First record of natural Tritrichomonas foetus infection of the feline uterus

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.

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.

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.

What is known about Tritrichomonas foetus infection in cats?

Tritrichomonas foetus is a parasite that has been definitively identified as an agent of trichomonosis, a disease characterized by chronic diarrhea. T. foetus colonizes portions of the feline large intestine, and manifests as chronic and recurrent diarrhea with mucus and fresh blood, which is often unresponsive to common drugs. Diagnosis of a trichomonad infection is made by either the demonstration of the trophozoite on a direct fecal smear, fecal culture and subsequent microscopic examination of the parasite, or extraction of DNA in feces and amplification by the use of molecular tools. T. foetus is commonly misidentified as other flagellate protozoa such as Giardia duodenalis and Pentatrichomonas hominis. Without proper treatment, the diarrhea may resolve spontaneously in months to years, but cats can remain carriers of the parasite. This paper intends to serve as a source of information for investigators and veterinarians, reviewing the most important aspects of feline trichomonosis, such as trichomonad history, biology, clinical manifestations, pathogenesis, world distribution, risk factors, diagnosis, and treatment.

Tritrichomonas foetus and Mycoplasma felis coinfection in the upper respiratory tract of a cat with chronic purulent nasal discharge

A 5-year-old indoor male neutered Siamese cat was presented with clinical signs of sneezing and chronic bilateral purulent nasal discharge. Multiple nasal cavity swabs were submitted for bacterial cultures, Mycoplasma felis-DNA qPCR, and cytology. M felisqPCR was positive and cytomorphologic diagnosis was severe, acute, purulent, rhinitis with intralesional protozoal microorganisms consistent with a Trichomonas spp. Nested PCR (nPCR) confirmed the diagnosis of Tritrichomonas foetus. Systemic therapy with doxycycline for M felis and metronidazole for T foetus was started with remission of clinical signs within 2 weeks; however, symptoms relapsed shortly after therapy was discontinued. This study represents the first documented case of T foetus associated with chronic nasal discharge in a cat, which supports the hypothesis that T foetus can live in the nasal cavity. It is also the first reported case of M felis and T foetus coinfection, which indicates that with mycoplasmal feline upper respiratory tract infections, T foetus should be considered as a coinfecting agent.

Detection of natural occurrence of Tritrichomonas foetus in cats in Araçatuba, São Paulo, Brazil

ABSTRACT: The aim of this study was to investigate the occurrence of Tritrichomonas foetus in cats in the area surrounding the city of Araçatuba municipality, State of São Paulo, Brazil. Fecal samples from 129 cats were collected by rectal flush technique. It was compared two diagnosis methods, direct examination of feces and PCR. The presence of T. foetus DNA was verified using PCR by amplification of 347-bp fragment from the primers TFR3 and TFR4 and amplicons of positive cases were sequenced. Statistical analyses were performed investigating the associations between T. foetus infection with gender, age, breed, presence of diarrhea and/or history of diarrhea, previous treatment, lifestyle, origin, environment, and co-infection. T. foetus was observed in one sample (n=129) by direct microscopic examination of feces while PCR was positive in five samples (3.9%). Giardia species and Cryptosporidium species co-infection was also observed. Statistical analyses showed no significant associations between T. foetus infection and all listed factors, although most positive cats were asymptomatic and lived in multi-cat household. The isolates of T. foetus showed 100% identical sequences with other T. foetus isolates from cats around the world. So, the occurrence of T. foetus was confirmed in cats in Araçatuba city (Brazil). This parasite must be considered as a differential diagnosis in cats with diarrhea and also in asymptomatic carriers as source of infection in multi-cat environments.

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.

The conundrum of feline Trichomonosis

Practical relevance: Trichomonosis of the large intestine of the cat was described as a cause of chronic diarrhea over 20 years ago. The trichomonad was identified as Tritrichomonas foetus, with a genotype that is distinct from venereal T foetus of cattle. Clinical challenges: Despite multiple means for diagnosis of the infection, including light microscopy, protozoal culture and PCR amplification using species-specific primers, tests with even greater sensitivity are needed. Feline trichomonosis is resistant to all commonly used antiprotozoal drugs. Ronidazole is currently the only drug demonstrated to be effective in eliminating the infection from cats; however, this drug has a narrow safety margin and clinical resistance is increasingly recognized. The more we learn about trichomonosis in cats, the more complicated and controversial the infection has become, ranging from what we should call the organism to whether we should even bother trying to treat it. Global importance: Feline trichomonosis is recognized to occur worldwide and is regarded as one of the most common infectious causes of colitis in the domestic cat. The infection is widespread in catteries and shelters; and, while remission of diarrhea may occur over time, persistence of the infection is common. Evidence base: This review provides a comprehensive examination of what is currently known about feline trichomonosis and pinpoints areas, based on the authors' opinion, where further research is needed.

