[Role of associative microsymbionts in functioning of associative symbiosis]

Study the role of associative microsymbionts in biocenosis based on comparative evaluation of interbacterial and epithelial-bacterial interactions on the example of vaginal biotope.

Corynebacterium spp., Staphylococcus aureus, Escherichia coli and Lactobacillus spp. and primary epitheliocytes isolated from the lower part of reproductive tract of women were used. Interactions by associant-macropartner vector were evaluated by changes of growth properties and antagonistic activity of the associant under the influence of exometabolites of vaginal epitheliocytes and expression of cytokines by epitheliocytes under the influence of associants. The nature of interaction by associant-dominant vector was evaluated by changes of adhesive properties and biofilm formation of associants and bactericidal activity of peroxide-producing lactobacilli.

Groups of associants that are opposite by their function in symbiosis were isolated. An example of associants that stabilize associative symbiosis by stimulating growth and antagonistic activity of dominant, moderate increase of cytokine production by epitheliocytes are corynebacteria, whose growth, biofilm formation, adhesion and antagonism during interaction with dominant and macropartner are also increased. The nature of interaction of associants of the other group (S. aureus and E. coli) with dominant and macropartner is the opposite. The determinative role of hydrogen peroxide in mechanisms of differentiation of associative microsymbionts and functioning of associative symbiosis ofvagina was shown.

The proposed approach allows to differentiate associative microsymbionts with various ecological roles, evaluate their contribution into maintenance of the stability of the symbiosis and open new possibilities of management of quality of microbiocenosis.