Gookin Jody L, Birkenheuer Adam J, St John Victoria, Spector Michelle, Levy Michael G
Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina 27606, USA.
J Parasitol. 2005 Aug;91(4):939-43. doi: 10.1645/GE-474R.1.
Trichomonads are occasionally observed in the feces of dogs with diarrhea. On the basis of superficial morphological appearance, these infections have been attributed to opportunistic overgrowth of the commensal, Pentatrichomonas hominis. However, molecular characterization of canine trichomonads has never been reported. This study was performed to determine, by means of rRNA gene sequence analysis, the identity of trichomonads observed in feces from dogs with diarrhea. Total DNA was isolated from fecal samples obtained from a 3-mo-old mixed breed dog and litter of German Shepherd puppies having profuse liquid diarrhea containing numerous trichomonads. Total DNA was subject to PCR amplification of partial 18S rRNA gene or 5.8S, ITS1, ITS2, and partial 18S and 28S rRNA genes using species-specific and universal primers, respectively. Products of 642 and 1864 base-pair length were amplified and cloned. On the basis of rRNA gene sequence, the trichomonads observed in the single dog and the litter of puppies shared 100% identity with Tritrichomonas foetus and P. hominis, respectively. The present study is the first to establish the molecular identity of trichomonads infecting dogs with diarrhea. These studies validate the longstanding assumption that canine trichomoniasis may be attributed to P. hominis. Importantly, these studies additionally recognize that canine trichomoniasis may also be caused by infection with T. foetus.
腹泻犬的粪便中偶尔会观察到毛滴虫。基于表面形态外观，这些感染被归因于共生的人五毛滴虫的机会性过度生长。然而，犬毛滴虫的分子特征从未被报道过。本研究旨在通过rRNA基因序列分析确定腹泻犬粪便中观察到的毛滴虫的身份。从一只3个月大的混种犬和一窝患有大量液体腹泻且含有大量毛滴虫的德国牧羊犬幼犬的粪便样本中分离总DNA。分别使用物种特异性引物和通用引物对总DNA进行部分18S rRNA基因或5.8S、ITS1、ITS2以及部分18S和28S rRNA基因的PCR扩增。扩增出长度为642和1864碱基对的产物并进行克隆。基于rRNA基因序列，在单只犬和幼犬窝中观察到的毛滴虫分别与人胎儿三毛滴虫和人五毛滴虫具有100%的同一性。本研究首次确定了感染腹泻犬的毛滴虫的分子身份。这些研究证实了长期以来的假设，即犬毛滴虫病可能归因于人五毛滴虫。重要的是，这些研究还认识到犬毛滴虫病也可能由胎儿三毛滴虫感染引起。
