Whole-genome surveillance of 41 carbapenem-resistant A. baumannii bloodstream isolates collected across Thailand in 2020-2024 found widespread international clone II (ST2). Resistance was dominated by blaOXA-23 with intrinsic blaOXA-66 and a penicillin-binding-protein mutation. A conserved blaNDM-5 mobile element appeared across ST2 sublineages and regions, consistent with horizontal spread followed by clonal expansion; blaNDM-1 was less frequent and linked to Tn125 in ST2 and ST16.
Key findings
- ST2 was the dominant widely distributed lineage. • blaOXA-23 was the main carbapenemase determinant. • A blaNDM-5 mobile element crossed regions and ST2 sublineages.
Why this matters globally
The work links hospital AMR to both clonal and mobile-gene spread, supporting surveillance of lineages and genetic elements together.
Thai researcher contribution
Thai public-health and Chulabhorn institutions form a national genomic-surveillance network.
Limitations to consider
The 41 bloodstream isolates may unevenly represent hospitals and time, so the study cannot estimate national prevalence.