Interbacterial Transfer of Carbapenem Resistance and Large Antibiotic Resistance Islands by Natural Transformation in Pathogenic Acinetobacter
Anne-Sophie Godeux, Elin Svedholm, Barreto Samuel, Anaïs Potron, Samuel Venner, Xavier Charpentier, Maria-Halima Laaberki
Abstract
Acinetobacter baumannii is a multidrug-resistant pathogen responsible for difficult-to-treat hospital-acquired infections. Understanding the mechanisms leading to the emergence of the multidrug resistance in this pathogen today is crucial. Horizontal gene transfer is assumed to largely contribute to this multidrug resistance. However, in A. baumannii, the mechanisms leading to genome recombination and the horizontal transfer of resistance genes are poorly understood. We describe experimental evidence that natural transformation, a horizontal gene transfer mechanism recently highlighted in A. baumannii, allows the highly efficient interbacterial transfer of genetic elements carrying resistance to last-line antibiotic carbapenems. Importantly, we demonstrated that natural transformation, occurring in mixed populations of Acinetobacter, enables the transfer of large resistance island-mobilizing multiple-resistance genes.