Efficacy of antiseptics in a novel 3-dimensional human plasma biofilm model (hpBIOM)

M Besser,J D Rembe,M Dietrich,L Weber,E K Stuermer

doi:10.1038/s41598-020-61728-2

M Besser, J D Rembe + Show 3 more

Open Access

https://doi.org/10.1038/s41598-020-61728-2

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Abstract

The increasing incidence of non-healing wounds constitutes a pivotal socio-economic burden. 60–80% of chronic wounds are colonized by pathogenic microorganisms within a protective extracellular polymeric substance, bearing a great challenge in wound management. Human plasma was used to prepare the biofilm model (hpBIOM), adding pathogens to the plasma and forming Coagula-like discs with integrated pathogens were produced. The antiseptics Octenisept and Lavasorb were tested regarding their antibacterial properties on clinically relevant biofilm-growing bacteria (MRSA, P. aeruginosa) in the hpBIOM. Biofilm-typical glycocalyx-formation was confirmed using immunohistochemical staining. Treatment of a 12 h-maturated biofilm with Octenisept resulted in complete eradication of P. aeruginosa and MRSA after 48 h. Lavasorb proved less effective than Octenisept in this setting. In more mature biofilms (24 h), both antiseptics showed a delayed, partially decreased efficacy. Summarized, the hpBIOM provides essential factors for a translational research approach to be used for detailed human biofilm analyses and evaluation of antimicrobial/-biofilm properties of established and novel therapeutic strategies and products. Octenisept and Lavasorb showed an attenuated efficacy in the hpBIOM compared to planktonic conditions and previously published biofilm-studies, prompting the question for the necessity of introducing new international standards and pre-admission requirements on a translational base.

Highlights

Due to demographic changes, the incidence of chronic wound development in the population increases constantly
Using immunohistological staining with FITC-labeled Concanavlin A, a lectin which selectively binds to carbohydrates, the production of the biofilm-characteristic extracellular polymeric substance (EPS) by P. aeruginosa and Methicillin-resistance Staphylococcus aureus (MRSA) was demonstrated within 24 h (Fig. 2)
The biofilm models disc-like structure remained stable for up to 84 h, its integrity depending on the individual microorganism or certain combinations

Summary

Introduction

The incidence of chronic wound development in the population increases constantly. Based on the importance of controlling biofilms in the management of chronic wounds and the threat posed to unimpaired wound healing, basic research to understand human wound-biofilm formation, organization and maintenance as well as the development and proper evaluation of therapeutic strategies is of most importance To address this need, appropriate model systems for in-vitro analyses are mandatory. Two 3-dimensional in-vitro models have been previously described: One based on a liquid-filled chamber[22,27,28], the other comprised of a collagen matrix with serum-proteins[29] All these models show important limitations for a translation of results into clinical wound care routine. The aim was to primarily observe two established antiseptics in the newly developed challenging human biofilm environment with regard to their antiseptic performance against two commonly encountered biofilm-forming pathogens (MRSA, P. aeruginosa) after 12 and 24 hours of biofilm maturation in the hpBIOM

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