PhD ceremony: Ms. E. Papaioannou, 13.15 uur, Aula Academiegebouw, Broerstraat 5, Groningen
Dissertaton: Silencing Pseudomonas virulence
Promotor(s): prof. W.J. Quax
Faculty: Mathematics and Natural Sciences
The use of antibiotics in the treatment of bacterial diseases has led to the emergence of antibiotic-resistant “superbugs”. For preventing this emergence of resistant bacteria, alternative treatment methods are required. Evelina Papaiaoannou invented such a method.
By understanding the mechanism by which the Gram-negative opportunistic pathogen Pseudomonas aeruginosa imposes its virulence, potential targets for alternative antimicrobial therapy to the often-fatal infections caused by this pathogen can be identified. Today, we appreciate that P. aeruginosa imposes its virulence via a tightly controlled cell-to-cell communication mechanism referred to as quorum sensing (QS) through diffusible signal molecules referred to as acyl-homoserine lactones (AHL). Interfering with these signal molecules, either by preventing their synthesis and/or accumulation or by prohibiting their binding to their cognate receptor, offers a promising strategy for controlling and eradicating Pseudomonas-related infections.
Prevention of AHL accumulation can be achieved by the degradation of these molecules. Papaiaoannou made clear that there are two groups of enzymes known to degrade AHLs: (1) AHL-lactonases, which hydrolyse the lactone ring and (2) AHL-acylases, which hydrolyse the amide bond between the acyl chain and the homoserine lactone in the AHL molecule, thus generating the corresponding free fatty acid and the homoserine lactone. Papaiaoannou proved P. aeruginosa PAO1 possesses at least three genes encoding for AHL-acylases that are able to degrade the 3-oxo-C12-HSL signal molecule produced by the pathogen itself. These AHL-acylases are thereby able to silence the communication system of this opportunistic pathogen and may therefore serve as potential antimicrobials against Pseudomonas infections.
Inspired by the importance of the European Wadden Sea for migratory birds, last week China successfully nominated parts of its own Wadden Sea - in the Yellow Sea - for the Unesco World Heritage Status. This means that the list of protected areas is...
The University of Groningen (UG) and Wageningen University & Research (WUR) have decided to work together more closely in the area of nature-inclusive and circular agriculture, and the rural development associated with this, in the Northern Netherlands...
Thirteen researchers from the University of Groningen (UG) and the UMCG have been awarded Veni grants within the framework of NWO’s Innovational Research Incentives Scheme.
A terrific result building on last year's successes, where 12 Groningen researchers...