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

摘要

: 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. Index Terms:??Co-infection; Tritrichomonas foetus; Pentatrichomonas hominis; domestic cats Resumo: Tritrichomonas foetus, um parasito bem conhecido por seu significado como um agente patog?anico transmitido venereamente em bovinos, tamb??m foi identificado como causa de diarreia cr?3nica do intestino grosso em gatos dom??sticos em muitos pa?-ses. No Brasil, v??rios estudos sobre o diagn?3stico de tricomonose bovina foram realizados, mas at?? agora, n?￡o h?? informa?§?￡o dispon?-vel em rela?§?￡o ?? trichomonose felina. Assim, este ?? o primeiro estudo a relatar a ocorr?ancia de T. foetus e Pentatrichomonas hominis em gatos por meio de an??lise morfol?3gica e molecular. Fezes de 77 gatos foram examinadas, a partir da qual quatro (5,2%) foram positivas para a presen?§a de parabasal?-deos. A an??lise morfol?3gica de esfrega?§os corados revelou trophozoitos piriformes com tr?as flagelos anteriores, n?ocleo alongado e ax?3stilo cuja proje?§?￡o termina abruptamente em formato de filete, caracter?-sticas estas de identifica?§?￡o morfol?3gica T. foetus. Al??m disso, microscopia eletr?′nica de varredura e transmiss?￡o, revelaram caracteres morfol?3gicos semelhantes aos descritos na literatura para esta esp??cie. A an??lise molecular de culturas utilizando iniciadores espec?-ficos para trofozo?-tos de T. foetus (TFR3 e TFR4), mostrou que as quatro amostras foram positivas para este parasito e osequenciamento dos fragmentos amplificados demonstraram 99,7-100% de similaridade com seq???ancias depositadas no GeneBank de T. foetus. Nenhum trofozo?-to com morfologia consistente com a descri?§?￡o de P. hominis foi visualizado nas amostras. No entanto, a an??lise molecular, utilizando iniciadores espec?-ficos para esta esp??cie (TH3 e TH5) detectou que tr?as das quatro amostras (75%) tamb??m foram positivas para P. hominis e o sequenciamento de nucleotideos revelou 100% de similaridade dos amplicons quando comparada com o mesmo fragmento de DNA de P. hominis depositado no GenBank. Como tal, o presente estudo relata a coinfec?§?￡o de gatos com T. foetus e P. hominis e destacou a exig?ancia de uma combina?§?￡o de m??todos para o diagn?3stico de coinfec?§?μes. Estes resultados demonstram a import?￠ncia do diagn?3stico correto para a aplica?§?￡o da terapia apropriada por parte dos veterin??rios. Termos de Indexa?§?￡o:??Coinfec?§?￡o; Tritrichomonas foetus; Pentatrichomonas hominis; gatos dom??sticos Introduction Historically, the observation of parabasalids in the feces of cats with diarrhea and/or dysentery owned low importance and attributed to an overgrowth of gut microflora that favoured the proliferation of protozoa (Dimski 1989, Barr 1998). An association between dysentery in the large intestine in cats and the presence of parabasalids as Pentatrichomonas hominis and Tritrichomonas foetus was recognized by Romatowski (1996, 2000), Gookin et al. (1999), Levy et al. (2003). There are practically one or more reports of the occurrence of feline tri