Affiliation:
1. Institute of Emerging Infectious Diseases, Korea University
2. Division of Infectious Diseases, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine
Abstract
Abstract
This study aimed to characterise the molecular features and virulence profile of carbapenem-resistant Acinetobacter baumannii (CRAB) isolates. Clinical CRAB isolates were obtained from blood cultures of adult patients with CRAB bacteraemia, collected between July 2015 and July 2021 in 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. A total of 170 clinical CRAB isolates harboured the blaOXA−23 and blaOXA−51 genes. MLST genotyping identified 11 CRAB sequence types (STs), of which ST191 was the most predominant (25.7%). Virulence genes were distributed as follows: basD, 58.9%; espA, 15.9%; bap, 92.4%; ata, 86.5%; chop, 7.1%; ompA, 77.1%; pbpG; 93.5%; bfmR, 92.9%; fhaB, 70.6%; abeD, 99.4%; cpaA, 0.6%; lipA, 99.4%; and recA, 100%. In the T. molitor model, ST195 showed a significantly higher mortality rate (73.3% vs. 66.7%, p = 0.015) and ST451 displayed a lower mortality rate (60.0% vs. 73.3%, p = 0.007) compared to counterpart groups. Our findings provided insight on the microbiological features of CRAB blood isolates. A potential framework for using a T. molitor infection model to characterise CRAB pathogen virulence is suggested.
Publisher
Research Square Platform LLC