In the present study, we examined whether a commensal gut bacterium
Escherichia coli might prevent the formation and development of the biofilm of
Staphylococcus epidermidis, a nosocomial extraintestinal pathogen but not a gut microorganism. When co-cultured with
S. epidermidis,
E. coli strain ATCC 35218, a non-pathogenic strain, was found to be dominant in the biofilm formed on the surface of wells of a microtiter plate. In addition,
E. coli significantly incorporated and grew in a niche preoccupied by
S. epidermidis biofilm. Two other
E. coli strains (strain K-12 and B) also showed to interfere the biofilm formation by
S. epidermidis. In contrast,
S. epidermidis could not grow in a niche preoccupied by
E. coli biofilm. These results suggest that, through inhibition of the formation and development of the biofilm,
E. coli may eliminate
S. epidermidis from the gastrointestinal tract.
View full abstract