Anticoccidial Drugs Research Articles

Migration and toxicity of toltrazuril and its main metabolites in the environment.

Veterinary drugs heavily used in livestock are passed into the environment through different ways, resulting in risks to terrestrial environments and humans. The migration of toltrazuril (TOL), an important anticoccidial drug used intensively in livestock, and its main metabolites between the chicken manure compost, soil and vegetables was investigated, and then the impacts of TOL on the soil bacterial community and ARGs, soil enzyme activities and phytotoxicity were detected. In the process of aerobic composting for 80 days, except for toltrazuril sulfoxide (the degradation half-life was 59.74d), TOL and ponazuril (PON) were not significantly degraded. However, TOL and its metabolites were significantly degraded in fertilized soil, and the degradation half-life was 28.17-346.50d. Among the three drugs, only PON could migrate from soil to vegetables, and the residual concentrations of PON in lettuce and radish were 2.64-70.02μgkg-1 and 0-2.80μgkg-1, respectively. Moreover, TOL and its main metabolisms had no significant effect on the bacterial community structure and the abundance of antibiotic resistance genes during composting, but affected the microbial activity in the soil. The presence of TOL and its main metabolites reduced soil urease activity, increased catalase activity, and decreased alkaline phosphatase activity at the beginning and then increased slightly. They had negative effects on plant growth. Compared with the control group, the inhibition rates of TOL and its metabolites on lettuce and radish seed germination were 8.33% and 26.74% respectively, and the inhibition rates of root elongation length were 25.88% and 34.45% respectively. These results showed that TOL and its main metabolites were ineffectively removed by aerobic composting, and could be migrated from composting to soil and vegetables, which had adverse effects on soil enzyme activity and plant growth. Therefore, its environmental ecological risk and human health risk needs to be further evaluated.

Effect of a multi-strains yeast fractions product plus anticoccidial drug on performance, anticoccidial index, intestinal health, and bone mineralization of broiler chickens infected with Eimeria spp

Effect of a multi-strains yeast fractions product plus anticoccidial drug on performance, anticoccidial index, intestinal health, and bone mineralization of broiler chickens infected with Eimeria spp

Effects of salinomycin and ethanamizuril on the three microbial communities in vivo and in vitro.

The fate of a drug is not only the process of drug metabolism in vivo and in vitro but also the homeostasis of drug-exposed microbial communities may be disturbed. Anticoccidial drugs are widely used to combat the detrimental effects of protozoan parasites in the poultry industry. Salinomycin and ethanamizuril belong to two different classes of anticoccidial drugs. The effect of salinomycin and ethanamizuril on the microbiota of cecal content, manure compost, and soil remains unknown. Our results showed that although both salinomycin and ethanamizuril treatments suppressed some opportunistic pathogens, they failed to repair the great changes in chicken cecal microbial compositions caused by coccidia infection. Subsequently, the metabolite5 profiling of cecal content by LC-MS/MS analyses confirmed the great impact of coccidia infection on chicken cecum and showed that histidine metabolism may be the main action pathway of salinomycin, and aminoacyl tRNA biosynthesis may be the major regulatory mechanism of ethanamizuril. The microbial community of manure compost showed a mild response to ethanamizuril treatment, but ethanamizuril in soil could promote Actinobacteria reproduction, which may inhibit other taxonomic bacteria. When the soil and manure were exposed to salinomycin, the Proteobacteria abundance of microbial communities showed a significant increase, which suggested that salinomycin may improve the ability of the microbiota to utilize carbon sources. This hypothesis was confirmed by a BIOLOG ECO microplate analysis. In the animal model of coccidia infection, the treatment of salinomycin and ethanamizuril may reconstruct a new equilibrium of the intestinal microbiota. In an in vitro environment, the effect of ethanamizuril on composting and soil microbiota seems to be slight. However, salinomycin has a great impact on the microbial communities of manure composting and soil. In particular, the promoting effect of salinomycin on Proteobacteria phylum should be further concerned. In general, salinomycin and ethanamizuril have diverse effects on various microbial communities.

