Bayesian estimation of Pseudomonas aeruginosa viscoelastic properties based on creep responses of wild type, rugose, and mucoid variant biofilms

Mohammad Nooranidoost; N G Cogan; Paul Stoodley; Erin S Gloag; M Yousuff Hussaini

doi:10.1016/j.bioflm.2023.100133

Bayesian estimation of Pseudomonas aeruginosa viscoelastic properties based on creep responses of wild type, rugose, and mucoid variant biofilms

Biofilm. 2023 Jun 3:5:100133. doi: 10.1016/j.bioflm.2023.100133. eCollection 2023 Dec.

Authors

Mohammad Nooranidoost¹, N G Cogan¹, Paul Stoodley^{2

3

4}, Erin S Gloag⁵, M Yousuff Hussaini¹

Affiliations

¹ Department of Mathematics, Florida State University, Tallahassee, FL, USA.
² Department of Microbial Infection and Immunity, The Ohio State University, Columbus, OH, USA.
³ Department of Orthopaedics, The Ohio State University, Columbus, OH, USA.
⁴ National Centre for Advanced Tribology at Southampton (nCATS), National Biofilm Innovation Centre (NBIC), Department of Mechanical Engineering, University of Southampton, UK.
⁵ Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, USA.

Abstract

Pseudomonas aeruginosa biofilms are relevant for a variety of disease settings, including pulmonary infections in people with cystic fibrosis. Biofilms are initiated by individual bacteria that undergo a phenotypic switch and produce an extracellular polymeric slime (EPS). However, the viscoelastic characteristics of biofilms at different stages of formation and the contributions of different EPS constituents have not been fully explored. For this purpose, we develop and parameterize a mathematical model to study the rheological behavior of three biofilms - P. aeruginosa wild type PAO1, isogenic rugose small colony variant (RSCV), and mucoid variant biofilms against a range of experimental data. Using Bayesian inference to estimate these viscoelastic properties, we quantify the rheological characteristics of the biofilm EPS. We employ a Monte Carlo Markov Chain algorithm to estimate these properties of P. aeruginosa variant biofilms in comparison to those of wild type. This information helps us understand the rheological behavior of biofilms at different stages of their development. The mechanical properties of wild type biofilms change significantly over time and are more sensitive to small changes in their composition than the other two mutants.

Keywords: Bayesian estimation; Biofilm; Biomechanics; Extracellular polymeric slime; Viscoelasticity.