Acinetobacter baumannii Evolves Into Global Superbug, Study Tracks Decades of Resistance

Scientists from the University of East Anglia, in partnership with the Quadram Institute and researchers in Canada and Mexico, reconstructed the genetic history of the hospital pathogen Acinetobacter baumannii. By sequencing 226 archival samples dating from the 1970s‑2000s and integrating over a thousand newer genomes from six continents, they built a detailed evolutionary tree. The analysis shows the bacterium adapted to hospital environments in successive waves, each conferring greater antibiotic resistance, and now comprises at least four distinct lineages. One lineage, marked by the acquisition of the oxa23 resistance gene, has become increasingly common in recent isolates, raising concern of a new, more resilient variant. The study confirms A. baumannii’s status as a WHO‑listed critical pathogen, highlighting its worldwide spread in healthcare settings and the urgent need for sustained research and antibiotic‑policy strategies.