Relationship between Eimeria tenella associated-early clinical signs and molecular changes in the intestinal barrier function

Exploring the interplay between Eimeria spp. infection and the host: understanding the dynamics of gut barrier function

Coccidiosis is a global disease caused by protozoans, typically including Eimeria spp., which pose a significant threat to the normal growth and development of young animals. Coccidiosis affects mainly the gut, where parasite proliferation occurs. The intestinal barrier, which consists of chemical, mechanical, biological, and immune defences, plays a crucial role in protecting the host against pathogens, xenobiotics, and toxins present in the gastrointestinal tract. When animals ingest sporulated Eimeria spp. oocysts, these parasites primarily reproduce in the intestinal tract, causing damage to the structure and function of the intestine. This disruption of intestinal homeostasis adversely affects animal health. Numerous studies have also revealed that Eimeria-infected animals experience slower bone growth rates, inferior meat quality, reduced egg production and quality, as well as impaired growth and development. Therefore, the purpose of this review is to examine the underlying mechanisms through which Eimeria spp. regulate intestinal damage and disturb the balance of the internal environment. Specifically, this review will focus on their effects on the structural basis of the host intestine's chemical, mechanical, biological and immune barriers. This understanding is crucial for the development of effective drugs to prevent the invasion of Eimeria spp. into the intestine, which is of paramount importance for maintaining host health.

Effects of Saccharomyces cerevisiae fermentation-derived postbiotics supplementation in sows and piglets' diet on intestinal morphology, and intestinal barrier function in weaned pigs in an intensive pig production system

This study evaluates the effects of Saccharomyces cerevisiae fermentation-derived postbiotics (SCFP) supplementation on diarrhea incidence, small intestinal morphology, and expression of tight junction genes in piglets. The study compared three groups: a control group (CON), which received a standard basal diet; a standard basal control diet containing 1.0 kg/mT of Beta-glucan 50 % (BG); and a standard basal control diet containing 2.0 kg/mT of SCFP (Diamond V XPC). The experimental design involved feeding the diets to the sows from the day when they were inseminated until their piglets were weaned and to piglets from birth to weaning. Diarrhea incidence was monitored, intestinal morphology was assessed, and gene expression of tight junction proteins (Claudin-1, Claudin-2, Occludin, and ZO-1) and inflammatory cytokines (IL-1β) was analyzed using qPCR. Results revealed that SCFP supplementation significantly reduced diarrhea incidence and upregulated the expression of tight junction proteins Claudin-1 (1.61-fold) and Occludin (1.90-fold) compared to CON. These improvements were not associated with changes in intestinal morphology. BG supplementation showed intermediate effects on tight junction gene expression but did not differ significantly from CON. These findings highlight the potential of SCFP as a dietary supplement to enhance gastrointestinal health in piglets by strengthening the intestinal epithelial barrier and reducing pathogen translocation. The study underscores the efficacy of SCFP in improving gut health without altering intestinal structure, offering an effective approach to manage pre-weaning diarrhea. Future studies are needed to explore the long-term impact of SCFP on growth performance and immunity.

Effects of dietary supplementation with a polyherbal based product on sporozoites viability and on growth performance, lesion score, gut permeability, oocyst shedding count, tight junction, pro-inflammatory cytokine, and antioxidant enzyme in broiler chickens challenged with Eimeria spp

