University of East Anglia, School of Environmental Sciences, Norwich NR4 7TJ, UK.
Institute of Zoology, Zoological Society of London, Regents Park, London NW1 4RY, UK.
Parasitology. 2013 Sep;140(10):1234-45. doi: 10.1017/S0031182013000930. Epub 2013 Aug 7.
Avian trichomonosis, caused by the flagellated protozoan Trichomonas gallinae, is a recently emerged infectious disease of British passerines. The aetiological agent, a clonal epidemic strain of the parasite, has caused unprecedented finch mortality and population-level declines in Britain and has since spread to continental Europe. To better understand the potential origin of this epidemic and to further investigate its host range, T. gallinae DNA extracts were collected from parasite culture and tissue samples from a range of avian species in Britain. Sequence typing at the ITS1/5.8S rRNA/ITS2 region resolved three distinct ITS region types circulating in free-ranging British birds. Subtyping by sequence analyses at the Fe-hydrogenase gene demonstrated further strain variation within these ITS region types. The UK finch epidemic strain was preponderant amongst columbids sampled, however, wide strain diversity was encountered in isolates from a relatively small number of pigeons, suggesting further strains present in columbid populations across the UK are yet to be identified. Fe-hydrogenase gene sequence data in isolates from birds of prey with disease were predominantly identical to the UK finch epidemic strain, demonstrating its presence as a virulent strain in UK birds of prey since at least 2009.
禽类组织滴虫病由鞭毛原生动物嗜肛滴虫（Trichomonas gallinae）引起，是一种新近出现的英国雀形目鸟类传染病。这种病原体是寄生虫的单克隆流行株，导致了前所未有的雀类死亡率和英国境内雀形目鸟类数量的下降，此后已传播到欧洲大陆。为了更好地了解此次流行的潜在起源，并进一步调查其宿主范围，从英国各种禽类的寄生虫培养物和组织样本中采集了嗜肛滴虫 DNA 提取物。在 ITS1/5.8S rRNA/ITS2 区域的序列分型解析出在自由放养的英国鸟类中循环的三种不同的 ITS 区类型。在这些 ITS 区类型内，通过铁氢化酶基因的序列分析进行的亚分型显示出进一步的菌株变异。在采集的鸠鸽目鸟类中，英国雀形目鸟流行株占优势，然而，在来自相对少数鸽子的分离株中遇到了广泛的菌株多样性，表明在英国的鸠鸽目鸟类种群中还存在其他尚未确定的菌株。在患有疾病的猛禽鸟类分离株中的铁氢化酶基因序列数据主要与英国雀形目鸟流行株相同，表明自 2009 年以来，它作为一种毒力株已存在于英国的猛禽中。
