Crawley Jennie A H, Chapman Simon N, Lummaa Virpi, Lynsdale Carly L
Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
Department of Animal and Plant Sciences, Alfred Denny Building, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
Vet Parasitol. 2016 May 15;221:130-3. doi: 10.1016/j.vetpar.2016.03.012. Epub 2016 Mar 16.
Parasite infection status, intensity and resistance have traditionally been quantified via flotation techniques, but the need for immediate analysis following defecation imposes limitations and has led to the use of several faecal storage techniques. However, their effect on nematode egg counts has not been systematically validated and is often generalised across taxa despite evidence of differences between species. Here, we take the domestic horse Equus ferus caballus as a model to examine the impact of commonly used storage techniques on egg recovery: 1) high and low concentrations of ethanol and formalin fixative solutions for up to four weeks and 2) refrigeration (3-5°C) over a two-week period. We found a significant decline in faecal egg counts (FEC) following storage in high and low concentrations of both fixative solutions after two weeks, which stabilised after four weeks, and this pattern was uniform across replicates. FECs remained relatively stable over a week of refrigeration, but declined when refrigeration exceeded 8 days. Prior to FEC analysis, we recommend sample refrigeration for no more than one week. Storage in either fixative solution is sub-optimal for the preservation of nematode eggs, although the uniformity of the decline across samples could hold potential for projective calculation of parasite egg shedding when storage time is effectively controlled for.
传统上，寄生虫感染状况、感染强度和抗性是通过浮选技术进行量化的，但排便后需要立即分析这一需求带来了限制，导致人们采用了多种粪便储存技术。然而，它们对线虫卵计数的影响尚未得到系统验证，尽管有证据表明不同物种之间存在差异，但通常仍在不同分类群中一概而论。在这里，我们以家养马（Equus ferus caballus）为模型，研究常用储存技术对虫卵回收率的影响：1）高浓度和低浓度的乙醇和福尔马林固定液，储存长达四周；2）在两周内冷藏（3-5°C）。我们发现，在两种固定液的高浓度和低浓度中储存两周后，粪便虫卵计数（FEC）显著下降，四周后趋于稳定，并且这种模式在各重复样本中是一致的。冷藏一周内，FEC相对稳定，但冷藏超过8天后会下降。在进行FEC分析之前，我们建议样本冷藏不超过一周。尽管在有效控制储存时间的情况下，样本间下降的一致性可能为寄生虫卵排出量的预测计算提供可能，但用任何一种固定液储存对线虫卵的保存都不是最佳选择。
