Dufernez Fabienne, Walker Richard L, Noël Christophe, Caby Stephanie, Mantini Clea, Delgado-Viscogliosi Pilar, Ohkuma Moriya, Kudo Toshiaki, Capron Monique, Pierce Raymond J, Villanueva Michelle R, Viscogliosi Eric
Inserm, U547, Institut Pasteur de Lille, 1 Rue du Professeur Calmette, BP 245, 59019 Lille Cedex, France.
J Eukaryot Microbiol. 2007 Mar-Apr;54(2):161-8. doi: 10.1111/j.1550-7408.2007.00247.x.
Tritrichomonas foetus is the causative agent of bovine trichomonosis. This protozoan is found in the preputial cavity of bulls and is transmitted to cows during coitus. Currently, the diagnosis of this parasite is based on microscopic examination of preputial washings or scrapings, but it was recently recognized that other trichomonads similar in size, shape, and motility to T. foetus can be present in preputial samples. Despite the serious consequences of an incorrect diagnosis for bovine trichomonosis, the precise speciation of these other trichomonads has remained uncertain. Here, a total of 12 non-T. foetus isolates were microscopically examined. On the basis of morphological criteria, seven of these isolates were identified as Tetratrichomonas sp., whereas four other isolates coincided with the description of Pentatrichomonas hominis. In the last isolate, a third non-T. foetus species was identified as belonging to the genera Pseudotrichomonas or Monocercomonas: the first time that species of either of these genera have been reported in preputial samples. To confirm these data, small subunit rRNA gene sequences were obtained by PCR from the 12 trichomonad isolates. These new sequences were analysed in a broad phylogeny including 72 other parabasalid sequences. From our phylogenetic trees, we confirmed the taxonomic status of non-T. foetus organisms isolated from preputial samples (Tetratrichomonas, Pentatrichomonas, and Pseudotrichomonas) and suggested the existence of two Tetratrichomonas species, despite their morphological similarity. The route of transmission of the non-T. foetus organisms identified in the bovine preputial cavity is discussed and we confirm that the PCR assay using the previously described T. foetus-specific primers TFR3 and TFR4 could be a useful alternative method for the diagnosis of bovine trichomonosis.
胎儿三毛滴虫是牛毛滴虫病的病原体。这种原生动物存在于公牛的包皮腔内，在交配时传播给母牛。目前，这种寄生虫的诊断基于对包皮洗液或刮片的显微镜检查，但最近人们认识到，包皮样本中可能存在其他大小、形状和运动性与胎儿三毛滴虫相似的毛滴虫。尽管错误诊断对牛毛滴虫病会造成严重后果，但这些其他毛滴虫的确切分类仍不确定。在此，共对12株非胎儿三毛滴虫分离株进行了显微镜检查。根据形态学标准，其中7株分离株被鉴定为四毛滴虫属，而另外4株分离株与人体五毛滴虫的描述相符。在最后一株分离株中，第三种非胎儿三毛滴虫被鉴定为属于伪三毛滴虫属或单鞭滴虫属：这是首次在包皮样本中报告这两个属的任何一种。为了证实这些数据，通过聚合酶链反应（PCR）从12株毛滴虫分离株中获得了小亚基核糖体RNA基因序列。这些新序列在一个广泛的系统发育分析中进行了分析，该分析包括72个其他副基体序列。从我们的系统发育树中，我们证实了从包皮样本中分离出的非胎儿三毛滴虫生物体（四毛滴虫属、五毛滴虫属和伪三毛滴虫属）的分类地位，并表明尽管形态相似，但存在两种四毛滴虫属物种。讨论了在牛包皮腔内鉴定出的非胎儿三毛滴虫生物体的传播途径，我们证实使用先前描述的胎儿三毛滴虫特异性引物TFR3和TFR4进行的PCR检测可能是诊断牛毛滴虫病的一种有用替代方法。
