EFFECTS OF ENTEROBACTERIAL CELL-FREE SUPERNATANTS ON THE PHENOTYPIC EXPRESSION OF PROTEIN ADHESINS RELATED TO THE BIOFILM FORMATION OF ESCHERICHIA COLI K-12

Anna Vacheva (1) , Radka Ivanova (1) , Stoyanka Stoitsova (1)

1 Institut Stephan Angeloff

In nature, bacterial biofilms occur as mixed consortia of species and strains which interact via cell-to-cell contacts and substances released in the environ- ment. We have previously shown biofilm stimulation in 8 Escherichia coli K-12 strains by released substances present in conditioned cell-free stationary-phase culture supernatants (CFS) from E. coli K-12, E. coli O157:H- and Y. enterocolitica O3. In an attempt to clarify the mode of action of these CFS, the present study concentrated on their effects on phenotypes associated with biofilm-related protein adhesins. CFS supplementation of 0.3% motility agar resulted in a dramatic increase of flagellar motility. Co-incubation with S. cerevisiae demonstrated changes in type 1 fimbriae-related co-aggregation when the E. coli strains had been grown in the presence of CFS. Some strain-specific re- sponses to CFS, like the intensified expression of F-like pili in the biofilm of E. coli W1655, were noted. The results show that the applied CFS have a pronounced impact on the E. coli bacterial surface-related phenotypes.

Keywords: biofilm; E. coli K-12; cell-free supernatants; protein adhesins

Domains: Life Sciences [q-bio]; Microbiology and Parasitology

Anna Vacheva, Radka Ivanova, Stoyanka Stoitsova. EFFECTS OF ENTEROBACTERIAL CELL-FREE SUPERNATANTS ON THE PHENOTYPIC EXPRESSION OF PROTEIN ADHESINS RELATED TO THE BIOFILM FORMATION OF ESCHERICHIA COLI K-12. Comptes rendus de l'Académie bulgare des Sciences, 2011, 65 (2), pp.173-180. ⟨pasteur-00748981⟩