Adhesion of Lactobacillus acidophilus to avian intestinal epithelial cells mediated by the crystalline bacterial cell surface layer (S‐layer)

Abstract

Lactobacillus acidophilus was isolated from washed and homogenized walls of the crop and caecum of an adult fowl. A strain that adhered well in the Fuller adhesion test was subcultured until colonies on Lactobacillus Selective agar changed from rough to smooth. This coincided with a change from aggregate to planktonic growth in liquid medium and a marked loss of ability to adhere. ultrastructure of cells from both types of culture was studied by electron microscopy. An S-layer formed the outermost part of the cell wall in the strongly-adherent strain, whereas this layer was covered with polymerized material or was absent in strains that lacked the ability to adhere, or those with reduced adherence.

Development of New Products: Probiotics and Probiotic Foods

“…The S-layer proteins act as adhesins in many bacteria such as lactobacilli and some representatives of the genus Bacillus, so they determine their adhesion to epithelial cells or extracellular matrix proteins [44,45,46,47].…”

The surface (S)-layer gene cspB of Corynebacterium glutamicum is transcriptionally activated by a LuxR-type regulator and located on a 6 kb genomic island absent from the type strain ATCC 13032

“…Due to their location, S-layers are generally involved in the interaction between a bacterium and its environment. The S-layers of several pathogenic bacteria have been reported to act as virulence factors by mediating resistance to bactericidal activities (Blaser et al, 1987;Merino et al, 1994) and adhesion to extracellular matrix proteins of the host (Schneitz et al, 1993). Furthermore, S-layers can serve as molecular sieves and act as additional stability factors for the bacterial cell envelope, in both pathogenic and nonpathogenic bacteria (Sara & Sleytr, 2000).…”

Effets des bact�ries lactiques ing�r�es avec des laits ferment�s sur la sant�

“…L'idée générale est qu'une forte adhésion des bactéries lactiques à l'épithélium intestinal interférerait avec celle des agents pathogènes par saturation des sites de fixation. L'adhésion des bacté-ries lactiques à l'épithélium digestif a été étudiée in vitro avec des lignées cellulaires d'origine colique ou intestinale (Caco-2 et HT-29 par exemple), animale [16,27,54,115] ou humaine [9,10,21]. Les bactéries lactiques capables d'adhérer in vitro à l'épi-thélium humain et animal sont principalement des lactobacilles et certaines bifidobactéries isolées de la microflore humaine [9,21,25].…”