Coccidial Infection Research Articles

The effects of different doses of curcumin compound on growth performance, antioxidant status, and gut health of broiler chickens challenged with Eimeria species

Supplementation of broiler diets with feed additives such as chemotherapeutic drugs and antibiotics has side effects, meat residues, and antibiotics resistance complications. Plant-derived natural compounds could be safe and easy substitutes for chemical additives. One of the natural compounds is curcumin, the extract from herbal plant Curcuma longa, known for its antioxidant and antimicrobial properties which may be effective in reducing coccidia infection in poultry. The objective of this study was to evaluate the effects of curcumin on Eimeria challenged (C) and nonchallenged (NC) Cobb 500 broilers. A total of 360 12-day-old male chicks were housed in 36 cages in a completely randomized design with 6 replicates per treatment of 10 birds each cage. The six corn–soybean meal–based treatment diets were fed from day 12 to 20 to C and NC birds in 3-by-two factorial arrangement: nonchallenged control (NCC), NC + 100 mg/kg curcumin, NC + 200 mg/kg curcumin, challenged control (CC), C + 100 mg/kg curcumin, and C + 200 mg/kg curcumin. Broilers in C groups were inoculated orally with 50,000 oocysts of Eimeria maxima, 50,000 oocysts of Eimeria tenella, and 250,000 oocysts of Eimeria acervulina on day 14. The intestinal permeability (day 19), growth performance parameters, and intestinal lesion scoring were measured and recorded on day 20. The means were subjected to two-way ANOVA, and main factors effect and their interactions were considered. The growth performance and permeability were higher (P < 0.001) in the NC and C groups, respectively. However, no interaction was observed between curcumin dose and cocci challenge on both of these parameters. Results from lesion scores and oocyst shedding showed reduction (P < 0.050) in birds fed C + 200 mg/kg curcumin compared with those fed C + 100 mg/kg curcumin or CC. Curcumin treatment showed higher production of GSH (P = 0.002) and total glutathione (GSH+2GSSG) (P = 0.002) but lower GSH/GSSG ratio (P < 0.001) than the NCC group. Curcumin exhibited some positive responses on antioxidant capacity, lesion score, and oocyst shedding in the present study, suggesting that curcumin alone or a combination with other feed additives could be a dietary strategy to improve gut health in broilers.

Analysis of potential risk factors of caprine coccidiosis.

Caprine coccidiosis represents a major concern in goat industry worldwide causing high economic losses, mainly due to poor weight gains, treatment costs and even death of kids. Therefore, analyses on risk factors involved in the establishment and outcome of this disease are important to improve infection status and herd management. In Portugal, approximately 400,000 goats are reared every year. The majority of them are allocated in the southern part of the country. In the current study, a representative number of animals (382 goats) and herds (37 herds) from Alentejo were monitored. Faecal samples from five young and five adult goats of each farm were collected rectally and examined individually by using the modified McMaster technique for oocyst counts (oocyst per gram of faeces - OPG). Additionally, a questionnaire on the husbandry conditions and anti-parasitic treatments was performed. Overall, a prevalence of Eimeria infections of 99% and 100% was detected on animal and herd level, respectively. Eimeria arloingi and E. ninakohlyakimovae as the two most pathogenic caprine species also constituted the most prevalent ones (34.91% and 29.90%, respectively), both in the young and the adult goat groups. As expected, OPG vales were significantly higher (p=0.031) in young than in adult goats. Furthermore, risk factor analyses revealed young age, higher total number of animals on the farm and outdoor kidding as strongly associated with a higher risk of caprine coccidiosis. Overall, the high prevalence of pathogenic Eimeria species on Portuguese goat farms in combination with the occurrence of related risk factors strengthen the importance of coccidiosis control in caprine industry.

