Pseudomonas aeruginosa biofilm formation in the cystic fibrosis airway

Abstract

The cystic fibrosis (CF) lung is chronically inflamed and infected by Pseudomonas aeruginosa, which is a major cause of morbidity and mortality in this genetic disease. Although aerosolization of Tobramycin into the airway of CF patients improves outcomes, the lungs of CF patients, even those receiving antibiotic therapy, are persistently colonized by P. aeruginosa. Recent studies suggest that the antibiotic resistance of P. aeruginosa in the CF lung is due to the formation of drug resistant biofilms, which are defined as communities of microbes associated with surfaces or interfaces, and whose growth is facilitated by thick and dehydrated mucus in the CF lung. In this review, we discuss some of the current models used to study biofilm formation in the context of biotic surfaces, such as airway cells, as well as the contribution of host-derived factors, including DNA, actin and mucus, to the formation of these microbial communities. We suggest that better in vitro models are required, both to understand the interaction of P. aeruginosa with the host airway, and as models to validate new therapeutics, whether targeted at bacteria or host.

Iron acquisition in the cystic fibrosis lung and potential for novel therapeutic strategies

“…Moreau-Marquis et al (2008) demonstrated reduced P. aeruginosa biofilm growth on epithelial cells treated with an iron chelator and subsequently demonstrated (Moreau-Marquis et al, 2009) tobramycin in combination with iron chelators can eliminate P. aeruginosa biofilms. In a recent study, the same group have shown that a combination of hypocyanite and lactoferrin enhances the ability of tobramycin and aztreonam to eliminate P. aeruginosa biofilms on lung epithelial cells (Moreau-Marquis et al, 2015).…”

Inhibition ofSteptococcus mutansbiofilm formation by extracts ofTenacibaculumsp. 20J, a bacterium with wide-spectrum quorum quenching activity

“…Biofilms are complex microbial communities which usually have a key role in virulence and antibiotic resistance in pathogenic bacteria [1,2]. In numerous bacterial species, biofilm formation and maturation are regulated by quorum sensing (QS), a chemical communication system mediated by extracellular signals that are thought to enable bacteria to assess population size and coordinate virulence factor expression [3].…”

Siderophore production and biofilm formation as linked social traits

“…Understanding selective pressures on cooperation is therefore likely to require consideration of multiple traits simultaneously. We investigated two clinically relevant cooperative traits: production of ironscavenging siderophores (Griffin et al, 2004;Harrison et al, 2006) and biofilm formation (Costerton et al, 2003;Brockhurst et al, 2006;Moreau-Marquis et al, 2008). Both can be exploited by 'cheats': cells that cease producing costly public goods (siderophores or biofilm matrix polymers) but benefit from the efforts of their neighbours.…”