Title : Study of potential probiotic of Lactobacillus strains isolated from Algerian traditional fermented milk and their antagonistic activity against resistan Staphylococcus aureus
Abstract:
Background: Probiotics have gained significant attention due to their potential health benefits, including their ability to modulate the gut microbiota and positively influence various aspects of human and animal health. Lactobacillus plantarum is a well-known probiotic strain known for its beneficial effects on gastrointestinal health. In Algeria a country traditionally a consumer of fermented milk products mad from raw milk the failure to comply with hygienic conditions, these products become a frequent cause of S. aureus food poisoning.
Objective: This study was conducted in order to evaluate the probiotic properties of thirty lactic acid bacteria (LAB) isolated from the traditionnal fermented milk.. Also the strains of Lactobacillus were tested against S.aureus resistant.
Methods: The major properties, including gastric juice (pH2) and bile salts tolerance (0,3%), antibiotic susceptibility (10 antibiotics are tested by antibiogram test), auto-aggregation, their adhesion to polystyrene microplates and in vitro antioxidant capabilities (DPPH and ABTS test) were investigated. The strains of Lactobacillus were tested for their antagonistic activity against S.aureus resistant via spot and wells test.
Results: 50% of the strain presented a viability rate of 100% at acid pH, adhere strongly to microplates, tolerance to bile stools and sensitivity to the antibiotics tested. The results obtained show that 50% of the l’ben samples are contaminated with S. aureus, in fact, 60 S.aureus strains are identified.The study of the sensitivity of these strains with respect to cefotaxime and ceftazidime made it possible to select 20 strains of S. aureus with a 32.62% strength of resistance. The The study of the antibacterial activity of the 15 strains of Lactobacillus revealed zones of inhibitions which vary between 15 and 35 mm. However, the well test showed that 5 Lactobacillus strains showed inhibitory zones that exceeded 15 mm after pH neutralization of the supernatant.
Conclusion: isolated Lactobacillus strains exhibited several characteristics to prove it's excellent as a potential probiotic candidate for developing quality fermented milks.
