Ulrike Lodemann1, Salah Amasheh2, Judith Radloff2, Martina Kern2, Astrid Bethe3, Lothar H Wieler3,4, Robert Pieper5, Jürgen Zentek5, Jörg R Aschenbach2. 1. Institute of Veterinary Physiology, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany. Ulrike.lodemann@fu-berlin.de. 2. Institute of Veterinary Physiology, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany. 3. Institute of Microbiology and Epizootics, Department of Veterinary Medicine, Freie Universität Berlin, Oertzenweg 19b, 14163, Berlin, Germany. 4. Robert Koch Institute, Nordufer 20, 13302, Berlin, Germany. 5. Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Königin-Luise-Str. 49, 14195, Berlin, Germany.
Abstract
BACKGROUND AND AIM: Enterotoxigenic Escherichia coli (ETEC) strains are involved in piglet post-weaning diarrhea. Prophylactic measures including probiotics have been examined in infection experiments with live piglets. In the present study, we have tested whether the early effects of ETEC infection can also be evoked and studied in a model in which ETEC is added to whole mucosal tissues ex vivo, and whether this response can be modulated by prior supplementation of the piglets with probiotics. METHODS: Jejunal barrier and transport properties of Enterococcus faecium-supplemented or control piglets were assessed in Ussing chambers. Part of the epithelia was challenged with an ETEC strain at the mucosal side. Fluxes of fluorescein as a marker of paracellular permeability, and the expression of selected tight junction (TJ) proteins and of proinflammatory cytokines were measured. RESULTS: The addition of ETEC ex vivo induced an increase in transepithelial resistance peaking in the first 2 h with a concomitant reduction in fluorescein fluxes, indicating tightening effects on barrier function. The response of short-circuit current after stimulation with PGE2 or glucose was reduced in epithelia treated with ETEC. ETEC induced a decrease in the TJ protein claudin-4 in the control diet group after 280 min and an increase in the mRNA expression of the proinflammatory cytokines interleukin-8 and TNF-α in both groups after 180 min. CONCLUSIONS: The addition of ETEC ex vivo affected barrier function and transport properties of the jejunal tissues and enhanced cytokine expression. The differences in claudin-4 expression in the jejunum might indicate a beneficial effect of E. faecium prefeeding.
BACKGROUND AND AIM: Enterotoxigenic Escherichia coli (ETEC) strains are involved in piglet post-weaning diarrhea. Prophylactic measures including probiotics have been examined in infection experiments with live piglets. In the present study, we have tested whether the early effects of ETECinfection can also be evoked and studied in a model in which ETEC is added to whole mucosal tissues ex vivo, and whether this response can be modulated by prior supplementation of the piglets with probiotics. METHODS: Jejunal barrier and transport properties of Enterococcus faecium-supplemented or control piglets were assessed in Ussing chambers. Part of the epithelia was challenged with an ETEC strain at the mucosal side. Fluxes of fluorescein as a marker of paracellular permeability, and the expression of selected tight junction (TJ) proteins and of proinflammatory cytokines were measured. RESULTS: The addition of ETEC ex vivo induced an increase in transepithelial resistance peaking in the first 2 h with a concomitant reduction in fluorescein fluxes, indicating tightening effects on barrier function. The response of short-circuit current after stimulation with PGE2 or glucose was reduced in epithelia treated with ETEC. ETEC induced a decrease in the TJ protein claudin-4 in the control diet group after 280 min and an increase in the mRNA expression of the proinflammatory cytokines interleukin-8 and TNF-α in both groups after 180 min. CONCLUSIONS: The addition of ETEC ex vivo affected barrier function and transport properties of the jejunal tissues and enhanced cytokine expression. The differences in claudin-4 expression in the jejunum might indicate a beneficial effect of E. faecium prefeeding.
Authors: Jutamat Klinsoda; Julia Vötterl; Qendrim Zebeli; Barbara U Metzler-Zebeli Journal: Appl Environ Microbiol Date: 2020-02-03 Impact factor: 4.792
Authors: Mohammad Naghizadeh; Laura Klaver; Anna A Schönherz; Sundas Rani; Tina Sørensen Dalgaard; Ricarda Margarete Engberg Journal: Animals (Basel) Date: 2022-01-04 Impact factor: 2.752