Methanolic extract of neem (Azadirachta indica) leaves mitigates experimentally induced coccidiosis challenge in Japanese quails

ABSTRACT Eimeria infection is a common parasitic disease in Japanese quails. A total of 150 male Japanese quails were equally assigned to five experimental treatments as follows: control (basal diet only), negative control (Eimeria challenged), amprolium treated, 130 mg/l methanolic extracts of neem leaves (NMLE 130) and 190 mg/l methanolic extracts of neem leaves (NMLE 190). All the E. tenella-infected quails were orally dosed with sporulated oocysts (n = 5.5 × 104). The results showed that compared to the negative control, supplementation of NMLE increased feed consumption, body weight and feed conversion ratio in Eimeria-infected quails. Mortality percentage and lesion score were significantly (P < .01) decreased in quails supplemented with NMLE. Moreover, oocysts per gram and histology of cecum in infected birds were restored in NMLE. The histological findings of NMLE-supplemented quails showed mild sloughed epithelium of cecal villi. In conclusion, NMLE is recommended as a naturally effective alternative to an anticoccidial drug to mitigate Eimeria infection in Japanese quails.

Inhibitory effect of morin on aldolase 2 from Eimeria tenella

Eimeria tenella (E. tenella) is a protozoal parasite that can cause severe cecal lesions and death in chickens, seriously harming the chicken industry. Conventional control strategies mainly rely on anticoccidial drugs. However, the emerging problems of anticoccidial resistance and drug residues necessitate exploring potential drug targets for developing new anticoccidial drugs. Fructose-1,6-bisphosphate aldolase (ALD) is an essential enzyme for parasite energy metabolism that has been considered a potential drug target. In this study, we analyzed the molecular and biochemical properties of E. tenella ALD2 (EtALD2). EtALD2 mRNA expression was highest in second-generation merozoites, whereas the protein level was highest in unsporulated oocysts. Indirect immunofluorescence showed that EtALD2 was mainly distributed in sporozoite’ cytoplasm. The natural product inhibitor (morin) was screened by computer-aided drug screening. Enzyme kinetic and inhibition kinetic assays showed that morin had a good inhibitory effect on EtALD2 activity (IC50 = 10.37 μM, Ki = 48.97 μM). In vitro inhibition assay demonstrated that morin had an inhibitory effect on E. tenella development, with an IC50 value of 3.98 μM and drug selection index of 177.49. In vivo, morin significantly improved cecal lesions (p < 0.05) and reduced oocyst excretion (p < 0.05) in E. tenella-infected chickens compared with the untreated group. The anticoccidial index of the group receiving 450 mg morin per kg feed was 162, showing a good anticoccidial effect. These findings suggest that EtALD2 could be a novel drug target for E. tenella treatment, and morin should be further evaluated as a therapeutic candidate for chicken coccidiosis.

A combination of functional amino acids and polyphenols can restore the performance of chickens challenged with coccidiosis: A meta-analysis

Coccidiosis is one of the major challenges in the poultry industry, leading to reduced animal performance and welfare and increased mortality. Currently, ionophores and chemicals are used to treat coccidiosis. However, the outbreak of resistant Eimeria strains and the growing customer demand for more sustainable products have prompted the need to identify nutritional strategies for coccidiosis control. In this study, we reviewed the efficiency of the supplementation of a combination of functional amino acids (arginine, threonine and glutamine) with grape extract polyphenols in broilers challenged with coccidiosis via a meta-analysis based on five independent trials. We observed that supplementation partially improved the performance of broilers affected with coccidiosis when compared with infected, untreated animals. In addition, there was no significant difference between the effect of supplementation of the combination of functional amino acids with grape extract polyphenols and that of anticoccidial drugs on animal performance when considering the overall trial period. This meta-analysis suggests that supplementing with a combination of functional amino acids with grape extract polyphenols could improve performance in broilers affected with coccidiosis. However, further research to understand the mechanisms involved is needed.

