Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
Animal Science, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
Vet Parasitol. 2022 Oct;310:109792. doi: 10.1016/j.vetpar.2022.109792. Epub 2022 Aug 27.
Ascaridia galli infection models use eggs isolated from chicken excreta, worm uteri and worms cultured in artificial media. The aim of this study was to compare the infectivity of A. galli eggs isolated from these sources under two infection regimens. A 3 × 2 factorial arrangement was employed to test the infectivity of A. galli eggs from the three sources and two modes of infection (single or trickle infection). One hundred and fifty-six Isa-Brown one day-old cockerels randomly assigned to the six treatment groups (n = 26) were orally infected with embryonated A. galli eggs obtained from the three A. galli egg sources (worm uteri, excreta or eggs shed in vitro) administered either as single dose of 300 eggs at one day-old or trickle infected with 3 doses of 100 eggs over the first week of life. Twenty-two negative control birds remained uninfected. Eggs obtained from cultured worms or excreta exhibited a higher embryonation capacity (P = 0.003) than eggs obtained from worm uteri. There were higher worm establishment (infectivity) rates from embryonated eggs originating from cultured worms and worm uteri compared with eggs obtained from fresh excreta (P < 0.0001). Trickle infection resulted in a significantly higher total worm burden (P = 0.002), establishment rate (P = 0.002) and excreta egg counts (EEC, P = 0.025) than single infection. Worm length was greater in birds infected with embryonated eggs from excreta than from uteri or cultured worms (P < 0.0001). However, mode of infection did not affect worm length (P = 0.719) and weight (P = 0.945). A strong significant positive linear correlation was observed between EECs and female worm counts at 12 weeks of post infection sampling (r = 0.75; P < 0.0001). Body weight of birds was negatively correlated with both worm burden (r = - 0.21; P < 0.01) and EEC (r = - 0.20; P < 0.05) at 12 weeks post infection. In conclusion, our results show that eggs shed by cultured worms or isolated from worm uteri had greater infective capacity than eggs harvested from excreta and that trickle rather than bolus infection resulted in higher worm establishment. These factors should be taken into account when considering artificial infection protocols for A. galli.
鸡蛔虫感染模型使用从鸡粪便、虫体子宫和人工培养的虫体中分离出的卵。本研究的目的是比较从这三种来源分离的鸡蛔虫卵在两种感染方案下的感染力。采用 3×2 析因设计来测试来自这三种来源的鸡蛔虫卵的感染力以及两种感染方式（单次感染或滴注感染）。156 只 1 日龄的 Isa-Brown 公鸡被随机分配到六个处理组（n=26），用从三种鸡蛔虫卵来源（虫体子宫、粪便或体外产的卵）获得的 300 个胚胎化鸡蛔虫卵进行口服感染，1 日龄时给予单剂量，或在生命的第一周内用 3 剂 100 个卵滴注感染。22 只阴性对照鸡未感染。与从虫体子宫获得的卵相比，从培养的虫体或粪便中获得的卵具有更高的胚胎化能力（P=0.003）。与从新鲜粪便中获得的卵相比，来自培养的虫体和虫体子宫的胚胎化卵具有更高的虫体定植（感染力）率（P<0.0001）。与单次感染相比，滴注感染导致总虫体负荷（P=0.002）、定植率（P=0.002）和粪便卵计数（EEC，P=0.025）显著增加。与从子宫或培养的虫体获得的胚胎化卵相比，从粪便中获得的卵感染的鸡的虫体长度更大（P<0.0001）。然而，感染方式对虫体长度（P=0.719）和重量（P=0.945）没有影响。在感染后 12 周的粪便卵计数与雌性虫体计数之间观察到强显著正线性相关性（r=0.75；P<0.0001）。感染后 12 周时，鸡的体重与虫体负荷（r=-0.21；P<0.01）和 EEC（r=-0.20；P<0.05）呈负相关。总之，我们的结果表明，与从粪便中收集的卵相比，从培养的虫体中分离或产的卵具有更高的感染力，并且滴注感染而不是单次感染会导致更高的虫体定植。在考虑鸡蛔虫的人工感染方案时，应考虑这些因素。
