title: [Interaction of Bifidobacterium bifidum with members of normal microflora in human intestine microsymbiocenosis].
abstract: OBJECTIVE
  Study the influence of exometabolites of B. bifidum on biological properties of bacteria that are the members of normoflora and their ability to interact with associative microsymbionts.
  
  
  METHODS
  Bacterial strains that are members of the normal microflora of human intestine: B. bifidum, Lactobacillus acidophilus, Enterococcusfaecium and Escherichia coli lactose positive non-hemolytic (lac "+"/hly "-") were used. As opportunistic microorganisms cultures of E. coli lactose negative hemolytic (lac "-"/hly "+"), Klebsiella pneumoniae and Staphylococcus aureus were used. Isolation and identification of microorganisms was performed by generally accepted methods according to guidances. In the first series of experiments influence of B. bifidum metabolites on biological properties of microorganisms that are members ofnormoflora was studied. In the second series--the influence of bifidobacteria supernatants on interrelations of B. bifidum, L. acidophilus and E. coli lac "+"/hly "-" with opportunistic associants. Growth properties (GP), biofilm formation (BFF) and anti-lysozyme activity (ALA) of microorganisms was studied photometrically. Optical density measurement were performed on ELx808 (BioTek, U.S.A.) photometer. The data obtained were treated by nonparametric method using Mann-Whitney criteria.
  
  
  RESULTS
  B. bifidum supernatant was established to stimulate in 33.3-66.7% of cases or did not alter growth/reproduction, BFF and ALA of microorganisms that are characteristic for eubiosis of intestine including bacteria of the same species that could have implications for realization by bifidobacteria ofbiotope colonization resistance. Features of interaction ofexometabolites of bifidobacteria with microorganisms that are characteristic for eubiosis of human intestine consisting in enchantment or changes of effects of the influence of normoflora members on BFF of associants were revealed. The maximum enchantment of inhibitory effect of indigenous strains under the influence ofbifidobacteria was noted in associations E. coli lac "+"/hly "-" E. coli lac "-"/hly "+" as well as E. faecium--S. aureus.
  
  
  CONCLUSIONS
  Thus, the data obtained may be used for detection of mechanisms of functioning of normal microsymbiocenosis in human associative symbiosis.
authors.forename: O V
authors.initials: OV
authors.lastname: Bukharin
authors.forename: N B
authors.initials: NB
authors.lastname: Perunova
authors.forename: E V
authors.initials: EV
authors.lastname: Ivanova
mesh_terms: D001644:Bifidobacterium / Q000502:physiology*; D018441:Biofilms / Q000187:drug effects / Q000254:growth & development; D017077:Culture Media, Conditioned / Q000494:pharmacology*; D016984:Enterococcus faecium / Q000187:drug effects / Q000254:growth & development; D004926:Escherichia coli / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D007422:Intestines / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000187:drug effects / Q000254:growth & development; D007779:Lactobacillus acidophilus / Q000187:drug effects / Q000254:growth & development; D007785:Lactose / Q000378:metabolism; D059013:Microbial Consortia / Q000502:physiology*; D009113:Muramidase / Q000037:antagonists & inhibitors; D019936:Probiotics / Q000378:metabolism; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development; D013559:Symbiosis
chemical_list: D017077:Culture Media, Conditioned; D009113:Muramidase; D007785:Lactose