Eimeria species occurrence varies between geographic regions and poultry production systems and may influence parasite genetic diversity.
Eimeria species occurrence varies between geographic regions and poultry production systems and may influence parasite genetic diversity.
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DOI：
10.1016/j.vetpar.2016.12.003
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发表时间：
2017-01-15
影响因子：
2.6
通讯作者：
Blake DP
中科院分区：
文献类型：
--
作者：
Chengat Prakashbabu B;Thenmozhi V;Limon G;Kundu K;Kumar S;Garg R;Clark EL;Srinivasa Rao AS;Raj DG;Raman M;Banerjee PS;Tomley FM;Guitian J;Blake DP
多变量分析显示，在印度北部和南部的家禽集群。艾美耳球虫物种的发生在系统集群之间变化。E. tenella发生在整个系统可能会支持特定区域的遗传多样性。E.发现necatrix在印度北部比南部更常见。球虫病是全球家禽业面临的最大挑战之一。最近的研究强调了所有艾美耳球虫物种的普遍分布，这些物种可导致鸡患这种疾病，但有趣的是，揭示了至少一个物种（柔嫩艾美耳球虫）的遗传多样性和种群结构存在区域差异。与这种独特的地理变异相关的驱动因素尚不清楚，但可能会影响抗球虫药物和未来亚单位疫苗耐药性的发生和程度。印度是世界上最大的家禽生产国之一，包括E。tenella种群由高和低遗传多样性定义。本研究的目的是确定与艾美耳球虫种定义的高和低致病性在印度的北方和南部各州的流行率相关的风险因素，并试图了解不同地区之间的差异遗传变异的可能驱动因素。从印度北方的107个农场和印度南部的133个农场收集粪便样本和与农场特征和管理相关的数据。使用显微镜和PCR分析粪便样本，以确定艾美耳球虫的发生。应用多重对应分析将相关的假定危险因素转化为较少数量的合成不相关因素。层次聚类分析被用来确定家禽养殖场类型，揭示了三个不同的集群在研究区域。通过逻辑回归评估簇与艾美耳球虫物种存在之间的关联。研究发现，北部的大型肉鸡养殖场存在艾美耳球虫的风险最大，这些养殖场中有较大比例的艾美耳球虫呈阳性。necatrix，最致病的物种。比较发现E. tenella在印度南部的生产系统中，但总体发生率较低。这种两极分化的区域和系统特异性分布可能有助于先前在印度观察到的不同水平的遗传多样性，并可能影响亚洲和非洲大部分地区的寄生虫种群结构。研究结果可用于优先考虑目标农场，以启动和优化适当的抗球虫策略，以实现长期控制。
Multivariate analysis revealed comparable poultry clusters in north and south India. Eimeria species occurrence varied between system clusters. E. tenella occurrence across systems may underpin region-specific genetic diversity. E. necatrix was found to be more common in north than south India. Coccidiosis is one of the biggest challenges faced by the global poultry industry. Recent studies have highlighted the ubiquitous distribution of all Eimeria species which can cause this disease in chickens, but intriguingly revealed a regional divide in genetic diversity and population structure for at least one species, Eimeria tenella. The drivers associated with such distinct geographic variation are unclear, but may impact on the occurrence and extent of resistance to anticoccidial drugs and future subunit vaccines. India is one of the largest poultry producers in the world and includes a transition between E. tenella populations defined by high and low genetic diversity. The aim of this study was to identify risk factors associated with the prevalence of Eimeria species defined by high and low pathogenicity in northern and southern states of India, and seek to understand factors which vary between the regions as possible drivers for differential genetic variation. Faecal samples and data relating to farm characteristics and management were collected from 107 farms from northern India and 133 farms from southern India. Faecal samples were analysed using microscopy and PCR to identify Eimeria occurrence. Multiple correspondence analysis was applied to transform correlated putative risk factors into a smaller number of synthetic uncorrelated factors. Hierarchical cluster analysis was used to identify poultry farm typologies, revealing three distinct clusters in the studied regions. The association between clusters and presence of Eimeria species was assessed by logistic regression. The study found that large-scale broiler farms in the north were at greatest risk of harbouring any Eimeria species and a larger proportion of such farms were positive for E. necatrix, the most pathogenic species. Comparison revealed a more even distribution for E. tenella across production systems in south India, but with a lower overall occurrence. Such a polarised region- and system-specific distribution may contribute to the different levels of genetic diversity observed previously in India and may influence parasite population structure across much of Asia and Africa. The findings of the study can be used to prioritise target farms to launch and optimise appropriate anticoccidial strategies for long-term control.