鸡球虫病及其防治措施

1流行特点与致病因素鸡球虫病主要是由艾美尔属球虫中的9种球虫引起,危害较大的是堆型、柔嫩、巨型、毒害、布氏艾美尔球虫。寄生于盲肠致病的为柔嫩艾美尔球虫,雏鸡常见。寄生于小肠前段致病的为堆型、哈氏、变位、和缓、早熟艾美尔球虫,寄生于小肠中段的为巨型和毒害艾美尔球虫;寄生于小肠后段、直肠和盲肠近端部的为布氏艾美尔球虫。青年鸡易感染小肠球虫病,一般为2种以上球虫混合感染。病鸡和球虫病携带者是发病群体的来源。维生素A和维生素K缺乏,圈     

球虫感染与铁吸收

球虫感染可影响家禽消化道对多种营养物质的吸收。4周龄仔鸡感染堆型艾美尔球虫、毒害艾美耳球虫、布氏艾美尔球虫及柔嫩艾美尔球虫形成孢子卵囊的试验,于感染卵囊后第6天增重率降低,大部分仔鸡转入严重感染阶段,于感染后35天体重恢复到对照鸡的水平。     

一例土鸡球虫病的诊治

鸡球虫病是对养鸡业危害十分严重的寄生虫病,是由艾美耳球虫寄生在鸡肠道引起的,可以由一种或者多种球虫寄生引起。艾美耳球虫有7种,即柔柔嫩艾美尔球虫、哈氏艾美耳球虫、巨型艾美尔耳、堆型艾美耳球虫、毒害艾美尔球虫、和缓艾美尔球虫及早熟艾美尔球虫。各类球虫寄生鸡肠道部位有所差异,例如嫩艾美尔球虫常侵害盲肠,哈氏艾美耳球虫损害小肠前端,巨型艾美尔耳球虫损害小肠中段部位,堆型艾美耳球虫多在上皮表层活动等。各品种鸡都会感染,雏鸡有母源抗体保护,10日龄以内很少发病,15~50日龄鸡的发病率和死亡率都是很高,发病率高达80%,死亡率30%左右。成年鸡对球虫也敏感,但很少死亡。病鸡是主要传染源,可通过粪便及被卵囊污染的饲料、饮水土壤或用具等传播。由于土鸡养殖多以散养的方式饲养,增加了土鸡发病的概率,因此预防和控制土鸡球虫病的发生是提高土鸡养殖效益的关键之一。     

饲料中添加氨丙嘧吡啶对艾美尔球虫的效力

据一些文献报告,在饲料中添加氨丙嘧吡啶(amprolium)药剂,可以抑制诸如堆型艾美尔球虫和巨型艾美尔球虫等球虫卵囊的孢子形成。Mathis等发现,对氨丙嘧吡啶产生抗药性的堆型艾美尔球虫株不能证实减少孢子形成。证实,在饮水中给予氨丙嘧吡啶而不是通过饲料给予是否有同样作用尚无报告。氨丙嘧吡啶对布氏艾美尔球虫或柔嫩艾美尔球虫卵囊的孢子形成没有影响。氨丙嘧吡啶对毒害艾美尔球虫卵囊的作用尚未研究。Ruff等证实,在给予不加药的鸡时,从加arprinocid鸡回收的卵囊感染力低于从未加过药鸡回收的等量卵囊。根     

一起慢性鸡球虫病的诊疗报告

鸡球虫病(Avian coccidiosip）是由艾美属的多种球虫(柔嫩、毒害、巨型、堆型、布氏、变位、和缓、早熟、哈氏)寄生于鸡的肠道引起的疾病，分布广泛，危害严重，是呈全球性流行的重要疾病，在养鸡业中发病率和死亡率都较高，严重影响着养鸡业的发展。以往认为鸡群发生球虫病多是由柔嫩艾美尔球虫或毒害艾美尔球虫感染引起的，现在发现由巨型艾美尔球虫和堆型艾美尔球虫引起的小肠球虫病也比较多见，     

浅谈鸡球虫病的防控

正鸡球虫病是由艾美尔属的多种球虫寄生于鸡肠黏膜内引起的一种原虫病。主要特征是雏鸡多发,患鸡白痢,发病率高。本病的发生具有普遍性,是养鸡业中重要而常见的一种疾病。寄生于鸡的球虫主要有7种,即柔嫩艾美尔球虫、毒害艾美尔球虫、堆型艾美尔球虫、巨型艾美尔球虫、哈氏艾美尔球虫、和缓艾美尔球虫和早熟艾美尔球虫。其中治病力最强、危害性最大的是柔嫩艾美尔球虫,其次为毒害艾美尔球虫,分别寄生于鸡盲肠、小肠的中断,人们在养鸡生产中通常称为盲肠球     