Molecular detection of Apicomplexan hemoparasites in anurans from Brazil

Amphibians are among the most threatened vertebrate groups in the world, and the main causes include climate change, habitat destruction, and emerging diseases. Herein, we investigated the occurrence and characterized molecularly Apicomplexa in anurans from southeastern Brazil. Forty individuals from seven anuran species were sampled in São Paulo state. In the molecular analyses, one Leptodactylus latrans and one Rhinella diptycha were positive in PCR assays for species of Hepatozoon. Two L. latrans were also positive for coccidian infections (Lankesterella sp. and an unidentified coccidian species). Phylogenetic analysis based on 18S rDNA clustered the sequences detected in anurans from the present study with Hepatozoon spp. detected in reptiles and other anurans from Brazil, albeit they were separate from Hepatozoon haplotypes detected in frogs from Africa and North America. Our study showed, for the first time, the molecular detection of Lankesterella sp. and another coccidian in L. latrans. Additionally, co-infection by different species of Hepatozoon haplotypes and an unidentified coccidian in anurans from Brazil was documented.

In vitro effects of 5 recombinant antigens of Eimeria maxima on maturation, differentiation, and immunogenic functions of dendritic cells derived from chicken spleen

Eimeria maxima possesses integral families of immunogenic constituents that promote differentiation of immune cells during host-parasite interactions. Dendritic cells (DCs) have an irreplaceable role in the modulation of the host immunity. However, the selection of superlative antigen with immune stimulatory efficacies on host DCs is lacking. In this study, 5 recombinant proteins of E. maxima (Em), including Em14-3-3, rhomboid family domain containing proteins (ROM) EmROM1 and EmROM2, microneme protein 2 (EmMIC2), and Em8 were identified to stimulate chicken splenic derived DCs in vitro. The cultured populations were incubated with recombinant proteins, and typical morphologies of stimulated DCs were obtained. DC-associated markers major histocompatibility complex class II, CD86, CD11c, and CD1.1, showed upregulatory expressions by flow cytometry assay. Immunofluorescence assay revealed that recombinant proteins could bind with the surface of chicken splenic derived DCs. Moreover, quantitative real-time PCR results showed that distinct gene expressions of Toll-like receptors and Wnt signaling pathway were upregulated after the coincubation of recombinant proteins with DCs. The ELISA results indicated that the DCs produced a significant higher level of interleukin (IL)-12 and interferon-γ secretions after incubation with recombinant proteins. While transforming growth factor-β was significantly increased with rEmROM1, rEmROM2, and rEmMIC2 as compared to control groups, and IL-10 did not show significant alteration. Taken together, these results concluded that among 5 potential recombinant antigens, rEm14-3-3 could promote immunogenic functions of chicken splenic derived DCs more efficiently, which might represent an effective molecule for inducing the host Th1-mediated immune response against Eimeria infection.

C. perfringens challenge reduces matrix metalloproteinase activity in the jejunal mucosa of Eimeria-infected broiler chickens

Matrix metalloproteinases (MMPs) play an important role in intestinal extracellular matrix homeostasis. An overexpression of MMPs results in tissue destruction and local inflammation and has been associated with multiple inflammatory diseases. These host proteases might also be important in tissue damage caused by infectious agents, such as in intestinal damage in Clostridium perfringens-induced avian necrotic enteritis (NE). The aim of the present study was to elucidate the effect of a C. perfringens infection on the MMP activity in the small intestine of birds with a pre-disposing coccidial infection to obtain a more thorough understanding of the pathogenesis of NE. For this purpose, the gelatinolytic activity present in jejunal tissue of Eimeria infected birds which were challenged with either a pathogenic C. perfringens type G strain or a commensal C. perfringens type A strain was analyzed using substrate zymography. The results show that infection of broilers with Eimeria and different C. perfringens strains, independent of their pathogenicity, decreases the expression of a 40–45 kDa host collagenase in the jejunum, as compared to the expression in Eimeria-infected control birds. It was also shown that the expression of 2 MMPs with molecular weights of approximately 50–60 and 60–70 kDa was significantly lower in necrotic tissue as compared to the activity in macroscopically healthy tissue adjacent to the lesion. These results indicate that host collagenases are not elicited by the C. perfringens infection for permeabilizing the host mucosa to allow penetration of the NetB toxin in Eimeria infected broilers.

