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

Abstract

RESUMO.-[Co-infecção por Tritrichomonas foetus e Pentatrichomonas hominis em gatos assintomáticos.] Tritrichomonas foetus, um parasito bem conhecido por seu significado como um agente patogênico transmitido venereamente em bovinos, também foi identificado como causa de diarreia crónica do intestino grosso em gatos domésticos em muitos países. No Brasil, vários estudos sobre o diagnósti-co de tricomonose bovina foram realizados, mas até agora, não há informação disponível em relação à trichomonose felina. Assim, este é o primeiro estudo a relatar a ocorrência 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.

Report of the first clinical case of intestinal trichomoniasis caused by Tritrichomonas foetus in a cat with chronic diarrhoea in Brazil

“…Coinfection with T. foetus and P. hominis was not observed herein, unlike the prior study conducted in Brazil, in which three of the four T. foetus -positive cats were infected with P. hominis, although both studies using the same set of primers for the molecular diagnosis of both infections [6]. The amplicon corresponding to T. foetus (347 bp) was purified using ExoSAP-IT PCR Product Cleanup (USB Products Affymetrix, Cleveland, OH) and submitted to bidirectional DNA sequencing with BigDye 3.1 (Applied Biosystems, Carlsbad, CA), according to the manufacturer’s protocols.…”

“…In Brazil, to date, infection with T. foetus has been reported only in asymptomatic cats [6]. This case report describes a case of naturally occurring T. foetus infection in a kitten inhabiting in Brazil, São Paulo state and the molecular analysis of this strain.…”

Pentatrichomonas hominis infection in two domestic cats with chronic diarrhea

“…Traditionally, P hominis has been considered commensal, being mentioned in cases of asymptomatic infections in cats, 20 and clinical signs such as diarrhea would be caused by an opportunistic overgrowth of endogenous fauna, favoring multiplication of the parasite. [21][22][23] Some authors have reported that P hominis was only detected in fecal samples that were also positive for T foetus infection.…”

“…Characteristics such as the numbers of anterior flagella and axostyle morphology are not clearly detected in living, motile specimens. 5,20 Therefore, the adoption of molecular tools, such as PCR and DNA sequencing, is indispensable to confirm the species of trichomonad. Additionally, the combination of the three techniques allowed an accurate diagnosis of P hominis in these two cats with diarrhea.…”

What is known about Tritrichomonas foetus infection in cats?

“…In Brazil, there are only three reports of T. foetus infection in domestic cats. In Rio de Janeiro, Santos et al (2015) found a prevalence of 5.2% of different-aged cats with diarrhea, using culture and PCR. In São Paulo, Hora et al In summary, the global prevalence of T. foetus infection in domestic cats, with and without diarrhea, ranges from 0-81.8%, according to the number of samples analyzed, the diagnostic method used, geographical region, and lifestyle of the cat population (Table 1).…”