Institute of Cellular and Intercellular Symbiosis, Orenburg, Russia
Aim. To determine features of species composition and factors of persistence of bifidobacteria of human gut microflora in healthy state and during dysbiosis. Materials and methods. Strains of bifidobacteria isolated from feces of patients with gut dysbiosis grades I — III (24 participants) and conditionally healthy persons (14 participants) were used for the study. Isolation and identification of microorganisms were performed by conventional methods. Antilysozyme activity was determined by photometric method and antilactoferrin sign — by immunoenzyme assay. Results. Bifidobacteria isolated from intestinal biotope have differences in species composition, which depended from age and state of microbiocenosis of studied persons. Bifidobacterium bifidum was dominated between strains of bifidobacteria isolated from infants with eubiosis, whereas B.longum dominated in persons >1 y.o. B.bifidum and B.adolescentis were mainly isolated in infants with gut dysbiosis, whereas in children >1 y.o. B.adolescentis was predominantly isolated. New characteristic of bifidoflora — antilactoferrin activity — was discovered for the first time. Expression of this sign, as well as antilysozyme activity, varied and depended from species of bifidobacteria. Conclusion. Obtained data widen our views on species composition of bifidobacteria and discover possible mechanisms of persistence of these microorganisms in intestinal biotope associated with inactivation of host defense factors — lysozyme and lactoferrin.
Zh. Mikrobiol. (Moscow), 2009, No. 2, P. 89—93