The probioticEscherichia colistrain Nissle 1917 interferes with invasion of human intestinal epithelial cells by different enteroinvasive bacterial pathogens

Abstract

The probiotic Escherichia coli strain Nissle 1917 (Mutaflor) of serotype O6:K5:H1 was reported to protect gnotobiotic piglets from infection with Salmonella enterica serovar Typhimurium. An important virulence property of Salmonella is invasion of host epithelial cells. Therefore, we tested for interference of E. coli strain Nissle 1917 with Salmonella invasion of INT407 cells. Simultaneous administration of E. coli strain Nissle 1917 and Salmonella resulted in up to 70% reduction of Salmonella invasion efficiency. Furthermore, invasion of Yersinia enterocolitica, Shigella flexneri, Legionella pneumophila and even of Listeria monocytogenes were inhibited by the probiotic E. coli strain Nissle 1917 without affecting the viability of the invasive bacteria. The observed inhibition of invasion was not due to the production of microcins by the Nissle 1917 strain because its isogenic microcin-negative mutant SK22D was as effective as the parent strain. Reduced invasion rates were also achieved if strain Nissle 1917 was separated from the invasive bacteria as well as from the INT407 monolayer by a membrane non-permeable for bacteria. We conclude E. coli Nissle 1917 to interfere with bacterial invasion of INT407 cells via a secreted component and not relying on direct physical contact with either the invasive bacteria or the epithelial cells.

The Front Line of Enteric Host Defense against Unwelcome Intrusion of Harmful Microorganisms: Mucins, Antimicrobial Peptides, and Microbiota

“…E. coli strain Nissle 1917 that produces microcin, was able to inhibit invasion of epithelial intestinal INT407 cells by Salmonella spp., S. flexneri, and L. monocytogenes without affecting the viability of the invasive bacteria (7). This E. coli strain, independently of the microcin production, is able to block the invasion process of the Crohn's disease-associated adherent-invasive E. coli LF82 (43).…”

“…The microcin inserts into the inner membrane, whereupon the potential becomes destabilized due to pore formation that leads to depolarization and permeabilization of the E. coli cytoplasmic membrane (25,84,328). Another mechanism of antibacterial activity has been reported for E. coli strain Nissle 1917 (129) that produces microcins (7). This E. coli strain induces the expression of hBD-2 in Caco-2 intestinal epithelial cells in a time-and dosedependent manner (407).…”

Escherichia coli Nissle 1917 Facilitates Tumor Detection by Positron Emission Tomography and Optical Imaging

“…EcN is one of the best studied probiotic bacterial strains and it has been successfully used in humans as an oral treatment for a number of intestinal disorders (e.g., diarrhea, inflammatory bowel diseases, and ulcerative colitis) for more than 90 years (18,19). Although the genome of EcN shows high similarity to the uropathogenic E. coli CFTR073 (20), the probiotic strain lacks any known protein toxins or mannoseresistant hemagglutinating adhesins (21).…”

Potentials and Limitations of Bile Acids and Probiotics in Diabetes Mellitus

“…Combinations of different bacterial strains can be used (Bezkorovainy 2001) but a mixture of Lactobacilli and Bifidobacteria is a common choice (Karimi & Pena 2003). Probiotics have been shown to be beneficial in wide range of conditions including infections, allergies, metabolic disorders such as diabetes mellitus, ulcerative colitis and Crohn's disease (Altenhoefer et al 2004;Rozanova et al 2002;Ziegler et al 2003). …”