鸡球虫早熟株的生物学特性及其在疫苗中的应用

按照Jeffers建立的艾美耳球虫早熟株选育方法选育出的球虫早熟株，其潜在期明显缩短，繁殖力和致病性显著降低，但保持良好的免疫原性.并且，早熟株的弱毒性和早熟性具有遗传稳定性，通过放松选择压力反复传代后无恢复现象。国内外学者根据早熟株的这些生物学特性，并在深入了解鸡球虫病的保护性免疫机制的基础之上研制了抗鸡球虫病的早熟株弱毒活苗。本文综述了球虫早熟株的生物学特性，并介绍了目前国内外研制出的球虫早熟苗在鸡球虫病防治方面的应用。     

鸡球虫疫苗研究进展

鸡球虫病是生产中严重危害养禽业的寄生虫病,长期以来以药物防治为主。目前,由于球虫耐药性的普遍存在,加上消费者对禽产品药物残留问题的关注,采用疫苗防治球虫病为人心所向。球虫活苗在实际生产中发挥了一定的作用,但由于球虫活苗存在“复壮”的可能且使用麻烦,人们将目光转向了分子疫苗。球虫基因组学研究为基因工程苗开发奠定了基础,目前已经筛选了上百个功能抗原基因。受表达系统的限制,原核表达的重组蛋白抗原性较差,虽有较多尝试,但鲜有成功。人们在探索体外真核表达(如酵母、杆状病毒表达系统等)的同时,核酸疫苗以其独特的诱发高水平细胞免疫反应的能力而倍受青睐,近几年发展较快。     

鸡球虫疫苗研究现状

鸡球虫病是危害养禽业的一类重要的寄生虫病,鸡球虫疫苗包括活疫苗、亚单位疫苗、基因工程亚单位疫苗、核酸疫苗及活载体疫苗等,论文对目前鸡球虫疫苗的研究与应用现状进行了综述.     

毒害艾美耳球虫早熟株与亲本株繁殖力的观察

为选育毒害艾美耳球虫(E.necatri)早熟株,了解其繁殖力,为早熟弱毒活苗的研制奠定基础,本试验运用球虫的单卵囊分离技术得到一株E.necatrix(P0),并对其进行了早熟选育,得到了E.necatrix早熟株P8。P0和P8分别以0.05×104、0.1×104、0.5×104和1×104个/只的剂量接种11日龄雏鸡,接种后第7～13天每天检测粪便中的卵囊产量。结果表明,P0与P8均为接种0.5×104个/只的卵囊产量最大;P8的繁殖力是P0的55%;P8的卵囊高峰期较P0有提前趋势。     

鸡球虫苗的研究进展

由于抗药性和研制新药成本增加，周期延长，药物使用中存在的一些问题，促进了免疫学防治的发展，利用鸡球虫苗来控制鸡球虫病成为一种有效途径，通过对鸡球虫苗的种类，作用特点，研究概况等方面的论述，进一步提出该虫苗的应用前景及展望，为更好地防治鸡球虫提供科学依据。     

兔球虫疫苗的研究现状

兔球虫病是家兔最常见、危害最严重的疾病之一,国内外多采用抗球虫药物对兔球虫病进行预防和治疗。目前为止,我国还没有研制出商品化的兔球虫疫苗,国内外仅有少部分学者开展了兔球虫病疫苗的研究工作。主要对兔球虫疫苗活虫苗、亚单位苗、基因工程苗的研究进展进行综述,以期为兔球虫疫苗的相关研究提供参考。     

鸡球虫病免疫预防研究进展

鸡球虫病是严重危害养禽业的重要寄生虫病之一,长期以来对其防治主要依靠药物,近年来因耐药虫株不断出现,尤其是药物残留对环境的污染及其对人类健康的威胁等一系列问题日益突出,药物在鸡球虫病控制中的使用越来越受到限制。许多学者认为通过免疫方法对鸡球虫病进行防治已是大势所趋,然而由于人们对鸡体抗球虫的免疫应答过程一直不很清楚,限制了免疫学方法在抗球虫方面的应用和发展。文章综述了近年来对鸡球虫免疫原性,宿主免疫应答尤其是肠道黏膜免疫在抗球虫中的作用及球虫疫苗的研究等方面的进展,相信随着分子生物学等技术的发展,免疫预防球虫病将会有更广阔的发展前景。     

鸡球虫重组活载体疫苗研究进展

对细菌和病毒为载体的鸡球虫重组活载体疫苗研究进行了综述,旨在为鸡球虫病的免疫预防提供新思路和参考.     

