Coccidiosis In Poultry Research Articles

Ethanol and isopropanol trigger rapid egress of intracellular Eimeria tenella sporozoites.

Egress from host cells is a vital step of the intracellular life cycle of apicomplexan parasites such as Toxoplasma gondii. This phenomenon has attracted attentions from many research groups. Previous studies have shown that ethanol could stimulate the release of microneme proteins by elevating intracellular Ca(2+) concentration of T. gondii, resulting in the parasite egress from host cells. However, little information about egress is known on Eimeria species, the causative agent of coccidiosis in poultry and livestock. In this report, we studied the effect of ethanol and isopropanol on the egress of eimerian parasites. Eimeria tenella sporozoites cultured in primary chicken kidney cells were treated with ethanol and isopropanol, then the egressed parasites were analyzed. Ethanol and isopropanol could induce the rapid egress of E. tenella sporozoites from host cells. No substantial damage was found in parasite-egressed host cells. Compared to the freshly isolated sporozoites, the re-invading ability and reproductivity of the egressed parasites significantly decreased by 43.4 and 44.1 % individually. We also found that fewer sporozoites egressed from host cells when the parasites developed for a longer time before the alcohol treatment. These results demonstrate an in vitro egress mode different from that of T. gondii, facilitating the deciphering of the mechanisms of egress of eimerian parasites.

The Impact of Fusarium Mycotoxins on Human and Animal Host Susceptibility to Infectious Diseases

Contamination of food and feed with mycotoxins is a worldwide problem. At present, acute mycotoxicosis caused by high doses is rare in humans and animals. Ingestion of low to moderate amounts of Fusarium mycotoxins is common and generally does not result in obvious intoxication. However, these low amounts may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host pathogen interactions and thus a different outcome of infection. This review summarizes the current state of knowledge about the impact of Fusarium mycotoxin exposure on human and animal host susceptibility to infectious diseases. On the one hand, exposure to deoxynivalenol and other Fusarium mycotoxins generally exacerbates infections with parasites, bacteria and viruses across a wide range of animal host species. Well-known examples include coccidiosis in poultry, salmonellosis in pigs and mice, colibacillosis in pigs, necrotic enteritis in poultry, enteric septicemia of catfish, swine respiratory disease, aspergillosis in poultry and rabbits, reovirus infection in mice and Porcine Reproductive and Respiratory Syndrome Virus infection in pigs. However, on the other hand, T-2 toxin has been shown to markedly decrease the colonization capacity of Salmonella in the pig intestine. Although the impact of the exposure of humans to Fusarium toxins on infectious diseases is less well known, extrapolation from animal models suggests possible exacerbation of, for instance, colibacillosis and salmonellosis in humans, as well.

Scientific opinion on the modification of authorisation of Deccox® (decoquinate) as feed additive for chickens for fattening

Deccox® contains decoquinate as the active substance for prevention of coccidiosis in poultry. The applicant requested a reduction in the withdrawal time from three days to zero days and the introduction of maximum residue limits (MRLs) for liver (1.0 mg/kg), kidney (0.8 mg/kg), muscle (0.5 mg/kg) and skin/fat (1.0 mg/kg). Decoquinate is not genotoxic and is not carcinogenic. The lowest no observed effect level (NOEL) was 15 mg/kg bw per day, observed in a 12-week oral toxicity study in dogs. The acceptable daily intake (ADI) of decoquinate (already established by the FEEDAP Panel in 2003 and since confirmed) is 0.075 mg/kg body weight (bw), based on the above NOEL, applying an uncertainty factor of 200. On the basis of new metabolism/residue studies in chicken and rat, major metabolites appear to be dissimilar in these two species. Nevertheless, the assessment of consumer safety refers to the ADI of decoquinate, considering the limited exposure of consumers to metabolites from chicken tissues. Decoquinate is the marker residue. A conservative estimate of consumer exposure, based on total residues measured after two and six hours withdrawal, indicates that it would be about 2 % of the ADI. Since a withdrawal period of two and six hours corresponds to a zero withdrawal time under practical husbandry conditions, a zero days withdrawal time does not compromise consumer safety. The new residue data submitted confirm that no MRLs are considered necessary.

