PDF(Pubmed)
Abstract：
Vaccination of chickens against avian coccidiosis in chickens often involves storing Eimeria oocysts for months after oocyst propagation and sporulation. The purpose of this study was to determine how long E. acervulina, E. maxima, and E. tenella oocysts remained viable when stored at refrigeration (4°C) or egg room (20°C) temperatures. Separate tubes containing E. acervulina, E. maxima, or E. tenella oocysts were stored at these temperatures and a sample removed every 3 mo for inoculating chickens for evidence of a patent infection. Also, an aliquot of each Eimeria species at each time-temperature combination was subjected to in vitro excystation to quantify the relative number of released sporozoites to intact (nonexcysted) sporocysts. Eimeria tenella appeared to be most susceptible to storage in that no oocyst production was observed at 9 mo at either temperature. Although E. maxima oocysts were viable at 9 mo, no oocyst production was observed at 12 mo storage at these 2 temperatures. Quite unexpected was that E. acervulina was much more stable than E. tenella and E. maxima remaining viable up to and including 27 mo at 4°C and up to and including 12 mo at 20°C. No consistent correlation was observed between in vivo oocyst production and in vitro excystation arising from these 2 respective temperatures (E. acervulina r = 0.58, r = 0.54; E. maxima r = 0.90, r = 0.54; E. tenella r = 0.38, r = 0.90). These data indicate that attention must be paid to time and temperature of Eimeria oocyst storage, and that sporozoite excystation may not be a good indicator of oocyst viability, particularly at later timepoints in incubation.
摘要：
在鸡中针对禽球虫病的鸡疫苗接种通常涉及在卵囊繁殖和孢子形成后将艾美球虫卵囊储存数月。这项研究的目的是确定断肠球菌多长时间，E.最大值，并且当在冷藏(4°C)或卵室(20°C)温度下储存时,E.tenella卵囊保持存活。装有E.acervulina的单独试管，E.最大值，或E.tenella卵囊在这些温度下储存，每3个月取出一个样品，用于接种鸡，以证明有专利感染。此外，在每个时间-温度组合下,对每个艾美球虫物种的等分试样进行体外卵裂,以量化释放的子孢子相对于完整(非卵裂)孢子囊的相对数量.艾美耳球虫似乎最容易储存，因为在任一温度下9个月时均未观察到卵囊产生。尽管最大卵囊在9个月时是可行的，在这两种温度下储存12个月时没有观察到卵囊产生。非常出乎意料的是，在4°C下保持活力的E.ervulina比E.tenella和E.maxima更稳定，包括27个月，在20°C下保持活力，包括12个月。在这2个各自的温度引起的体内卵囊产生和体外卵裂之间没有观察到一致的相关性（E.针尖r=0.58，r=0.54；E.maximar=0.90，r=0.54；E.tenellar=0.38，r=0.90）。这些数据表明，必须注意艾美耳球虫卵囊的储存时间和温度，子孢子脱落可能不是卵囊活力的良好指标，特别是在孵化的后期时间点。