Mechanisms of Tritrichomonas foetus Pathogenicity in Cats with Insights from Venereal Trichomonosis

Almost 20 years has passed since trichomonosis was first recognized as a potential cause of diarrhea in domestic cats. Despite progress in confirming disease causation, developing means for diagnosis, and identifying approaches to treatment of the infection, we still know very little about how this parasite causes diarrhea. With increasing recognition of resistance of trichomonosis to treatment with 5‐nitroimidazole drugs, new treatment strategies based on an understanding of disease pathogenesis are needed. In this review, lessons learned from the pathogenesis of venereal trichomonosis in people and cattle are applied to clinical observations of trichomonosis in cats in effort to generate insight into areas where further research may be beneficial.

Tritrichomonas foetus infection, a cause of chronic diarrhea in the domestic cat

Tritrichomonas foetus is a very intriguing trichomonad protozoan with respect to its varied choice of residence in the different host species. It is an obligate parasite of the reproductive and the gastrointestinal tract of bovine and feline host respectively, leading to trichomonosis. Bovine trichomonosis is a sexually transmitted disease whereas feline trichomonosis is a disease with a purported fecal-oral route of spread. Further, the trichomonad is a commensal in the nasal passages, stomach, cecum and colon of swine host. Advances have been exponential in understanding the trichomonad biology and specifically feline trichomonosis since late 1990s and early 2000s when T. foetus was soundly determined to be a causative agent of chronic diarrhea in the domestic cat. It is a challenging task, even for a skilled investigator not to mention the busy clinical veterinarian, to keep up with the vast volume of information. Here we comprehensively reviewed the trichomonad biology, clinical manifestations, pathogenesis, host immunity, world map of distribution, risk factors, diagnosis and treatment. Risk factors associated with T. foetus-positive status in the domestic cat include young age, purebred, history of diarrhea, co-infections with other enteral pathogens. In addition, molecular similarity of bovine and feline isolates of T. foetus in DNA sequence was concisely discussed. The data presented serve as an information source for veterinarians, and investigators who are interested in biology of T. foetus and feline trichomonosis.

Detection of Tritrichomonas foetus and Pentatrichomonas hominis in intestinal tissue specimens of cats by chromogenic in situ hybridization

In this retrospective study 102 cats were analyzed for the presence of trichomonads in intestinal tissue sections using chromogenic in situ hybridization (CISH). Two intestinal trichomonad species are described in cats: Pentatrichomonas hominis and Tritrichomonas foetus. While P. hominis is considered a mere commensal, T. foetus has been found to be the causative agent of feline large-bowel diarrhea. For the detection of both agents within intestinal tissue CISH assays using three different probes were performed. In the first CISH run a probe specific for all relevant members of the order Trichomonadida (OT probe) was used. In a second CISH run all positive samples were further examined on three consecutive tissue sections using the OT probe, a probe specific for the family of Tritrichomonadidae (Tritri probe) and a newly designed probe specifically detecting P. hominis (Penta hom probe). In total, four of the 102 cats were found to be positive with the OT probe. Thereof, one cat gave a positive reaction with the P. hominis probe and three cats were positive with the T. foetus probe. All Trichomonas-positive cats were pure-bred and between 8 and 32 weeks of age. In one cat positive for T. foetus large amounts of parasites were found in the gut lumen and invading the intestinal mucosa. The species of the detected trichomonads were confirmed by polymerase chain reaction and nucleotide sequencing of a part of the 18S ribosomal RNA gene. In this study, the usefulness of CISH to detect intestinal trichomonads within feline tissue samples was shown. Additionally, the specific detection of P. hominis using CISH was established. Generally, it was shown that CISH is well suited for detection and differentiation of trichomonosis in retrospective studies using tissue samples.

A cross-sectional study of Tritrichomonas foetus infection among healthy cats at shows in Norway

Background

In recent years, the protozoan Tritrichomonas foetus has been recognised as an important cause of chronic large-bowel diarrhoea in purebred cats in many countries, including Norway. The aim of this cross-sectional study was to determine the proportion of animals with T. foetus infection among clinically healthy cats in Norway and to assess different risk factors for T. foetus infection, such as age, sex, former history of gastrointestinal symptoms and concurrent infections with Giardia duodenalis and Cryptosporidium sp.