Protective effects of oral immunization with live Lactococcus lactis expressing Eimeria tenella 3-1E protein

The codon-optimized Eimeria tenella 3-1E gene was introduced into the lactic acid bacterial vector pTX8048 to construct plasmid pTX8048-3-1E. The plasmid pTX8048-3-1E was transformed into Lactococcus lactis NZ9000 by electroporation to create the strain of L. lactis pTX8048-3-1E. The expression of objective protein was verified by Western blot. The live bacteria L. lactis pTX8048-3-1E were administered orally, and an animal challenge experiment was carried out to evaluate the protective efficacy. The results indicated the strain of L. lactis pTX8048-3-1E was constructed successfully. Oral immunization to specific pathogen-free (SPF) chickens with L. lactis pTX8048-3-1E provided partial protection against homologous challenge including significant increased oocyst decrease ratio, reduced average lesion score in cecum, and improved body weight gain compared to control bacteria L. lactis pTX8048. These results demonstrate the use of Lactococcus as live vector for delivery of Eimeria antigen is feasible and promising method to control coccidiosis in poultry.

Safety Evaluation of Lasalocid Use in Chinese Ring-Necked Pheasants (Phasianus colchicus)

Coccidiosis remains a significant threat to the welfare of game farm-reared pheasants in the United States. Although lasalocid has been demonstrated to be effective against pheasant specific coccidia, information regarding its safety in this species is lacking. The purpose of this study was to gather data on the safety of lasalocid when fed to Chinese ring-necked pheasants at one, two, and three times the recommended high dose of lasalocid used for prevention of coccidiosis in other poultry at three times the normal treatment period. Pheasant chicks (approximately 1 day-old; n = 160) were randomly blocked by sex into four treatment groups and given their respective diets continuously for 6 wk. No significant differences were observed in overall feed consumption, weight gain, feed conversion rates, clinical pathology measurements, or tissue gross and histopathologic evaluations between controls and treatment groups associated with lasalocid administration. Based on the results of this study it appears that lasalocid fed at the recommended rate of 125 ppm is safe in Chinese ring-necked pheasants.

Toxicity of the ionophore antibiotic lasalocid to soil-dwelling invertebrates: Avoidance tests in comparison to classic sublethal tests

Lasalocid is a veterinary ionophore antibiotic used for prevention and treatment of coccidiosis in poultry. It enters the environment with the use of contaminated manure on agricultural land. Despite its extensive use, the effects of lasalocid on non-target soil organisms are poorly explored. We used classical subleathal ecotoxicity tests to assess the effects of lasalocid on earthworms (Eisenia andrei) and isopods (Porcellio scaber) and compared the results with tests using avoidance behaviour as the endpoint. The results showed that avoidance is a much more sensitive endpoint. For earthworms, EC50 for avoidance (12.3mgkg−1 dry soil) was more than five times lower than EC50 for reproduction (69.6mgkg−1 dry soil). In isopods the sensitivity of the behavioural response test was even higher. While the highest lasalocid concentration 202mgkg−1 had no significant effects on isopod growth or survival, already the lowest used concentration in the behavioural assay (4.51mgkg−1) caused significant impact on isopod behaviour. Using the avoidance test results for calculating the predicted no-effect concentration (PNEC) of lasalocid to soil invertebrates, the value is close to the predicted environmental concentration (PEC). This indicates that the use of lasalocid-contaminated manure could potentially impair the habitat function of agricultural soils.

