Probiotic Potential of Lactic Acid Bacteria Strains Isolated from Artisanal Cheeses: Impact on Listeria monocytogenes Infection

Abstract

Listeriosis is a disease associated with the consumption of food contaminatedwith Listeria monocytogenes. Probiotic lactic acid bacteria (LAB) or their postbiotics havebeen of interest for their anti-listerial effect. This study focused on isolating LAB fromartisanal cheeses and characterizing their potential as probiotics. Twelve LAB isolatesexhibiting typical LAB traits were evaluated for their ability to survive in simulated gastricjuice, hydrolyze bile salts, auto-aggregate, hydrophobicity, and antagonistic activity againstL. monocytogenes. The four most promising LAB strains demonstrated anti-listerial probioticpotential and were identified as Latilactobacillus (Lat.) curvatus SC076 and Lactiplantibacillus(Lact.) paraplantarum SC291, SC093, and SC425. The antimicrobial activity of these strainswas mainly attributed to bacteriocin-like substances and organic acids. While three Lact.paraplantarum strains were resistant to ampicillin, Lat. curvatus was sensitive to all testedantibiotics. All selected strains exhibited no hemolytic, gelatinase, and lecithinase activity.Exposure to LAB supernatants resulted in a significant reduction in the adhesion andintracellular count of L. monocytogenes in Caco-2 cells, with Lat. curvatus SC076 showingthe most significant effect. Based on its probiotic characteristics, Lat. curvatus SC076 isa promising candidate for functional foods, pending further in vivo studies to assess itspotential in the food industry.