Three New Lactobacillus plantarum Strains in the Probiotic Toolbox against Gut Pathogen Salmonella enterica Serotype Typhimurium

Abstract

SummaryThe benefi ts of probiotic bacteria have been widely explored. However, fermented foods and digestive system of humans and animals are an inexhaustible source of new potentially probiotic microorganisms. In this study we present three new Lactobacillus plantarum strains isolated from diff erent dairy products: cow′s cheese, sheep′s cheese and whey. In order to determine the antibacterial activity of yet unexplored L. plantarum strains against Salmonella enterica serotype Typhimurium, in vitro competition and co-culture tests were done. Furthermore, adhesion of these strains to Caco-2 cells and their infl uence on the adhesion of Salmonella were tested. Results showed the potential probiotic activity of isolated strains. L. plantarum strains survived in the presence of 1 % bile salts, they possessed acidifi cation ability, antibacterial activity and signifi cantly att enuated the growth of S. Typhimurium in brain heart infusion broth. All tested L. plantarum strains were able to adhere to Caco-2 cells and signifi cantly impair the adhesion of S. Typhimurium. All three L. plantarum strains exhibited signifi cant probiotic potential and anti-Salmonella activity; therefore, further testing on in vivo models should follow.

Lactobacillus plantarum with Functional Properties: An Approach to Increase Safety and Shelf-Life of Fermented Foods

“…plantarum in raw milk and its low technological importance in standard milk processing. However, strains with probiotic properties have been isolated from different dairy-related niches, for example, camel milk [ 25 ], cow's or ewe's raw-milk cheeses, and whey [ 103 – 106 ]. Hence, recent studies are more focused on implementing probiotic strains of Lb.…”

Protective Effect of Potential Probiotic Strains from Fermented Ethiopian Food against Salmonella Typhimurium DT104 in Mice

“…by potential probiotic LAB strains in the coculture assay [16,33,34]. In line with this, Potočnjak et al [25] reported that all the tested Lactobacillus plantarum strains (A, B, and S1) were able to inhibit (p < 0.05) the growth of Salmonella Typhimurium at all-time points (6, 12, and 24 h) in the coculture assay. e same author reported that after 24 h of cocultivation, the number of Salmonella cells was reduced 1000 times in comparison with Salmonella monoculture and the inhibition was most pronounced after 12 h of coincubation and amounted to 97, 98, and 94% by strains A, B, and S1, respectively.…”

“…To evaluate the effect of selected potential pure strains (Lactococcus lactis E124, Lactobacillus paracasei K114 and Lactobacillus plantarum K132) and their combinations on the growth of Salmonella Typhimurium DT104, liquid coculture technique was used as described by Potočnjak et al [25] with some modifications. Before cocultivation, the selected strains and Salmonella Typhimurium DT104 were grown separately in de Man, Rogosa, and Sharpe (MRS) broth and tryptic soy broth (TSB), respectively.…”

Determination of competition and adhesion abilities of lactic acid bacteria against gut pathogens in a whole-tissue model

“…Although the same strains adhered to epithelial cells at high rates, their competition abilities were limited against S. Enteritidis. On the other hand, Lau and Chye [ 12 ], Potočnjak et al [ 52 ] and Feng et al [ 53 ] reported that Lactobacillus strains prevented Salmonella spp. from sticking to Caco-2 cells.…”

“…Survival of passage through the challenging conditions in the digestive tract and adhesion to human cells are important for strains to show their health effects in the human gut. The resistance to such conditions is crucial, as exposure to bile salts causes dissociation of the lipid bilayer of cell membranes and disruption of the integrity of cells [ 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ]. Consumption of approximately 1.0 × 10 6 to 1.0 × 10 10 viable cells per day is generally accepted as the minimum limit required in order to gain satisfactory probiotic functions in the intestine [ 15 , 55 , 56 , 57 ].…”