猪体内的日本血吸虫：一种估算肠道组织虫卵计数的新技术。

Giver H, Johansen M V, Christensen N O, Nansen P

Danish Bilharziasis Laboratory, Charlottenlund, Denmark.

Southeast Asian J Trop Med Public Health. 1999 Dec;30(4):664-9.

This study introduced a new method for estimating intestinal tissue Schistosoma japonicum egg counts, based on scraping of the mucosal layer of different sections of the intestines. Twenty-eight Danish Landrace/Yorkshire/Duroc crossbred pigs were divided into 3 groups of 15, 5 and 8 pigs, respectively. Pigs were fed either a high- or low- protein diet and were infected by an intra-muscular or per-oral route of infection with doses of either 1,000, 1,500 or 3,000 S. japonicum cercariae. The pigs were killed 9-11 weeks post infection. For all 28 pigs the intestines were divided into 3 sections: cecum, colon and rectum and the entire mucosa was scraped off the serosa of each section and homogenized. Subsequently, samples corresponding to 5 g homogenised mucosal tissue were digested and egg counts were determined and correlated to liver egg counts. In order to compare the relative distribution of eggs in the mucosa and the serosa, small intestinal wall subsamples formerly taken from each section from a subgroup of 5 pigs were homogenized and egg counts determined for both the mucosa and serosa. The number of eggs were significantly higher in the mucosa than in the serosa. Egg counts estimated from digestion of mucosa subsamples either over or underestimated egg counts based on scrapings of the entire mucosa when compared, reflecting the very patchy distribution of S. japonicum eggs in the intestinal wall. Correlating liver egg counts with the number of eggs based on scrapings from the entire mucosa from cecum, colon and rectum, respectively, significant correlations were found for 2 out of 3 groups of pigs. The present study revealed that estimating intestinal tissue egg counts based on scrapings of the entire mucosa is a reliable and convenient approach, nicely supporting the liver tissue digestion approach. In addition, a reduction of the processing time of intestinal tissue in general was achieved due to the very simple scraping technique.

本研究介绍了一种基于刮取肠道不同部位黏膜层来估算肠道组织日本血吸虫卵计数的新方法。28头丹麦长白/约克夏/杜洛克杂交猪分别分为3组，每组猪的数量分别为15头、5头和8头。给猪喂食高蛋白或低蛋白饮食，并通过肌肉注射或经口途径感染，感染剂量分别为1000、1500或3000条日本血吸虫尾蚴。感染后9 - 11周处死猪。对所有28头猪，将肠道分为3个部分：盲肠、结肠和直肠，将每个部分的整个黏膜从浆膜上刮下并匀浆。随后，对相当于5克匀浆黏膜组织的样本进行消化，并确定虫卵计数，并与肝脏虫卵计数进行关联。为了比较虫卵在黏膜和浆膜中的相对分布，对之前从5头猪的一个亚组的每个部分采集的小肠壁子样本进行匀浆，并确定黏膜和浆膜的虫卵计数。黏膜中的虫卵数量显著高于浆膜。与基于刮取整个黏膜的虫卵计数相比，从黏膜子样本消化估算的虫卵计数要么高估要么低估，这反映了日本血吸虫卵在肠壁中的分布非常不均匀。分别将肝脏虫卵计数与基于从盲肠、结肠和直肠刮取的整个黏膜的虫卵数量进行关联，在3组猪中有2组发现了显著相关性。本研究表明，基于刮取整个黏膜来估算肠道组织虫卵计数是一种可靠且方便的方法，很好地支持了肝脏组织消化法。此外，由于刮取技术非常简单，总体上减少了肠道组织的处理时间。