Anti-coccidial, anthelmintic and antioxidant activities of pomegranate (Punica granatum) peel extract

Coccidiosis and helminthosis in poultry are responsible for worldwide economic losses. The methanolic extract of Punica granatum (pomegranate) peel was used in vivo for its pharmacological, antioxidant and anti-coccidial properties and in vitro for its anthelmintic activity. For the in vivo study, four groups of mice were investigated. The first group was inoculated only with sterile saline and served as the control group. The second group was treated by oral gavage with pomegranate extract (300 mg/kg) daily for 5 days. The third and fourth groups were infected with 10(3) sporulated oocysts of Eimeria papillata. The fourth group was also treated once daily with pomegranate peel extract for 5 days. For the in vitro study, the anthelmintic effect of pomegranate peel extract was observed on live adult Allolobophora caliginosa. Paraffin sections from jejunum as well as jejunal homogenate were prepared for the histopathological and biochemical investigations, respectively. The data showed that mice infected with E. papillata revealed an output of approximately 2.9 × 10(5) oocysts per gram faeces on day 5 p.i. This output is significantly decreased to 50 % in pomegranate-treated mice. Infection with E. papillata induced marked histopathological alterations in jejunum in the form of inflammation, vacuolation of the epithelium and destruction of some villi. In addition, pomegranate extract caused a great diminish in body weight loss of infected mice. Moreover, the number of goblet cells stained with Alcian blue within the infected villi was significantly increased by about 26 % after pomegranate treatment. In addition, Pomegranate significantly lowered the increased number of apoptotic cells due to E. papillata infection by about 36 %. The results showed that E. papillata enhanced hydrogen peroxide, lipid peroxidation and nitric oxide production with concomitant reduction in glutathione. Pomegranate induced marked improvements in all of the studied parameters as well as the histopathological features of jejunum. In addition, pomegranate was able to exert a significant anthelmintic effect on live adult A. caliginosa worms in terms of the paralysis and death of the worms at different concentrations (100, 200 and 300 mg/ml). The study revealed that pomegranate as a natural product has protective effects against E. papillata-induced coccidiosis as well as it possesses an anthelmintic activity.

Scientific Opinion on the safety and efficacy of diclazuril (Clinacox® 0.5 %) as feed additive for chickens reared for laying

Clinacox® 0.5 % is a feed additive containing 0.5 % diclazuril and is used to control coccidiosis in poultry. The previous conclusion on the safety of diclazuril in chickens for fattening at the use level of 1 mg/kg complete feed is extended to chickens reared for laying. Chickens reared for laying are in a similar physiological stage as chickens for fattening. The use level proposed for diclazuril in feed is the same for both categories of birds. Consequently, the metabolic fate and residue status of this additive described for chickens for fattening can be extrapolated to chickens reared for laying. Feeding diclazuril at 1 mg/kg complete feed to chickens reared for laying for the first 16 weeks of life would result in negligibly low or absent residues of diclazuril in the first eggs for production. Therefore, maximum residue levels (MRLs) for eggs are not necessary. The previous assessment of consumer safety for the use of diclazuril in chickens for fattening is confirmed and extended to chickens reared for laying. The same MRLs for tissues as already established can be applied. Clinacox® has a low irritation potential for the eye and skin. Skin sensitisation was not observed. Considering the particle size (particle of respirable size) and dusting potential, exposure by inhalation cannot be excluded, although workers’ exposure has been calculated to be low in comparison with the ADI. In the absence of any data on respiratory toxicity, a hazard from inhalation of dust cannot be entirely excluded and appropriate protective measures should be taken. The use of Clinacox® at 1 mg/kg complete feed does not pose a risk to the terrestrial or aquatic environment. One mg diclazuril/kg complete feed is effective in controlling coccidiosis in chickens reared for laying.

Protective effect of Azadirachta indica extract against Eimeria papillata-induced coccidiosis

