Xylitol affects virulence factors production in Pseudomonas aeruginosa by quorum sensing interference

ELEONORA MENGONI; CONFORTE, VALERIA P.; RODRIGUEZ-PUEBLA, MARCELO L.; VOJNOV, ADRIAN A.

Buenos Aires

Congreso; SAIB-SAMIGE Joint Meeting 2020 ? Online; 2020

SAIB - SAMIGE

Pseudomonas aeruginosa is a highly adaptable bacterium that inhabits a wide range of environmental niches and causes diseasein many species, including humans. Some strains of this organism cause a variety of infections in immunocompromisedpatients, as well as destructive chronic respiratory disease in individuals with cystic fibrosis. Furthermore, P. aeruginosa isone of the main causes of nosocomial infections and exhibits resistance to a broad range of antibiotics which makes it a realproblem to human health. As a consequence, it is necessary to create new strategies to prevent its development. Infection ofP. aeruginosa requires the expression of virulence factors such as proteases, elastases, biofilm formation, etc. that are regulatedby quorum sensing systems (QS). P. aeruginosa has two well-known QS systems: las and rhl. Both of them involve theproduction of small diffusible signal molecules called acyl homoserine lactones (AHLs) that bind to and activate transcriptionalregulators to induce gene expression. Xylitol, a polyalcohol widely used in the pharmaceutical industry, has been described asan anti-biofilm compound against few bacterial species. The aim of this work was to explore the effect of xylitol on theproduction of virulence factors and biofilm in P. aeruginosa PAO1 strain (PAO1). This study shows that xylitol moderatelyinhibited the QS and virulence factors production in PAO1. Pyocyanin and elastase synthesis, motility and biofilm formationwere significantly reduced when bacteria were cultured in medium containing a sublethal concentration of xylitol, withoutsignificantly affecting growth of PAO1. Expression analysis of QS genes revealed that the effect of xylitol on biofilm formationand virulence factor production can be explained by its inhibitory action on the expression of the QS response regulators. Ourresults indicate that the influence of xylitol in these processes is mediated, at least in part, through interference with the las QSsystem via a possible inhibition of the interaction between their response regulators and autoinducers.