A complex regulating pattern induced by the effects of predation and parasites on root vole (Microtus oeconomus) populations during the breeding season

Abstract Predators and parasites have synergistic effects on the phenotype of the species they share as prey and host. Experimental studies that incorporate the interactions between predation and parasitism are, however, scarce in small-mammal populations. Our previous work has shown that the combined effects of predation and coccidian infection reduce overwinter survival and population density in root voles (Microtus oeconomus). Here, we examined the separate and combined effects of these two drivers on the population growth of root voles during the breeding season. We carried out a two-level factorial experiment, in which we manipulated predator exclusion and the removal of parasites in enclosures and measured survival, fecal corticosterone metabolite (FCM) concentration, recruitment, and population density. An expected synergistic effect of predators and parasites on vole population was not found, due to no effect of parasites on FCM level and recruitment rate during the period of the experiment. Instead, we found phase-related effects of predation on demography. Predation reduced the survival rate of voles in spring, which was intensified by parasite infection. Predation risk reduced recruitment rate in early summer by elevating FCM levels. Consequently, both direct and indirect effects of predation lowered population density during the experimental period. In addition, for populations free of predators, the peak density that occurred in early autumn elevated FCM level of adult voles, which reduced recruitment rates and halted population growth. Moreover, predation, parasites, and density affected the quality of the offspring. Our study suggests that multiple regulation processes influence population fluctuations during the breeding season. We conclude that a population experiencing stress acts as a common interface through which interactions between intrinsic and extrinsic factors can be important determinants of fluctuations. We propose a new hypothesis of integrative stress effects to explain small-mammal population fluctuations.

Morphometric and molecular identification of Eimeria species from commercial chickens in Nigeria

Eimeria species are important coccidian parasites causing significant economic losses from clinical and subclinical coccidiosis in poultry worldwide. The objective of this study was to identify the abundance of Eimeria species responsible for coccidial infections in commercial chicken flocks in Nigeria. Morphometric methods by oocyt sedimentation and microscopy were used to identify Eimeria species from pooled faecal samples randomly obtained from commercial chicken farms. While Real-Time quantitative Polymerase Chain Reaction (RT-qPCR) targeting the Sequence Characterized Amplified Region (SCAR) from the genomic DNA extracted from the faecal samples was used to determine the specific species of Eimeria. Morphometry identification resulted in threegroups of oocyst category Eimeria based on the length were identified (BM group: E. brunetti and E. maxima;AM group: E. acervulina and E. mitis and NTP group: E. necatrix, E. tenella and E. praecox). The relative abundance of 3.0%, 52.0% and 45.0% were obtained for BM group, AM group and NTP group respectively. Molecular method detected Five Eimeria species were identified by real-time qPCR from the samples with species-specific relative abundance of 37.8%, 1.1%, 7.1%, 3.1% and 50.9% E. acervulina, E. maxima, E. necatrix, E. tenella and E. mitis; while E. praecox and E. brunetti were not detected. All markers utilized in these qPCR assays were absolutely species-specific and support reproducible quantification across a wide linear range, unaffected by the presence of non-target species or other contaminating DNA. The sensitivity of this assay indicated that DNA equivalent to a single sporulated oocyst can be consistently detected. Only five out of the conventional pathogenic species of Eimeria were detected in commercial chickens sampled in Nigeria. The epizootiological significance of the identified circulating Eimeria species is to enhance coccidiosis vaccination prophylaxis in Nigeria.

EtMIC3 and its receptors BAG1 and ENDOUL are essential for site-specific invasion of Eimeria tenella in chickens

Avian coccidian parasites exhibit a high degree of site specificity in different Eimeria species. Although the underlying mechanism is unclear, an increasing body of evidence suggests that site specificity is due to the interaction between microneme proteins (MICs) and their receptors on the surface of target host cells. In this study, the binding ability of E. tenella MICs (EtMICs) to different intestinal tissue was observed by immunofluorescence to identify the key surface molecule on the parasite responsible for the site specificity. Subsequently, we identified the corresponding host-cell receptors by yeast two-hybrid screening and glutathione-S-transferase pull-down experiments and the distribution of these receptors was observed by immunofluorescence in chicken intestinal tissues. Finally, we evaluated the efficacy of receptor antiserum against the infection of E. tenella in chickens. The results showed that EtMIC3 could only bind to the caecum while EtMIC1, EtMIC2, and EtAMA1 did not bind to any other intestinal tissues. Anti-serum to EtMIC3 was able to block the invasion of sporozoites with a blocking rate of 66.3%. The receptors for EtMIC3 were BCL2-associated athanogene 1 (BAG1) and Endonuclease polyU-specific-like (ENDOUL), which were mainly distributed in the caecum. BAG1 and ENDOUL receptor antiserum reduced weight loss and oocyst output following E. tenella infection, showing partial inhibition of E. tenella infection. These data elucidate the mechanism of site specificity for Eimeria infection and reveal a potential therapeutic avenue.

