幼龄仔猪PEDV感染肠道损伤模型的建立

The Establishment of the Intestinal Injury Model of PEDV Infection in Young Piglets

试验旨在建立猪流行性腹泻病毒(PEDV)感染幼龄仔猪肠道损伤模型。试验选用16头7日龄健康幼龄仔猪(杜×长×大),随机分为两个处理组:对照组和PEDV组,每个处理8个重复,每个重复1头猪。试验期为10d,试验期间两个处理组饲喂相同的基础日粮。于试验第7天晚上对PEDV组仔猪口腔灌服PEDV病毒(剂量为104.5 TCID50),对照组灌服等量的生理盐水。于试验第10天早上空腹灌服D-木糖(0.1g/kg体重),1h后前腔静脉采血,屠宰取样,取十二指肠、空肠、回肠等组织样品,测定平均日增重(ADG)、腹泻率(DR)、肠道形态结构、肠道黏膜损伤相关基因mRNA水平。试验结果表明:(1)PEDV感染显著降低了仔猪ADG(P<0.05),极显著提高了仔猪腹泻率(P<0.01);(2)PEDV感染极显著降低了血浆D-木糖含量、空肠和回肠绒毛高度、十二指肠、空肠和回肠绒毛高度与隐窝深度的比值(P<0.01),显著提高了十二指肠和空肠隐窝深度(P<0.05);(3)PEDV感染极显著提高了仔猪空肠黏膜PEDV M基因的相对表达量(P<0.01),极显著降低了肠绒毛蛋白(villin)和肠型脂肪酸结合蛋白(i-FABP)基因的相对表达量(P<0.01)。以上结果表明,口腔灌服PEDV可以成功诱导建立幼龄仔猪肠道损伤模型。

This study was conducted to establish the intestinal injury model of porcine epidemic diarrhea virus（PEDV）infection in neonatal piglets.Sixteen crossbred healthy piglets（Ducoc×Landrace×Yorkshire,7-day-old neonatal pigs）were randomly allocated to control and PEDV groups.During a 10-day trial,all the pigs were fed the basal diet.On the 7 th day,the infected pigs were orally administrated with 104.5 TCID50 of PEDV per pig,while the control pigs were given equal amount of sterile saline.On the 10 th day,all pigs were orally gavaged with D-xylose（0.1 g/（kg·BW））.One hour later,blood was collected from jugular vein,and then all pigs were killed to obtain the small intestines.The average daily weight gain（ADG）,diarrhea rate（DR）,intestinal morphological structure,mucosal injury correlated gene mRNA level were measured.The results showed that：（1）PEDV infection increased the incidence of diarrhea（P〈0.05）,while reduced ADG（P〈0.01）;（2）PEDV infection decreased the plasma D-xylose content,villus height inthe jejunum and ileum,the ratio of villus height to crypt depth in the duodenum,jejunum and ileum（P〈0.01）,and increased crypt depth in the duodenum and jejunum（P〈0.05）;（3）PEDV infection up-regulated the mRNA level of PEDV M gene in the jejunum（P〈0.01）,and down-regulated mRNA levels of villin and i-FABP in the jejunum（P〈0.01）.In conclusion,the intestinal injury model was successfully established with PEDV infection in neonatal piglets.