Bacterial Interactions with Immobilized Liquid Layers

Abstract

Bacterial interactions with surfaces are at the heart of many infection-related problems in healthcare. In this work, the interactions of clinically relevant bacteria with immobilized liquid (IL) layers on oil-infused polymers are investigated. Although oil-infused polymers reduce bacterial adhesion in all cases, complex interactions of the bacteria and liquid layer under orbital flow conditions are uncovered. The number of adherent Escherichia coli cells over multiple removal cycles increases in flow compared to static growth conditions, likely due to a disruption of the liquid layer continuity. Surprisingly, however, biofilm formation appears to remain low regardless of growth conditions. No incorporation of the bacteria into the layer is observed. Bacterial type is also found to affect the number of adherent cells, with more E. coli remaining attached under dynamic orbital flow than Staphylococcus aureus, Pseudomonas aeruginosa under identical conditions. Tests with mutant E. coli lacking flagella confirm that flagella play an important role in adhesion to these surfaces. The results presented here shed new light on the interaction of bacteria with IL layers, highlighting the fundamental differences between oil-infused and traditional solid interfaces, as well as providing important information for their eventual translation into materials that reduce bacterial adhesion in medical applications.

Silica–gentamicin nanohybrids: combating antibiotic resistance, bacterial biofilms, and in vivo toxicity

“…Bacterial motility constitutes a critical virulence factor in bacterial colonization by initiating the contact of bacterial cells with surfaces. 8 A recent study 31 has paid attention to the role of bacterial morphology in adhesion to immobilized liquid layers under dynamic conditions, advocating the more efficient adhesion of E. coli cells in comparison with that of S. aureus and P. aeruginosa, under dynamic conditions, to the flagella of E. coli. Furthermore, the most predominant clinical bacteria involved in orthopedic implant infections belong to the Staphylococcus genus followed by Enterobacteriaceae genus.…”

Designing Liquid‐Infused Surfaces for Medical Applications: A Review

“…For example, while dense bacterial attachment almost invariably leads to biofilm formation on synthetic solid surfaces, this may not be the case on a liquid surface. In a recent study, silicone‐oil‐infused PDMS showed a significant number of E. coli colony‐forming units, comparable to noninfused PDMS, under orbital flow, despite preventing all attachment under static conditions . Yet surprisingly, the infused PDMS samples still showed minimal biofilm coverage under both flow and static conditions, suggesting that the progression to biofilm formation may have been blocked.…”

“…Solids textured by LbL deposition, UV‐initiated polymerization, or osmotically driven wrinkling and coated with either perfluorinated or silicone liquids have also proven generally effective at resisting both bacterial and fungal biofilm adhesion, frequently preventing more than 97% of the biofilms from remaining on the surfaces ( Figure A,B). Multiple reports have also demonstrated the ability of silicone‐oil‐infused PDMS and other silicone compounds, separately already widely used in medicine, to resist S. aureus , P. aeruginosa , and E. coli biofilm attachment under both static and flow conditions (Figure C) …”

“…It is known that bacteria can form biofilms at oil/water interfaces, although the structure and adhesive strength of such biofilms can vary significantly among species . Preliminary work using immobilized liquid layers has also revealed evidence of biofilm formation at their oil/water interfaces that can differ between species and strains . The first reports of microorganism growth on layers of silicone oil on PDMS noted a “peeling away” of a combined bacterial/algal biofilm that had formed on the oil layer when the samples were exposed to an air/water interface, often leaving an intact biofilm floating on the surface of the liquid medium ( Figure A).…”

Slippery Lubricant‐Infused Surfaces: Properties and Emerging Applications

“…The same authors also demonstrated higher number of adhered bacteria cultured under dynamic conditions in comparison to the static conditions. [98] An excellent review about antiadhesion properties of SLIPS for medical applications including antibacterial and antithrombogenic uses of SLIPS has been recently published by Sotiri et al [15] SLIPS based on medically relevant materials (such as expanded polytetrafluoroethylene and perfluoroperhydrophenanthrene) was prepared, coated onto the implant surface, and then studied in a rat model. [95] The prepared SLIPS showed good in vivo stability and could enable bacterial elimination at the implant surface, while showing low innate immune response as well as reduced inflammatory capsule formation.…”