Understanding the emergence of a multidrug resistant pathogen : a multiscale approche
Causative agent of infections in humans and animals, Acinetobacter baumannii concerns because of its startling ability to acquire antibiotic resistance through horizontal gene transfer. Our work on horizontal gene transfer in this pathogen unveil the role of natural transformation in its rapid acquisition of multidrug resistance and identify the signal that trigger natural transformation. Combining experimental work with mathematical modeling, we enlighten the dual function of this mechanism enabling both acquisition of mobile genetic elements and genome curing. More recently, to understand how multidrug resistance emerged associated with specific A. baumannii clones, we conducted extensive cross-sectoral sampling campaigns encompassing clinical (human and companion animals), livestock (cattle) and natural environments. This 3-year sampling effort resulted in the Ab-One collection, the first One-Health collection of A. baumannii isolates. Sequencing of this collection sheds new light on A. baumannii populations across three ecological sectors. It captured human-associated global lineages, underscoring the species’ capacity for worldwide dissemination. We uncovered grass- and soil-associated lineages shared with the animal sector (cattle or wild animals), some of which were also detected in other Western European countries. Human and animal sectors also share closely related lineages arguing for their recent emergence. Finally, taking advantage of genome completeness, we show that mobile genetic elements can be shared within and between sectors, promoting gene flow across ecological barriers.
Short bio
Maria-Halima Laaberki is a DVM and Associate Professor at VetAgro Sup and a lead researcher at the CIRI in Lyon. As a member of the « Horizontal Gene Transfer in Bacterial Pathogens » team, she specializes in the genetics of antibiotic resistance and zoonotic transmission. Her work focuses on how pathogens like Acinetobacter baumannii adapt and evolve through gene exchange. Bridging animal and human health, she plays a key role in « One Health » research and veterinary education.
Laboratory of the speaker
Centre international de recherche en infectiologie (CIRI), Lyon
Invited by
Eugen PFEIFER
