Antimicrobial susceptibility and immunomodulatory properties of lamb isolate of lactobacillus mucosae, new probiotic candidate

In the process of selecting a new probiotic candidate, several bacteria were isolated from the stomach mucosa of a lamb. Among them, three lactobacilli strains were identified and partially characterised. The strain, Lactobacillus mucosae D, showed several characteristics appropriate to the probiotics. In this study, we have focused on the further characterisation of L. mucosae D and testing of its ability to modulate metabolic and immunomodulatory activities of human mononuclear cells in vitro. L. mucosae D is resistant to antibiotics, like penicillin G, oxacillin, vancomycin and chemotherapeutics ofloxacin and ciprofloxacin. In in vitro conditions, L. mucosae D caused a significant increase in phagocytic activity and index (relative activities 1.05 and 1.44, respectively) of human monocytes. It decreased bactericidal activities of monocytes against Escherichia coli (relative activity 0.73) and Staphylococcus aureus (relative activity 0.36), whereas, candidacidal activity was enhanced (relative activity 1.15). Metabolic activities, lysozyme and peroxidase activity, of mononuclear cells were not changed or increased, respectively. L. mucosae D displayed the ability to enhance production of pro-inflammatory cytokine, IL-1β, in monocytes in vitro (relative activity 2.60). Therefore, we state that lamb isolate, L. mucosae D, has the required attributes for being a potential probiotic candidate.