Acinetobacter baumannii genetic study reveals decades‑long rise of antibiotic resistance

An international consortium reconstructed the evolutionary history of the hospital superbug Acinetobacter baumannii. By sequencing 226 historical isolates from the 1970s‑2000s and more than 1,000 recent samples from six continents, researchers built a phylogenetic tree from 1,281 genomes using long‑read Oxford Nanopore technology. The analysis traced stepwise genetic changes that created successive waves of increasingly drug‑resistant strains, identifying when key resistance genes appeared and spread worldwide.

The work was led by the University of East Anglia and Norwich Research Park in the United Kingdom, with partners at the University of Sherbrooke and the CISS Montérégie‑Centre in Canada, the National Autonomous University of Mexico, and the Canadian Institute for Advanced Research. Funding came from the UK Biotechnology and Biological Sciences Research Council and Canadian research agencies. The study provides a detailed framework for understanding how A. baumannii adapted to antibiotics, informing future strategies to combat this dominant, hard‑to‑treat pathogen in hospitals.