Coccidiosis in poultry is caused by protozoan parasites of the genus Eimeria, which is responsible for worldwide economic losses. The methanolic extract of Azadirachta indica (neem) leaves was used in vivo for its pharmacological, antioxidant, and anticoccidial properties. Four groups of mice were investigated. The first group was inoculated only with sterile saline and served as the control group. The second group was treated by oral gavage with neem extract (500mg/kg) daily for 4days. The third and fourth groups were infected with 10(3) sporulated oocysts of Eimeria papillata. The fourth group was also treated once daily with neem extract for 4days. Paraffin sections from the jejunum as well as jejunal homogenate were prepared for the histopathological and biochemical investigations, respectively. The data showed that mice infected with E. papillata revealed an output of 6.5 × 10(5) ± 29,753 oocysts per gram feces on day 4 postinoculation. This output is significantly decreased to 2.7 × 10(5) ± 37,341 oocysts in neem-treated mice. Infection with E. papillata induced marked histopathological alterations in the jejunum in the form of inflammation, vacuolation of the epithelium, and destruction of some villi. Also, the neem extract greatly diminished body weight loss of infected mice. Moreover, the number of goblet cells stained with Alcian blue within the infected villi was significantly lowered (P ≤ 0.05). In addition, E. papillata enhanced lipid peroxidation and nitric oxide production in both serum and jejunum with concomitant reduction in glutathione. Neem induced marked improvements in all of the studied parameters as well as the histopathological features of the jejunum. Our study revealed that neem as a natural product has protective effects against E. papillata-induced coccidiosis.

In vitro inhibition of Eimeria tenella invasion of epithelial cells by phytochemicals

Resistance to coccidiostats and possible future restrictions on their use raise the need for alternative methods of reducing coccidiosis in poultry. The aim of this study was to evaluate the effect of selected phytochemicals on Eimeria tenella sporozoite invasion in vitro. Four phytochemicals were selected on the basis that they reduce the virulence of Eimeria spp. and/or provide immune modulatory benefits to host cells: betaine, carvacrol, curcumin and Echinacea purpurea extract (EP).Madin–Darby bovine kidney (MDBK) cells were covered by medium containing phytochemicals at the highest concentration which was non-toxic to the cells. Salinomycin 50μg/ml was positive control; negative control was medium only. E. tenella (Houghton strain) sporozoites were added to wells and after incubation for 2, 4 or 20h at 37°C, cells were fixed and stained with hematoxylin–eosin. Ten evenly spaced fields per well were photographed and the percentage of cells invaded by sporozoites was calculated and normalized to the control.At 2h, carvacrol, curcumin and EP showed a significantly lower percentage of sporozoite invasion than the untreated control; in contrast, betaine treatment represented a significantly higher invasion percentage. Combining carvacrol with EP inhibited E. tenella invasion more effectively than applying the compounds individually, but the further addition of curcumin did not reduce invasion further.In conclusion, this study shows that invasion of MDBK epithelial cells by E. tenella sporozoites is inhibited in the presence of carvacrol, curcumin, or EP and enhanced by betaine. There may be potential for developing these phytochemicals as anti-coccidial feed or water additives for poultry.

Thomas K. Jeffers: pioneer of coccidiosis research

Thomas K. Jeffers has made many significant contributions to our understanding of the biology of the parasite Eimeria, the cause of coccidiosis in poultry. His work has had direct practical application for the control of this widespread disease. Topics discussed include Jeffers’ pioneering work concerned with genetics of the host response to infection, the nature of biological and immunological intraspecific variation, drug resistance and discovery, field surveys of resistance, and his most recognized achievement—the demonstration that the lifecycle of coccidia may be altered by artificial selection. Parasites so modified are attenuated but retain their immunogenicity, a discovery that has led to the development of live vaccines that are inherently non-pathogenic. This article provides a brief biography and describes the contributions that Jeffers has made to our knowledge of coccidiosis.

Determination of lasalocid residues in the tissues of broiler chickens by liquid chromatography-tandem mass spectrometry

Lasalocid is a polyether ionophoric coccidiostat used for the prevention of coccidiosis in poultry at a prescribed concentration and during a certain time interval. Due to a public health concern about the presence of coccidiostat residues in poultry, the aim of the present study was to determine the levels of lasalocid residues in the edible tissues of broiler chickens (breast muscle, thigh muscle, heart, liver, gizzard, kidneys and skin/fat) fed commercially produced feed containing 100 mg kg−1 of lasalocid in complete feed throughout the 5-day withdrawal period (WP). The residues were investigated by liquid chromatography coupled with electrospray ionisation (ESI) tandem mass spectrometry (MS/MS) with triple quadrupole. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were 0.47 and 1.44 µg kg−1, respectively. The average recovery based on the matrix-fortified calibrations for chicken tissues ranged between 79% and 98%. Lasalocid was found to accumulate in the liver, followed by the heart, skin/fat, kidneys, thigh muscle and gizzard. The lowest concentrations of lasalocid residues were found in the breast muscle. On day 5 of the WP, residue concentrations of lasalocid did not decline below the LOQ of the method, but were far below the maximum residue level (MRL) established for lasalocid in poultry from 20 to 100 µg kg−1 by European Commission Regulation (EU) No. 37/2010. The results confirmed that the WP established for lasalocid is sufficient to ensure the decline of its residues in the tissues of broiler chickens to the safe residue level.