Evaluation of optimum conditions for decoquinate nanoliposomes and their anticoccidial efficacy against diclazuril-resistant Eimeria tenella infections in broilers

Decoquinate (DQ) is used for prophylaxis against coccidian infections within the digestive tract of chickens, but DQ is extremely insoluble in water. Hence, improving the water solubility of DQ is extremely important. First, decoquinate nanoliposomes (DQNLs) were prepared by the thin-film dispersion–ultrasonic method. The preparation conditions of DQNLs were optimized using the orthogonal test. The optimal preparation conditions of DQNLs were: a ratio of egg-yolk lecithin:drug (w/w) of 10:1, ratio of egg-yolk lecithin:cholesterol (w/w) of 5:1, rotary-evaporation temperature of 50 ℃, and ultrasound duration of 15 min. The encapsulation efficiency of DQNLs prepared under these conditions reached 99.24 % and drug loading was 5.67 %. The characterization of optimized DQNLs was also done. Transmission electron microscopy of DQNLs showed that they had the characteristic structure of liposomes. The mean particle size was 115.6 nm. The polydispersity index was 0.175. The zeta potential was −39.1 mV. The stability of DQNLs was high upon storage at 4 ℃. In vivo studies demonstrated that the lower dose (5 mg/L) of DQNLs in drinking water obtained the similar anticoccidial efficacy to that of 40 mg/kg DQ in feed against diclazuril-resistance Eimeria tenella isolate. The in vitro inhibitory effect of DQNLs on the sporulation of Eimeria tenella oocysts was dose-dependent. Therefore, the anticoccidial efficacy of DQ was enhanced significantly after being encapsulated into nanoliposomes.

Still naïve or primed: Anticoccidial vaccines call for memory

Despite decades of investigation to clarify protective mechanisms of anticoccidial responses, one crucial field is neglected, that is, protective memory responses in primed birds. Protective memory immunity is critical for host resistance to reinfection and is the basis of modern vaccinology, especially in developing successful subunit vaccines. There are important differences between the immune responses induced by infections and antigens delivered either as killed, recombinant proteins or as live, replicating vector vaccines or as DNA vaccines. Animals immunized with these vaccines may fail to develop protective memory immunity, and is still naïve to Eimeria infection. This may explain why limited success is achieved in developing next-generation anticoccidial vaccines. In this review, we try to decipher the protective memory responses against Eimeria infection, assess immune responses elicited by various anticoccidial vaccine candidates, and propose possible approaches to develop rational vaccines that can induce a protective memory response to chicken coccidiosis.

2-Nitro-1-propanol improved nutrient digestibility and oocyst shedding but not growth performance of Eimeria-challenged broilers

A 2 × 3 factorial arrangement study was conducted to evaluate 3 dosages of 2-nitro-1-propanol (NP; 0, 150, and 200 ppm) on intestinal health of birds with or without Eimeria challenge. A total of 432 thirteen-day-old male broiler chickens were randomly allocated to 6 treatments with 8 replicate cages of 9 birds per cage. All birds were fed with treatment diets from day 13 to 21. Birds in the challenge groups were gavaged with Eimeria maxima (50,000 oocysts per bird), Eimeria tenella (50,000 oocysts per bird), and Eimeria acervulina (250,000 oocysts per bird) on day 15. Growth performance was evaluated from day 13 to 21, and gut permeability was measured by fluorescein isothiocyanate dextran on day 20. The intestinal lesion, intestinal morphology, and oocysts shedding were determined at the end of the trial. The linear and quadratic orthogonal polynomial contrasts were used to evaluate the effects of increasing NP doses in responses to Eimeria challenge. The results showed that NP was not able to maintain efficient growth performance but improved gut leakage during Eimeria infection period. On the other hand, Eimeria infection increased gut permeability (P < 0.0001) and reduced ileal digestible energy (IDE) and apparent ileal digestibility (AID) of nitrogen. However, the increase of NP linearly enhanced IDE and AID of nitrogen (P < 0.01). Moreover, an interaction between challenge and linear dosage effects was observed for IDE (P = 0.0066) and AID of nitrogen (P = 0.0462). The results indicated that NP improved nutrient digestibility and reduced total oocysts shedding in birds challenged with Eimeria spp. Besides, higher NP doses numerically improved villi height in the intestine. In summary, NP was not able to maintain growth performance of birds but presented positive outcomes on nutrient digestibility and reduced oocysts shedding during mixed Eimeria infection.

