Biofilm architecture of Pseudomonas aeruginosa: a relevant key to improve the infectious diseases treatments

It is not a secret anymore that antibiotic resistance constitutes a serious threat in healthcare. Across the world, antibiotic resistance has reached an unsafe level and, if the situation doesn't change, even benign infections will be dangerous. The damages can be counted by thousands of deaths per year. More over, this count is predicted to reach 10 millions deaths per year by 2050 (1). The healthcare domain isn't the only one to be impacted, even in the economic domain, the spread of multidrug resistances (MDR) will have a big impact: by 2050 this issue will cost more than US$100 billion to the global economy (2).
The problem really must be taken seriously, it's why the world health organization (WHO) provides a priority list for bacteria antibiotic resistance, divided into three groups according to the urgent need for new treatments. Pseudomonas aeruginosa is part of the group 1: « critical » level (3). P. aeruginosa, a gram negative, opportunistic pathogenic bacterium, is a major cause of various infections because of its ability to form biofilms in several environments (4,5). In this context, the aim of this work is to discover new natural antimicrobial agents with original modes of action. The strategy we propose relies on the disruption of the biofilm architecture with natural products to improve the penetration of antimicrobial agents. Thanks to a CDC bioreactor system, we generated biofilms imitating in vivo conditions and characterized their architecture using several microscopy techniques. Confocal microscopy and scanning electronic microscopy are interesting technics bringing several details about the architecture of the biofilm but the pre-treatment required to perform this technics could lead to some artefacts. The HIROX 3D digital microscopy doesn't need pre-treatment and might bring additional informations about it by avoiding all the artefacts. We propose here a summary of the image of the P.aeruginosa biofilm through the time with this three technics.