Efficacy of diclazuril in the prevention and cure of intestinal and hepatic coccidiosis in rabbits

The efficacy of diclazuril against intestinal and hepatic coccidiosis was studied in artificially infected rabbits. Prophylaxis against intestinal coccidiosis was evaluated using a mixed infection of Eimeria intestinalis, Eimeria magna and Eimeria perforans. Continuous medication in the feed at 1 p.p.m. was 100% effective in reducing oocyst output and faecal scores, and weight gain and feed efficiency were normal. Hepatic coccidiosis induced by Eimeria stiedai was prevented at 0.5 and 1 p.p.m. as shown by negative oocyst counts, normal liver weight, absence of liver lesions, and normal body-weight gain and feed efficiency. Medication at 1 p.p.m. for 7 consecutive days during the prepatent phase of hepatic coccidiosis resulted in large reductions in oocyst counts and lesion scores with a normal liver weight and growth performance. Diclazuril at 1 p.p.m. in the feed prevented both intestinal and hepatic coccidiosis in rabbits and can be advocated for safe mass medication.     

强效艾美耳牌鸡球虫疫苗免疫效果的研究

本实验研究了强效艾美耳牌鸡球虫疫苗免疫预防鸡球虫病的效果。实验结果表明：强效艾美耳牌鸡球虫疫苗是安全有效的，基保滴服免疫的效果优于拌料免疫，滴服免疫不仅对攻毒后鸡有100％的保护效果，而且能有效地控制球虫病的发生，对小鸡的生长也有明显的保护作用。与常用抗球虫药氯苯胍相比，强效艾美耳牌鸡球虫疫苗预防鸡球虫病的效果优于氯苯胍，其对小鸡增重率、料肉比显示的效果也优于氯苯胍。     

鸡球虫病疫苗研究进展

鸡球虫病广泛分布于世界各地,是危害养鸡业的重要寄生虫疫病之一。对鸡球虫病疫苗的研究已成为广大动物医学工作者关注和研究的热点之一。文章对鸡球虫病疫苗的研究现状以及核酸疫苗在鸡球虫病防制中的应用等研究新进展作简要综述。     

鸡球虫病免疫学研究进展

鸡球虫病是严重危害养禽业的一种寄生虫病。一直以来,鸡球虫病主要依靠药物来进行防治。但是,随着球虫抗药性问题的日益严重,抗球虫新药开发困难及人们对食品安全的关注,药物在球虫病控制中的作用越来越受到限制,因而用免疫方法来控制鸡球虫病日益受到重视,并有望成为主要的技术手段。目前鸡球虫免疫学研究主要集中在鸡球虫免疫原性、宿主免疫应答及寻找有效的鸡球虫保护性抗原等方面。近年来随着分子生物学和现代生物技术的发展,鸡球虫基因工程疫苗以其独特的优势显示其在未来球虫病控制中的诱人前景,并可能取代传统疫苗而成为鸡球虫病防治的主要手段。     

Control of Coccidiosis in Caged Egg Layers: A Paper Plate Vaccination Method

Coccidiosis continues to affect caged layers worldwide despite keeping them on wire all their productive lives. Coccidiosis in caged layers, diagnosed either in clinical or subclinical forms, has one feature in common, unpredictability. Until recently, despite the use of vaccine, coccidiosis remained problematic, particularly at the beginning of lay, likely related to the low protective immunity for a lack of vehicle for recycling. An approach for using paper plates, both for vaccination as well as recycling is described. Caged layers that were vaccinated once with gel-puck coccidiosis vaccine laid at over 90% continuously for over 24 wk with little or no problem of coccidiosis.     

In vivo effects of CpG oligodeoxynucleotide on Eimeria infection in chickens

Poultry coccidiosis is the major parasitic disease of poultry and, until now, no recombinant vaccine has been developed. Short oligodeoxynucleotides (ODNs) containing unmethylated CpG motifs (CpG ODNs) have been shown to be effective immunoprotective agents and vaccine adjuvants in mammalian systems. Their use in poultry to protect against intracellular parasites has not been reported to date. The present work investigated the effects of CpG ODN treatment on host susceptibility to Eimeria infection in two chicken strains with different genetic background, SC and TK. The data show that CpG ODN enhanced the birds' resistance to coccidiosis in a normally susceptible chicken strain (TK), as shown by reduced oocyst shedding and improved weight gain. CpG treatment had a differential effect on body weight gains and serum antibody responses, depending on the chicken strain and ODN dose, delivery route, and backbone. This study shows for the first time that CpG ODNs could be used as immunoprotective agents in Eimeria-infected chickens to enhance resistance to the pathogen and improve performance. Future research is needed to optimize their use alone and as vaccine adjuvants that may lead to better and more efficient vaccine applications.     

