What Do We Know about Surface Proteins of Chicken Parasites Eimeria?

Abstract

Poultry is the first source of animal protein for human consumption. In a changing world, this sector is facing new challenges, such as a projected increase in demand, higher standards of food quality and safety, and reduction of environmental impact. Chicken coccidiosis is a highly widespread enteric disease caused by Eimeria spp. which causes significant economic losses to the poultry industry worldwide; however, the impact on family poultry holders or backyard production—which plays a key role in food security in small communities and involves mainly rural women—has been little explored. Coccidiosis disease is controlled by good husbandry measures, chemoprophylaxis, and/or live vaccination. The first live vaccines against chicken coccidiosis were developed in the 1950s; however, after more than seven decades, none has reached the market. Current limitations on their use have led to research in next-generation vaccines based on recombinant or live-vectored vaccines. Next-generation vaccines are required to control this complex parasitic disease, and for this purpose, protective antigens need to be identified. In this review, we have scrutinised surface proteins identified so far in Eimeria spp. affecting chickens. Most of these surface proteins are anchored to the parasite membrane by a glycosylphosphatidylinositol (GPI) molecule. The biosynthesis of GPIs, as well as the role of currently identified surface proteins and interest as vaccine candidates has been summarised. The potential role of surface proteins in drug resistance and immune escape and how these could limit the efficacy of control strategies was also discussed.

Protective Efficacy Induced by the Common Eimeria Antigen Elongation Factor 2 against Challenge with Three Eimeria Species in Chickens

“…Eimeria species are an obligate intracellular parasitic protozoan and can cause avian coccidiosis clinically, which seriously affects the health, efficiency and sustainable development of the domestic poultry industry and brings tremendous and irreversible loss worldwide [ 1 , 41 , 42 ]. The data report on avian coccidiosis shows that the prevalence range of Eimeria spp.…”

“…The data report on avian coccidiosis shows that the prevalence range of Eimeria spp. is widespread and the infection rate is high [ 41 ]. Recent reports estimate that avian coccidiosis in poultry is responsible for a global cost of around GBP 10.4 billion [ 3 , 4 , 43 ].…”

Effect of an Alliaceae Encapsulated Extract on Growth Performance, Gut Health, and Intestinal Microbiota in Broiler Chickens Challenged with Eimeria spp.

“…Table 5. Medians and ranges (Q25-Q75) of oocysts per gram of feces (OPG) in broiler chickens supplemented with different doses of Alliaceae encapsulated extract (AE-e) 1 or anticoccidial drugs (Ion) 2 , under challenge with Eimeria spp. 3 .…”

“…Currently, coccidiosis disease continues to be one of the most serious problems in the commercial broiler poultry industry, resulting in great economic loss all over the world [1]. Eimeria acervulina, Eimeria maxima, and Eimeria tenella are the main species that cause disease in broiler chickens, impairing both intestinal function and growth performance [2].…”

Microneme-located VP2 in Eimeria acervulina elicits effective protective immunity against infectious bursal disease virus

“…Given the need for optimizing genetic manipulation strategies for Eimeria species as vaccine vectors, we envisioned that E. acervulina and E. mitis are safer than E. tenella and E. necatrix as both have low pathogenicity in chickens. Meanwhile, although E. mitis is less pathogenic than E. acervulina , the latter is more practical as it is more prevalent in the field ( 15 ) and commonly used in oocysts-based live vaccines against coccidiosis. Extensive research on E. acervulina , including the selection of precocious and serotinous lines, high-quality and high-resolution genome assembly, as well as the optimization of genetic hybridization system ( 16 ), have resulted in an in-depth knowledge of E. acervulina .…”