Evaluation of therapeutic and prophylactic use of the drug anticoccidial "Сoсcimax" and feed additives "Mintov" and "NitaminOR Active" in experimental coccidiosis of chickens

The article presents the evaluation of curative and preventive efficacy of the anticoccidial drug "Coccimax" in a joint application of the feed additive "Mintov" and "NitaminOR Active", in experimental coccidiosis of chickens. For this purpose, the morphological and biochemical parameters of the blood of broiler chickens were analyzed. Based on the work done, it was concluded that with the development of chicken eimeriosis, there is a negative effect on the liver of birds, expressed by an increase in the activity of aspartate aminotransferase. However, the drug "Coccimax", both when mono used, and when combined with feed additives "Mintov" and "NitaminOR Active", contributes to the normalization of this indicator in comparison with the control group.

Epidemiological investigation and drug resistance of Eimeria species in Korean chicken farms

BackgroundCoccidiosis is a poultry disease that occurs worldwide and is caused by Eimeria species. The infection is associated with reduced feed efficiency, body weight gain, and egg production. This study aimed to investigate the current status of coccidiosis and anticoccidial resistance to anticoccidial drugs used as part of control strategies for this disease in Korean chicken farms.ResultsAn overall prevalence of 75% (291/388) was found. Positive farms contained several Eimeria species (mean = 4.2). Of the positive samples, E. acervulina (98.6%), E. maxima (84.8%), and E. tenella (82.8%) were the most prevalent species. Compared with cage-fed chickens, broilers and native chickens reared in free-range management were more at risk of acquiring an Eimeria infection. Sensitivities to six anticoccidial drugs (clopidol, diclazuril, maduramycin, monensin, salinomycin, and toltrazuril) were tested using nine field samples. Compared with untreated healthy control chickens, the body weight gains of infected chickens and treated/infected chickens were significantly reduced in all groups. Fecal oocyst shedding was significantly reduced in four clopidol-treated/infected groups, three diclazuril-treated/infected groups, two toltrazuril-treated/infected groups, one monensin-treated/infected group, and one salinomycin-treated/infected group, compared with the respective untreated/infected control groups. Intestinal lesion scores were also reduced in three clopidol-treated/infected groups, one monensin-treated/infected group, and one toltrazuril-treated/infected group. However, an overall assessment using the anticoccidial index, percent optimum anticoccidial activity, relative oocyst production, and reduced lesion score index found that all field samples had strong resistance to all tested anticoccidial drugs.ConclusionThe results of this large-scale epidemiological investigation and anticoccidial sensitivity testing showed a high prevalence of coccidiosis and the presence of severe drug resistant Eimeria species in the field. These findings will be useful for optimizing the control of coccidiosis in the poultry industry.

Development of UPLC-MS/MS method for determining hainanmycin in foods of animal origin

Hainanmycin is a polyether antibiotic. Toxicological studies have shown the adverse effects of hainanmycin on animals and humans. At present, no study is available on the detection of hainanmycin in edible tissues of animals. Hence, a fast and accurate detection method for hainanmycin is essential. This study aimed to develop a new analytical method based on ultra-high-performance liquid chromatography-tandem mass spectrometry to detect hainanmycin in 10 matrices, including milk, eggs, fat, kidney, muscles and livers of chicken, beef and sheep. The limit of detection and the limit of quantitation of the 10 matrices were 0.1–0.4 μg/kg and 0.25–1 μg/kg, respectively, and were far below the maximum residue limits of other polyether anticoccidial drugs (1–150 μg/kg). The recoveries of hainanmycin ranged from 79% to 105%, and the relative standard deviation ranged from 2.8% to 12.0%. The research results prove that the proposed method is operational and simple in detecting hainanmycin, and has high precision and accuracy in a variety of matrices.

Research progress of the avian coccidiosis vaccine

Coccidiosis is an intestinal disease of poultry that endangers animal health and causes economic loss to poultry production. For decades, the control of the coccidiosis relies mainly on anticoccidial drugs and live vaccines. However, problems such as widespread of drug resistance, public health pressure after mass administration of anticoccidial drugs, and the risk of expansion of coccidia after administration of live avian coccidiosis vaccine make new anticoccidial alternatives urgent for health development of avian industry. A number of new vaccines have emerged recently, including recombinant vaccines, DNA vaccines and genetically engineered live vaccines. Additionally, various adjuvants, such as DNA adjuvants, recombinant adjuvants, plant-derived adjuvants, probiotics and prebiotics have been evaluated in animal trials. In this article, an overview of the host immune response to avian coccidia is presented, and current vaccine and adjuvant control strategies are outlined as well. It is hoped that this review will contribute to a deeper understanding of avian coccidiosis prevention and control strategies and lay a theoretical foundation in the field.