Two in vivo and in vitro studies were conducted to investigate the effects of supplementation of a natural polyherbal mixture (PHM) manufactured from selected herbs in broiler chickens challenged with coccidiosis. For the in vitro trial, E. tenella and E. maxima sporozoites were used to test how PHM affected sporozoites viability at 24, 48, and 72 h. The treatments were as follows: negative control with phosphate buffered saline (NC-PBS), solvent control containing 1 % dimethyl sulfoxide (DMSO), salinomycin at 12 mg/kg with 1 % DMSO in PBS (SAL), and 500 mg/kg PHM in PBS (PHM). For the in vivo trial, a total of 288 0-day-old male Cobb 500 were randomly distributed into 3 treatments with 8 replicates, and study lasted for 28 days. Treatments were as follows: non-challenge control with a basal diet (NC), Eimeria spp. challenge with a basal diet (CC), and Eimeria spp. challenge with a basal diet containing 500 mg/kg of the PHM (PHM). Chickens in challenged groups were inoculated with 62,500 oocyst of E. acervulina, 12,500 oocyst of E. maxima and E. tenella on 14 days. In vitro results showed that PHM increased (P < 0.001) a Eimeria sporozoite reduction percentage. As for in vivo results, the PHM group had similar body weight gain, feed intake, and feed efficiency compared to the NC group. The use of PHM reduced fecal oocyst counts of E. tenella and E. maxima from 6 to 9 days post inoculation (DPI; P < 0.05). Moreover, PHM supplementation decreased duodenum and ceca lesion scores (P < 0.001). The PHM group also had reduced expression levels of claudin 1 (CLDN-1), interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in the jejunum compared to the CC group (P < 0.01). In conclusion, the supplementation with 500 mg/kg of polyherbal mixture both in vitro and in vivo reduced the viability of E. tenella and E. maxima sporozoites, and this could explain that PHM effectively mitigated negative effects caused by the challenge with Eimeria spp., suggesting that it could be a dietary strategy to improve performance and gut health in broilers under coccidiosis.

Single-cell transcriptomic atlas of the chicken cecum reveals cellular responses and state shifts during Eimeria tenella infection

Eimeria tenella (E. tenella) infection is a major cause of coccidiosis in chickens, leading to significant economic losses in the poultry industry due to its impact on the cecum. This study presents a comprehensive single-cell atlas of the chicken cecal epithelium by generating 7,394 cells using 10X Genomics single-cell RNA sequencing (scRNA-seq). We identified 13 distinct cell types, including key immune and epithelial populations, and characterized their gene expression profiles and cell-cell communication networks. Integration of this single-cell data with bulk RNA-seq data from E. tenella-infected chickens revealed significant alterations in cell type composition and state, particularly a marked decrease in APOB+ enterocytes and an increase in cycling T cells during infection. Trajectory analysis of APOB+ enterocytes uncovered shifts toward cellular states associated with cell death and a reduction in those linked to mitochondrial and cytoplasmic protection when infected with E. tenella. These findings highlight the substantial impact of E. tenella on epithelial integrity and immune responses, emphasizing the parasite's role in disrupting nutrient absorption and energy metabolism. Our single-cell atlas serves as a critical resource for understanding the cellular architecture of the chicken cecum and provides a valuable framework for future investigations into cecal diseases and metabolic functions, with potential applications in enhancing poultry health and productivity.

Effects of Eimeria challenge on growth performance, intestine integrity, and cecal microbial diversity and composition of yellow broilers

The invasion of Eimeria causes damage to the intestinal barrier, nutrient leakage, and microbial imbalance in poultry. We aimed to investigate the effects of Eimeria infection on growth performance, intestinal integrity, and cecal microbial diversity and composition of yellow broilers. A total of 180 male yellow broilers were randomly divided into an unchallenged control and an Eimeria challenge treatment group within 18 floor pens (10 chicks/pen, 9 replicate pens/group). On day 10, 90 chicks received a cocktail of E. maxima, E. acervulina, and E. tenella oocysts (105/chick) to induce coccidial infection, and the other 90 received an aliquot of PBS. The Eimeria challenge resulted in increased bird feed consumption and FCR from day 11 to 21 (all P < 0.01). Higher fecal Eimeria counts, duodenal, jejunal, and cecal lesions were observed in the challenge group on day 12, 15, 15, 18 respectively (all P < 0.05). Furthermore, the infected birds had larger livers and small intestines, deeper villus crypt, and decreased expression of Claudin-1 on day 21 (all P < 0.05). The 16S rRNA sequencing indicated that alpha diversity (Sobs, Shannon, Simpson, Ace, or Chao) of cecal microbials was not affected by Eimeria challenge (all P > 0.05). However, the PCoA and LEfSe analyses indicated that the Eimeria challenge altered microbial distribution by decreasing the abundance of Firmicutes and enriching the abundance of Proteobacteria at the phylum level. At the genus level, Clostridia vadin BB60 and Lachnospiraceae NK4A136 group were reduced, while Escherichia-Shigella were enriched in the challenged yellow broilers (all P < 0.05). Correlation analyses demonstrated that the birds with higher Lachonospiraceae NK4A136 group and Clostridia vadin BB60, and lower Escherichia-Shigella in their cecal content gained more BW and reached a lower FCR from day 11 to 21 (all P < 0.05). In conclusion, Eimeria infection compromised feed efficiency of yellow broilers by damaging intestinal barrier and shifting cecal microbiota towards colonizers associated with poor performance. Restoring the dysbiotic microbiome could be a potential strategy for improving feed efficiency in yellow broilers under coccidial challenge.

