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1.
四种兔艾美耳球虫卵囊产量的比较 总被引：1，自引：0，他引：1
分别用4种兔艾美耳球虫经口接种45日龄无球虫感染兔,接种剂量为1×104个卵囊/兔。感染后4d～20d,以麦克马斯特氏法计数每天排出的卵囊。结果表明,肠艾美耳球虫排卵量最多,为365.76×106个,中型艾美耳球虫为317.26×106个、黄艾美耳球虫为304.36×106个,大型艾美耳球虫排卵量最少,为200.12×106个。大型艾美耳球虫在感染后第6.5天有卵囊排出,第10.5天达到高峰(66.50×106个/只),占总量的33.23%;肠艾美耳球虫在感染后第9天有卵囊排出,第13天达到高峰(138.40×106个/只),占总量的37.83%;黄艾美耳球虫在感染后第9天有卵囊排出,第11天达到高峰(102.80×106个/只),占总量的33.78%;中型艾美耳球虫在感染后第4.5天有卵囊排出,第6.5天达到高峰(167.8×106个/只),占总量的52.89%。 相似文献
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鸡柔嫩艾美耳球虫广西株的分离与鉴定 总被引：3，自引：0，他引：3
目的建立一种简单、实用的单卵囊分离方法，并对一株广西柔嫩艾美耳球虫进行分离。方法采用电泳制胶槽来制作琼脂块进行球虫单卵囊的分离，单卵囊实验感染9只1日龄雏鸡，感染后收集粪便，用饱和盐水漂浮法进行卵囊检测。纯种卵囊经口感染10只1日龄雏鸡，观测卵囊寄生部位、最短孢子化时间，以及其潜在期和排卵高峰期。结果2只雏鸡粪便中检出卵囊，单卵囊感染成功率为22％。通过对其中一株球虫的研究，根据其卵囊的形状、大小、寄生部位、潜在期、卵囊最短孢子化时间、排卵高峰期等生物特征，鉴定该株球虫为柔嫩艾美耳球虫（Eimeria tenella）。结论本研究成功建立一种单卵囊分离技术，可作为球虫单卵囊分离的常规方法。 相似文献
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《中国家禽》2019,(1)
为研究不同感染剂量对毒害艾美耳球虫繁殖力的影响,设4个感染剂量组:500、2 500、5 000和10 000个孢子化卵囊/鸡,每组5只23日龄雏鸡,经鸡嗉囊接种卵囊。感染后鸡粪便中出现卵囊起至第16天,每天用麦克马斯特氏法对各组粪便中卵囊进行计数;在感染后第16天扑杀鸡,取盲肠进行卵囊计数。结果显示,各试验组鸡均无发生死亡,但10 000个卵囊感染组的临床症状最为严重;感染后144 h粪便中查见卵囊,500、2 500和5 000个卵囊感染组均出现2个排卵囊峰值,10 000个卵囊感染组只出现1个峰值,在第7～13天产出的卵囊量均占总产量的94.74%以上;每鸡粪便中排出的卵囊数随感染剂量的增加而增多,但单个卵囊的产量随感染剂量的增加而减少;感染后第16天盲肠中卵囊数不到总卵囊量的1%。结论:在疫苗生产或增殖传代时,感染剂量可选择10 000个卵囊/鸡,在感染后第7～13天收集粪便中卵囊。 相似文献
4.
为了解不同地区鸡源贝氏隐孢子虫的致病特点,对收集到的郑州、林州两地区鸡源贝氏隐孢子虫卵囊经雏鸡传代扩增纯化后,分别以1×106个卵囊量接种3日龄罗曼公雏鸡,从其排卵囊情况、临床症状和病理学变化比较了2个分离株的致病情况。结果表明:2个隐孢子虫分离株均主要引起雏鸡呼吸道症状和法氏囊炎病变;接种雏鸡均于感染后第4天开始排卵囊,林州株和郑州株排卵囊持续期分别为23 d和13 d;排卵囊高峰期均为感染后第8~12天。雏鸡感染2个地区鸡源贝氏隐孢子虫分离株后,排卵囊量及排卵囊规律存在差异。 相似文献
5.