鸡球虫病的药物防治

鸡球虫病是危害养鸡业的一种重要寄生虫疾病,主要发生于温暖多雨的春夏季,秋冬季较少。目前已证实为有危害或致病性的球虫包括堆型艾美尔球虫、巨型艾美尔球虫、毒害艾美尔球虫、柔嫩艾美尔球虫和布氏艾美尔球虫。但生产中经常出现多种球虫的混合感染。在生产实际中,按实际危害的严重性排序为柔嫩、堆型、巨型、毒害和布氏艾美尔球虫,其中以柔嫩、堆型、巨型、毒害艾美尔球虫对鸡造成的侵害最为严重。     

柔嫩艾美尔球虫郑州株的分离与鉴定

鸡球虫病是对养鸡业危害最大的寄生虫病之一。在鸡的多种球虫中,柔嫩艾美尔球虫感染最普遍,致病力最强,致死率最高,危害最严重。为了建立柔嫩艾美尔球虫郑州株纯种体系,为进一步研究该球虫的致病性、免疫防治及临床评价抗球虫药药物效用和球虫耐药性,我们进行了柔嫩艾美尔球虫郑州株的单卵囊分离与感染和单卵囊后代扩大试验,结果如下:     

家兔球虫病防控

正球虫是寄生于家兔体内的一种寄生虫,是危害家兔健康的常见严重疾病。1病原学兔球虫属艾美尔科艾美尔属。兔球虫有11种,分别为黄艾美尔球虫、肠艾美尔球虫、小型艾美尔球虫、穿孔艾美尔球虫、无残艾美尔球虫、中型艾美尔球虫、维氏艾美尔球虫、盲肠艾美尔球虫、大型艾美尔球虫、梨型艾美尔球虫和斯氏艾美尔球虫。兔是兔球虫的唯一自然宿主。兔球虫卵囊对外界环境的抵抗力强,可在潮湿的恶劣环境中存活,低浓度的苯酚、高锰酸     

神木县某奶牛场奶牛球虫种类的调查

为了摸清神木县奶牛球虫感染情况,制定更好的奶牛球虫病防治对策,采用粪便漂浮法、斯陶尔法和卵囊培养法对榆林市神木县某奶牛场49头奶牛的球虫感染情况进行了初步调查,并对各虫种进行鉴定。结果发现8种艾美尔球虫(Eimeria),即牛艾美尔球虫(E.bovis)、加拿大艾美尔球虫(E.canadensis)、邱氏艾美尔球虫(E.zuernii)、亚球艾美尔球虫(E.subspherica)、奥博艾美尔球虫(E.auburnensis)、柱状艾美尔球虫(E.cylindrica)、椭圆艾美尔球虫(E.ellips)、阿拉巴艾美尔球虫(E.alabamensis),其中加拿大艾美尔球虫和椭圆艾美尔球虫为该奶牛场的优势种,总感染率为51.02%,犊牛感染率为57.14%,青年牛感染率为64.29%,成年牛感染率为38.10%。平均感染强度为275个/g粪便,其中犊牛感染强度为433.33个/g粪便,青年牛感染强度为300个/g粪便,成年牛感染强度为183.33个/g粪便。     

堆型艾美耳球虫保定株裂殖子3-1E基因的克隆与序列分析

依据GenBank中收录的堆型艾美耳球虫(Eimeria acervulina,E.acervulina)关国株(US)3-1E基因序列,设计特异性引物,以堆型艾美耳球虫保定株裂殖子基因组RNA为模板,利用反转录-聚合酶链式反应(RT-PCR)扩增获得3-1E基因序列部分片段,将此片段克隆至pGM-T Easy载体中,经PCR、限制性内切酶鉴定和克隆片段的序列测定、比较,结果表明该克隆片段扩增准确、可靠.序列比较发现,此片段与E.acervulina美国株(US)株、E.acervulina QH株cDNA的核苷酸同源性分别为99.4%和99.6%.     

Experimental coccidiosis provoked by Eimeria acervulina in chicks simultaneously fed on ochratoxin A contaminated diet

The progression of coccidiosis provoked by Eimeria acervulina was followed in chicks fed on OTA-contaminated as well as on OTA-free diets. More heavy progress of duodenal coccidiosis, including mortality, occurred in OTA-treated chicks as can be seen from the higher value of lesion (3.50) and oocyst (31.65) indices. A stronger decrease of serum total protein was found in OTA-treated chicks (22.80 g/l) than in chicks infected with E. acervulina(24.20 g/l), but that decrease was strongest in chicks treated with OTA and simultaneously infected with E. acervulina (19.71 g/l). The serum concentration of uric acid was significantly increased in all chicks exposed to OTA, most notably in those additionally infected with E. acervulina (1020.6 (micro mol/L), whereas the serum enzyme activity of AST was increased only in chicks infected with E. acervulina and highest in those fed OTA contaminated diet (122.2 U/L). OTA induced degenerative changes in kidneys, liver and heart as well as a depletion of lymphoid tissue in the lymphoid organs and a decrease of body weight. Coccidiosis induced only a slight growth depression and duodenal hemorrhages in addition to characteristic duodenal damages. The impairment of kidney function, histopathological changes and general growth depression were stronger when chicks infected with E. acervulina were also given OTA.     