Generation and Characterization of an Anti-diclazuril Monoclonal Antibody and Development of a Diagnostic Enzyme-Linked Immunosorbent Assay for Poultry.

An anti-diclazuril monoclonal antibody (mAb) was developed for use in enzyme-linked immunosorbent assay (ELISA)-based detection of diclazuril with high sensitivity and specificity, which can be used to measure anti-coccidial drug residues. The anti-diclazuril mAb had a half-maximal inhibitory concentration of 0.449–0.517 ng/mL. The mAb cross-reactivity with toltrazuril, toltrazuril 18 sulfone, clozaril, monesin, madurmycin, and salinomycin was very minimal (< 0.1%). The detection limit of the ELISA using this mAb was 0.10 ng/mL and the sensitivity was 0.05 ng/mL. A standard curve generated in the range of 0.05–16.2 ng/mL had a linear correlation coefficient value of ≥ 0.99. The average recoveries of diclazuril from chicken and duck samples ranged from 85.0 to 102.5%.Intra- and inter-assay coefficients of variation ranged from 5.9 to 8.5% and 9.2 to 12.6%, respectively. Using the International Immunogenetics Information System®, the VH domain of the mAb was found to be encoded by an IGHV3 family gene and had the following complementarity determining region (CDR) sequences: GFTFSRY (CDR1), SRGGS (CDR2), and GDDNYAFAY (CDR3). The VL domain was encoded by an IGKV1 family gene and had the following CDR sequences: KSSQSLLNSRTRKNYLA (CDR1), WASTRES (CDR2), and KQSYNLHT (CDR3). This study provides a method to generate anti-diclazuril mAbs and determine their variable region sequences. The diagnostic ELISA developed using this mAb may drive additional studies on the monitoring and detection of food and veterinary drug residues.

Assessment of curative and preventive efficacy of the anticoccidial drug “Сoсcimax” together with the feed additive “Mintov” in experimental eimeriosis of chickens

The article presents the evaluation of curative and preventive efficacy of the anticoccidial drug “Coccimax” in a joint application of the feed additive “Mintov”, in experimental eimeriosis of chickens. Were determined the degree of infection and the dynamics of changes in body weight in the experimental bird. It was found that the use of the anticoccidium drug “Coccimax” together with the feed additive “Mintov” helps to reduce the infestation of chickens (at the end of the experiment, the infection of birds in the control group was higher by 90-91 % compared to the experimental groups), provides increased survival rate (by 13.3% compared to the control group) and body weight gain (by 8.5–11.8 % compared to the control group).

Effects of Chlorogenic Acid on Performance, Anticoccidial Indicators, Immunity, Antioxidant Status, and Intestinal Barrier Function in Coccidia-Infected Broilers.

