Avian and Rabbit Virology, Immunology, Parasitology Unit, ANSES, Laboratory of Ploufragan-Plouzané-Niort, PO Box 53, 22440 Ploufragan, France.
Parasite. 2021;28:32. doi: 10.1051/parasite/2021031. Epub 2021 Apr 2.
The sporulation of oocysts of Eimeria that infect poultry is known to be under the influence of environmental conditions, including temperature, oxygen supply, and moisture. However, even when these conditions are optimal, the level of sporulation can remain low. The effect of oocyst maturity on their ability to sporulate was investigated for two species of Eimeria: E. acervulina of chickens, and E. meleagrimitis of turkeys. After oral infection of birds, oocysts were collected at their production site in the intestine at different times around the prepatent period. The percentage of sporulation was determined by observation of 100 oocysts for each sample. With E. acervulina, it was observed that sporulation depended on the time of collection of the oocysts in the intestine, and that it increased with aging oocysts (from 5% to 40% globally in 8 h). With E. meleagrimitis, sporulation remained low with oocysts collected in the duodenum (below 20%), but oocysts collected in the midgut and in the lower intestine sporulated more efficiently (around 80%) than oocysts collected in the duodenum at the same time. One explanation for these results is the assumption that oocysts may be produced before fertilization, and that microgametes have not yet fertilized the newly produced oocysts. As time goes on, more oocysts would be fertilized, locally in the duodenum for E. acervulina, and descending along the gut for E. meleagrimitis. This hypothesis needs to be investigated further, but it could lead to new approaches to control these parasites by targeting the microgametes.
已知感染家禽的艾美耳球虫的卵囊形成受到环境条件的影响，包括温度、氧气供应和湿度。然而，即使这些条件最佳，卵囊形成率仍可能很低。本研究调查了两种艾美耳球虫（鸡的柔嫩艾美耳球虫和火鸡的毒害艾美耳球虫）卵囊成熟度对其形成能力的影响。通过对鸟类进行口服感染，在潜伏前期的不同时间，从肠道中采集卵囊的产生部位的卵囊。通过观察每个样本的 100 个卵囊来确定卵囊的形成率。对于柔嫩艾美耳球虫，观察到卵囊的形成取决于在肠道中收集卵囊的时间，并且随着卵囊的老化而增加（在 8 小时内从 5%增加到 40%）。对于毒害艾美耳球虫，在十二指肠中采集的卵囊的形成率仍然较低（低于 20%），但在中肠和下肠中采集的卵囊的形成率（与同一时间在十二指肠中采集的卵囊相比）更高（约 80%）。这些结果的一个解释是假设卵囊可能在受精前产生，并且新产生的卵囊中的微配子尚未受精。随着时间的推移，更多的卵囊会在十二指肠中对柔嫩艾美耳球虫进行局部受精，或者在毒害艾美耳球虫沿肠道下降时受精。需要进一步研究这个假设，但它可能会为通过靶向微配子来控制这些寄生虫提供新的方法。
