Schroeder B, Duncker S, Barth S, Bauerfeind R, Gruber A D, Deppenmeier S, Breves G
Department of Physiology, School of Veterinary Medicine Hannover, Germany.
Dig Dis Sci. 2006 Apr;51(4):724-31. doi: 10.1007/s10620-006-3198-8.
Pretreatment with the probiotic Escherichia colistrain Nissle 1917 (EcN) was assessed in a pig model of intestinal infection to prevent acute secretory diarrhea. In the model 10(10) colony forming units of the porcine enterotoxigenic Escherichia coli Abbotstown (EcA) was given via orogastric tube to weaned piglets at day 21 postpartum (-EcN/+EcA group, n = 7). Forty-eight hours after challenge electrophysiological parameters of isolated intact jejunal epithelia were characterized in Ussing chambers. In agreement with clinical signs of diarrhea, tissues of challenged animals showed an overshoot of secretory response after stimulation of the cAMP-mediated second messenger pathway by forskolin, indicating higher excitability of chloride secretory systems under infected conditions. The data were compared with respective measurements from animals that got a daily dose of 10(10) cfu of the probiotic EcN over 10 days before EcA challenge (+EcN/+EcA group; n = 4), from a group that received only EcN (+EcN/-EcA; n = 4), or from a group that remained totally untreated (-EcN/-EcA; n = 6). EcN pretreatment completely abolished clinical signs of secretory diarrhea in +EcN/+EcA animals. Furthermore, jejunum epithelia of these animals did not exhibit an overshoot of secretory response upon stimulation with forskolin. Our studies demonstrate for the first time the efficacy of prophylactic EcN in pig small intestine for preventing an effect of toxigenic EcA. This infection model with freshly weaned piglets may be predestinated to further characterize EcN effects on the cellular level, i.e., involved second messenger pathways, or it may also be useful to examine the efficacy of other substrates or microbe strains against secretory stimuli.
在肠道感染的猪模型中评估了用益生菌大肠杆菌Nissle 1917（EcN）进行预处理以预防急性分泌性腹泻的效果。在该模型中，于产后第21天经口胃管给断奶仔猪投喂10¹⁰个猪产肠毒素大肠杆菌Abbotstown（EcA）菌落形成单位（-EcN/+EcA组，n = 7）。攻毒48小时后，在尤斯灌流小室中对分离的完整空肠上皮的电生理参数进行表征。与腹泻的临床症状一致，攻毒动物的组织在通过福司可林刺激cAMP介导的第二信使途径后显示出分泌反应的超调，表明在感染条件下氯分泌系统的兴奋性更高。将这些数据与在EcA攻毒前10天每天给予10¹⁰ cfu益生菌EcN的动物（+EcN/+EcA组；n = 4）、仅接受EcN的组（+EcN/-EcA；n = 4）或完全未处理的组（-EcN/-EcA；n = 6）的相应测量结果进行比较。EcN预处理完全消除了+EcN/+EcA动物分泌性腹泻的临床症状。此外，这些动物的空肠上皮在用福司可林刺激时未表现出分泌反应的超调。我们的研究首次证明了预防性EcN在猪小肠中预防产毒EcA作用的功效。这种用刚断奶仔猪建立的感染模型可能非常适合进一步在细胞水平上表征EcN的作用，即所涉及的第二信使途径，或者它也可能有助于研究其他底物或微生物菌株对分泌刺激的功效。
