Schistosoma japonicum: day to day variation in excretion and hatchability of parasite eggs in the domestic pig, Suis suis.
Schistosoma japonicum: day to day variation in excretion and hatchability of parasite eggs in the domestic pig, Suis suis.
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DOI：
10.1006/expr.2000.4506
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发表时间：
2000-05
影响因子：
2.1
通讯作者：
H. Giver;S. Vlas;M. V. Johansen;N. Ø. Christensen;Peter Nansen
中科院分区：
文献类型：
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作者：
H. Giver;S. Vlas;M. V. Johansen;N. Ø. Christensen;Peter Nansen
本研究的目的是描述随着时间的推移，在个别猪的日本血吸虫感染的过程中，特别关注粪便虫卵计数和卵孵化率，强调期间和之间的变化程度。用5头无特定病原体的丹麦长白猪/约克郡猪/杜洛克杂交公猪，每头肌肉注射尾蚴3500条。从感染后第36天至第62天，从每头猪的早晨和晚上收集粪便样品。感染后62天灌注猪。测定实际粪便虫卵计数、毛蚴计数和蠕虫负荷。粪卵排泄量的变化趋势可用三次多项式和对数连接函数来描述。毛蚴计数通过简单的线性函数与早晨粪便虫卵计数直接相关。该研究揭示了所有猪的鸡蛋排泄的总体模式相当相似，直到第8周鸡蛋排泄量增加，随后显著减少至几乎为零。一般而言，所有猪均观察到围绕该趋势的大幅波动，如同一天内以及不同天之间的蛋计数变化所示。然而，正如估计的模型线所揭示的那样，这些波动是由于粪便中卵密度的随机变化而不是由生物学确定的周期引起的。预测每头猪粪便中首次出现虫卵（感染后第35-38天）和虫卵计数峰值（感染后第44-48天）的确切时间。此外，该模型显示，毛蚴计数可以通过代表孵化率的参数与同一天的预期粪便虫卵计数直接相关。发现该孵化率参数与每头猪感染后的时间无关，但猪之间的孵化率存在较大的个体差异。
The aim of the present study was to describe the course of an Schistosoma japonicum infection in individual pigs over time, with special regards to fecal egg counts and egg hatchability, emphasizing the extent of variation during and between days. Five specific pathogen free Danish Landrace/Yorkshire/Duroc crossbred male pigs were each given 3500 cercariae intramuscularly. From day 36 to 62 post infection, fecal samples were collected from each pig, morning and evening. Pigs were perfused 62 days post infection. Actual fecal egg counts, miracidial counts, and worm burdens were determined. The trend of fecal egg excretion was adequately described with a third order polynomial and logarithmic link function. Miracidial counts were related directly to morning fecal egg counts through a simple linear function. The study revealed a fairly similar overall pattern of egg excretion for all pigs, showing an increase in egg excretion until week 8, followed by a marked reduction to almost zero. In general, large fluctuations around this trend were seen for all pigs, as revealed in variations in egg counts within the same day as well as between days. However, as revealed by the estimated model lines, these fluctuations are due to random variation in egg density in stools rather than being caused by biologically determined cycles. An exact time for both first occurrence of eggs in feces (days 35-38 post infection) and for peak egg counts (days 44-48 post infection) was predicted for each individual pig. Furthermore, the model revealed that miracidial counts can be related directly to the expected fecal egg counts of the same day through a parameter, which represents hatchability. This hatchability parameter was found to be independent of time post infection for each pig, but large individual differences were seen in hatchability between the pigs.