Methods

The sample population consisted of 52 cats participating in three cat shows in Norway in 2009. Samples were examined for motile T. foetus by microscopy, after culturing and for T. foetus-DNA by species-specific nested PCR, as well as for Giardia cysts and Cryptosporidium oocysts by immunofluorescent antibody test (IFAT).

Results

By PCR, T. foetus-DNA was demonstrated in the faeces of 11 (21%) of the 52 cats tested. DNA-sequencing of five positive samples yielded 100% identity with previous isolates of T. foetus from cats. Only one sample was positive for T. foetus by microscopy. By IFAT, four samples were positive for Giardia cysts and one for Cryptosporidium oocysts, none of which was co-infected with T. foetus. No significant associations were found between the presence of T. foetus and the various risk factors examined.

Conclusions

T. foetus was found to be a common parasite in clinically healthy cats in Norway.

First report of feline intestinal trichomoniasis caused by Tritrichomonas foetus in Korea

Feline intestinal tritrichomoniasis by Tritrichomonas foetus was first recognized in USA in 1999 and has so far been reported from UK, Norway, Switzerland, and Australia, but not from the Far East Asian countries. In November 2008, 2 female and male littermate Siamese cats, 6-month old, raised in a household in Korea were referred from a local veterinary clinic with a history of chronic persistent diarrhea. A direct smear examination of fecal specimens revealed numerous trichomonad trophozoites which were isolated by the fecal culture in InPouch TF-Feline medium. A PCR testing of the isolate based on the amplification of a conserved portion of the T. foetus internal transcribed spacer (ITS) regions (ITS1 and ITS2) and the 5.8S rRNA gene, and the molecular sequencing of the PCR amplicons confirmed infection with T. foetus. This is the first clinical case of feline intestinal trichomoniasis caused by T. foetus in Korea.

Assessment of reproductive tract disease in cats at risk for Tritrichomonas foetus infection

OBJECTIVE

To determine whether Tritrichomonas foetus infection resides in reproductive tract tissues from cats housed for breeding and for which a high prevalence of colonic T foetus infection has been reported.

ANIMALS

61 purebred cats in 36 catteries undergoing elective ovariohysterectomy or castration and for which reproductive tract tissues, feces, and a reproductive history were obtained.

PROCEDURES

Reproductive tract tissues were examined for T foetus via light microscopy, immunohistochemical analysis, and PCR assay. History of reproductive tract disease was examined to detect statistical associations with identified or reported exposure to colonic T foetus infection.

RESULTS

15 of 61 (25%) cats and 22 of 33 (67%) catteries were identified with active or reported T foetus infection. Light microscopic, immunohistochemical, or molecular evidence of T foetus infection of the reproductive tract was not detected in any cats, including 15 cats with colonic T foetus infection, 29 cats residing in a cattery in which T foetus-infected cats were identified, and 8 cats for which gross or light microscopic evidence of reproductive tract disease was identified. There were no differences in total number of litters, number of litters per breeding, kitten mortality rate, or birth defects between cats or catteries infected with T foetus and those for which T foetus infection was not identified.

CONCLUSIONS AND CLINICAL RELEVANCE

No evidence of reproductive tract colonization by T foetus was detected in this study. Accordingly, it is unlikely that reproductive tract infection with T foetus plays an important role in overall disease transmission.

Intestinal Tritrichomonas foetus infection in cats in Switzerland detected by in vitro cultivation and PCR

Tritrichomonas foetus, a parasite well known for its significance as venereally transmitted pathogen in cattle, has recently been identified as a cause of chronic large-bowel diarrhea in domestic cats in the US, UK, and, more recently, also in Norway. In a period of 3 months (October to December 2007), 45 cats of Switzerland suffering from chronic diarrhea were investigated for intestinal infections, including a search for trichomonads. A commercially available in vitro culture system was used to screen for infection, complemented with a PCR and subsequent amplicon sequencing to support speciation. The PCR is based upon amplification of a sequence derived from the internal transcribed spacer region 1 (ITS1) on the ribosomal RNA gene (rRNA) using primers designed to detect a broad range of genera and species belonging to the family of Trichomonadidae. The method was furthermore adapted to the uracil DNA glycosylase (UDG) system in order to prevent carry-over contamination and it included a recombinant internal control to track for inhibitory reactions. Eleven out of the 45 cats were culture-positive, as revealed by microscopic identification of trichomonadid organisms. One of the isolates was subjected to scanning electron microscopy and findings revealed the presence of three flagella, thus placing the isolate into the gender Tritrichomonas sp. PCR and subsequent amplicon sequencing were carried out with ten of the 11 isolates. A total homology with published T. foetus sequences was confirmed in all of the cases. T. foetus therefore appears to range among those organisms that can cause chronic diarrhea in cats in Switzerland.