本文以１．２５×１０７Ｃ．ｂａｉｌｅｙｉ卵囊的剂量人工经口感染３～７５日龄雏鸡，通过Ｃ．ｂａｉｌｅｙｉ卵囊排出规律和临床发病情况的观察，研究了雏鸡对Ｃ．ｂａｉｌｅｙｉ感染的年龄免疫现象。结果表明，３～７５日龄雏鸡均能感染Ｃ．ｂａｉｌｅｙｉ；３～１０日龄雏鸡易感性高，感染后排出印囊的量大，排出印囊的时间长，持续到感染后第２０天；２０日龄以上的雏鸡随着年龄的增长，感染后排出卵囊的量逐渐减少，排出印囊的时间缩短，仅持续到感染后第１５天。５０日龄以下的雏鸡感染后排出卵囊的量明显地高于５０日龄以上的雏鸡，５０～７５日龄的雏鸡易感性很低，排出卵囊的量趋于恒定地极少量排出。从而揭示随着雏鸡年龄增长免疫系统发育逐步完善，感染后排出印囊的量逐渐减少、排出卵囊的时间缩短、对Ｃ．ｂａｉｌｅｙｉ的易感性逐渐降低的规律。首次实验证实Ｃ．ｂａｉｌｅｙｉ作为一种原发性病原主要侵害５０日龄以下的雏鸡，尤其是１０日龄以内的雏鸡易感性最高，发病和死亡主要见于１０日龄以内感染的雏鸡。 相似文献
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7.
本试验应用1.0×103、1.0×104和5.0×1043个不同剂量的柔嫩艾美耳球虫孢子化卵囊,进行人工感染发病。对雏鸡感染后不同时间的卵囊排出情况进行了观察。结果表明用3个剂量水平分别感染雏鸡时,卵囊排出均集中在第6～12d之间。其中第7d时的卵囊排出量最高,且3个剂量水平中,1.0×103组OPG最高达81.00;1.0×104个/只和5.0×104个剂量组略次之,分别为76.50和68.85;第7d以后各组的卵囊排出量均逐渐减少,到第13d时基本不再向外排卵囊。 相似文献
8.
挑选120羽体况相近的15日龄罗斯(Ross)公鸡,均分为5组,用柔嫩艾美球虫(Eimeria tenella)实验室保种天山株,分50、500、5000、50000个孢子化卵囊进行感染,另设不感染球虫组。观察用不同剂量感染,对鸡生长的影响程度;并于感染后96小时起,收集各组每天排出的粪便,进行虫卵计数;感染后13天,各组称重,并抽取6羽剖杀,进行盲肠病变记分。剩余鸡进行抗攻击试验,每羽攻击10万个孢子化卵囊,攻击后8天剖杀,结束试验。结果为:①感染50、500个卵囊的组,鸡平均增重与不感染组无差异;感染5000、50000个卵囊的组,增重则明显低于不感染组(P<0.05);各组盲肠病变和血便记分随感染量增加而增高。②各组在感染后5天之内的粪便中均未检出卵囊;感染50、500个卵囊组,在感染后6～7天的粪便中查出卵囊;感染5000、50000个卵囊组,则在5～6天的粪便中发现卵囊;50000个卵囊组,排卵高峰集中在感染后6～7天(占排出总量的62.23％),而另三个组的排卵高峰不集中;所有感染组在第13天的粪便中,卵囊量已降到很低(仅占总量的0.07～7.37％)。③各组的抗攻击能力随感染剂量增加而提高;各感染攻击组的平均增重均与不感染攻击组差异达极显著(P<0.01),感染5000个卵囊攻击组的增重最好;各组的盲肠卵囊计数、血便记分、盲肠病变记分均随原感染量的增加而降低。 相似文献
9.
巨型艾美耳球虫(Eimeria maxima)地理株研究Ⅱ.11株巨型艾美耳球虫的致病性分析 总被引：4，自引：0，他引：4
分别用0.1×104、1×104、10×104个/只孢子化卵囊的剂量感染黄羽肉公雏,以临床症状、肉眼病变、平均增重、病变记分和死亡率为判定指标,对11株E.maxima的致病性进行了分析.结果表明各虫株引起的临床症状和各病死鸡的肉眼病变基本相似.各感染组的增重(0.1×104组例外)与对照组相比均有显著差异(P＜0.05).在感染10×104个/只的剂量时,上海株增重最少,苏州株和龙岩株增重最多;扬州株的病变记分最大,苏州株和龙岩株的最小,相比有显著差异(P＜0.05);扬州株、连云港株、福州株、广州株和美国株引起鸡死亡,死亡率分别为20%、10%、10%、10%和10%.结论11个虫株均有致病性,扬州株和上海株的致病力较强,而苏州株和龙岩株的致病力较弱. 相似文献
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11.