Prior or concurrent exposure to different species of avian Eimeria: effect on sporozoite invasion and chick growth performance.

The effects of prior (immunity) or concurrent administration of Eimeria acervulina or Eimeria tenella on cellular invasion in vivo and in vitro and on growth performance in white leghorn chickens (WLC) were examined. Weight gains of WLC immunized with E. acervulina and challenged with E. tenella were significantly greater than those of nonimmunized chicks challenged with E. tenella (this occurred despite the increased invasion by E. tenella in E. acervulina-immunized chicks that was reported earlier). The weight gains and modest but consistent improvements in intestinal lesion scores, feed conversion ratios, and oocyst shedding in immunized/challenged WLC indicated that E. acervulina conferred a small measure of protection against E. tenella infection that was independent of the effect on invasion. In contrast, immunization of WLC with E. tenella significantly decreased (41%-51%) invasion by E. acervulina as compared with that in nonimmunized WLC but had little effect on chick growth performance. Concurrent inoculation of chicks with E. tenella and E. acervulina had little effect on invasion by E. tenella sporozoites or on subsequent performance of the chicks. In vitro, prior exposure of cultured cells to either of two isolates of E. tenella also caused a significant decrease in invasion by E. acervulina. No gross changes occurred in the culture morphology between the E. tenella-inoculated and noninoculated cultures. Collectively, the data indicate that prior exposure of WLC and cultured cells to single isolates of avian coccidia markedly influenced invasion by other species but had less effect on the growth performance of the birds.     

Does Plasmodium gallinaceum induce relapse of Eimeria acervulina infection in chickens?

An experiment was carried out to test the hypothesis that chickens previously infected with Eimeria acervulina, but having ceased producing oocysts, recommence E acervulina oocyst production when infected with Plasmodium gallinaceum. No relapse of coccidiosis was caused by the malarial infection. Subsequent treatment with the immunosuppressant betamethasone of the control chicks infected with E acervulina only did not reveal any occult coccidial infection. The results are critically compared with previously published results which apparently supported the hypothesis.     

Etiology and pathogenesis of necrotic enteritis

Sporulated oocysts of Eimeria acervulina were administered orally to cage-housed broilers at a dose of 3.5 X 10(5) resulted in mild subclinical coccidiosis. Clostridium perfringens incorporated in feed at a level of 2.5 X 10(8) organisms/g. produced lesions characteristic of necrotic enteritis. Mortality of 8% (7/80) occurred in birds fed a ration inoculated with Cl. perfringens alone. Mortality of 35% (28/80) was observed in birds which received an oral dose of E. acervulina and which were fed simultaneously with a ration containing Cl. perfringens. Birds which were fed an inoculated ration two days after an oral dose of E. acervulina showed 41% (33/80) mortality. Birds which received an inoculated ration for two days before administration of an oral dose of E. acervulina demonstrated 18% mortality (15/80). Birds which were fed an inoculated ration four days after an oral dose of E. acervulina showed 10% mortality. Infection with E. acervulina reduced the pH of intestinal contents with a simultaneous depression in serum protein. A 39% increase in intestinal passage time from 178 to 248 minutes occurred on the fifth day after infection with E. acervulina. These experiments suggest that necrotic enteritis, attributed to proliferation of a toxigenic strain of Cl. perfringens, followed intestinal stasis and minimal lesions induced by mild intestinal coccidiosis.     

Energy and nitrogen metabolism of chickens infected with either Eimeria acervulina or Eimeria tenella.

1. The effects of sublethal infections of E. acervulina and E. tenella on the energy and nitrogen metabolism of groups of five broilers aged 16 d were studied for 16 d in respiration chambers. 2. The metabolisable energy content of the diet for chickens infected with E. acervulina was 0.689 of its gross energy content and N retention was 42.5 g/100 g N intake compared with 0.738 and 47.1 g respectively, in uninfected pair-fed controls. Chickens infected with E. tenella were similarly affected. 3. Efficiency of utilisation of ME by chickens infected with E. acervulina was 0.43 during the first 8 d after infection, and 0.52 during the second 8 d compared with an overall efficiency by non-infected chickens fed ad libitum of 0.73. Maintenance energy requirement of infected chickens was higher during the first 8 d after infection than during the second 8-d period. 4. Body composition measurements showed that of the total gain in weight of chickens infected with E. acervulina, only 7.5 g/kg gain was fat and 213 g/kg was protein compared with 45 g and 210 g respectively for non infected chickens fed ad libitum. 5. E. acervulina and E. tenella infections reduced the apparent digestibility of total mineral, calcium and phosphorus.     