Loop-mediated isothermal amplification (LAMP) assays for the species-specific detection of Eimeria that infect chickens

BackgroundEimeria parasites can cause the disease coccidiosis in poultry and even subclinical infection can incur economic loss. Diagnosis of infection predominantly relies on traditional techniques including lesion scoring and faecal microscopy despite the availability of sensitive molecular assays, largely due to cost and the requirement for specialist equipment. Despite longstanding proven efficacy these traditional techniques demand time and expertise, can be highly subjective and may under-diagnose subclinical disease. Recognition of the tight economic margins prevailing in modern poultry production and the impact of avian coccidiosis on poverty in many parts of the world has highlighted a requirement for a panel of straightforward and sensitive, but cost-effective, Eimeria species-specific diagnostic assays.ResultsLoop-mediated isothermal amplification (LAMP) is an uncomplicated, quick and relatively inexpensive diagnostic tool. In this study we have developed a panel of species-specific LAMP assays targeting the seven Eimeria species that infect the chicken. Each assay has been shown to be genuinely species-specific with the capacity to detect between one and ten eimerian genomes, equivalent to less than a single mature schizont. Development of a simple protocol for template DNA preparation from tissue collected post mortem with no requirement for specialist laboratory equipment supports the use of these assays in routine diagnosis of eimerian infection. Preliminary field testing supports this hypothesis.ConclusionsDevelopment of a panel of sensitive species-specific LAMP assays introduces a valuable new cost-effective tool for use in poultry husbandry.

Cd(II) and Pb(II) complexes of the polyether ionophorous antibiotic salinomycin

BackgroundThe natural polyether ionophorous antibiotics are used for the treatment of coccidiosis in poultry and ruminants. They are effective agents against infections caused by Gram-positive microorganisms. On the other hand, it was found that some of these compounds selectively bind lead(II) ions in in vivo experiments, despite so far no Pb(II)-containing compounds of defined composition have been isolated and characterized. To assess the potential of polyether ionophores as possible antidotes in the agriculture, a detailed study on their in vitro complexation with toxic metal ions is required. In the present paper we report for the first time the preparation and the structure elucidation of salinomycin complexes with ions of cadmium(II) and lead(II).ResultsNew metal(II) complexes of the polyether ionophorous antibiotic salinomycin with Cd(II) and Pb(II) ions were prepared and structurally characterized by IR, FAB-MS and NMR techniques. The spectroscopic information and elemental analysis data reveal that sodium salinomycin (SalNa) undergoes a reaction with heavy metal(II) ions to form [Cd(Sal)2(H2O)2] (1) and [Pb(Sal)(NO3)] (2), respectively. ion of sodium ions from the cavity of the antibiotic is occurring during the complexation reaction. Salinomycin coordinates with cadmium(II) ions as a bidentate monoanionic ligand through the deprotonated carboxylic moiety and one of the hydroxyl groups to yield 1. Two salinomycin anions occupy the equatorial plane of the Cd(II) center, while two water molecules take the axial positions of the inner coordination sphere of the metal(II) cation. Complex 2 consists of monoanionic salinomycin acting in polydentate coordination mode in a molar ratio of 1: 1 to the metal ion with one nitrate ion for charge compensation.ConclusionThe formation of the salinomycin heavy metal(II) complexes indicates a possible antidote activity of the ligand in case of chronic/acute intoxications likely to occur in the stock farming.

