| Autor: |
Dorel, Corinne, Vidal, Olivier, Prigent‐Combaret, Claire, Vallet, Isabelle, Lejeune, Philippe |
| Zdroj: |
FEMS Microbiology Letters; September 1999, Vol. 178 Issue: 1 p169-175, 7p |
| Abstrakt: |
In a genetic screening directed to identify genes involved in biofilm formation, mutations in the cpxAgene were found to reduce biofilm formation by affecting microbial adherence to solid surfaces. This effect was detected in Escherichia coliK12 as well as in E. colistrains isolated from patients with catheter‐related bacteremia. We show that the negative effect of the cpxAmutation on biofilm formation results from a decreased transcription of the curlin encoding csgAgene. The effect of the cpxAmutation could not be observed in cpxR−mutants, suggesting that they affect the same regulatory pathway. The cpxA101mutation abolishes cpxAphosphatase activity and results in the accumulation of phosphorylated CpxR. Features of the strain carrying the cpxA101mutation are a reduced ability to form biofilm and low levels of csgAtranscription. Our results indicate that the cpxAgene increases the levels of csgAtranscription by dephosphorylation of CpxR, which acts as a negative regulator at csgA. Thus, we propose the existence of a new signal transduction pathway involved in the adherence process in addition to the EnvZ‐OmpR two‐component system. |
| Databáze: |
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