MODULATION OF C-DI-GMP LEVELS REGULATE VIRULENCE IN PSEUDOMONAS AERUGINOSA

Abstract

ACUTE AND CHRONIC INFECTIONS CAUSED BY PATHOGENIC BACTERIA, ARE TYPICALLY MEDIATED BY THE PLANKTONIC AND BIOFILM (MULTICELLULAR COMMUNITIES) LIFESTYLES RESPECTIVELY. THE ROLES OF BIOFILM FORMATION IN INFECTIONS ARE WELL-STUDIED, BUT THE BIOFILM DISPERSAL FOR DISSEMINATION OF INFECTIONS AND INDUCTION OF VIRULENCE AGAINST IMMUNE SYSTEMS, REMAINS LARGELY UNKNOWN.

HERE, DISPERSED CELLS FROM PSEUDOMONAS AERUGINOSA BIOFILMS WERE FIRST SHOWN TO POSSESS A UNIQUE TRANSCRIPTOME, AS COMPARED TO PLANKTONIC AND BIOFILM CELLS. DISPERSED CELLS DISPLAYED INCREASED VIRULENCE AGAINST MURINE MACROPHAGES AND CAENORHABDITIS ELEGANS, BUT WERE HIGHLY SENSITIVE TO IRON STRESS. NEXT, BIOFILMS WERE ABLE TO BE DISPERSED BY NITRIC OXIDE (NO), A KILLING FACTOR PRODUCED BY THE MACROPHAGES. THIS RESULTED IN THE PRODUCTION OF CYTOTOXIC RHAMNOLIPIDS BY THE BACTERIAL CELLS VIA SMALL RNA SIGNALLING, TO KILL MACROPHAGES. THESE RESULTS SHED NEW LIGHT THAT BIOFILMS COULD DISPERSE AND ELICIT VIRULENCE AGAINST IMMUNE CELL