Achromobacter xylosoxidans isolates exhibit genome diversity, variable virulence, high levels of antibiotic resistance, and potential intrahost evolution

Abstract

This study provides a comprehensive examination of Achromobacter xylosoxidans , an emerging pathogen of global concern due to its high antibiotic resistance (AR) and increasing clinical relevance. By analyzing over 200 genomes, we offer critical insights into the population structure, resistance mechanisms, and virulence factors of this species. The identification of a small core genome underscores its potential for genomic plasticity. The existence of multiple secretion systems highlights the great capacity of A. xylosoxidans as a pathogen. Variations in virulence among A. xylosoxidans isolates indicate the complexity of this pathogen, underscoring the need for further studies on its virulence mechanisms. Evolution within the host includes the loss of motility-associated systems and enhanced AR and biofilm formation. This work showed that A. xylosoxidans is resistant to relebactam when combined with imipenem, a combination effective in other bacteria. These findings emphasize the urgent need for targeted therapeutic strategies to combat this opportunistic pathogen.