Effects of Eimeria maxima and Clostridium perfringens infections on cecal microbiome components and correlation with body weight in broiler chickens

Authors: LU, MINGMIN - US Department Of Agriculture (USDA); LI, ROBERT - US Department Of Agriculture (USDA); ZHAO, HONGYAN - US Department Of Agriculture (USDA); Yan, Xianghe; Lillehoj, Hyun; SUN, ZHIFENG - US Department Of Agriculture (USDA); OH, SUNGTAEK - US Department Of Agriculture (USDA); WANG, YUEYING - Henan Agricultural University; Li, Charles

Submitted to: Research in Veterinary Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2020
Publication Date: 5/25/2020
Citation: Lu, M., Li, R., Zhao, H., Yan, X., Lillehoj, H.S., Sun, Z., Oh, S., Wang, Y., Li, C.Z. 2020. Effects of Eimeria maxima and Clostridium perfringens infections on cecal microbiome components and correlation with body weight in broiler chickens. Research in Veterinary Science. https://doi.org/10.1016/j.rvsc.2020.05.013.
DOI: https://doi.org/10.1016/j.rvsc.2020.05.013

Interpretive Summary: Intestinal microbiota are important components for the development of defense mechanisms and nutrient acquirement in the gut mucosa of the animals, as well as being associated with the effects on emotion, gas production, obesity, and diabetes and other metabolic disorders. With the reduction and eventual withdraw of antibiotics as growth promoter from animal feed due to the public concern and government regulation over the antibiotics abuse, Eimeria spp-causing coccidiosis and Clostridium perfringens (CP)-causing necrotic enteritis (NE) are the top two enteric infectious diseases worldwide responsible for around $3 and 6 billion economic loss worldwide, respectively. Coccidiosis is also the major predisposing factors for NE. Alternatives to antibiotics assume essential to promote the gut health, animal growth and host immunity. We have developed animal models to evaluate the efficacies of various alternative approaches. However, it has not been clearly established what changes in gut microbiota occur post Eimeria spp. and CP infection in this model. In this report, we analyzed cecal microbiota of 4 groups of broiler chickens (n = 12) using 16S rRNA sequencing technology which is a well-established common approach by sequencing the conservative 16S rRNA housekeeping genes to identify and compare bacteria present within given samples: (1) uninfected control, (2) infection with parasite Eimeria maxima (EM), (3) infection with bacteria CP, (4) coinfection by both EM and CP. We found that the infections with EM and CP had different effects on the intestinal cecal microbiota composition and structure. Some bacterial populations may increase to protect the host against pathogenic invasions. EM and CP infection also induced different changes in metabolic pathways. Dual infections induced significant changes in the gut microbiota which may indicate complex interaction.

Technical Abstract: Intestinal microbiota are important components for the development of defense mechanisms and nutrient acquirement in the gut mucosa of the animals, as well as being associated with the effects on emotion, gas production, obesity, and diabetes and other metabolic disorders. With the reduction and eventual withdraw of antibiotics as growth promoter from animal feed due to the public concern and government regulation over the antibiotics abuse, Eimeria spp-causing coccidiosis and Clostridium perfringens (CP)-causing necrotic enteritis (NE) are the top two enteric infectious diseases worldwide responsible for around $3 and 6 billion economic loss worldwide, respectively. Coccidiosis is also the major predisposing factors for NE. Alternatives to antibiotics assume essential to promote the gut health, host immunity and animal growth. We have developed animal models to evaluate the efficacies of various alternative approaches. However, it has not been clearly established what changes these infections cause to predispose birds to succumb to necrotic enteritis. We analyzed cecal microbiota of 4 groups of broiler chickens (n = 12) using deep pyrosequencing of 16S rDNA amplicons: (1) naïve control, (2) infection with parasite Eimeria maxima (EM), (3) infection with bacteria CP, (4) coinfection by both EM and CP. We found that the infections with EM and /or CP had a different effect on the intestinal cecal microbiota. At the family level, major abundance reductions were observed in the in the Bacteroidaceae, Peptostreptococcaceae, Rikenellaceae in the microbiota after EM or EM/CP dual infection. At the genus level, we noted major changes in the prevalence with abundance increase in Enterobacteriaceae spp., and Eubacteriaceae anaerofustis in the ceca of EM infected chickens, while in CP infected birds, major changes with abundance increase of Eubacteriaceae anaerofustis, other Clostridiaceae and Lachnospiraceae clostridium were identified. In the dual infections, 3 bacteria were prevalent including increase of Clostridiaceae and Enterobacteriaraceae in the ceca. Compared to the naïve control, 4 to 6 bacterial abundance became reduced in the ceca of EM and/or CP infected birds. Some species were most affected by EM or CP infection with increase of Eubacteriaceae and reduction in Bacteroidaceae at the operational taxonomic units (OTUs) level. EM and/or CP infection induced different changes in KEGG and pathway as well with increases in secretion system, butanoate metabolism, signal transduction mechanism for dual infections. Eimeria maxima and C. perfringens infections induced significant changes in the gut microbiota which may indicate complex interaction.