堆形艾美耳球虫早熟株选育及相关生物学特性研究

为了选育堆形艾美耳球虫（Eimeria acervulina）早熟株及观测其生物学特性,运用Jeffers创立的艾美耳属球虫早熟株选育方法,对实验室保存的堆形艾美耳球虫进行连续传代早熟选育,并对获得的早熟株与母株孢子化卵囊大小、繁殖能力、致病性以及免疫保护力等指标进行了测定,比较堆形艾美耳球虫早熟株与母株之间的基本生物学特性差异。经过18代早熟选育后,堆形艾美耳球虫的潜在期由母株的99h缩短至84h。与母株相比,早熟株的孢子化卵囊大小明显减小（P〈0．05）,卵囊繁殖能力降低了17％～42%。致病性试验中,早熟株感染组的平均增重均高于母株,而病变记分相当。免疫保护试验中,早熟株与母株的免疫保护力相当,其卵囊抑制率略低于母株,差异不明显（P〉0．05）。结果表明,本研究成功选育出堆形艾关耳球虫早熟株,对母株攻击具有保护力,为鸡球虫疫苗的研制奠定了基础。     

堆型艾美耳球虫早熟株对常用抗球虫药的敏感性测定

The study was aimed to explore the sensitivity of Eimeria acervulina （E.acervulina） precocious strain to some common anticoccidials (diclazuril, toltrazuril, sulfamonomethoxine, dinitolmide, decoquinate, nicarbazin, maduramicin, salinomycin and oxytetracycline). The sensitivity of E.acervulina precocious strain to 9 kinds anticoccidials was assessed by using 4 indices: anticoccidial activity percentage (POAA), reduction of lesion scores (RLS), relative oocyst production (ROP) and anticoccidial index (ACI). The results of these sensitivity trials indicated that the four indices POAA, RLS, ROP and ACI of groups toltrazuril, sulfamonomethoxine, dinitolmide, decoquinate, nicarbazin, salinomycin and oxytetracycline were all negative; the ROP index of diclazuril group was positive, the other three indices were negative. The ROP and ACI indices of maduramicin group were positive, the other two indices were negative. The results showed that the Eimeria acervulina precocious strain was sensitive to diclazuril, toltrazuril, sulfamonomethoxine, dinitolmide, decoquinate, nicarbazin, salinomycin and oxytetracycline, it was partly sensitive to maduramicin.     

Pathogenicity of Eimeria praecox alone or associated with Eimeria acervulina in experimentally infected broiler chickens

Eimeria praecox and Eimeria acervulina are two species of coccidia parasites infecting chickens, which develop in the duodenum. The purpose of this study was to evaluate the pathogenicity of E. praecox and to study interactions of this coccidium with E. acervulina. The results showed that the pathogenicity of E. praecox was related to the infective dose, and that its impact on individual weight and weight gain was significant from the lowest administered dose: 5000 oocysts per bird. No morbidity was observed, even with the highest infective dose, but faecal consistency alteration was higher with increasing infective doses. No consistent lesion was observed. When E. praecox was associated with E. acervulina with a low infective dose, performance deterioration seemed to be an additional effect of the two species. However, in the case of heavy infections, signs worsened along with duration of negative impact on growth, compared to a mono-infection.     

Characterization of stage-specific and cross-reactive antigens from Eimeria acervulina by chicken monoclonal antibodies

The characterization of five chicken monoclonal antibodies (mAbs) that were developed against apical complex antigens of Eimeria acervulina sporozoites is realized and the mAbs reactivity to merozoites belonging to this species is tested. Using immuno-fluorescence assay (IFA), one mAb (HE-4) that recognized apical antigens common to sporozoites of E. acervulina and E. brunetti bound antigens localized on the apical tip of merozoites from all stages of development examined. The mAb 8E-1, reactive with antigens found on the apical tip of all chicken Eimeria sporozoites, also showed binding to antigens common to merozoites from all generations. Another mAb, 8C-3, which identified an antigen shared by sporozoites apical tip and sporocysts wall of E. acervulina reacted very weak and inconstantly with the merozoites from all generations whereas the mAbs 5D-11 and 8D-2 that recognized antigens shared by the sporozoites of E. acervulina and E. maxima (mAb 5D-11) and E. acervulina and E. brunetti (mAb 8D-2) did not react with the merozoites from any generation. Collectively, these results showed that the invasive stages of chicken Eimeria share cross reactive apical complex antigens which are inter-species and inter-generation-specific that might be components of a potential recombinant vaccine.