Multi-omics analysis reveals regime shifts in the gastrointestinal ecosystem in chickens following anticoccidial vaccination and Eimeria tenella challenge

Coccidiosis, caused by Eimeria parasites, significantly impacts poultry farm economics and animal welfare. Beyond its direct impact on health, Eimeria infection disrupts enteric microbial populations leading to dysbiosis and increases vulnerability to secondary diseases such as necrotic enteritis, caused by Clostridium perfringens. The impact of Eimeria infection or anticoccidial vaccination on host gastrointestinal phenotypes and enteric microbiota remains understudied. In this study, the metabolomic profiles and microbiota composition of chicken caecal tissue and contents were evaluated concurrently during a controlled experimental vaccination and challenge trial. Cobb500 broilers were vaccinated with a Saccharomyces cerevisiae-vectored anticoccidial vaccine and challenged with 15,000 Eimeria tenella oocysts. Assessment of caecal pathology and quantification of parasite load revealed correlations with alterations to caecal microbiota and caecal metabolome linked to infection and vaccination status. Infection heightened microbiota richness with increases in potentially pathogenic species, while vaccination elevated beneficial Bifidobacterium. Using a multi-omics factor analysis, data on caecal microbiota and metabolome were integrated and distinct profiles for healthy, infected, and recovering chickens were identified. Healthy and recovering chickens exhibited higher vitamin B metabolism linked to short-chain fatty acid-producing bacteria, whereas essential amino acid and cell membrane lipid metabolisms were prominent in infected and vaccinated chickens. Notably, vaccinated chickens showed distinct metabolites related to the enrichment of sphingolipids, important components of nerve cells and cell membranes. Our integrated multi-omics model revealed latent biomarkers indicative of vaccination and infection status, offering potential tools for diagnosing infection, monitoring vaccination efficacy, and guiding the development of novel treatments or controls.IMPORTANCEAdvances in anticoccidial vaccines have garnered significant attention in poultry health management. However, the intricacies of vaccine-induced alterations in the chicken gut microbiome and its subsequent impact on host metabolism remain inadequately explored. This study delves into the metabolic and microbiotic shifts in chickens post-vaccination, employing a multi-omics integration analysis. Our findings highlight a notable synergy between the microbiome composition and host-microbe interacted metabolic pathways in vaccinated chickens, differentiating them from infected or non-vaccinated cohorts. These insights pave the way for more targeted and efficient approaches in poultry disease control, enhancing both the efficacy of vaccines and the overall health of poultry populations.

Expression profile of Toll-like receptors and cytokines in the cecal tonsil of chickens challenged with Eimeria tenella

