柔嫩艾美尔球虫和巨形艾美尔球虫混合感染致病性研究

材料和方法１．试验动物ＡＡ肉鸡，购自江苏省家禽研究所，出壳后运回实验室饲养在杀灭卵囊的笼具中至１５日龄，经数次粪检未见卵囊后供试验。２．球虫卵囊为本教研室分离鉴定的纯种柔嫩艾美尔球虫和巨形艾美尔球虫孢子化卵囊，４℃保存。３．试验分组挑选体况相近的１５日龄ＡＡ肉鸡５０羽，分成５组。第１组为不感染对照组；第２组为单种球虫感染组，每羽经口接种柔嫩艾美尔球虫孢子化卵囊１万个；第３、４和５组为混合感染组，每羽分别同时感染柔嫩艾美尔球虫和巨形艾美尔球虫孢子化卵囊：０．５＋５万、１＋１０万和２＋２０万个。４．…     

雏鸡实验感染柔嫩艾美尔球虫的病理学研究

１１４只２３日龄无球虫罗斯小公鸡，分为三组，第１和第２每只鸡分别口服１．０８×１０＾５和５．４２×１０＾４个柔嫩艾美尔球虫孢子化卵囊，第３组对照。结果，第１、２组在感染后第４天呈现血便，第５天发性死亡，其死亡率分别为１３．６％５０和５．４％。尸体剖检，盲肠明显肿大，肠壁出血；后期，盲肠萎缩，并出现干酪样肠 芯。病理组织学变化特点，为出血一坏死性或出血一卡地他性盲肠炎，以及出血一卡他性直肠炎。第８天     

柔嫩艾美尔球虫（荣昌株）对球佳等三种抗球虫药的抗药性试验

采用鸡体药效试验法测定了柔嫩艾美尔球虫对球佳,球安,加福三种药物的抗药性。试验结果表明：球佳,加福的最适抗球虫活性百分率（POAA）分别为58．99％,78．23％,90．27％;病变记分减少率（RLS）为100％,72．73％,74．03％,相对盲肠卵囊产量（ROP）为10．26％,577．6％,288．6％。POAA,RLS显示柔嫩艾美尔球虫对三种药物均无抗药性,而ROP显示对球安,加福有抗药。综合POAA,RLS,ROP三项参数指标判定柔嫩艾美尔球虫对球佳敏感,对球安,加福有轻度抗药性。     

柔嫩艾美耳球虫石家庄株的生物学特性与抗药性研究

用5×104个柔嫩艾美耳球虫石家庄株孢子化卵囊感染14日龄雏鸡,对卵囊潜隐期、最早孢子化时间、形态及大小等生物学特性进行了测定。并以最适抗球虫活性百分率（POAA）、病变记分减少率（RLS）、相对卵囊产量（ROP）和抗球虫指数（ACI）为指标,检测了常用抗球虫药对其敏感性。结果表明：（1）该虫株寄生于盲肠,呈宽卵圆形,壁光滑,分2层,多数可见极粒。卵囊大小范围为（19.68～27.76）μm×（15.21～23.99）μm,平均大小为（23.41±2.22）μm×（19.34±2.27）μm,卵囊指数1.21。孢子囊大小范围为（8.30～14.28）μm×（4.05～9.15）μm,平均大小为（11.69±1.53）μm×（6.74±1.26）μm,孢子囊指数1.73。潜隐期和最短孢子化时间分别为133h和20h。（2）该虫株对马杜霉素、克球粉与球敌呈完全抗药性;对瑞冠球呈轻度抗药性;而对氨丙啉和金三特无抗药性。     

柔嫩艾美尔球虫裂殖子免疫原性的研究

本文评价了柔嫩艾美尔球虫第二代裂殖子的免疫原性。试验采用弗氏完全佐剂乳化的裂殖子抗原及从组织中分离得的活游离殖子，以不同剂量的不同时间接种健康小鸡，随后用同源球虫进行攻击。效果评价指标为：（１）比较各抗原组的鸡只死亡率及盲肠病变记分；（２）各抗原组鸡只的增重差异。结果表明，柔嫩艾美尔球虫第二代裂殖子抗原不能刺激鸡体产生保护性免疫力；具有活力的裂殖子接种于健康鸡盲肠能诱发部分免疫力，但较自然感染者为     

