Increased EHEC survival and virulence gene expression indicate an enhanced pathogenicity upon simulated pediatric gastrointestinal conditions

Abstract

Differences in digestive physicochemical parameters may partially explain why children are more susceptible to EHEC infection than adults. Such data are essential for a full understanding of EHEC pathogenesis and would help in designing novel therapeutic approaches.

Extending in vitro digestion models to specific human populations: Perspectives, practical tools and bio-relevant information

“…Based on the current physiological knowledge of the infant GI, various static and dynamic IVD models have been applied by researchers (Blanquet et al, 2004;de Oliveira et al, 2015;Dupont et al, 2010a;Roussel et al, 2016;Shani-Levi et al, 2013). Yet, the development of a harmonized static infant IVD is needed.…”

“…Further, there are some dynamic IVD models described in recent literature (Blanquet et al, 2004;Havenaar et al, 2013;Menard et al, 1995;Menard et al, 2014;de Oliveira et al, 2015;Roussel et al, 2016;Shani-Levi et al, 2013). In essence, these models try to recreate some of the dynamic aspects of digestion, e.g.…”

“…However, in this study, not all GI parameters applied to this commercial IVD model have been made publicly available. The same model has been very recently adapted to mimic, based on in vivo data, the gastric and small intestinal conditions of infant from 6 months to 2 years (Roussel et al, 2016). Some dynamic colonic models have also been developed (Cinquin, Le Blay, Fliss, & Lacroix, 2004;Cinquin, Le Blay, Fliss, & Lacroix, 2006a, 2006b).…”

Enterotoxigenic and Enterohemorrhagic <i>Escherichia coli</i>: Survival and Modulation of Virulence in the Human Gastrointestinal Tract

“…Other more recent studies have evaluated the survival of EHEC strains by using dynamic multicompartmental in vitro models that closely mimic the gastric, small intestinal, and colonic human digestive conditions. In the TNO GastroIntestinal model (TIM), which simulates the stomach and the three segments of the human small intestine, it has been shown that EHEC survival was affected in the stomach and duodenum (when ingested within a food matrix but not with a glass of water), while bacterial growth was observed at the end of digestion in the jejunum and ileum [47][48][49]. This growth renewal in the distal parts of the small intestine was probably linked to the occurrence of less stringent conditions, such as neutral pH and lower concentrations of bile salts due to their reabsorption (as occurred in vivo).…”

“…by food matrices [47][48][49] and age conditions [48]. In particular, thanks to the potential of the TIM model, Roussel et al [49] have shown that differences in digestive physicochemical parameters related to age conditions may partly explain the higher susceptibility of children (compared to adults) to EHEC infections and HUS.…”