【摘要】 为研究猪抗大肠杆菌(E.coli)K88的口服疫苗,本研究构建了表达猪乳铁蛋白的重组戊糖乳杆菌(pPG2-pLF/L.pentosus),并将其连续10 d灌喂小鼠后,采用E.coliK88口服攻毒。攻毒后7d,取小肠样本通过扫描电镜检测,并对盲肠内容物进行菌落分离计数,取血液样本,检测IgG、sIgA、IL-2、IL-4和INF-α指标评价其免疫效果。结果显示:灌服pPG2-p LF/L.pentosus组小鼠肠绒毛高度与健康对照组无显著变化,其IgG、sIgA、IL-2和INF-α水平显著提高;小鼠肠道中E.coli总数显著低于攻毒对照组,而且攻毒后小鼠的死亡率显著降低(p<0.05)。这些数据表明,饲喂pPG2-pLF/L.pentosus可以抵抗E.coli K88对小鼠的致病力,减轻病原菌攻毒对小鼠肠道组织的功能损伤,降低肠道内致病菌数量,提高小鼠免疫机能。更多还原

【Abstract】 To develop the oral vaccine against E.coli K88, the Lactobacillus pentosus expressing porcine lactoferrin(p PG2-p LF/L.pentosus) was constructed and evaluated in mice which were orally fed with the p PG2-p LF/L.pentosus for 10 days and challenged orally by E.coli K88. In addition, the immunoresposes and lesions were examined at 7 days post challenge. The results showed the villus height in the jejunum, duodenum and ileum were not significantly different in the mice treated with p PG2-p LF/L.pentosus from that of the mice in healthy control group, while, the total Ig G, s Ig A, IL-2 and TNF-α levels were significantly increased compering with the control groups. Moreover, death rate of the mice and the total number of E.coli in the intestine of the mice were significantly lower in the p PG2-p LF/L.pentosus group than that in the challenge control groups when challenged with E.coli K88. These data suggested that the p PG2-p LF/L.pentosus had a potential to be developed as an oral vaccine against E.coli K88 infection in pigs.更多还原