Efficacy of dietary supplemental insoluble fibrous materials in ameliorating adverse effects of coccidial challenge in broiler chickens

ABSTRACT The current experiment was designed to examine effects of dietary supplemental sunflower hulls (SH) and rice hulls (RH) on growth performance, carcass traits, intestinal morphology, lesion score and oocyst shedding in broiler chickens exposed to coccidial challenge. A total of 540 broiler chickens (Ross 308) were assigned to six dietary treatments based on a factorial arrangement (2 × 3) across 1–14, 14–28 and 28-42-d periods. Experimental treatments consisted of broiler chickens without or with coccidial challenge each offered with three different diets: a basal diet or basal diet supplemented with either RH or SH at 40 g/kg diet, respectively. Infection with Eimeria impaired daily weight gain (DWG) and feed conversion ratio (FCR) of broiler chickens during growing period (p < 0.05) while supplementation of SH or RH reduced the adverse effect of coccidiosis so that birds had similar DWG to those fed the basal diet without infection. However, only dietary SH improved the FCR of broilers challenged with coccidiosis. Regardless of coccidial challenge, dietary access to insoluble fibre improved performance of broilers across the growing period (p < 0.05); however, this effect was not observed during the entire rearing period. Relative weights of liver and pancreas were increased in birds subjected to coccidial challenge on d 21 of age (p < 0.05). Moreover, relative weights of the intestinal segments were enhanced (p < 0.05). Furthermore, gizzard weights were higher in birds receiving diets added with fibre (p < 0.05). Infection with coccidiosis decreased villus height and villus height to crypt depth ratio in duodenum of broilers which received the basal diet compared with those fed the same feed without coccidial challenge (p < 0.05). However, supplemental SH could decrease the negative effect of infection on the noted intestinal morphometric attributes. Similarly, a marked reduction was observed for lesion score and faecal oocyst excretion of challenged broilers fed on dietary supplemental fibre (p < 0.05). In conclusion, supplementation of insoluble fibre could ameliorate negative effects of coccidial challenge on DWG of broiler chickens and inclusion of SH in diet of birds exposed to Eimeria infection could be recommended.

Dry Season Prevalence of Gastrointestinal Parasites in Ruminants in Sokoto Metropolis

This study was conducted with the aim of determining the dry season (January-May, 2018) prevalence of gastrointestinal parasites in special breeds of ruminants in Sokoto Metropolis. A total of 100, 85 and 75 faecal samples were collected from Sudanese breed of Sheep, WAD/Sahel Goats and Friesian Cattle respectively. Faecal samples were examined using standard parasitological techniques (Simple flotation and Centrifugal sedimentation). For the Sheep, a total of 51 samples were positive for presence of gastrointestinal parasites. Male animals have higher prevalence (52.9%) than their female (47.1%) counterparts. The major parasites observed were Eimeria and Strongyles with prevalence of (64.71%), while the least observed parasites were mixed infections (35.29%). From the total of 85 goat faecal samples examined, an overall prevalence of 54.7% was observed. The prevalence rates for Strongyle, Eimeria and mixed infections were 57.5%, 34.0% and 8.5% respectively. The prevalence was more in males than in the females. Strongyleeggs were more, compared to other helminthes eggs. For the Friesian Cattle, sixty (60) samples out of 75 samples analyzed were positive for either Strongyleeggs or Eimeria (oocyst) infection or both (mixed) constituting about 80% prevalence. Forty-two (70%) samples were positive for Strongyle eggs, 14 (23.3%) for Eimeria oocyst and 4 (6.7%) for mixed infection of both. From the overall prevalence, female had a high prevalence of 34(56.7%) than male cattle 26(43.3%). Based on the results of the present findings, it was concluded that gastrointestinal parasitic infections also occur during the dry season in Sokoto which may be as a result of carry-over of infection during the succeeding rainy season.