柔嫩艾美尔球虫野外株对3种聚醚类离子载体抗生素的敏感性试验

采用鸡体药效试验法测定了柔嫩艾美尔球虫对３种聚醚类离子载体抗生素的敏感性。试验证明，柔嫩艾美尔球虫野外分离株对盐霉素（６６×１０－６）、莫能菌素（１２０×１０－６）和拉沙菌素（１２５×１０－６）产生了耐药性。上述３种药物的抗球虫指数（ＡＣＩ）分别为１４９．３９、１３４．０４和１５６．１１。但这３种药物对柔嫩艾美尔球虫标准株仍然有效     

巨型艾美耳球虫纯种鉴定和致病性研究

采用单卵囊感染技术，从鸡球虫混合种中分离出一个纯种球虫，经鉴定为巨型艾美耳球虫（ＥｉｍｅｒｉａＭａｘｉｍａＴｙｚｚｅｒ，１９２９）。该种球虫卵囊为卵圆形，测２４０个的大小范围为２１．２５～３６．２５×１７．５～３０．０μｍ，平均为２８．８１±３．０７×２２．９８±２．７７μｍ，形状指数１．２５。卵囊内有一颗折光性极粒，位于窄端，无外残体。测１２０个孢子囊的大小范围为１５．５～１８．５×７．５～１０．０μｍ，平均为１７．３５±０．６６×８．７４±０．５１μｍ。最短孢子化时间为３０小时，潜伏期１４２小时。用此卵囊对鸡作致病性试验，挑选６０羽１３日龄伊莎（ＩＳＡ）公鸡分为１个不感染组和４个感染组，每羽口服感染１万、５万、１０万或２０万个孢子化卵囊。结果所有感染组与不感染组的平均增重差异达到显著（Ｐ＜０．０５）或极显著（Ｐ＜０．０１）水平，整个试验仅在２０万个的感染组出现１６．７％的死亡率，各感染组的肠道病变记分分别为１．３３、１．８３、２．４２和３．０８。     

毒害艾美球虫纯种分离的初步鉴定和致病性研究

采用从寄生部位分离和单卵囊感染技术,对现场采集的鸡球虫混合种进行单种纯化,获得了毒害艾美球虫(Eimeria necatrix)。该种卵囊呈卵圆形,经测240个卵囊,平均为19.06±1.54×16.50±1.26 μm,形状指数1.16。测120个孢子囊,平均为11.27±0.70×6.21±0.51μm。无卵囊残体和孢子囊残体,未观察到卵膜孔和极帽。最短孢予化时间为19小时,感染后最早排出时间143小时,最大裂殖体68.75×66.25μm。用此卵囊1万、5万、10万和20万个分别感染10日龄伊莎公鸡,结果感染5～20万个卵囊组的死亡率为41.67～50.00％,感染组的肠道病变记分为1.33、3.42、3.67和3.83,其平均增重与不感染对照组差异极显著(P<0.01)。E.necatrix对鸡致病性很强,在生产上需高度重视,做好预防工作。     

鸡球素防治柔嫩艾美尔球虫的疗效试验

试验对15日龄无球虫海赛克斯雏鸡人工接种感染柔嫩艾美尔球虫孢子化卵囊10×10~4个,用鸡球素5mg拌饲进行预防,有很好的效果;试验期平均增重与不感染不给药(健康组)相近,雏鸡存活率100％,抗球虫指数(ACI)172.25。鸡球素与氯苯胍联合使用,表现有相加作用,雏鸡存活率100％,抗球虫指数(ACI)180.25;而氯苯胍单用防治效果很差,表明该株球虫已对氯苯胍产生了抗药性。     