Control of poultry coccidiosis: changing trends

Coccidiosis is the most important protozoan disease affecting the poultry industry worldwide. Control of poultry coccidiosis is presently based on managerial skills and the use of prophylactic coccidiostatic drugs. With the emergence of drug resistant Eimeria strains, emphasis has been laid on development and use of safer vaccines; some of them have been commercialized successfully. The present review deals with the various factors responsible for the development of clinical coccidiosis in poultry as well as an overview of the currently available inducers and boosters of immunity against coccidiosis. There are three groups of vaccines currently available against coccidiosis which can be distinguished on the basis of characteristics of the Eimeria species included in the respective products, viz. vaccines based on live virulent strains, vaccines based on live attenuated strains, and vaccines based on live strains that are relatively tolerant to the ionophore compounds. The latter vaccine combines the early chemotherapeutic effect of ionophores with the late prophylactic effect of vaccination. Although in the near future more varieties of oocyst based live vaccines are expected, identification of selective coccidian-specific immunoprotective molecules is likely to get more attention to facilitate the sustainable control of poultry coccidiosis.

Scientific Opinion on the modification of the authorisation of the feed additive Coxidin® (monensin sodium) for chickens and turkeys for fattening

Coxidin® is based on the active ingredient monensin sodium and is intended to be used to control coccidiosis in poultry. The additive is presently authorised for use in feedingstuffs for chickens and turkeys for fattening at maximum doses of 125 mg and 100 mg, respectively. The applicant is now seeking authorisation for an additional formulation containing the same amount of monensin sodium and intended to deliver the same dose. The only change in composition proposed is the replacement of the wheat bran carrier used in the current formulation with calcium carbonate. In the view of the FEEDAP Panel, there is no reason to suppose that the proposed change in carrier would, in itself, constitute a hazard or alter the exposure of target species directly and consumers indirectly to the active substance. Similarly, the proposed change in formulation is not expected to measurably alter the environmental risk associated with the presently authorised form of the additive. The additive is non-irritant to skin and is not a skin sensitiser, but the presently authorised formulation is labelled as an eye irritant. In the absence of data, it should be assumed that the change in formulation will not exclude the risk to the eye. The dustiness of the new formulation and the observations that 50 % of the dust fraction consisists of potentially respirable particles and that monensin sodium is present as 24 % of the dust indicates a significant risk for users. Protective measures should be taken to avoid inhalation exposure. The new formulation is as effective as the authorised form in the control of Eimeria infections in chickens for fattening. Given the nature of the change introduced and the evidence for comparable effects in chickens, the FEEDAP Panel considers that this conclusion can be extended to turkeys for fattening.

Most frequent deviations from the principles of prevention against coccidiosis in poultry

The coccidiosis is the most remarkable widespread parasitic poultry disease. Due to its clinical or subclinical course which is even more significant, high economical losses are evident. The health and the economical implications of coccidiosis are emphasized in intensive poultry farming. In this paper investigation was performed on the most frequent deviations in application of preventive means against the coccidiosis. The data were analyzed during the period from the year 2005 to 2010. In order to locate possible factors that could contribute to the decreased prophylactic effects of anticoccidials, the flocks of broiler chickens, laying hens and parents were clinically examined and critical steps in farming technology were evaluated in detail. The type of equipment and its performance, and the duration of empty resting period between flocks were noted as the predominant technical determinants. Also some oversights were found in the design of programs for the control of coccidiosis, including the previously used coccidiostats and their efficacy in chicken flocks, the availability of drugs on market and the important elements of epizootiology of the disease. By permanent hygiene practice on poultry farms the infectious pressure may decrease. Anticoccidial drugs are mostly applied and are considered very efficient. However, since coccidia can acquire resistance to antibiotics and residual coccidiostats in consumer meat are found occasionally, their prophylactic use may be limited. The immunoprophylaxis is the most promising method so far. The use of anticoccidial vaccines in poultry stimulates its own immunological capacities and moreover, it enables the production of safe food and products. In recent years there is an increasing interest for the immunoprophylaxis in our country. In our region, the vaccination against coccidiosis is performed in about 90% of parent flocks and in 10 to 20% of commercial layers. However, development of the immune response against coccidia is complex and immune suppression can occur by different factors such as stress inducing conditions, bacterial (salmonella) and viral (Reo, IBDV, MDV, CAV) infections, aflatoxicosis and other. The noted deviations in preventive measures applied to combat coccidiosis were clearly defined. The obligative introduction of HACCP in intensive poultry production implicate planned solutions for the control of coccidiosis.