Chicken coccidiosis, caused by Eimeria spp., seriously affects the development of the poultry breeding industry. Currently, extensive studies of chicken coccidiosis are mostly focused on acquired immune responses, while information about the innate immune response of chicken coccidiosis is lacking. Toll-like receptor (TLR), the key molecule of the innate immune response, connects innate and adaptive immune responses and induces an immune response against various pathogen infections. Therefore, the quantitative real-time PCR was used to characterize the expression profile of chicken TLRs (chTLRs) and associated cytokines in the cecal tonsil of chickens infected with Eimeria tenella. The results showed that the expression of chTLR1a, chTLR2a, and chTLR5 was significantly upregulated at 3 h post-infection, while chTLR1b, chTLR2b, chTLR3, chTLR7, chTLR15 and chTLR21 was significantly downregulated (p < 0.05). In addition, chTLR1a expression rapidly reached the peaked expression at 3 h post-infection, while chTLR2b and chTLR15 peaked at 168 h post-infection, and chTLR2a expression was highest among chTLRs, peaking at 48 h post-infection (p < 0.05). For cytokines, interleukin (IL)-6 and tumor necrosis factor (TNF)-α peaked at 96 h post-infection, IL-4 and IL-12 peaked at 144 h post-infection, and interferon-γ expression was highest among cytokines at 120 h post-infection. In addition, IL-12 and IL-17 were markedly upregulated at 6 h post-infection (p < 0.05). These results provide insight into innate immune molecules during E. tenella infection in chickens and suggest that innate immune responses may mediate resistance to chicken coccidiosis.

Correlation of caecal microbiome endotoxins genes and intestinal immune cells in Eimeria tenella infection based on bioinformatics

Introduction

The infection with Eimeria tenella (ET) can elicit expression of various intestinal immune cells, incite inflammation, disrupt intestinal homeostasis, and facilitate co-infection with diverse bacteria. However, the reciprocal interaction between intestinal immune cells and intestinal flora in the progression of ET-infection remains unclear.

Objective

The aim of this study was to investigate the correlation between cecal microbial endotoxin (CME)-related genes and intestinal immunity in ET-infection, with subsequent identification of hub potential biomarker and immunotherapy target.

Methods

Differential expression genes (DEGs) within ET-infection and hub genes related to CME were identified through GSE39602 dataset based on bioinformatic methods and Protein-protein interaction (PPI) network analysis. Moreover, immune infiltration was analyzed by CIBERSORT method. Subsequently, comprehensive functional enrichment analyses employing Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis along with Gene Ontology (GO), gene set enrichment analysis (GSEA), and gene set variation analysis (GSVA) were performed.

Results

A total of 1089 DEGs and 25 hub genes were identified and CXCR4 was ultimately identified as a essential CME related potential biomarker and immunotherapy target in the ET-infection. Furthermore, activated natural killer cells, M0 macrophages, M2 macrophages, and T regulatory cells were identified as expressed intestinal immune cells. The functional enrichment analysis revealed that both DEGs and hub genes were significantly enriched in immune-related signaling pathways.

Conclusion

CXCR4 was identified as a pivotal CME-related potential biomarker and immunotherapy target for expression of intestinal immune cells during ET-infection. These findings have significant implications in elucidating the intricate interplay among ET-infection, CME, and intestinal immunity.

Microbiota promotes recruitment and pro-inflammatory response of caecal macrophages during E. tenella infection

BACKGROUND

Eimeria genus belongs to the apicomplexan parasite phylum and is responsible for coccidiosis, an intestinal disease with a major economic impact on poultry production. Eimeria tenella is one of the most virulent species in chickens. In a previous study, we showed a negative impact of caecal microbiota on the physiopathology of this infection. However, the mechanism by which microbiota leads to the physiopathology remained undetermined. Macrophages play a key role in inflammatory processes and their interaction with the microbiota during E. tenella infection have never been investigated. We therefore examined the impact of microbiota on macrophages during E. tenella infection. Macrophages were monitored in caecal tissues by immunofluorescence staining with KUL01 antibody in non-infected and infected germ-free and conventional chickens. Caecal cells were isolated, stained, analyzed and sorted to examine their gene expression using high-throughput qPCR.

RESULTS

We demonstrated that microbiota was essential for caecal macrophage recruitment in E. tenella infection. Furthermore, microbiota promoted a pro-inflammatory transcriptomic profile of macrophages characterized by increased gene expression of NOS2, ACOD1, PTGS2, TNFα, IL1β, IL6, IL8L1, IL8L2 and CCL20 in infected chickens. Administration of caecal microbiota from conventional chickens to germ-free infected chickens partially restored macrophage recruitment and response.

CONCLUSIONS

Taken together, these results suggest that the microbiota enhances the physiopathology of this infection through macrophage recruitment and activation. Consequently, strategies involving modulation of the gut microbiota may lead to attenuation of the macrophage-mediated inflammatory response, thereby limiting the negative clinical outcome of the disease.

