Data from: Mitochondrial genomes of Australian chicken Eimeria support the presence of ten species with low genetic diversity among strains

Modern molecular approaches have vastly improved diagnostic capabilities for differentiating among species of chicken infecting Eimeria. Consolidating information from multiple genetic markers, adding additional poultry Eimeria species and increasing the size of available data-sets is improving the resolving power of the DNA, and consequently our understanding of the genus. This study adds information from 25 complete mitochondrial DNA genomes from Australian chicken Eimeria isolates representing all 10 species known to occur in Australia, including OTU-X, −Y and −Z. The resulting phylogeny provides a comprehensive view of species relatedness highlighting where the OTUs align with respect to others members of the genus. All three OTUs fall within the Eimeria clade that contains only chicken-infecting species with close affinities to E. maxima, E. brunetti and E. mitis. Mitochondrial genetic diversity was low among Australian isolates likely reflecting their recent introduction to the country post-European settlement. The lack of observed genetic diversity is a promising outcome as it suggests that the currently used live vaccines should continue to offer widespread protection against Eimeria outbreaks in all states and territories. Flocks were frequently found to host multiple strains of the same species, a factor that should be considered when studying disease epidemiology in the field.

现代分子生物学方法极大提升了感染鸡的艾美耳球虫属（Eimeria）物种的鉴别诊断能力。整合多遗传标记信息、补充禽类艾美耳球虫物种数据并扩大可用数据集规模，可提升DNA检测的分辨能力，进而深化对该球虫属的认知。本研究纳入了来自澳大利亚鸡源艾美耳球虫分离株的25条完整线粒体DNA基因组序列，涵盖澳大利亚已报道的全部10种鸡源艾美耳球虫，其中包含操作分类单元（Operational Taxonomic Unit，OTU）-X、-Y及-Z。所得系统发育树全面展示了各物种的亲缘关系，明确了这三个操作分类单元在该属内与其他物种的演化定位。这三个操作分类单元均隶属于仅包含鸡源艾美耳球虫的演化支，且与巨型艾美耳球虫（E. maxima）、布氏艾美耳球虫（E. brunetti）及缓艾美耳球虫（E. mitis）亲缘关系密切。澳大利亚分离株的线粒体遗传多样性较低，这大概率反映出该类球虫是在欧洲殖民时期才被引入澳大利亚的。未检测到显著遗传多样性是一项可喜的结果，这表明当前使用的活疫苗仍可在澳大利亚所有州及领地内，为防控艾美耳球虫病暴发提供广泛保护。研究还发现鸡群常同时感染同一物种的多个毒株，这一因素在开展野外疾病流行病学研究时需予以考量。