Simple SummaryCoccidiosis impairs the growth performance, intestinal health, and immunity of broilers, resulting in significant economic losses to the poultry industry. The use of anticoccidial drugs can lead to the emergence of resistant strains and drug resistance, and the control effect of vaccines is limited. Thus, there is an urgent need to develop substitutes for anticoccidial drugs. Chlorogenic acid (CGA) was reported to have positive effects on the performance and intestinal health of broilers. However, little is known about the application and mechanism of CGA in coccidia-infected broilers. The results of this study showed that dietary supplementation with CGA exhibited anticoccidial activities, and improved growth performance, immunity, antioxidant status, and intestinal barrier function in coccidia-infected broilers.The effects of chlorogenic acid (CGA) on growth performance, anticoccidial indicators (oocysts per gram of excreta, cecal lesion score, and bloody diarrhea score), immunity, antioxidant status, and intestinal barrier function in coccidia-infected broilers were investigated. A total of 240 one-day-old Arbor Acres broilers were randomly divided into four groups with six replicates of ten broilers each for 42 days. Four treatments included control diet (non-infected control, NC), control diet +Eimeria infection (infected control, IC), control diet +0.5 g/kg CGA + Eimeria infection (CGA0.5), and control diet +1 g/kg CGA + Eimeria infection (CGA1). At day 14, each broiler in IC, CGA0.5, and CGA1 groups was orally inoculated with 1 mL saline containing 4 × 105 sporulated oocysts. The results showed that the CGA1 group increased the average daily gain by 12.57% (p < 0.001) and decreased the feed/gain ratio (p = 0.010) and mortality (p = 0.030) by 13.00% and 77.76%, respectively, of broilers from 14 to 42 days compared with the IC group. The CGA1 group decreased the oocysts per gram of excreta (p < 0.001) and bloody diarrhea score (p = 0.001) compared with the IC group. The CGA0.5 and CGA1 groups increased total antioxidant capacity (p < 0.001) at day 21 and villus height (p < 0.001) in the duodenum and jejunum at day 42, and decreased the levels of interleukin 6 (IL-6) (p = 0.002), malondialdehyde (MDA) (p < 0.001), D-lactic acid (p < 0.001), and diamine oxidase (DAO) (p < 0.001) at day 21 and the levels of MDA (p < 0.001) and D-lactic acid (p = 0.003) at day 42 compared with the IC group. In the CGA1 group, villus height in the duodenum (p < 0.001) and jejunum (p = 0.017) increased at day 21 and in the ileum (p < 0.001) at day 42, and the level of DAO (p < 0.001) decreased at day 42 compared with the IC group. Broilers in the IC group had a higher IL-6 level (p = 0.048) at day 42 and lower IL-10 (p = 0.027) and immunoglobulin A (p = 0.042) levels at day 21, and IL-10 level (p = 0.017) at day 42 than those in the NC group, while no significant differences were observed among the NC, CGA0.5, and CGA1 groups. In conclusion, dietary supplementation with 1 g/kg CGA improved growth performance, immunity, antioxidant status, and intestinal barrier function in coccidia-infected broilers.

Molecular characterization of glyceraldehyde-3-phosphate dehydrogenase from Eimeria tenella.

Chicken coccidiosis is an extremely common and lethally epidemic disease caused by Eimeria spp. The control measures of coccidiosis depend mainly on drugs. However, the ensuing drug resistance problem has brought considerable economic loss to the poultry industry. In our previous study, comparative transcriptome analyses of a drug-sensitive (DS) strain and two drug-resistant strains (diclazuril-resistant (DZR) and maduramicin-resistant (MRR) strains) of Eimeria tenella were carried out by transcriptome sequencing. The expression of glyceraldehyde-3-phosphate dehydrogenase of E. tenella (EtGAPDH) was upregulated in the two resistant strains. In this study, we cloned and characterized EtGAPDH. Indirect immunofluorescence localization was used to observe the distribution of EtGAPDH in E. tenella. The results showed that the protein was distributed mainly on the surface of sporozoites and merozoites, and in the cytoplasm of merozoites. qPCR was performed to detect the transcription level of EtGAPDH in the different developmental stages of the E. tenella DS strain. The transcription level of EtGAPDH was significantly higher in second-generation merozoites than in the other three stages. The transcription level of EtGAPDH in the different drug-resistant strains and DS strain of E. tenella was also analyzed by qPCR. The results showed that the transcription level was significantly higher in the two drug-resistant strains (MRR and DZR) than in the DS strain. As the concentration of diclazuril and maduramicin increased, the transcription levels also increased. Western blot results showed that EtGAPDH protein was upregulated in the DZR and MRR strains. Enzyme activity showed that the enzyme activity of EtGAPDH was higher in the two resistant strains than in the DS strain. These results showed that EtGAPDH possess several roles that separate and distinct from its glycolytic function and maybe involved in the development of E. tenella resistance to anticoccidial drugs.