日粮中加硒对鸡柔嫩艾美尔球虫的效力试验

试验在日粮中添加两个水平（０．５ｍｇ／ｋｇ、０．７５ｍｇ／ｋｇ）亚硒酸钠，分试验组与对照组对海赛鸡人工感染柔嫩艾美尔球虫（Ｅ．ｔｅｎｅｌｌａ）进行试验，通过抗球虫指数（ＡＣＩ）、平均增重、病变值、死亡率等几项指标测定，说明日粮中添加硒对鸡抗柔嫩艾美尔球虫的效力。     

鹅艾美耳球虫(Eimeriaanseris)克隆株的建立及生物学特性研究

采用单种卵囊分离技术建立了鹅艾美耳球虫(Eimeriaanseris)克隆株,并对其基本生物学特性进行了研究。卵囊呈梨形,一端截平,另一端钝圆。卵囊壁单层,光滑无色或淡黄色,狭窄截平端有卵膜孔。无极粒,外残余体似一块不规则的塞状物,位于卵膜孔的正下方。测量100个卵囊,平均大小为19·37μm×16·06μm,形状指数为1·20。孢子囊卵圆形,斯氏体明显,有内残余体。测量100个孢子囊,平均大小为9·09μm×6·83μm。潜在期为168~173h,显露期为107~118h,最短孢子发育时间为55h。用不同剂量感染时,E·anseris的繁殖力差异显著(P<0·05)。     

Eimeria capricornis n.sp., E. nihonis n.sp., E. naganoensis n.sp., and E. kamoshika n.sp. (Protozoa: Eimeriidae) from the Japanese serow, Capricornis crispus

Eimeria capricornis n.sp., E. nihonis n.sp., E. naganoensis n.sp. and E. kamoshika n.sp. were detected from the Japanese serow, Capricornis crispus. The oocysts of these species were ovoid to ellipsoid, measuring 48.02 +/- 0.53 x 33.93 +/- 0.35 microns, 29.73 +/- 0.45 x 21.01 +/- 0.29 microns, 20.04 +/- 0.05 x 15.77 +/- 0.04 microns and 30.02 +/- 4.24 x 14.58 +/- 2.03 micron, respectively. In all the species the micropyle was observed, but the micropylar cap and oocyst residuum were not present. The polar granules were observed in the oocysts of E. capricornis. The sporocysts of the above species were spherical to elongate ovoid, measuring 15-23 x 8-13 microns, 14-16 x 7-10 microns, 11-13 x 6-8 microns and 8-10 x 6-7 microns, and the sporulation time was 6, 3, 3 and 6 days, respectively. The sporocyst residuum and refractile body were seen in all the species. In the sporocysts of E. naganoensis and E. kamoshika tiny Stieda body was seen, but not in the other two species. These four Eimeria species were not infective to goats.     

Distribution of oocysts, sporocysts and sporozoites of Eimeria tenella and Eimeria maxima in the digestive tract of chicken.

The distribution of oocysts, sporocysts and sporozoites of Eimeria tenella and Eimeria maxima in the digestive tract of chicken and in excreta was investigated. At 1 h after the oral inoculation of E. tenella oocysts, the number of sporocysts in the cecum was 3.4 x 10(6) and decreased gradually thereafter, and the number of sporozoites in the cecum increased and remained at a high level until 12 h after the inoculation. Small numbers of sporocysts and sporozoites of E. tenella were found in other intestinal sites. A great number of E. maxima sporozoites was found, especially in the jejunum, 2 h after the inoculation. The findings that the largest populations of sporozoites of E. tenella and E. maxima were found in the cecum and the jejunum, respectively, indicate that the site specificity of sporozoite invasion for each species is determined before the invasion takes place.     

