Vrba Vladimir, Pakandl Michal
BIOPHARM, Research Institute of Biopharmacy and Veterinary Drugs, Pohori-Chotoun, Jilove u Prahy 254 49, Czech Republic.
BIOPHARM, Research Institute of Biopharmacy and Veterinary Drugs, Pohori-Chotoun, Jilove u Prahy 254 49, Czech Republic.
Vet Parasitol. 2015 Mar 15;208(3-4):118-24. doi: 10.1016/j.vetpar.2015.01.017. Epub 2015 Jan 28.
Protozoan parasites of the Eimeria genus have undergone extensive speciation and are now represented by a myriad of species that are specialised to different hosts. These species are highly host-specific and usually parasitise single host species, with only few reported exceptions. Doubts regarding the strict host specificity were frequent in the original literature describing coccidia parasitising domestic turkeys. The availability of pure characterised lines of turkey and chicken Eimeria species along with the recently developed quantitative PCR identification of these species allowed to investigate the issue of host specificity using well-controlled cross-transmission experiments. Seven species of gallinaceous birds (Gallus gallus, Meleagris gallopavo, Alectoris rufa, Perdix perdix, Phasianus colchicus, Numida meleagris and Colinus virginianus) were inoculated with six species and strains of turkey Eimeria and six species of chicken coccidia and production of oocysts was monitored. Turkey Eimeria species E. dispersa, E. innocua and E. meleagridis could complete their development in the hosts from different genera or even different families. Comparison of phylogenetic positions of these Eimeria species according to 18S rDNA and COI showed that the phylogeny cannot explain the observed patterns of host specificity. These findings suggest that the adaptation of Eimeria parasites to foreign hosts is possible and might play a significant role in the evolution and diversification of this genus.
艾美耳属的原生动物寄生虫经历了广泛的物种形成，现在由无数专门寄生于不同宿主的物种代表。这些物种具有高度的宿主特异性，通常寄生于单一宿主物种，只有少数例外报道。在描述寄生于家火鸡的球虫的原始文献中，对严格的宿主特异性经常存在疑问。火鸡和鸡艾美耳属物种的纯特征品系的可用性以及最近开发的这些物种的定量PCR鉴定，使得能够使用严格控制的交叉传播实验来研究宿主特异性问题。给七种鸡形目鸟类（原鸡、火鸡、石鸡、灰山鹑、雉鸡、珠鸡和弗吉尼亚鹑）接种六种火鸡艾美耳属物种和菌株以及六种鸡球虫，并监测卵囊的产生。火鸡艾美耳属物种分散艾美耳球虫、无害艾美耳球虫和火鸡艾美耳球虫能够在来自不同属甚至不同科的宿主中完成其发育。根据18S rDNA和COI对这些艾美耳属物种的系统发育位置进行比较表明，系统发育不能解释观察到的宿主特异性模式。这些发现表明，艾美耳属寄生虫适应外来宿主是可能的，并且可能在该属的进化和多样化中发挥重要作用。
