Distribution characteristics and genomic epidemiology of carbapenem-resistant Acinetobacter baumannii

Carbapenem-resistant Acinetobacter baumannii poses significant challenges in clinical settings due to rapid emergence and limited treatment options. This study aimed to investigate the distribution characteristics and genomic epidemiology of carbapenem-resistant A. baumannii in a regional healthcare context to identify novel trends and genetic determinants.

A total of 120 clinically isolated strains of carbapenem-resistant A. baumannii were collected in our hospital from July 2021 to June 2023. Distribution characteristics were assessed based on infection sites. Whole genome sequencing was performed to profile resistance genes.

The resistance rates of carbapenem-resistant A. baumannii to 15 antibiotics, such as tobramycin and amikacin, increased yearly during the three years (p < 0.05). Respiratory tract and urinary tract infections were dominant. Whole genome sequencing revealed high prevalence rates of β-lactamase genes (AmpC: 82.5%, OXA-23: 70.83%, IMP-1: 54.17%) and efflux system genes (adeB: 78.33%, adeJ: 93.33%, adeG: 90.00%).

Our study provides novel insights by identifying significant increases in antibiotic resistance and revealing critical genomic co-occurrence patterns of resistance genes in carbapenem-resistant A. baumannii. These findings enhance the understanding of resistance mechanisms and support targeted strategies for improved prevention, control, and monitoring of nosocomial infections.