Antagonistic Activity of Probiotic Bacteria

Objective.

Objective: To investigate antagonistic activity of multicomponent probiotic products resulting from interactions of microorganisms; to develop bacterial selection criteria for multi-component biological products.

Materials and Methods.

Culture fluid of the paired probiotic strain associations: Bifidobacterium longum with Enterococcus faecium («Bifiform» product), Escherichia coli M-17 («Colibacterin» product) and Lactobacillus plantarum 8РА-3 («Lactobacterin» product) were tested for bactericidal activity against Staphylococcus aureus. Also, culture fluid of the each strain was treated with metabolites and peptidoglycan of the associative species and then tested for bactericidal activity against Staphylococcus aureus.

Results.

Using the «Bifiform» product as an example, mechanism of action of multi-component probiotic products was studied. This included an increase in antagonistic activity of one species through the interaction with the cellular components of another species. In particular, metabolites of E. faecium were shown to be able to enhance antagonistic activity of B. longum. Similarly to «Bifiform» product, other probiotic strain associations were studied. Antagonism of E. faecium in association with E. coli М-17 was found to be determined by mutually enhanced antagonistic activity of the both strains. The rest of the studied bacterial associations demonstrated no significant enhancement.

Conclusions.

Antagonistic activity of microorganisms is a result of microbial interactions, where an active strain produces antimicrobial substances, and associative strains determine potential for and magnitude of antagonism. The probiotic strain selection criteria and a model for compiling multi-component probiotic products. This model includes one strain with antagonistic activity and another strain enhancing the growth and/or antagonistic properties of the former one.