Impact of Eimeria tenella experimental Infection on intestinal and splenic reaction of broiler chickens

This work assesses the cell-mediated immune reaction IL-6, TNF-α, and IFN-γ of experimentally challenged broiler chicken with Eimeria tenella (E. tenella). Therefore, ninety, 2-weeks-old healthy broiler chicks were allocated as eighty chicks infected orally with 2.5 × 104 E. tenella sporulated oocysts, and the other ten birds were kept as control negative birds. Post-challenge, mortality rate, symptoms, oocysts shedding, and lesion score were evaluated. Tissue samples (cecum and spleen) were collected at 0, 4, 8, and 12 days post-infection (dpi). Ten chickens were ethically slaughtered at 0, 4, 8, and 12 days post-infection, as well as two birds from the negative control group; parts from cecal and spleen samples were kept in cryopreservation containers, and other parts were preserved in formaline 10% for further investigation. The evaluated genes (IL-6, TNF-α, and IFN-γ) were normal at 0 days and upregulated at 4 and 8 days, which reached maximum upregulation at eight dpi. The histopathological examination of the ceca and spleen were evaluated before and after challenge. It could be concluded that E. tenella revealed direct severe macroscopic and microscopic changes in cecal tissues and indirectly induced alteration in splenic tissues, resulting in upregulation of different cell mediated immune response in cecum and spleen in relation to the experimental period.

Impacts of Eimeria coinfection on growth performance, intestinal health and immune responses of broiler chickens

Coccidiosis caused by Eimeria is one of the most severe chicken diseases and imposes huge economic losses to the poultry industry globally. Multi-Eimeria species coinfections are common with the most prevalent combination being mixtures of Eimeria acervulina and Eimeria tenella. Although detrimental impacts of either E. acervulina or E. tenella on chicken health are well recognized, no information is available regarding their coinfection effects so far. This study was designed to investigate the influence of coinfection with E. acervulina and E. tenella on broiler chickens. 144 one-day-old broiler chickens within each of trials (trial I or II) were divided into four groups, namely, control group (CG), E. acervulina infection group (EAIG), E. tenella infection group (ETIG) and dual (E. acervulina and E. tenella) infection group (DIG). Then, chickens were measured for weight loss, lesion scores, oocyst outputs, histological changes and expressions of pro-inflammatory (interleukin [IL]-6, IL-8 and IL-18), regulatory (IL-10 and IL-22) cytokines and Toll-like receptors (TLR; TLR2 and TLR4) as well as intestinal barrier (mucin 2 [MUC2] and fattey acid-bingding proteins 2 and 6 [FABP2 and FABP6])- and tight junction (TJ; zonula occluden-1 [ZO-1], occludin [OCLN], and claudins 1 and 5 [CLDN1 and CLDN5])-related proteins at 3, 5, 7, 10, 14 and 21 days post-infection, respectively. Our results consistently showed that although ETIG and DIG exhibited a higher level of weight loss and a more amount of oocyst excretion than EAIG, DIG had lighter lesions than EAIG in the early phase because of coinfection with E. tenella. A higher (P < 0.05) ratio of duodenal villous height to crypt depth was also observed in DIG than EAIG. Moreover, histological changes in the duodenum and cecum varied by single and dual Eimeria infections. Expressions of the intestinal barrier- and TJ-related genes of EAIG, ETIG and DIG were significantly (P < 0.05) upregulated but their levels exhibited differential changes among infected chickens. Similarly, the infected chickens showed significant (P < 0.05) inflammatory responses and higher (P < 0.05) expressions of TLRs in the intestines in comparison to CG. These results presented a comprehensive physiological, pathological and immunological characterization of E. acervulina and E. tenella coinfection in broiler chickens and also shed insights into pathogenesis of multi-coccidia coinfections.

The caecal microbiota promotes the acute inflammatory response and the loss of the intestinal barrier integrity during severe Eimeria tenella infection

Introduction

Coccidiosis, a disease caused by intestinal apicomplexan parasites Eimeria, is a threat to poultry production. Eimeria tenella is one of the most pathogenic species, frequently causing a high prevalence of opportunistic infections.