F Noordeen N U Horadagoda A C M Faizal R P V J Rajapakse M A A Razak A Arulkanthan 《Veterinary parasitology》2002,103(3):217-225
An experimental study was carried out in neonatal goat kids to examine the infectivity of Cryptosporidium oocysts, pattern of oocyst shedding and morphological changes in the intestine during the infection. Cryptosporidium oocysts isolated from adult asymptomatic goats, and identified as C. parvum by polymerase chain reaction (PCR) were used in this study. Of three 4-day-old goat kids, two were orally infected with C. parvum oocysts (10(5) oocysts in 10 ml PBS/kid). One goat kid given 10 ml PBS only by the oral route served as a control. Cryptosporidium oocysts were detected in the faeces of one infected kid on day 3 post-inoculation (pi) whereas in the other 6 days pi. The faecal oocyst counts gradually increased and the peak counts in the two kids were 2 x 10(6)g(-1) (on day 12 pi) and 3.2 x 10(6)g(-1) (on day 14 pi). The increase in faecal oocyst output coincided with diarrhoea in an infected kid from days 10-17 pi. Although the oocyst excretion declined gradually after the peak, both infected kids excreted oocysts until euthanized on days 20 and 22 pi. Light and scanning electron microscopic investigations of the ileum revealed the endogenous stages on the brush border of the enterocytes, infiltration of neutrophils and mononuclear cells into the lamina propria, atrophy, stunting and fusion of villi. For purposes of comparison, goat Cryptosporidium oocysts were inoculated orally (10(3) oocysts/mouse) to eight, 1-week-old mice. All experimental mice excreted oocysts from day 3 pi, and four infected mice continued to excrete oocysts up to day 42 pi. The experimental infection described in goat kids resembled the natural disease in terms of oocyst excretion, clinical signs and intestinal pathology. The ability of oocysts excreted by asymptomatic goats, to infect goat kids and mice is likely to have a major impact on the epidemiology of cryptosporidiosis in livestock and man. 相似文献
12.
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。 相似文献
13.
Christensen, S. AA. Henriksen: Shedding of oocysts in piglets experimentally infected with Isospora suis. Acta vet scand., 1994, 35, 165-172.–Forty-seven piglets were inoculated with doses of 100 to 50,000 sporulated oocysts of Isospora suis. After 5-7 days oocysts were found in faeces. The patent period extended from 8 to 16 days. The shedding of oocysts showed a cyclic pattern with 2-3 peaks separated by intervals of approximately 5 days. Subpatent periods were often seen between the peaks.The level of oocyst shedding during the initial days of the patent period reflected, to some extent, the inoculation dose. However, a maximum of OPG at the 100,000 level was observed among one or more piglets from all groups, regardless of the inoculation dose. Among the majority of piglets inoculated with more than 100 oocysts, the highest OPG-figures were observed in the first peak of the cyclic pattern. Unlike this, the maximum of OPG was observed in the second peak of the cycle among 6 of the 7 piglets inoculated with 100 oocysts only. The triphasic pattern was most pronounced in the low dosed group.The marked upscaling of oocyst production, as particularly registered in the low dosed groups, seams to explain at least part of the problems met under practical conditions, when trying to eliminate the transmission of oocysts between successive litters in the farrowing boxes.The cyclic excretion pattern and an apparent absence of autoinfections may indicate that the development of I. suis in the host includes several oocyst producing generations descending from the same initial infection.The presence of subpatent periods can probably explain the marked variation in OPG, as they are often recorded when examining faecal samples from piglets, even when the samples are originating from the same litter. 相似文献
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The infection dynamics of Eimeria species determine the clinical manifestation of the disease coccidiosis in poultry flocks, and a better understanding of the dynamics may contribute to improvement of control measures. Our aim was to study the course of infection and the transmission of Eimeria acervulina in groups of broilers by quantifying the transmission rate parameter and oocyst output. Three transmission experiments were carried out with groups of 20 male SPF broilers. At 2 days of age, one bird in each trial was orally inoculated with five sporulated E. acervulina oocysts (D0 post-inoculation, pi). One day after inoculation (D1 pi), the inoculated bird was housed with 19 non-inoculated contact birds. Individual faecal droppings were examined daily from D3-D32 pi to quantify the number of oocysts per gram faeces. The inoculated bird started shedding oocysts at D5 pi and contact birds between D10 and D17 pi. Contact birds that became infected due to oocyst excretion by the inoculated bird were characterized as first generation contact birds (C1). Contact birds excreting from D15 pi onwards (C2) became infected after the first C1 birds had started shedding and were considered to belong to a successive generation of the flock infection. Oocyst output was significantly lower for C1 compared to C2 birds, but the transmission rate parameter remained constant for both infection generations. These results suggest that although oocyst load increases, the transmission rate of E. acervulina remains constant between successive generations of infection in a flock. 相似文献
15.