Effect of dehydrated grapefruit peels on intestinal integrity and Eimeria invasion of caprine epithelial cells in vitro and anticoccidial activity in vivo

Anticoccidial drugs are among the preferred resources to control coccidiosis, but the need to have natural alternatives has prompted research into plant products that improve animal performance and might also reduce Eimeria oocyst shedding while avoiding problems of drug residues. Two studies were conducted to evaluate the effects of dehydrated grapefruit peels (GDP) on Eimeria infection and intestinal health. In the first study, an in vitro culture system was used to evaluate the integrity of caprine epithelial cells infected with Eimeria ninakohlyakimovae and incubated with GDP, as well as the infection rate and schizont development of parasites exposed to GDP. In the second study, the anticoccidial effect of the inclusion of 15% GDP1 or 30% GDP2 in the diet and toltrazuril was evaluated in goat kids naturally infected with Eimeria spp. Parameters assessed included the reduction in oocyst counts, weight gain, fecal consistency, intestinal integrity, and malondialdehyde and nitric oxide (NO) production. In vitro, GDP2 and TTZ not only increased transepithelial electric resistance (TEER) values in infected caprine epithelial cells, but also decreased the mean cell invasion rate of sporozoites of E. ninakohlyakimovae and reduced the number and size of schizonts/mm2 of the intestinal cells culture. In vivo, the GDP2 group showed higher mean daily weight gains, reduced fecal oocyst output and decreased oxidative stress in goat kids. These findings demonstrate the beneficial activities of GDP in the enhancement of growth performance and gut health, and the feasibility of using a 30% inclusion of GDP for the replacement of corn in goat production.

Prevalence of Eimeria Spp. Among Goats in China: A Systematic Review and Meta-Analysis.

Eimeria spp. infection can cause weight loss in goats, and severe cases can lead to the death of lambs, resulting in economic losses to the goat industry. To explore the pooled prevalence of Eimeria spp. in goats in China, we obtained 70 related publications from five databases and conducted a meta-analysis. In China, the combined prevalence of Eimeria spp. in goats was 78.7% (95% confidence interval (CI): 68.15–87.67). Among them, the most serious infections occurred in Northeast China (88.0%, 95% CI: 83.54–91.86). The main Eimeria species were E. alijevi (43.7%, 95% CI: 29.53–58.45), E. arloingi (49.7%, 95% CI: 34.83–64.49), E. christenseni (41.2%, 95% CI: 27.07–56.16), and E. ninakohlyakimovae (35.9%, 95% CI: 21.02–52.31). In the sampling year subgroup, 2006 or later presented a lower prevalence (75.3%, 95%CI: 58.72–88.72). In terms of age, the point estimate for young goats (≤ 1 year) was higher (89.9%, 95% CI: 80.82–96.48). The Float (NaCl) method showed the lowest prevalence of Eimeria spp. in goats (75.9%, 95%CI: 62.00–87.46). In the season subgroup, the highest prevalence was in summer (81.5%, 95%CI: 49.62–99.18). Female goats presented a higher prevalence of Eimeria spp. infection than male goats (70.7%, 95%CI: 27.90–98.96). The prevalence was lower in the intensive feeding model (77.4%, 95%CI: 66.56–86.67) and higher in free feeding goats (79.4%, 95%CI: 66.46–89.92). In addition, we also analyzed the potential relationship between geographical factors and the prevalence of Eimeria spp. infection in goats in China. Our findings suggested that Eimeria spp. infection in goats is widespread in China. Despite the overall downward trend, this infection cannot be ignored. We recommend that breeders use anticoccidial drugs to prevent and treat this disease, while improving the feeding conditions and managemental practices to reduce the economic losses caused by Eimeria infection to the goat industry.

Anticoccidial effects of the Houttuynia cordata extract on experimental animal infection model

Coccidiosis is caused by infection of Eimeria species and an significant parasitic disease in poultry. Various kinds of natural products have been studied to find alternative treatments for coccidiosis in chickens, but the effect of Houttuynia cordata on Eimeria infection has not been investigated. The aim of this study is to study the anticoccidial effect of H. cordata extract (HCE) in chickens after oral infection by Eimeria tenella. Anticoccidial effects of the HCE was evaluated in chickens after oral infection with E. tenella. This study was performed on three-day-old chicks (n = 30). These animals were divided into 3 groups; HCE 0.2% treated/infected (n = 10), HCE untreated/infected (n = 10) and non-infected control (n = 10). The effect of HCE on E. tenella infection was assessed by two parameters; fecal oocysts shedding and body weights gain. the chicks fed HCE significantly reduced fecal oocysts when compared to the E. tenella-infected group fed standard diets (p&lt;0.05). Furthermore, the HCE-based diet improved weight loss due to E. tenella infection. Our data shows that HCE had significant antiprotozoal activity against E. tenella. These findings may have implications for the development of anticoccidial drugs.