Objective

The objective of this study is to investigate the role of the microbiota in the pathogenesis of severe Eimeria tenella infection.

Methods

We have previously shown that microbiota can promote parasite development. To study the effect of the microbiota on the pathogenesis of this infection, we used an experimental condition (inoculum of 10 000 oocysts E. tenella INRAE) in which the parasite load is similar between germ-free and conventional broilers at 7 days post-infection (pi). Thirteen conventional and 24 germ-free chickens were infected. Among this latter group, 12 remained germ-free and 12 received a microbiota from conventional healthy chickens at 4 days pi. Caeca and spleens were collected at 7 days pi.

Results

Our results demonstrated caecal lesions and epithelium damage in conventional chickens at 7 days pi but not in germ-free infected chickens. Administration of conventional microbiota to germ-free chickens partially restored these deleterious effects. At day 7 pi, both infected conventional and germ-free chickens exhibited increased gene expression of inflammatory mediators, including IL15, IFNγ, TNFα and the anti-inflammatory mediator SOCS1, whereas the inflammatory mediators CXCLi2, CCL20, IL18, CSF1, NOS2, PTGS2, IL1β, IL6, the receptor CCR2, and the anti-inflammatory mediators TGFβ1 and IL10 were upregulated only in infected conventional chickens. Notably, the IL18, PTGS2 gene expression was significantly higher in the infected conventional group. Overall, the inflammatory response enhanced by the microbiota might be in part responsible for higher lesion scores. Epithelial tight junction protein gene expression analysis revealed a significant upregulation of CLDN1 with the infection and microbiota, indicating a potential loss of the intestinal barrier integrity.

Conclusion

These observations imply that, during E. tenella infection, the caecal microbiota could trigger an acute inflammatory response, resulting in a loss of intestinal integrity. Increase in bacterial translocation can then lead to the likelihood of opportunistic infections. Hence, modulating the microbiota may offer a promising strategy for improving poultry gut health and limiting caecal coccidiosis.

Matrine provides a protective effect against Eimeria tenella challenge by alleviating intestinal barrier damage

As a virulent and harmful protozoan, Eimeria tenella (E.tenella) causes harmful chicken coccidiosis, inducing high economic losses in the chicken industry. The management of the coccidial disease has been greatly hampered by drug resistance. Matrine is an active ingredient from Ku Shen (Radix Sophorae Flavescentis), a typical pesticide in chinese medicine. The aim of this study was to examine matrine's possible effectiveness in the treatment of coccidiosis and its protective function on the intestinal barrier. The anticoccidial index (ACI), the levels of anti-oxidant indexes, and secretory immunoglobulin A (sIgA) were detected. The levels of mRNA and protein expression of Occludin, ZO-1, and Claudin-1 were determined through quantitative real-time PCR (RT-qPCR) and immunohistochemistry (IHC) analysis. Matrine exhibited a moderate ACI value, and ACI values of 122.51 and 143.42 corresponded to 5 and 10 mg/kg of matrine, respectively. Compared to the infective control group, the expression of tight junction proteins significantly increased in the matrine-treatment group by RT-PCR and IHC analysis, which are essential for the mucosal immune system and the intestinal barrier. Besides, the matrine-treatment group showed a more complete intestinal structure, fewer bleeding spots, and coccidian by histopathology analysis. We also found that, matrine significantly enhanced the antioxidant ability and significantly increased the content of sIgA. Above all, matrine was considered an efficient drug against E.tenella by the anti-oxidant efficacy, and the ability to protect the composition and function of the intestinal barrier.

