Comparison of Hypervirulent and Non-Hypervirulent Carbapenem-Resistant <i>Acinetobacter baumannii</i> Isolated from Bloodstream Infections: Mortality, Potential Virulence Factors, and Combination Therapy In Vitro
Likang Yao,
Ningjing Liu,
Yingyi Guo,
Chuyue Zhuo,
Xu Yang,
Yijing Wang,
Jiong Wang,
Feifeng Li,
Jiahui Li,
Nanhao He,
Jiakang Chen,
Yexin Lin,
Shunian Xiao,
Chao Zhuo
Affiliations
Likang Yao
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Ningjing Liu
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Yingyi Guo
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Chuyue Zhuo
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Xu Yang
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Yijing Wang
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Jiong Wang
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Feifeng Li
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Jiahui Li
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Nanhao He
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Jiakang Chen
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Yexin Lin
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Shunian Xiao
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Chao Zhuo
State Key Laboratory of Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou 510000, China
Hypervirulent carbapenem-resistant Acinetobacter baumannii (hv-CRAB) has emerged in bloodstream infections (BSI). Cases of BSI caused by hv-CRAB (hv-CRAB-BSI) had posed a significant threat to hospitalized patients. In this study, 31 CRAB strains isolated from Chinese BSI patients were analyzed, of which 24 were identified as hv-CRAB-BSI and 7 as non-hv-CRAB-BSI, using the Galleria mellonella infection model. Patients with hv-CRAB-BSI had higher rates of septic shock (79.2% vs. 14.3%, p = 0.004) and mortality (66.7% vs. 14.3%, p = 0.028). All strains were resistant to most antibiotics but sensitive to colistin. Hv-CRAB-BSI showed lower resistance to minocycline than non-hv-CRAB-BSI (54.2% vs. 100%, p = 0.03). Whole-genome sequencing revealed that the detection rates of immune modulation genes ptk and epsA in hv-CRAB-BSI were significantly higher than in non-hv-CRAB-BSI (91.7% vs. 28.6%, p = 0.002). Additionally, all ST457 hv-CRAB-BSI lacked abaR, and all ST1486 non-hv-CRAB-BSI lacked adeG. The checkerboard dilution method assessed the efficacies of various antibiotic combinations, revealing that although synergism was rarely observed, the combination of colistin and minocycline showed the best efficacy for treating CRAB-BSI, regardless of whether the infections were hv-CRAB-BSI or non-hv-CRAB-BSI. These findings highlight the importance of analyzing molecular characteristics and exploring effective treatment strategies for hv-CRAB-BSI.
