A multivariate approach to correlate bacterial surface properties to biofilm formation by lipopolysaccharide mutants of Pseudomonas aeruginosa

Abstract

Bacterial biofilms are involved in various medical infections and for this reason it is of great importance to better understand the process of biofilm formation in order to eradicate or mitigate it. It is a very complex process and a large range of variables have been suggested to influence biofilm formation. However, their internal importance is still not well understood. In the present study, a range of surface properties of Pseudomonas aeruginosa lipopolysaccharide mutants were studied in relation to biofilm formation measured in different kinds of multi-well plates and growth conditions in order to better understand the complexity of biofilm formation. Multivariate analysis was used to simultaneously evaluate the role of a range of physiochemical parameters under different conditions. Our results suggest the presence of serum inhibited biofilm formation due to changes in twitching motility. From the multivariate analysis it was observed that the most important parameters, positively correlated to biofilm formation on two types of plates, were high hydrophobicity, near neutral zeta potential and motility. Negative correlation was observed with cell aggregation, as well as formation of outer membrane vesicles and exopolysaccharides. This work shows that the complexity of biofilm formation can be better understood using a multivariate approach that can interpret and rank the importance of different factors being present simultaneously under several different environmental conditions, enabling a better understanding of this complex process.

The Role of Pseudomonas aeruginosa Lipopolysaccharide in Bacterial Pathogenesis and Physiology

“…In fact, it was the first organism implicated in a medically associated biofilm when cell aggregates were observed in the sputum of CF patients [125]. The O antigen is linked to biofilm formation, although, whether biofilm production is positively or negatively affected by the presence of O antigen varies between bacterial species and may be influenced by the surface tested [126].…”

The Social Life of Aeromonas through Biofilm and Quorum Sensing Systems

“…The cell surface hydrophobicity and charge conferred by LPS were involved in P. aeruginosa biofilm formation (Ruhal et al, 2015), but their exact roles in the Aeromonas biofilm development are not fully understood. The A. hydrophila surface α-glucan independent of the LPS also improves biofilm formation (Merino et al, 2012).…”

Bacteria-Host Crosstalk: Sensing of the Quorum in the Context of <b><i>Pseudomonas aeruginosa</i></b> Infections

“…The last-resort antibiotic colistin, also known as polymyxin E, binds to LPS with high affinity; LPS modifications lead to the development of antibiotic resistance and changes in bacterial fitness and virulence potential [39]. LPS is able to enhance bacterial cell surface hydrophobicity, and therefore increase P. aeruginosa motility and impact adhesion and biofilm formation [40]. Flagellin and LPS of P. aeruginosa can associate with host pattern recognition receptors, e.g., Toll-like receptors (TLR5 and TLR4) expressed on different host cells, and thereby initiate an inflammatory response via the NF-κB signaling pathway [4].…”