Life cycle of Isospora burrowsi n sp (Protozoa: Eimeriidae) from the dog Canis familiaris

Exogenous and endogenous stages of Isospora burrowsi n sp from the dog are described. Oocysts were spherical or ellipisoidal and 17 to 22 by 16 to 19 micrometer (mean 20.3 by 17.3 micrometer). Micropyle, oocyst residuum, and polar granule were not present. Sporocysts were 12 to 16 by 8 to 11 micrometer (mean 14.4 by 9.7 micrometer). Stieda body was absent, but a sporocyst residuum was present. Endogenous stages were in the caudal three-fifths of the small intestine and in the cecum. Mature 1st-generation schizonts (11 to 18 by 9 to 18 micrometer) were present on the 4th day of infection. One day later, mature 2nd-generation schizonts (18 to 35 by 17 to 22 micrometer) were present. Immature gamonts were found 5 days after infection, and unsporulated oocysts were also present later that day. The prepatent period was 6 days, and the mean patent period was 11 days. The oocysts of I burrowsi differ markedly in size from all other Isospora species from dogs, except Isospora ohioensis; however, the endogenous stages of the 2 species differ.     

Fatal coccidiosis by Isospora icterus (Upton & Whitaker, 2000) in captive Campo Troupial (Icterus jamacaii) in Brazil

An outbreak of coccidiosis by Isospora icterus (I. icterus, Upton & Whitaker, 2000) in captive Campo Troupial (Icterus jamacaii) (Gmelin, 1788) at the Wild Animals Triage Center (IBAMA, Belo Horizonte, Brazil) is described. Clinical history and the necropsy findings documented diarrhea with diffuse necrotic enteritis. Sporulated oocysts (n = 100) had a bilayered wall, were subspherical, and measured 30.1 (27.5-32.5) microm in length and 28.5 (26.2-30.0) microm in width. A polar body but no micropyle was present and the length/width ratio was 1.1 (1.00-1.2). Each oocyst contained two ellipsoidal sporocysts measuring 17.6 (15.0-20.0) microm in length and 12.9 (12.5-15.0) microm in width, with a length/width ratio of 1.4 (1.2-1.5), and with Stieda and sub-Stieda bodies. Each sporocyst contained four sporozoites with granular sporocyst residuum. Oocysts were compatible with those from I. icterus, previously described in Campo Troupial.     

柔嫩艾美耳球虫广西南宁株的分离及鉴定

利用从南宁市郊养鸡场球虫病鸡粪便中收集的球虫混合种卵囊感染小鸡,再应用单卵囊分离感染技术,从感染鸡盲肠中收集的卵囊分离纯化获得1株纯种球虫,经鸡体传代增殖,对该虫株的卵囊大小和卵形指数、潜在期、排卵高峰期、最短孢子化时间、寄生部位、致病性等指标进行观察和测定。结果测得该虫株卵囊的平均大小为(25.743±1.94126)μm×(21.4±1.85985)μm,平均卵型指数为1.2067±0.07;潜在期为140 h;其排卵囊峰期在第6～9天,最高峰在第7天;最短孢子化时间为19 h;寄生部位在盲肠;对两周龄的艾维茵鸡,当使用5×104的孢子化卵囊感染剂量时死亡率为7.5%。根据这些测定和观察到的指标综合鉴定该分离株球虫为柔嫩艾美耳球虫,并命名为柔嫩艾美耳球虫广西南宁株(Eimeria.tenella-GXNN),该研究结果为进一步研究本地区鸡球虫病的药物治疗和免疫预防等奠定了基础。     

The prepatent and patent periods of Eimeria alabamensis and further description of the exogenous stages

Eimeria alabamensis infections were established in calves 5 to 6 weeks of age by adminestering 10 million, 80 million, or 100 million sporulated oocysts. The prepatent period was 6 to 8 days (mean 6.6). Oocyst discharges usually lasted for 2 to 3 days although a few calves passed oocysts throughout the rest of the 3-week observation period. Calves with oocyst discharge exceeding 1 million oocysts per g of feces had a moderate diarrhea at the time of peak oocyst discharge. No other clinical signs were observed in any of the infected calves. Reinoculations with 100 million sporulated oocysts given 3 weeks after the initial inoculations of 10 million or 80 million oocysts resulted in infections characterized by greatly reduced oocyst discharges. Sporulated oocysts of E. alabamensis were 16 to 24 μ by 12 to 16 μ and were usually ovoid. The oocyst wals consisted of two layers. Sporocysts were elongate-ellipsoid, had a distinct Stieda body, and were 10 to 12 μ by 4 to 6 μ. Completely sporulated oocysts were first observed after 5 days at 25 °C, and most were sporulated after 8 days. Oocysts did not sporulate at 4 °C, 33 °C, and 37 °C.     