京海黄鸡杂交组合亲本鸡球虫抗性指标的比较

为研究京海黄鸡杂交组合亲本BB鸡与FF鸡鸡球虫病抗性的差异,试验选取BB和FF公鸡各30只,饲养至9日龄时,每个群体随机分为免疫组(n=15)和非免疫对照组(n=15),分组当天免疫组京海黄鸡杂交组合亲本按正典鸡球虫病四价活疫苗说明书要求接种鸡球虫疫苗,疫苗免疫后第8天采用生物素双抗体酶联免疫吸附法(ELISA)测定免疫组和非免疫对照组8个血浆球虫抗性指标,并进行差异显著性检验.结果显示,BB鸡免疫组过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和白介素17(IL-17)的含量显著高于FF鸡免疫组(P <0.05);BB杂交组合亲本免疫组CAT含量极显著高于对照组(P <0.01),SOD含量显著高于对照组(P <0.05);FF杂交组合亲本免疫组CAT和谷胱甘肽过氧化物酶(GSH-Px)含量均显著高于对照组(P <0.05).综合分析结果表明,BB鸡免疫效果优于FF鸡群体,BB鸡球虫病抗性优于FF鸡群体.     

Role of oregano and Citrus species-based essential oil preparation for the control of coccidiosis in broiler chickens

Background: Due to presence of drug-resistant Eimeria strains and raised public health safety concerns about drug residues in the meat, there is renewed interest in the search for natural alternatives to the coccidiosis control agents. This study was conducted to test the anticoccidial efficacy of oregano and Citrus spp.-based essential oils for broilers.Methods: A total of 280 7-day-old broiler chicks were fed a control diet or diets with salinomycin or essential oils for up to 35 d of age. On d 14, half of the control groups and the treated groups were orally challenged with a coccidiosis vaccine at 25 times higher than the recommended vaccine dose. Control diet-fed chickens that were gavaged with phosphate-buffered saline were considered non-challenged control group.Results: Eimeria challenge or dietary additives failed to affect growth performance during the 7 to 20 d growth period although essential oil-fed chickens exhibited the lowest body wight gain(P = 0.332) and the highest feed conversion ratio(P = 0.062). Oocysts in the litter were detected in the challenged control diet group and the challenged/essential oil-fed groups at 21 and 35 d, respectively. Superoxide dismutase activity in the serum was elevated(P = 0.059) in the salinomycin-fed chickens compared to the challenged controls. Alpha-1-acid glycoprotein was decreased by 28.7% in the salinomycin-fed chickens but increased by 38.1% in the essential oil group compared with the challenged control group. Challenged control group exhibited a significantly higher cooking loss of the thigh meat, compared to the non-challenged control diet group, which was marginally mitigated by dietary supplementation with essential oils. Chickens fed essential oil-added diet had the highest branched-chain fatty acids contents in the cecum.Conclusions: In conclusion, this study shows that oregano and Citrus-based essential oil preparation did not affect growth performance in broiler chickens challenged with the coccidiosis vaccine nor did Eimeria-specific duodenal lesion. However, dietary essential oil preparation lowered oocysts present in litter materials and altered branchedchain fatty acids in cecal digesta. Beneficial findings of the essential oil preparation on volatile fatty acids and oocysts output may warrant further research into assessing its effectiveness and its efficacy in pathogenic fieldisolate Eimeria spp.-induced coccidiosis disease model.     

