Phenotypic analysis of host-parasite interactions in lambs infected with Teladorsagia circumcincta
Phenotypic analysis of host-parasite interactions in lambs infected with Teladorsagia circumcincta
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DOI：
10.1016/j.ijpara.2008.04.011
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发表时间：
2008-11-01
影响因子：
4
通讯作者：
Pemberton, J. M.
中科院分区：
文献类型：
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作者：
Beraldi, D.;Craig, B. H.;Pemberton, J. M.
雌性黑脸羔羊有望表现出对胃肠道线虫抗性的遗传变异性，他们要么暴露于连续的环皮端藻实验感染中，要么假药以监测对感染的表型反应。作为寄生和宿主反应的衡量标准，在3个月内计算粪便中的虫卵（粪卵计数，FEC），并在死后确定蠕虫负荷。宿主对感染的反应也通过白细胞的差异计数来测量。anti-T。IgA抗体水平和体重的关系结果表明，线虫丰度（每个宿主的平均寄生虫数）和流行率（受感染动物的比例）在感染开始后不久（21天）达到最大值，当时几乎所有受感染动物都在排出虫卵。增加抗t包皮环切IgA抗体和嗜酸性粒细胞浓度与成虫总数减少和早期L4s频率增加有关。这些数据还表明，增强的抗t环切IgA反应的遗传选择可能补充基于降低FEC的选择，作为选择胃肠道线虫抗性的策略。(C) 2008澳大利亚寄生虫学学会Elsevier Ltd.出版。版权所有。
Female Blackface lambs expected to exhibit genetic variability for resistance to gastrointestinal nematodes, were either exposed to continuous experimental infections of Teladorsagia circumcincta or were sham-dosed to monitor phenotypic responses to infection. As a measure of parasitism and host response, worm-eggs in faeces (faecal egg count, FEC) were counted over a 3-month period and worm burdens were ascertained at post-mortem. The host response to the infection was also measured by differential counts of white blood cells. anti-T. circumcincta IgA antibody levels and body weight. Results suggest that nematode abundance (mean number of parasites per host) and prevalence (proportion of infected animals) were maximal shortly after the beginning of infection (21 days p.i.) when virtually all the infected animals were shedding worm eggs. Increasing anti-T circumcincta IgA antibody and eosinophil concentrations were associated with a reduction in total numbers of adult worms and an increase in the frequency of early L4s. The data also suggest that genetic selection for an enhanced anti-T circumcincta IgA response might complement selection based on a reduced FEC as a strategy to select for resistance to gastrointestinal nematodes. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.