FDA Approved Drug Library Screening Identifies Robenidine as a Repositionable Antifungal.

Due to the increasing prevalence of pathogenic fungal infections, the emergence of antifungal resistant clinical isolates worldwide, and the limited arsenal of available antifungals, developing new antifungal strategies is imperative. In this study, we screened a library of 1068 FDA-approved drugs to identify hits that exhibit broad-spectrum antifungal activity. Robenidine, an anticoccidial agent which has been widely used to treat coccidian infections of poultry and rabbits, was identified in this screen. Physiological concentration of robenidine (8 μM) was able to significantly inhibit yeast cell growth, filamentation and biofilm formation of Candida albicans – the most extensively studied human fungal pathogen. Moreover, we observed a broad-spectrum antifungal activity of this compound against fluconazole resistant clinical isolates of C. albicans, as well as a wide range of other clinically relevant fungal pathogens. Intriguingly, robenidine-treated C. albicans cells were hypersensitive to diverse cell wall stressors, and analysis of the cell wall structure by transmission electron microscopy (TEM) showed that the cell wall was severely damaged by robenidine, implying that this compound may target the cell wall integrity signaling pathway. Indeed, upon robenidine treatment, we found a dose dependent increase in the phosphorylation of the cell wall integrity marker Mkc1, which was decreased after prolonged exposure. Finally, we provide evidence by RNA-seq and qPCR that Rlm1, the downstream transcription factor of Mkc1, may represent a potential target of robenidine. Therefore, our data suggest that robenidine, a FDA approved anti-coccidiosis drug, displays a promising and broadly effective antifungal strategy, and represents a potentially repositionable candidate for the treatment of fungal infections.

Effects of bambermycin with amprolium or monensin on beef cattle growth performance, coccidia infection, and bovine respiratory disease morbidity during receiving

ABSTRACT Objective The objectives of this research were to determine the effects of medicated feed additives on performance, health, and coccidia infection in newly received calves classified as high risk for bovine respiratory disease infection. Materials and Methods Growing steers and bulls were received to evaluate the effects of supplying 20 mg/calf bambermycin or 0.77 mg/kg of BW monensin in receiving supplements (20% CP and 78% TDN) compared with a nonmedicated supplement. Fecal samples were collected from 6 steers/pen on d 0, 14, and 28 to evaluate coccidia infection. Water in the bambermycin pens was treated from d 14 to 19 with 10 mg/kg of BW amprolium. Steers remained on treatment for 56 to 84 d for block 1, 49 d for block 2, and 42 d for block 3, depending on availability of wheat forage for subsequent grazing. Results and Discussion There were no differences (P ≤ 0.36) in morbidity, mortality, or animals identified as chronically morbid. Monensin decreased coccidia (P ≤ 0.03) compared with control and bambermycin, which did not differ (P = 0.85). At the end of receiving, BW and ADG for control calves was less than (P ≤ 0.04) for calves receiving bambermycin and monensin. Implications and Applications Monensin or bambermycin can effectively improve BW gain of calves at high risk for bovine respiratory disease. Monensin provides superior control of natural infection of coccidia based on fecal oocyst counts compared with bambermycin. Neither medicated feed additive altered morbidity or mortality due to bovine respiratory disease or treatment response to bovine respiratory disease.

Molecular Characterisation of Eimeria tenella Porin, A Potential Anticoccidial Drug Target

Eimeria tenella is an apicomplexan parasite that causes the economically important disease coccidiosis in chickens. An estimated loss over $3 billion USD per annum has been reported. Control of coccidiosis relies on chemotherapy and vaccination but drug resistance is common and live vaccines are relatively expensive. Therefore, there is an urgent need to develop new drugs to control Eimeria infections. Recent studies have shown that the pore forming structures of porin play important roles in many eukaryotic organisms. In this study, we have generated and characterised a putative porin cDNA sequence from E. tenella that we have named Etporin. Sequence alignments showed that Etporin is 47 % similar to the putative porin sequence of Toxoplasma gondii, while a search against the Conserved Domain Database (CDD) shows that Etporin contains the Porin3 superfamily domain. Multiple sequence alignment with porin sequences from various eukaryotic organisms showed that the conserved VKXKX and GLK/STK motifs are present in Etporin. Analysis of the predicted Etporin 3D structure showed a classic beta barrel structure consisting of 19 beta-strands. Taken together, these results suggested Etporin has the potential to be developed into an anticoccidial drug target.

