表达乳铁蛋白肽的猪源罗伊氏乳酸杆菌对断乳仔猪抗霍乱沙门菌感染的效果分析

Analysis of Effects of Lactobacillus reuteri from Piglets Secreting Lactoferrin Peptides against Salmonella Choleraesuis Infection of Weaned Piglets

旨在分析表达牛乳铁蛋白肽的重组猪源罗伊氏乳酸杆菌pPG-LFCA-E/LR-CO21作为饲用微生态制剂对仔猪促生长与抵抗猪霍乱沙门菌感染的作用。将该重组菌连续饲喂28日龄断乳仔猪21 d,并设立空菌组、对照组以及抗生素组。第21天时对断乳仔猪连续口服感染猪霍乱沙门菌3 d,并设置7 d的观察期;仔猪感染后采集试验组与对照组血清、肠黏液及肠组织。检测结果显示重组菌组仔猪平均日增重与免疫器官指数均显著提高(P<0.05),料重比极显著降低(P<0.01)。感染猪霍乱沙门菌后,相对于对照组,重组菌组仔猪日增重提高,腹泻率降低;重组菌组仔猪血液中IgG以及肠黏液中IL-4、sIgA的量极显著提高(P<0.01),IL-2、IL^(-1)2、IL-6的量显著降低(P<0.05);重组菌组仔猪肠道紧密连接蛋白ZO-1、Claudin-1的基因转录水平和TLR4、Myd88和MLCK的基因转录水平极显著提高(P<0.01),仔猪肠道内猪霍乱沙门菌的数量极显著降低(P<0.01);重组菌组与抗生素组无明显差异(P>0.05)。以上结果表明,表达牛乳铁蛋白肽的重组猪源罗伊氏乳酸杆菌pPG-LFCA-E/LR-CO21可以提高断乳仔猪的生长性能、促进肠道形态发育、增强肠道屏障功能,并且在一定程度上可以保护仔猪免受猪霍乱沙门菌的感染,表明重组菌作为微生态制剂替代断乳仔猪的饲用抗生素具有一定的应用前景。

The purpose of this study was to analyze the effect of recombinant Lactobacillus reuteri from piglets expressing bovine lactoferrin peptide(pPG-LFCA-E/LR-CO21)as microecological on the growth promotion of piglets and resistance to Salmonella Choleraesuis CVCC79102 infection.In this experiment,the recombinant bacteria were continuously fed to 28-day-old weaned piglets for 21 days,and empty bacteria group,control group and antibiotic group were set up.On the 21st day,weaned piglets were orally infected with Salmonella Choleraesuis for 3 days,and the observation period was set for 7 days,and the serum,intestinal mucus and intestinal tissue of the experimental groups and the control group were collected after infection.The results showed that the average daily gain,feed gain ratio and immune organ index of piglets in the recombinant bacteria group were significantly increased(P<0.05).After being infected with Salmonella Choleraesuis CVCC79102,in the recombinant bacteria group,application of the recombinant bacteria increased the daily gain of piglets and reduced the rate of diarrhea compared with the control group;it significantly increased the amount of IgG in blood and IL-4 and sIgA in intestinal mucus(P<0.01).and significantly reduced the amount of IL-2,IL^(-1)2,IL-6(P<0.05).It significantly increased the gene transcription level of intestinal tight junction protein ZO-1,Claudin-1 and the gene transcription levels of TLR4,Myd88 and MLCK,and significantly decreased the number of Salmonella Choleraesuis in the intestinal tract of piglets(P<0.01).There was no significant difference between the recombinant bacteria group and the antibiotic group.The above results show that pPG-LFCA-E/LR-CO21 can regulate the growth performance,intestinal morphology and intestinal barrier function of weaned piglets,and can protect piglets from Salmonella Choleraesuis infection to a certain extent,indicating that the recombinant bacteria have a certain application prospect feeding as microecological for weaned piglets.