Toltrazuril-Loaded Polymeric Nanocapsules as a Promising Approach for the Preventive Control of Coccidiosis in Poultry.

Coccidiosis is a disease caused by intracellular protozoan parasites of the genus Eimeria that affect the intestinal tract of poultry. However, strain resistance and drug residue in the carcass have drawn the attention of the productive sector. The nanotechnology can improve the biological effect of drugs, reducing of administered doses and toxic effects. Due to this, toltrazuril-load polymeric nanoparticles based on Eudragit® S100 (NCt) or poly-ε-caprolactone (LNCt) were developed to prevent coccidiosis in broilers. Nanoformulations were produced and showed homogeneous particle diameter distribution in the nanometer range (z-average and D (4.3) < 200 nm), negative zeta potential (<−8.93 mV), drug content ~100%, and encapsulation efficiency >90%. Cell viability assays using avian fibroblasts showed that LNCt presented no relevant toxicity up to 72 h. LNCt was then prophylactically administrated to chicken followed by challenge with Eimeria oocysts. The evaluation of the small intestine and cecum showed that the treatment with LNCt (3.5 mg/kg/day) in drinking water reduced the lesion scores and oocysts excretion, similar to the reference medicine containing toltrazuril (Baycox®, 7 mg/kg/day). The current study shows the potential protective use of nanoencapsulating anticoccidial drugs as a promising approach for the control of coccidiosis in poultry.

The use of Anticoccidial Sensitivity Tests (ASTs) by the Poultry Industry.

Anticoccidial drug resistance in coccidia has been known since the 1960s, and experimental selection for resistance in the laboratory has been done for most available products. However, routine testing for sensitivity in field isolates has only begun in recent years. Poultry producers are faced with greater challenges because of consumer preferences for 'antibiotic-free' products and a lack of new products for disease control. The classification of some of our most effective anticoccidials as 'antibiotics' has severely limited their use, causing us to rely on older products that are prone to resistance development. The interaction between coccidiosis and other diseases such as necrotic enteritis places more importance on routine testing for drug sensitivity. In this review, we have summarized the use of the anticoccidial sensitivity test (AST) as it is conducted and interpreted by poultry health specialists.

In vitro anticoccidial activity of nanoencapsulated bromelain against Eimeria spp. oocysts isolated from goats in Kenya.

Background and Aim:The emergence of drug-resistant strains of Eimeria spp. calls for the development of novel anticoccidial drugs. Plant extracts provide a possible natural source for such drugs. This study aimed to investigate the in vitro anticoccidial activity of encapsulated bromelain (EB) in chitosan nanocarriers on Eimeria spp. oocysts isolated from goats kept by farmers in Kenya.Materials and Methods:Bromelain was extracted from the peel of ripe pineapples using standard methods. Eimeria spp. oocysts were isolated from the feces of goats using a flotation method. The inhibition of sporulation was assayed after exposing the oocysts to solutions of EB, non-EB (NEB), and diclazuril (positive control) at concentrations between 4 mg/mL and 0.125 mg/mL for 48 h. The oocysts were examined under a microscope (40x) to determine the effects of the drugs on the sporulation process. The percentage of sporulation inhibition was calculated after 48 h and the inhibition concentration 50% (IC50) was determined by probit analysis.Results:Bromelain manifested anticoccidial activity through the inhibition of the sporulation of coccidia oocysts. EB achieved inhibition with a lower dose compared with NEB. The IC50 values of diclazuril, EB, and NEB were 0.078 mg/mL, 0.225 mg/mL, and 0.575 mg/mL, respectively. There were significant differences (p<0.01) between the IC50 of EB and NEB compared with the standard treatment drug.Conclusion:This preliminary study showed that EB has anticoccidial activity supporting further evaluation at an in vivo level to develop a novel drug for the management of coccidiosis in goats.