Scientific Reports (Nov 2023)

Molecular and virulence characteristics of carbapenem-resistant Acinetobacter baumannii isolates: a prospective cohort study

  • Seung Min Park,
  • Jin Woong Suh,
  • Yong Kuk Ju,
  • Jeong Yeon Kim,
  • Sun Bean Kim,
  • Jang Wook Sohn,
  • Young Kyung Yoon

DOI
https://doi.org/10.1038/s41598-023-46985-1
Journal volume & issue
Vol. 13, no. 1
pp. 1 – 8

Abstract

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Abstract This study aimed to characterize the molecular features and virulence profiles of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. Clinical CRAB isolates were obtained from blood cultures of adult patients with CRAB bacteremia, collected between July 2015 and July 2021 at a Korean hospital. Real-time polymerase chain reaction was used to detect 13 virulence genes, genotyping was conducted via multilocus sequence typing (MLST), and a Tenebrio molitor infection model was selected for survival analysis. Herein, 170 patients, from whom CRAB isolates were collected, showed the in-hospital mortality rate of 57.6%. All 170 clinical CRAB isolates harbored bla OXA-23 and bla OXA-51. MLST genotyping identified 11 CRAB sequence types (STs), of which ST191 was predominant (25.7%). Virulence genes were distributed as follows: basD, 58.9%; espA, 15.9%; bap, 92.4%; and ompA, 77.1%. In the T. molitor model, ST195 showed a significantly higher mortality rate (73.3% vs. 66.7%, p = 0.015) than the other groups. Our findings provide insights into the microbiological features of CRAB blood isolates associated with high mortality. We suggest a potential framework for using a T. molitor infection model to characterize CRAB virulence. Further research is warranted to elucidate the mechanisms by which virulence improves clinical outcomes.