Isolation and selection of ionophore-tolerant Eimeria precocious lines: E. tenella, E. maxima and E. acervulina

Eimeria parasites were isolated from Nanhai Guangdong province (southern China) and studied in chickens in wire cages to evaluate their drug resistance against commonly used ionophores: monensin (100 mg/kg of feed), lasolacid (90 mg/kg), salinomycin (60 mg/kg), maduramicin (5 mg/kg) and semduramicin (25 mg/kg). Chinese Yellow Broiler Chickens were infected with 40,000 crude sporulated Eimeria oocysts at 15 days of age and prophylactic medication commenced a day prior to infection. Drug resistance was assessed for each ionophore drug by calculating the anticoccidial index (ACI) and percentage optimum anticoccidial activity (POAA) based on relative weight gain, rate of oocyst production and lesion values. Results revealed that Nanhai Eimeria oocysts comprising of E. tenella, E. maxima and E. acervulina, were resistant to monensin, sensitive to both salinomycin and lasolacid and partially sensitive to maduramicin and semduramicin. By selection for early development of oocysts during passage through chickens, the prepatent time of E. tenella, E. maxima and E. acervulina were reduced by 49, 36 and 22 h, respectively. The precocious lines are less pathogenic than the parent strains from which they were selected and conferred a satisfactory protection for chickens against coccidiosis. These ionophore-tolerant precocious lines could have wider applications in the development of anticoccidial vaccines for sustainable control of coccidiosis.     

布氏艾美耳球虫南宁株的分离及鉴定

本试验从南宁市郊区某鸡场感染球虫病的病鸡粪便中收集到混合卵囊,采用改良过的琼脂单卵囊分离法从中分离纯化出2个球虫虫株,并对其中的1个球虫分离株进行了鉴定,鉴定结果为:该株球虫卵囊呈椭圆形或卵圆形,卵囊平均大小为(22.51±0.4790)μm×(15.94±0.5599)μm,平均卵型指数为1.41212±0.06714,裂殖体平均大小为31.33 μm×27.46 μm,潜在期为120 h 50 min,排卵高峰期为感染后第6天,最短孢子化时间为18 h 50 min,寄生部位为小肠中、下段,属中等毒力的球虫虫株。通过将这些测定和观察到的指标与各类文献中所记载的各种鸡艾美耳球虫的特征进行了对比,经过综合分析后,将该分离株球虫鉴定为布氏艾美耳球虫,并且将它命名为布氏艾美耳球虫南宁株,记为Eimeria.brunetti-GXNN。对该虫株的成功分离鉴定,为进一步了解本地球虫虫株的生物学特性,开展鸡球虫病的免疫预防奠定了基础。     

Evaluation of interspecific hybrids of the chicken, guinea fowl, and Japanese quail for innate resistance to coccidia

Experimental chicken/guinea fowl hybrids, guinea fowl, and chickens were orally inoculated with Eimeria acervulina or E. tenella, which are specific for chickens, or with E. grenieri, which is specific for guinea fowl. No intact oocysts were found in feces within 24 hr of inoculation, suggesting that excystation occurred in the normal and abnormal hosts. No oocysts were found in the feces of hybrids during a 9-day postinoculation period. The guinea fowl passed oocysts of guinea fowl coccidia (E. grenieri) but not those of chicken coccidia, and the chickens passed oocysts of chicken coccidia (E. acervulina and E. tenella) but not those of guinea fowl coccidia. Some asexual development (schizogony) occurred in hybrids inoculated with E. tenella, but sexual development (gametogony) did not. In contrast, quail/chicken hybrids became infected with oocysts of chicken coccidia (E. acervulina, E. tenella, and E. maxima) and quail coccidia (E. bateri) and passed a few oocysts during the normal patent period; control chickens and quails became heavily infected with oocysts of chicken and quail coccidia, respectively.