frequent. Surveys of neonates and infants suggest that aberrant Trichomonas vaginalis infections can be higher and more serious than suggested by the few case reports. The density and location of infection might be as important, if not more so, than species in determining pathogenicity. Molecular diagnostic methods including DNA sequencing can be used to better diagnose infections and enable identification to assist in determining the clinical significance of different species. Raising awareness of these infections among clinicians and adding them to their differential lists are strongly suggested.

Development of loop-mediated isothermal amplification (LAMP) assay for detection of Hepatozoon canis infection in dogs

The laboratory diagnosis of canine hepatozoonosis, caused by Hepatozoon canis is tedious, especially in chronic and latent infections. In the present investigation, a loop mediated isothermal amplification (LAMP) assay was developed and standardized targeting the partial 18S rRNA gene (GenBank accession no. KU096058). The LAMP primers specifically amplified H. canis DNA, whereas no amplification was detected in DNA samples from dogs infected with Babesia vogeli, B. gibsoni, Ehrlichia canis and Trypanosoma evansi, and no amplification was observed in DNA samples from H. canis-free dogs. The threshold sensitivity level of the assay was determined to be 15 fg of genomic DNA of H. canis. Furthermore, evaluation of blood samples collected from 250 dogs presented at Small Animal Clinics, Teaching Veterinary Clinical Complex, Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, Punjab (India) was carried out for the presence of H. canis by microscopy, 18S PCR assay and LAMP assay. Of the total samples subjected to these tests, LAMP detected H. canis in 75 samples, while 18S PCR and microscopy detected H. canis in 28 and 9 samples, respectively. The present investigation has developed, for the first time, a highly sensitive, specific and rapid LAMP assay for the detection of H. canis, which has practical applications for the screening of field samples.

Clearance of Tritrichomonas foetus in experimentally infected heifers protected with vaccines based on killed-T. foetus with different adjuvants

Tritrichomonas foetus is a flagellated protozoan that causes a sexually transmitted disease in cattle. Trichomonosis is characterized by early abortions, subfertility and a significant decrease in productivity. Vaccine preparations containing whole T. foetus can reduce the time of residence of the pathogen in the host cervix after experimental infection. Here, T. foetus vaccines prepared with different adjuvants were tested, in parallel with a commercial vaccine, for their efficacy to clear the infection. The median time for clearance of infection was 69days in non-immunized animals, 55days in animals treated with aluminum hydroxide, 41days with oil-in-water or saponin based vaccines or with a commercial vaccine and 27days in animals treated with saponin plus aluminum hydroxide. A slight increase in the risk of T. foetus clearance from the genital tract was found with the saponin based vaccine (hazard ratio, 2.52; 95% confidence interval, 1.03-6.17) or the commercial vaccine (hazard ratio, 2.61; 95% confidence interval, 1.07-6.38). A significant increase in the risk of T. foetus clearance was found with the combination of saponin plus aluminum hydroxide based vaccine (hazard ratio, 5.12; 95% confidence interval, 2.04-12.83).

Co-infection by Tritrichomonas foetus and Pentatrichomonas hominis in asymptomatic cats

Abstract: Tritrichomonas foetus, a parasite well known for its significance as a venereally transmitted pathogen in cattle, has been identified as a cause of chronic large bowel diarrhea in domestic cats in many countries of the world. In Brazil, several studies on the diagnosis of bovine trichomoniasis have been performed, but until now, no study was made regarding feline trichomoniasis. Thus, this is the first study to report the occurrence of T. foetus and Pentatrichomonas hominis in cats using morphological and molecular analysis. Feces from 77 cats were examined, four of which (5.2%) were positive for the presence of parabasalids. Morphological analysis of stained smears revealed piriform trophozoites showing the three anterior flagella, elongated nucleus and axostyle ending abruptly in fillet, characteristic of T. foetus. In scanning and transmission electron microscopy, identification characters similar to those previously reported for T. foetus were observed. The cultures containing trophozoites were submitted for molecular analysis, which resulted positive for T. foetus DNA using specific primers (TFR3 and TFR4), and all samples were positive and subjected to sequencing in which they showed 99.7-100% similarity with another isolate sequencing of T. foetus (JX960422). Although no trophozoite with consistent morphology of P. hominis has been visualized in the samples, differential diagnosis was performed using specific primers for P. hominis (TH3 and TH5) amplicon. In three of the four samples (3.89%) sequencing revealed 100% similarity when compared with another sequence of P. hominis deposited in Genbank (KC623939). Therefore, the present study revealed through the diagnostic techniques employed the simultaneous infection by T. foetus and P. hominis in the feces of cats. However, it was necessary to use more than one technique for the diagnosis of the co-infection. These results demonstrate the importance of a correct diagnosis to allow an appropriate treatment by the veterinarian.

Development of loop-mediated isothermal amplification (LAMP) for detection of Babesia gibsoni infection in dogs

Diagnosis of canine babesiosis, caused by Babesia gibsoni is difficult, especially in chronically infected dogs. A loop mediated isothermal amplification (LAMP) assay was developed and standardized by using four oligonucleotide primers targeting the hypervariable region of 18S rRNA gene (GenBank Acc. no. KC461261). The primers specifically amplified B. gibsoni DNA, while no amplification was detected with DNA from non-infected dogs as well as from dogs infected with Babesia canis vogeli, Hepatozoon canis, Ehrlichia canis and Trypanosoma evansi. The assay could detect 1.35 × 10(-7) parasitaemia and 10(-4) dilution of recombinant plasmid, equivalent to 12 pg of target DNA. All the samples were tested by nested PCR as well as LAMP assay. LAMP was found to be 10 times more sensitive than nested PCR targeting the same gene. Out of 75 suspected field samples, collected from different parts of the country, LAMP could detect B. gibsoni in 43 samples, while nested PCR and microscopy could detect 37 and 23 samples, respectively. High sensitivity, specificity and rapidity of LAMP assay may be exploited for screening large number of samples in a field setting.

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.

Loop-mediated isothermal amplification assay for detection of Histomonas meleagridis infection in chickens targeting the 18S rRNA sequences

Histomonas meleagridis is the causative agent of histomonosis, a disease of gallinaceous fowl characterized by necrotic typhlitis, hepatitis, and high mortality. To develop a rapid and sensitive method for specific detection of H. meleagridis, an assay based on loop-mediated isothermal amplification (LAMP) targeting the 18S rRNA gene was established. The detection limit of the LAMP assay was 10 copies for standard plasmids containing an 18S rRNA gene fragment, which was superior to that of a classical PCR method. Specificity tests revealed that there was no cross-reaction with other protozoa such as Trichomonas gallinae, Blastocytis sp, Tetratrichomonas gallinarum, Plasmodium gallinaceum, Toxoplasma gondii, Eimeria tenella, Leucocytozoon caulleryi and Leucocytozoon sabrazesi. The assay was evaluated for its diagnostic utility using liver and caeca samples collected from suspected field cases, the detection rate was 100 and 97.92%, respectively. These results indicate that the LAMP assay may be a useful tool for rapid detection and identification of H. meleagridis in poultry.