A newly described strain of Eimeria arloingi (strain A) belongs to the phylogenetic group of ruminant-infecting pathogenic species, which replicate in host endothelial cells in vivo

Liliana M.R Silva,Fernando Chávez-Maya,Sarah Macdonald,Elaine Pegg,Damer P Blake,Anja Taubert,Carlos Hermosilla

doi:10.1016/j.vetpar.2017.10.014

Liliana M.R Silva, Fernando Chávez-Maya + Show 5 more

Open Access

https://doi.org/10.1016/j.vetpar.2017.10.014

Copy DOI

Abstract

Coccidiosis caused by Eimeria species is an important disease worldwide, particularly in ruminants and poultry. Eimeria infection can result in significant economic losses due to costs associated with treatment and slower growth rates, or even with mortality of heavily infected individuals. In goat production, a growing industry due to increasing demand for caprine products worldwide, coccidiosis is caused by several Eimeria species with E. arloingi and E. ninakohlyakimovae the most pathogenic. The aims of this study were genetic characterization of a newly isolated European E. arloingi strain (A) and determination of phylogenetic relationships with Eimeria species from other ruminants. Therefore, a DNA sequence of E. arloingi strain (A) containing 2290 consensus nucleotides (the majority of 18S rDNA, complete ITS-1 and 5.8S sequences, and the partial ITS-2) was amplified and phylogenetic relationship determined with the most similar sequences available on GenBank. The phylogenetic tree presented a branch constituted by bovine Eimeria species plus E. arloingi, and another one exclusively populated by ovine Eimeria species. Moreover, E. arloingi, E. bovis and E. zuernii, which all replicate in host intestinal endothelial cells of the lacteals, were found within the same cluster. This study gives new insights into the evolutionary phylogenetic relationships of this newly described caprine Eimeria strain and confirmed its close relationship to other highly pathogenic ruminant Eimeria species characterized by macromeront formation in host endothelial cells of the central lymph capillaries of the small intestine.

Highlights

More than 1200 Eimeria species are known (Chapman et al, 2013) and it is assumed that many more remain to be discovered (Blake, 2015)
The second clade (B) included bovine (E. bovis and E. zuernii) and caprine (E. arloingi) species which replicate within host intestinal endothelial cells of the lacteals, and a bovine species which replicates in host epithelial cells (E. ellipsoidalis)
Ruminant coccidiosis caused by parasites of the genus Eimeria is still one of the most widespread infections of livestock worldwide (Daugschies and Najdrowski, 2005; Witcombe and Smith, 2014)

Summary

Introduction

More than 1200 Eimeria species are known (Chapman et al, 2013) and it is assumed that many more remain to be discovered (Blake, 2015). The great majority of these species are monoxenous enteropathogens of vertebrates which usually induce only mild pathology and mild or non-clinical disease. Certain species such as E. bovis, E. zuernii, E. alabamensis (cattle), E. ovinoidalis, E. bakuensis (sheep), E. cameli, E. dromedari (camels), E. ninakohlyakimovae and E. arloingi (goat) are considered highly pathogenic, defined by the formation of macromeronts, and severe intestinal lesions. Coccidiosis is relevance to ruminant and poultry production (Chapman et al, 2013; Daugschies and Najdrowski, 2005). The economic impact in both industries is enormous and was recently valued as a 6-9% reduction in gross margin for ruminants, and to exceed US$3 billion for poultry (Blake and Tomley, 2014; Lassen and Ostergaard, 2012). More than one billion goats are reared worldwide (FAOSTAT, 2014) and coccidiosis constitutes a major concern for the caprine industry

Objectives

Methods

Results

Conclusion