The effect of cell surface components on adhesion ability of Lactobacillus rhamnosus

Abstract

The aim of this study was to analyze the cell envelope components and surface properties of two phenotypes of Lactobacillus rhamnosus isolated from the human gastrointestinal tract. The ability of the bacteria to adhere to human intestinal cells and to aggregate with other bacteria was determined. L. rhamnosus strains E/N and PEN differed with regard to the presence of exopolysaccharides (EPS) and specific surface proteins. Transmission electron microscopy showed differences in the structure of the outer cell surface of the strains tested. Bacterial surface properties were analyzed by Fourier transform infrared spectroscopy, fatty acid methyl esters and hydrophobicity assays. Aggregation capacity and adhesion of the tested strains to the human colon adenocarcinoma cell line HT29 was determined. The results indicated a high adhesion and aggregation ability of L. rhamnosus PEN, which possessed specific surface proteins, had a unique fatty acid content, and did not synthesize EPS. Adherence of L. rhamnosus was dependent on specific interactions and was promoted by surface proteins (42–114 kDa) and specific fatty acids. Polysaccharides likely hindered bacterial adhesion and aggregation by masking protein receptors. This study provides information on the cell envelope constituents of lactobacilli that influence bacterial aggregation and adhesion to intestinal cells. This knowledge will help to understand better their specific contribution in commensal–host interactions and adaptation to this ecological niche.

A Novel Rhamnose-Rich Hetero-exopolysaccharide Isolated from Lactobacillus paracasei DG Activates THP-1 Human Monocytic Cells

“…The identification of putative EPS operons in the genome of L. paracasei DG, along with the formation of a pellet much weaker than those of other L. paracasei strains after centrifugation (12), was considered an indication of the probable ability of strain DG to produce EPS molecules. Consequently, we undertook experiments aimed at the extraction and purification of the EPS fraction from broth cultures of DG.…”

Lactobacillus fermentum ATCC 23271 Displays In vitro Inhibitory Activities against Candida spp.

“…to bind to mucin, the greater their ability to impair pathogen binding to the genital tract. It was previously described that microorganisms with a hydrophobic cell wall harbor a large variety of surface glycoproteins, increasing the probability of adhesion to cellular receptors (Kos et al, 2003) or to cell wall-anchored proteins (Polak-Berecka et al, 2014; Zhang et al, 2015). Indeed, adhesion-promoting proteins that are involved in the binding of distinct Lactobacillus species to mucin have been previously identified, including a mucin adhesion-promoting protein (MAPP) in L. fermentum strain 104R (Rojas et al, 2002), the elongation factor Tu in L. johnsonii strain La1 (Granato et al, 2004), and a fibronectin-binding protein (FbpB) in L. acidophilus strain NCFM (Hymes et al, 2016).…”

Mechanisms and therapeutic effectiveness of lactobacilli

“…8 9 Indeed, adhesion of lactobacilli to the host's GI tract, by means of an interaction with toll-like receptors, is of crucial importance due to its ability to trigger the host's immune response. 10 11 Nevertheless, adhesion to the GI tract can also be driven by surface proteins and fatty acids, as observed for L. rhamnosus PEN, 12 and proteinaceous surface layer components, as observed for L. plantarum 91. 13 Therefore, the ability of lactobacilli to adhere and colonise the GI tract mucosa has been investigated in the clinical setting and is summarised in table 1.…”