Vaccines composed of either virulent or attenuated Eimeria spp. oocysts have been developed as an alternative to medication of feed with ionophore drugs or synthetic chemicals. The purpose of this study was to evaluate the use of gel-beads containing a mixture of Eimeria acervulina, Eimeria maxima, and Eimeria tenella oocysts as a vaccine against coccidiosis. Newly hatched chicks (Gallus gallus domesticus) were either sprayed with an aqueous suspension of Eimeria oocysts or were allowed to ingest feed containing Eimeria oocysts-incorporated gel-beads. Control day-old chicks were given an equivalent number of Eimeria oocysts (10(4) total) by oral gavage. After 3 days, chicks were randomly assigned to individual cages, and feces were collected between days 5 and 8 postinfection. All samples were processed for total Eimeria oocysts. At 4 wk of age, all chickens and a control nonimmunized group received a high-dose E acervulina, E maxima, and E. tenella challenge infection. Oocyst excretion by chicks fed gel-beads or inoculated by oral gavage was 10- to 100-fold greater than that of chicks spray-vaccinated with the Eimeria oocysts mixture (log 6.3-6.6 vs. log 4.8). Subsequent protection against challenge as measured by weight gain and feed conversion efficiency was significantly greater (P < 0.05) in gel-bead and oral gavage groups compared with spray-vaccinated or nonimmunized groups. Also, gel-bead and oral gavage groups showed no significant difference (P > 0.05) in weight gain and feed conversion efficiency compared with nonchallenged controls. These findings indicate that incorporation of Eimeria spp. oocysts in gel-beads may represent an effective way to deliver live oocyst vaccines to day-old chicks for preventing subsequent outbreaks of coccidiosis in the field. 相似文献
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The acquisition of immunity to Eimeria maxima by chicks infected 18 hr after hatch with a single dose of 100 oocysts was investigated. In the first experiment, birds were moved each day to clean cages in order to prevent the possibility of secondary infection resulting from ingestion of oocysts passed in their feces. Immunity was measured at 4 wk of age by calculation of oocyst production following challenge with 500 oocysts or weight gain following challenge with 100,000 oocysts. Large numbers of oocysts were produced by infected birds following challenge, although numbers were significantly less than those from birds that had been reared in the absence of infection (susceptible controls). The weight gain of infected birds following challenge was significantly greater than that of susceptible controls but less than that of unchallenged controls. Thus, only partial protection had been acquired, whether parasite replication or body weight gain was used to assess the extent of immunity development. In a second experiment, acquisition of immunity at 4 wk by chicks infected 18 hr after hatch with 100 oocysts of E. maxima and reared in floor pens in contact with their droppings was investigated. Infected birds produced no oocysts following challenge, and weight gains were not significantly different from the unchallenged controls, which indicates that full immunity had developed by 4 wk. It is concluded that if oocysts of Eimeria species are used to vaccinate day-old chicks, reinfection by oocysts present in the litter is necessary for the establishment of protective immunity. 相似文献
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给18日龄鸡胚接种一定剂量的柔嫩艾美耳球虫(Eim eria tenella)和/或堆形艾美耳球虫(E.acervulina)孢子化卵囊,出雏后在无球虫环境中笼养,1~10日龄每天收集各组粪便样本,计数克粪便卵囊数(OPG),并于14日龄时以大剂量同源孢子化卵囊攻虫,以相对增重率(RWG)、饲料转化率(FCR)、相对卵囊产量(ROP)评价免疫保护效果。结果显示,以E.tenella或E.acervulina卵囊免疫18日龄鸡胚,其卵囊排出的潜隐期及达到峰值的时间与1日龄雏鸡接种组相一致,有相似的排卵囊曲线,提示其诱导免疫的建立是在出雏后开始建立的。攻虫后各免疫组的RWG由攻虫对照组的31.9%~51.7%提高到了76.5%~83.6%,RCR由攻虫对照组的4.11~4.89改善为2.72~2.96,ROP降至4.7%~23.5%。结果表明以一定剂量E.tenella和E.acervulina卵囊单独或混合经羊膜腔免疫18日龄鸡胚都可以建立起针对出雏后14日龄同源攻虫的良好免疫保护力。比较混合免疫E.tenella和E.acervulina卵囊组与单一接种E.tenella或E.acervulina卵囊组的免疫效果发现,混合免疫组的各项指标均稍优于后者。 相似文献