Effects of anticoccidial and antibiotic growth promoter programs on broiler performance and immune status

This study investigated the effects of various coccidiosis control programs in combination with antibiotic growth promoters (AGPs) on growth performance and host immune responses in broiler chickens. The coccidiosis programs that were investigated included in ovo coccidiosis vaccination (CVAC) with Inovocox or in-feed medication with diclazuril as Clinacox (CLIN) or salinomycin (SAL). The AGPs were virginiamycin or bacitracin methylene disalicylate plus roxarsone. As a negative control, chickens were non-vaccinated and fed with non-supplemented diets (NONE). All animals were exposed to used litter from a commercial broiler farm with confirmed contamination by Eimeria parasites to simulate in-field exposure to avian coccidiosis. Broiler body weights in the CVAC group were greater at 14 and 32 days of age, but not at day 42, compared with the NONE, CLIN, and SAL groups. At day 14, the SAL group showed decreased body weight and reduced ConA-stimulated spleen cell proliferation compared with the CLIN and SAL groups. In contrast, at days 34 and 43, splenocyte proliferation was greater in the CVAC and CLIN groups compared with the NONE and SAL groups. Lymphocyte subpopulations and cytokine mRNA expression levels in the intestine and spleen were also altered by the denoted treatments. Collectively, these results suggest that in ovo coccidiosis vaccination or coccidiostat drug medication programs in combination with AGPs influences chicken growth and immune status in an Eimeria-contaminated environment.     

Efficacy of toltrazuril in broilers and development of a laboratory model for sensitivity testing of Eimeria field isolates

(1) The efficacy of toltrazuril (Baycox) against coccidiosis was established on a broiler farm in an intermittent application during five consecutive growing periods. Treated birds were fed a broiler ration without anticoccidials. The efficacy of Baycox was compared with the nicarbazin-salinomycin shuttle. It was concluded that Baycox retarded the onset of Eimeria infection for several weeks. During the fifth rearing period coccidiosis problems emerged on the farm in all birds during medication, suggesting development of resistance. (2) During a laboratory experiment the efficacy of Baycox was studied in birds after inoculation with different numbers of oocysts at 7, 10 or 15 days of age. Baycox was applied at 10 and 11 days of age. In all cases medication with Baycox protected birds from coccidiosis during a period of at least 7 days. This effect of Baycox could be due to the long-existing tissue levels of the product and its metabolites as well as its specific effect on the second generation of schizonts. (3) In another laboratory experiment coccidia obtained from field trials were tested for sensitivity to Baycox in conjunction with two strains obtained from farms were coccidiosis emerged during application. The inoculation model developed in this study was used for sensitivity testing. One of the Eimeria strains tested was resistant to the product, one strain was tolerant and the remaining two strains, including the control strain, were fully sensitive to Baycox.     

鸡球虫病活疫苗不同卵囊计数方法的比较

为了解鸡球虫活疫苗不同卵囊计数方法对检测结果的影响,分别采用血细胞计数板4角方格法和9方格法以及麦氏计数板法对3种鸡球虫活疫苗各进行了6次卵囊计数,然后采用t检验和Z比分值方法比较筛选出最适宜的计数方法,并对检测方法进行了验证和变异系数统计。结果显示：采用每批检品抽检1瓶,通过血细胞计数板4角方格法重复计数6次,去除最大值和最小值后取平均值作为该瓶检品卵囊计数结果,如果首次检验结果不符合规定可重检一次的方法,人员误差最小。该方法提高了鸡球虫活疫苗卵囊计数结果的可重复性和准确性,增强了疫苗质量控制的可靠性。     

Use of Yucca schidigera Extract in Broiler Diets and Its Effects on Performance Results Obtained with Different Coccidiosis Control Methods

A trial was conducted to assess the effects of the dietary supplement Yucca schidigera extract on the performance of broilers subjected to different coccidiosis control methods. Six hundred male broiler chicks were randomly allocated to 1 of 5 treatments with 4 replicates each. The treatments were as follows: T1, vaccinated against coccidiosis; T2, nonvaccinated, a dietary coccidiostat; T3, vaccinated against coccidiosis, diet supplemented with Y. schidigera extract (0.01%); T4, coccidiostat plus Y. schidigera extract added to feed (0.01%); and T5, nonvaccinated, nonsupplemented control. The parameters analyzed were bird performance and morphology of the intestinal mucosal surface. The intestinal villi were higher at 6 d of age in broilers treated with coccidiostats or vaccinated against coccidiosis and supplemented with Y. schidigera extract compared with groups receiving the vaccine only or no treatment. Addition of the Y. schidigera extract to the diet of vaccinated birds improved average daily gain and feed conversion rate at 42 d of age compared with the other treatments, suggesting there might be a beneficial, synergistic effect between the coccidiosis vaccine and the Y. schidigera extract.