THE LIFE-CYCLE OF CRYPTOSPORIDIUM-BAILEYI N-SP (APICOMPLEXA, CRYPTOSPORIDIIDAE) INFECTING CHICKENS
THE LIFE-CYCLE OF CRYPTOSPORIDIUM-BAILEYI N-SP (APICOMPLEXA, CRYPTOSPORIDIIDAE) INFECTING CHICKENS
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DOI：
10.1111/j.1550-7408.1986.tb05608.x
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发表时间：
1986-05-01
期刊：
影响因子：
--
通讯作者：
HAYNES, TB
中科院分区：
文献类型：
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作者：
CURRENT, WL;UPTON, SJ;HAYNES, TB
本文报道了一种从未报道过的从商品肉鸡中分离出的隐孢子虫的生活史和形态。隐孢子虫隐孢子虫隐孢子期对2日龄鸡和1月龄及6月龄鸡的开放期分别为接种后4-24天和4-14天。在感染后的前三天，C.在回肠和大肠肠上皮细胞的微绒毛区发现baileyi。感染后第4天，大多数寄生虫出现在泄殖腔和腔上囊的肠上皮细胞中。具有8个裂殖子的成熟I型裂殖体在感染后12小时首次出现，测得为5.0 × 10 - 6。4.9μ m。具有四个裂殖子和大颗粒残留物的成熟II型裂殖体在PI 48小时首次出现，测量为5.1 × 104。5.1μ m。具有8个短裂殖子和大的均匀残留物的III型裂殖体在感染后72小时首次出现，测量为5.2 × 104。5.1μ m。小配子（4.0 ×4.0μ m）。16个小配子进入大配子（4.7 × 106）。4.7μ m）。大配子产生两种类型的卵囊，在宿主细胞内形成孢子。大多数是厚壁卵囊（6.3 × 104）。5.2μ m），即在粪便中通过而未改变的抗性形式。有些是薄壁卵囊，其壁（膜）在从宿主细胞释放时容易破裂。在粘膜涂片中观察到来自薄壁卵囊的子孢子穿透肠上皮细胞。薄壁的自身感染卵囊的存在和I型meront的再循环可以解释为什么鸡发生持续长达21天的重肠道感染。C.将百乐虫经口接种到几只动物体内，以确定其宿主特异性。贝氏隐孢子虫在乳鼠和山羊或两日龄或两周龄鹌鹑中未产生感染。6只10日龄火鸡中有1只在BF中有少量的无性阶段。六只一天大的火鸡中有四只在BF中发生轻度感染，并且在四只中只有一只中观察到寄生虫的性阶段。所有7只1日龄鸭和7只2日龄鹅只在BF中出现严重感染，所有已知的发育阶段都存在。
The life cycle and morphology of a previously undescribed species of Cryptosporidium isolated from commercial broiler chickens is described. The prepatent period for Cryptosporidium baileyi n. sp. was three days post oral inoculation (PI) of oocysts, and the patent period was days 4-24 PI for chickens inoculated at two days of age and days 4-14 for chickens inoculated at one and six months of age. During the first three days PI, most developmental stages of C. baileyi were found in the microvillous region of enterocytes of the ileum and large intestine. By day 4 PI, most parasites occurred in enterocytes of the cloaca and bursa of Fabricius (BF). Mature Type I meronts with eight merozoites first appeared 12 h PI and measured 5.0 .times. 4.9 .mu.m. Mature Type II meronts with four merozoites and a large granular residuum first appeared 48 h PI and measured 5.1 .times. 5.1 .mu.m. Type III meronts with eight short merozoites and a large homogeneous residuum first appeared 72 h PI and measured 5.2 .times. 5.1 .mu.m. Microgamonts (4.0 .times. 4.0 .mu.m) produced .apprx. 16 microgametes that penetrated into macrogametes (4.7 .times. 4.7 .mu.m). Macrogametes gave rise to two types of oocysts that sporulated within the host cells. Most were thick-walled oocysts (6.3 .times. 5.2 .mu.m), the resistant forms that passed unaltered in the feces. Some were thin-walled oocysts whose wall (membrane) readily ruptured upon release from the host cell. Sporozoites from thin-walled oocysts were observed penetrating enterocytes in mucosal smears. The presence of thin-walled, autoinfective oocysts and the recycling of Type I meronts may explain why chickens develop heavy intestinal infections lasting up to 21 days. Oocysts of C. baileyi were inoculated orally into several animals to determine its host specificity. Cryptosporidium baileyi did not produce infections in suckling mice and goats or in two-day-old or two-week-old quail. One of six 10-day-old turkeys had small numbers of asexual stages only in the BF. Four of six one-day-old turkeys developed mild infections only in the BF, and sexual stages of the parasite were observed in only one of the four. All seven one-day-old ducks and seven two-day-old geese developed heavy infections only in the BF with all known developmental stages present.