Comparative efficacy of herbal and allopathy drugs against coccidiosis in poultry

For this study, 240 one-day-old broiler chicken were used to test the anti-coccidial efficacy of a herbal drug Coxigon® compared with a chemical synthetic Diclazuril® against Coccidiosis in broilers. These birds were divided into six groups (A, B, C, D, E, F) of forty birds each. There were six treatments, non-infected non-medicated (A), infected non-medicated (B), infected and medicated with Coxigon® at 3 g/1 kg of feed (C) infected and medicated with Diclazuril® at 0.20 g/1 kg of feed (D), non-infected but treated with Coxigon® at 3 g/50 kg of feed (E), and non-infected but treated with Diclazuril® (F) at 0.20 g/1 kg of feed. Groups B, C, and D were given a challenge dose of coccidial oocysts at the age of 22 days. Weight gain, feed consumption, oocysts count in the faeces, clinical findings and mortality were recorded. The mean values of birds feed intake during experimental period (0–6 weeks) were 3770.4, 3206.5, 3493.3, 3333.3, 3751.5 and 3764.1 g for the groups A, B, C, D, E and F, respectively. The results revealed that the birds of group E had better (P<0.05) weight gain (g) as compared to other groups. Moreover, Coxigon® at 3 g/1 kg of feed (C) had excellent performance in terms of oocysts count (31700/g feaces) and lower mortality as compared with Diclazuril® (D).

English

Eimeria acervulina is a species of Eimeria that causes coccidiosis in older poultry. Lesions are limited to anterior or first third of the small intestine . Peptide fragments of antigen protein can be used to select nonamers for use in rational vaccine design and to increase the understanding of roles of the immune system in infectious diseases. Analysis shows MHC class II binding peptides of antigen protein from Eimeria acervulina are important determinant for protection of host form parasitic infection. In this assay, we used PSSM and SVM algorithms for antigen design and predicted the binding affinity of antigen protein having 299 amino acids, which shows 291 nonamers. Binding ability prediction of antigen peptides to major histocompatibility complex (MHC) class I & II molecules is important in vaccine development from Eimeria acervulina . Keywords - antigen protein, epitope, PSSM, SVM, MHC, peptide vaccine

Effect of Synbiotics on Caecal Morphology and Lesion Score in Broilers Infected with Eimeria Tenella

The extensive use of the anti-coccidial drugs for prevention and control of coccidiosis in poultry has been a major factor in the success of the industry. The aim of this study was to investigate the influence of a synbiotic which combined between 106cfu/mL of Lactobacillus plantalum CMU-FP002, and 2% Shallot extract v/v mix in water on Eimeria tenella infections in broiler chickens. One hundred and thirty-five day-old male broiler chicks were randomly assigned to three cages with three replications per treatment, with treatment groups including: (1) No synbiotic feeding to a non-infected, group; (2) no synbiotic feeding to chicks infected with 20,000 Eimeria tenella sporulated oocysts; and (3) synbiotic feeding to chicks infected with 20,000 Eimeria tenella sporulated oocysts. Lesion scores were assessed by gross pathological examination based on a scale of 0-4 at 0, 3, 6, 9, and 12 days post infection. Untreated broilers infected with E. tenella were found to have highly damaged caeca (P&lt;0.05) at days 6 and 12, whereas broilers infected with E. tenella but treated with the synbiotic also had damaged caeca, but with less damage than infected broilers fed no synbiotic. Broilers fed the synbiotic were also found to have altered epithelial morphology, but less so than the non-treated group. These results indicate that synbiotics may have a preventative effect on coccidiosis in broilers, but do not fully protect against the negative impact of the infection.