Effects of Inorganic Zn and Cu Supplementation on Gut Health in Broiler Chickens Challenged With Eimeria spp.

An experiment was conducted to evaluate the effect of different levels of inorganic copper and zinc on growth performance, intestinal permeability, intestinal lesion scores, oocyst shedding, antioxidant properties and bone quality in broilers challenged with Eimeria spp. A total of 360 d-old male Cobb broiler chickens were housed in floor cages for 12 days at the Poultry Research Center. At 12 days of age, birds were placed in grower Petersime batteries and distributed in a completely randomized design with 10 birds per cage, six replicates per treatment, and six treatments. There were six corn-soybean meal-based dietary treatments: non-challenged control (NC), challenged control (CC), 100 ppm Cu (100 Cu), 150 ppm Cu (150 Cu), 80 ppm Zn (80 Zn), and 100 ppm Zn (100 Zn). Broilers received the treatment diets for 9 days (12–20d). Birds, except NC, were challenged with Eimeria maxima (50,000 oocysts/bird), Eimeria tenella (50,000 oocysts/bird), and Eimeria acervulina (250,000 oocysts/bird) on 14d. On 20d, the growth performance was recorded, and one bird/cage was used for analysis of intestinal permeability, antioxidant properties and bone quality. Lesion score was recorded at 20 days of age in eight birds/cage. The means were subjected to ANOVA and, when significant, compared by Duncan's test. Intestinal permeability was significantly improved when birds received the 100 Zn diet (P < 0.05). In addition, lesion scores on duodenum were reduced when broilers received diets 150 Cu as compared to CC diet (P < 0.05). However, growth performance was not positively influenced by inclusion of inorganic minerals as compared to the NC diet. Furthermore, activity of superoxide dismutase and bone quality were not affected, whereas glutathione status was improved with mineral supplementation in all groups. This study showed that Cu and Zn supplementation improves intestinal integrity during the Eimeria spp. infection, suggesting that Cu and Zn supplementation would be a potential strategy to reduce detrimental effects of Eimeria infection in broilers.

A Data-Driven Prediction Method for an Early Warning of Coccidiosis in Intensive Livestock Systems: A Preliminary Study.

Simple SummaryThe development of new methods, able to promptly detect the onset of the infection, is highly important to control parasitic infections of the intestinal tract (coccidiosis) in poultry. The early detection of this disease would reduce the use of anticoccidial and antimicrobials drugs, thus lowering the risk of antibiotic resistance. A data-driven machine learning algorithm was built to relate air quality data to the time of enteric disorders. The results show that this procedure has great potential to be used as a rapid technique to detect coccidiosis.Coccidiosis is still one of the major parasitic infections in poultry. It is caused by protozoa of the genus Eimeria, which cause concrete economic losses due to malabsorption, bad feed conversion rate, reduced weight gain, and increased mortality. The greatest damage is registered in commercial poultry farms because birds are reared together in large numbers and high densities. Unfortunately, these enteric pathologies are not preventable, and their diagnosis is only available when the disease is full-blown. For these reasons, the preventive use of anticoccidials—some of these with antimicrobial action—is a common practice in intensive farming, and this type of management leads to the release of drugs in the environment which contributes to the phenomenon of antibiotic resistance. Due to the high relevance of this issue, the early detection of any health problem is of great importance to improve animal welfare in intensive farming. Three prototypes, previously calibrated and adjusted, were developed and tested in three different experimental poultry farms in order to evaluate whether the system was able to identify the coccidia infection in intensive poultry farms early. For this purpose, a data-driven machine learning algorithm was built, and specific critical values of volatile organic compounds (VOCs) were found to be associated with abnormal levels of oocystis count at an early stage of the disease. This result supports the feasibility of building an automatic data-driven machine learning algorithm for an early warning of coccidiosis.

