Developing a model for cystic fibrosis sociomicrobiology based on antibiotic and environmental stress

Abstract

Cystic fibrosis (CF) infections are invariably biofilm-mediated and polymicrobial, being safe to assume that a myriad of factors affects the sociomicrobiology within the CF infection site and modulate the CF community dynamics, by shaping their social activities, overall functions, virulence, ultimately affecting disease outcome. This work aimed to assess changes in the dynamics (particularly on the microbial composition) of dual-/three-species biofilms involving CF-classical (Pseudomonas aeruginosa) and unusual species (Inquilinus limosus and Dolosigranulum pigrum), according to variable oxygen conditions and antibiotic exposure. Low fluctuations in biofilm compositions were observed across distinct oxygen environments, with dual-species biofilms exhibiting similar relative proportions and P. aeruginosa and/or D. pigrum populations dominating three-species consortia. Once exposed to antibiotics, biofilms displayed high resistance profiles, and microbial compositions, distributions, and microbial interactions significantly challenged. The antibiotic/oxygen environment supported such fluctuations, which enhanced for three-species communities. In conclusion, antibiotic therapy hugely disturbed CF communities' dynamics, inducing significant compositional changes on multispecies consortia. Clearly, multiple perturbations may disturb this dynamic, giving rise to various microbiological scenarios in vivo, and affecting disease phenotype. Therefore, an appreciation of the ecological/evolutionary nature within CF communities will be useful for the optimal use of current therapies and for newer breakthroughs on CF antibiotherapy.

Keywords: Antibiotic therapy; Cystic fibrosis; Interspecies interactions; Polymicrobial biofilms; Pseudomonas aeruginosa.