Dietary Weizmannia coagulans Strain SANK70258 Ameliorates Coccidial Symptoms and Improves Intestinal Barrier Functions of Broilers by Modulating the Intestinal Immunity and the Gut Microbiota

To determine the mechanisms by which Weizmannia coagulans SANK70258 (WC) supplementation improved growth performance and coccidial symptoms, we assessed the gene expressions and the microbiota compositions in the small intestinal tissues and digestas of coccidium-infected broilers previously given WC or lasalocid-A sodium (AM). WC supplementation significantly upregulated the gene expressions related to intestinal immunity and barrier functions, such as IL17A, IL17F, IL10, cathelicidin-2 and pIgR. Body weights, and Claudin-1 and IL10 expressions were positively correlated (r = 0.41, p < 0.05 and r = 0.37, p = 0.06, respectively), whereas lesion scores of the small intestine and IL17A expression were negatively correlated (r = −0.33, p = 0.09). The microbiota analysis detected that genus Alistipes was more abundant in WC-supplemented broilers than in control, and positively correlated with body weights and Claudin-1 expression (r = 0.61, p < 0.05 and r = 0.51, p < 0.05, respectively). Intriguingly, genus Enterococcus was most abundant in WC-supplemented broilers and positively correlated with IL17A expression (r = 0.49, p < 0.05). Interestingly, Escherichia-Shigella was significantly more abundant in the small intestinal digestas of AM-administered broilers than in those of control. To summarize, WC supplementation modulated and immunostimulated the microbiotas of broilers, specifically genera Alistipes and Enterococcus, which led to the improvement of weight gain and coccidial symptoms, without disrupting the intestinal microbiota compositions, as AM did.

Reduction of oocyte shedding and cecal inflammation by 5-aminolevulinic acid daily supplementation in laying hens infected with Eimeria tenella

The present study aimed to evaluate the effects of 5-aminolevulinic acid (5-ALA) on Eimeria tenella infection in laying hens. Oocyst shedding and histopathology were evaluated. A reduced oocyst shedding was observed 5 and 7 days post-infection (dpi) in the 5-ALA-administered group, but the total number of oocysts during the first infection period was not different between control and 5-ALA-treated groups. After E. tenella attack infection, the period of oocyst shedding in the 5-ALA-administered group lasted less long than that in controls. During the attack infection period, the total number of fecal oocysts in the 5-ALA-treated group was significantly lower than that in the control group. However, the parasite burden score in hens receiving 5-ALA was higher than that in controls after E. tenella attack infection. The lesion scores at 5 and 30 dpi in the control group were significantly lower than those in the 5-ALA-administered group. Therefore, 5-ALA administration might be beneficial against E. tenella infection in laying hens.

Combined oral immunization with probiotics Entercoccus faecalis delivering surface-anchored Eimeria tenella proteins provide protective efficacies against homologous infection in chickens

Background and Objectives

Avian coccidiosis is an intestinal parasitic disease exerting a highly negative impact on the global poultry industry. The aim of the present study is to evaluate the immune protective efficacies against Eimeria tenella infection in chickens orally immunized with combined recombinant probiotics Entercoccus faecalis (E. faecalis) delivering surface-anchored E. tenella proteins.

Methods

Four kinds of novel probiotics vaccines that surface-expressing four Eimeria tenella (E. tenella) proteins EtAMA1, EtIMP1, EtMIC2 and Et3-1E were produced, respectively. The expression of four target proteins on the surface of recombinant bacteria was detected by Western blot and indirect immunofluorescence assay (IFA). Then the four kinds of recombinant E. faecalis were combined to immunize chickens via oral route in different combinations. The immunizations were performed three times at two-week intervals, and each for three consecutive days. After immunizations, chickens in each immunized group were orally challenged with E. tenella sporulated oocysts. The immune responses and protective efficacies against homologous infection were evaluated.

Results

The results showed that three or four live recombinant E. faecalis induced effective antigen-specific humoral, intestinal mucosal immune responses, stimulated peripheral T lymphocytes proliferation, and displayed partial protections against homologous challenge as measured by cecal lesions, oocyst shedding, and body weight gain (BWG). Notably, higher levels of protective efficacies were observed when the four recombinant E. faecalis delivering target proteins were combined.

Conclusion

Chickens orally administrated with three or four, especially the four combined recombinant E. faecalis stimulated specific immune responses, which provided anti-coccidial effects. This study offers an idea for future development of novel vaccines based on multi-antigens delivered by probiotic bacteria.