Biofilms

Dental plaque

Problems associated to biofilms

1- Physical effects: ships, tubing…

2- Metal surface corrosion

3- Development on medical implants

4- Associated diseases

Tubing obstruction

Equipamiento dental >30años

MS2-

M+

Biofilm formation on a voice implant

Contact lens

Catheter

P. Aeruginosa biofilm in lung

Structure

Structure

Biofilm formation process

Glass surface in the lab

MBF HBFLBFWT

Citrate

Glucose+Caa

Genetic analysis of biofilm formation

Genetic characterization of biofilm formation

- Requirement of movement

- Adhesins

-Signaling

-Glycocalyx formation

Movement requirement

-Flagelar-mediated mobility-Non-motile mutants in P. Fluorescens

-Twitching-Mutants in type IV pili in P. aeruginosa

-Suppression by cells “stickier”-ompR and adhesin Curli in E. coli

Adhesins

-Type I pilus (fimH) in E. coli-Type IV (MSHA) pilus in V. cholerae-Curli adhesin

Signaling

-Quorum sensing

QUORUM SENSING:DENSITY-DEPENDENT EXPRESSION

CULTURE DENSITY

AU

TO

IND

UC

ER

TRESHOLD

GRAM-NEGATIVE COMMUNICATION:THE LuxI/LuxR LANGUAGE

LuxI

LuxR

LuxR

Target gene

GRAM-NEGATIVE COMMUNICATION:THE LuxI/LuxR LANGUAGE

-Light production in Vibrio fisheri-Virulence in Pseudomonas aeruginosa (LasI/R, RhlI/R)-Opine formation in Agrobacterium tumefaciens (TraR/I)

GRAM-positive COMMUNICATION:THE PHEROMONE LANGUAGE

ABC

D

Target genePheromone gene

H

HYBRID LANGUAGES: THE CASE OF Vibrio harvey

LuxO

Target gene

LuxN

LuxLM LuxS

LuxQ

-Competence for DNA uptake in Bacillus subtilis and Streptoccocus pneumoniae (ComX/ComP/ComA)-Sporulation in Bacillus subtilis -Conjugation in Enteroccus fecalis-Virulence in Staphylococus areus

GRAM-positive COMMUNICATION:THE PHEROMONE LANGUAGE

QS-mutants

Glycocalyx formation

-Alginate production in P. aeruginosa- EPS in V. cholerae (vps)

fimA

lasI

vps

flagella

rhl

algfimH

Curli

Natural process of biofilm formation / Control by a blocking analogue