Inhibition of adhesion of enteroinvasive pathogens to human intestinal Caco-2 cells byLactobacillus acidophilusstrain LB decreases bacterial invasion

Abstract

Salmonella typhimurium and enteropathogenic Escherichia coli (EPEC) were found to adhere to the brush border of differentiated human intestinal epithelial Caco-2 cells in culture, whereas Yersinia pseudotuberculosis and Listeria monocytogenes adhered to the periphery of undifferentiated Caco-2 cells. All these enterovirulent strains invaded the Caco-2 cells. Using a heat-killed human Lactobacillus acidophilus (strain LB) which strongly adheres both to undifferentiated and differentiated Caco-2 cells, we have studied inhibition of cell association with and invasion within Caco-2 cells by enterovirulent bacteria. Living and heat-killed Lactobacillus acidophilus strain LB inhibited both cell association and invasion of Caco-2 cells by enterovirulent bacteria in a concentration-dependent manner. The mechanism of inhibition of both adhesion and invasion appears to be due to steric hindrance of human enterocytic pathogen receptors by whole-cell lactobacilli rather than to a specific blockade of receptors.

Anti-Infective Activities of Lactobacillus Strains in the Human Intestinal Microbiota: from Probiotics to Gastrointestinal Anti-Infectious Biotherapeutic Agents

“…L. casei DN-114 001 inhibited by ϳ5 log CFU/ml the interaction of adherent-invasive E. coli isolated from Crohn's disease patients with cultured human intestinal epithelial cells (185) but failed to block the adhesion of EPEC (186). It is noteworthy that heat-treated L. acidophilus LB culture or CFCS conserved the antagonistic activity of the live strain against the attachment at the brush borders of Caco-2 cells of ETEC (181,183,187,188), EPEC (182,183), and Afa/Dr DAEC (125). Moreover, L. rhamnosus GG and L. casei Shirota inhibited the adhesion of enterovirulent bacteria onto mucus (177,178,189).…”

“…Inhibition of the intestinal cell association of enterovirulent bacteria involved in acute infantile and traveler's diarrhea by human probiotic Lactobacillus strains has been reported (Table 1). Inhibition (ϳ5 to 6 log CFU/ml) of the adhesion of ETEC expressing colonization factors CFA/I and CFA-II, EPEC, EHEC, and Afa/Dr DAEC to the brush border of cultured human enterocyte-like Caco-2 cells (176) (125,(181)(182)(183). The interaction of S. Typhimurium with enterocyte-like Caco-2 cells was inhibited by ϳ6 to 7 log CFU/ml in the presence of L. rhamnosus GG (128)(129)(130)178), L. johnsonii NCC 533 (128,129,180), and L. casei Shirota (128,129,178) cultures and CFCSs.…”

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

“…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]. Ces interactions sont hôte-spé-cifique.…”

“…Plusieurs études suggèrent que l'adhésion est médiée par des protéines [10,27,54] alors que d'autres suggèrent un rôle des acides lipoteichoiques [19,50] et des carbohydrates [10,16]. Pour certaines souches, deux facteurs semblent impliqués dans l'adhésion, un facteur lié à la paroi cellulaire et un facteur sécrété [25].…”

Antimicrobial Activity of Lactic Acid Bacterial Isolates

“…Each of the antimicrobial compounds, produced by lactic acid bacteria especially in combination, can be used to extend the shelf life and safety of food products 6 . Bacteriocins produced by lactic acid bacteria are subject of intense research because of their antimicrobial activity against food born bacteria such as Listeria monocytogenes, Staphylococcus aureus, Bacillus cereus, Clostridium botulinum and several others 7 . The local lactic acid bacteria may have such antimicrobial potential and hence they must be isolated and screened for the purpose.…”