Immune response and protective efficacy of recombinant Enterococcus faecalis displaying dendritic cell–targeting peptide fused with Eimeria tenella 3-1E protein

Avian coccidiosis causes significant economic losses on the global poultry breeding industry. Exploration of new-concept vaccines against coccidiosis has gradually become a research hotspot. In this study, an Enterococcus faecalis strain (MDXEF-1) showing excellent performance isolated from chicken intestinal tract was used as a vector to deliver Eimeria target protein. The plasmid pTX8048-SP-DCpep-NAΔ3-1E-CWA harboring dendritic cell–targeting peptide (DCpep) fusion with Eimeria tenella NAΔ3-1E gene (3-1E protein–coding gene without start codon ATG and terminator codon TAA) was electrotransformed into MDXEF-1 to generate the recombinant bacteria MDXEF-1/pTX8048-SP-DCpep-NAΔ3-1E-CWA in which NAΔ3-1E protein was covalently anchored to the surface of bacteria cells by cell wall anchor (CWA) sequence. The expression of target fusion protein DCpep-NAΔ3-1E-CWA was detected by Western blot. Each chicken was immunized 3 times at 2-wk intervals with live E. faecalis expressing DCpep-NAΔ3-1E fusion protein (DCpep-NAΔ3-1E group), live E. faecalis expressing NAΔ3-1E protein (NAΔ3-1E group), and live E. faecalis containing empty vector only. The 3 immunized groups were then challenged with homologous E. tenella sporulated oocyst after immunizations, and the immune response and protective efficacy in each group were evaluated. The results showed that serum IgG levels, secretory IgA levels in cecal lavage, proportion of CD4+ and CD8α+ cells in peripheral blood, and mRNA expression levels of IL-2 and IFN-γ in the spleen were significantly higher in chickens in the DCpep-NAΔ3-1E group than in chickens of the NAΔ3-1E group (P < 0.05). Oral immunization to chickens with live E. faecalis expressing DCpep-NAΔ3-1E offered more protective efficacy against homologous challenge including significant improved body weight gain, increased oocyst decrease ratio, and reduced average lesion scores in cecum compared with chickens with live E. faecalis expressing NAΔ3-1E protein. These results suggest that recombinant E. faecalis expressing dendritic cell–targeting peptide fusion with E. tenella 3-1E protein could be a potential approach for prevention of Eimeria infection.

The Effects of a Combination of Quillaja saponaria and Yucca schidigera on Eimeria spp. in Broiler Chickens.

A series of studies was carried out to determine the anticoccidial effects of a product derived from plant material sourced from Quillaja saponaria and Yucca schidigera. These plants are known to contain high concentrations of triterpenoid and steroidal saponins, substances that are known to display an array of biological effects. Battery tests involving individual Eimeria acervulina, Eimeria maxima, and Eimeria tenella infections and graded levels of a quillaja/yucca combination (QY) (0, 200, 250, and 300 ppm) were conducted. Body weight gain, coccidial lesion scores, and total oocysts per gram of feces (OPG) were used to evaluate anticoccidial effects. In addition, three floor pen trials evaluated the effects of 250 ppm QY in the control coccidial infections. The first pen trial measured the effects of 250 ppm QY, both alone and in combination with 66 ppm salinomycin (Sal), in a 2 3 2 factorial treatment arrangement. Two additional 42-day pen studies assessed the effects 250 ppm QY in birds vaccinated for coccidiosis. Data from the three battery trials indicated that at doses of 250 ppm QY or more, weight gain was improved, E. acervulina and E. tenella lesion scores were reduced, and OPG was lowered. In general, OPG was reduced by about 50% across all species by 250 and 300 ppm QY. Results of the pen study indicated that 250 ppm QY and Sal, when fed individually, reduced OPG and lesion scores and improved final performance. However, when QY and Sal were administered concurrently, further significant reductions in OPG occurred. The final performance of broilers vaccinated for coccidiosis was also improved at 250 ppm QY, as was OPG at both 21 and 28 days. Thus, at QY doses of 250 ppm or more, anticoccidial activity was evident but lacked the potency exhibited by many standard anticoccidials. When combined with either Sal or a live coccidiosis vaccine, QY improved the anticoccidial effects and performance of these anticoccidial methods.