Abstract：
OBJECTIVE: To investigate the virulence profiles and identify clinical and microbiological predictors of mortality in patients with carbapenem-resistant Acinetobacter baumannii (A. baumannii) bacteremia.
METHODS: This retrospective cohort study enrolled adult patients with carbapenem-resistant A. baumannii (CRAB). Multivariate logistic regression was used to identify the predictors of 30-day mortality. All isolates were subjected to real-time polymerase chain reaction for virulence factors and genotyped using multilocus sequence typing.
RESULTS: Among the 153 patients with CRAB bacteremia, 66 % received appropriate definitive antibiotic therapy. The in-hospital and 30-day mortality rates were 58.3 and 23.5 %, respectively. Ultimately, we enrolled 125 patients with CRAB bacteremia in the analysis, excluding early mortality cases. All CRAB isolates carried blaOXA-23 and blaOXA-51. The clinical strains belonged to 10 sequence types (STs), and the major genotypes were ST191, ST195, ST451, and ST784. The distribution of virulence factors included surface adhesion (Ata, 84.8 %; ChoP, 7.2 %), biofilm formation (OmpA, 76.8 %), killing of host cells (AbeD, 99.2 %), toxins (LipA, 99.2 %), and conjugation (BfmR, 90.4 %). In multivariate logistic regression analysis, hemodialysis due to acute kidney injury and moderate to severe thrombocytopenia were significant risk factors associated with 30-day mortality. However, microbiological factors were not significant predictors.
CONCLUSIONS: Clinical factors such as hemodialysis due to acute renal injury and moderate to severe thrombocytopenia have a greater influence on mortality in CRAB bacteremia compared with microbiological factors.
METHODS: This retrospective cohort study enrolled adult patients with carbapenem-resistant A. baumannii (CRAB). Multivariate logistic regression was used to identify the predictors of 30-day mortality. All isolates were subjected to real-time polymerase chain reaction for virulence factors and genotyped using multilocus sequence typing.
RESULTS: Among the 153 patients with CRAB bacteremia, 66 % received appropriate definitive antibiotic therapy. The in-hospital and 30-day mortality rates were 58.3 and 23.5 %, respectively. Ultimately, we enrolled 125 patients with CRAB bacteremia in the analysis, excluding early mortality cases. All CRAB isolates carried blaOXA-23 and blaOXA-51. The clinical strains belonged to 10 sequence types (STs), and the major genotypes were ST191, ST195, ST451, and ST784. The distribution of virulence factors included surface adhesion (Ata, 84.8 %; ChoP, 7.2 %), biofilm formation (OmpA, 76.8 %), killing of host cells (AbeD, 99.2 %), toxins (LipA, 99.2 %), and conjugation (BfmR, 90.4 %). In multivariate logistic regression analysis, hemodialysis due to acute kidney injury and moderate to severe thrombocytopenia were significant risk factors associated with 30-day mortality. However, microbiological factors were not significant predictors.
CONCLUSIONS: Clinical factors such as hemodialysis due to acute renal injury and moderate to severe thrombocytopenia have a greater influence on mortality in CRAB bacteremia compared with microbiological factors.
摘要：
目的：调查耐碳青霉烯鲍曼不动杆菌的毒力谱，并确定临床和微生物学指标。（A.鲍曼不动杆菌)菌血症。
方法：这项回顾性队列研究纳入了耐碳青霉烯类鲍曼不动杆菌（CRAB）的成年患者。采用多因素logistic回归分析确定30天死亡率的预测因子。对所有分离株进行实时聚合酶链反应以检测毒力因子，并使用多位点序列分型进行基因分型。
结果：在153例CRAB菌血症患者中，66%接受了适当的确定性抗生素治疗。住院和30天死亡率分别为58.3和23.5％，分别。最终,我们在分析中纳入了125例CRAB菌血症患者，排除早期死亡病例。所有CRAB分离物携带blaOXA-23和blaOXA-51。临床菌株属于10种序列类型(STs)，主要基因型为ST191、ST195、ST451和ST784。毒力因子的分布包括表面粘附(Ata，84.8%；选择，7.2%），生物膜形成(OmpA，76.8%），杀死宿主细胞(AbeD，99.2%)，毒素（LipA，99.2%)，和共轭(BfmR，90.4%）。在多变量逻辑回归分析中，由于急性肾损伤和中度至重度血小板减少导致的血液透析是与30天死亡率相关的重要危险因素。然而,微生物学因素不是显著的预测因子。
结论：与微生物学因素相比，急性肾损伤导致的血液透析和中重度血小板减少等临床因素对CRAB菌血症死亡率的影响更大。
方法：这项回顾性队列研究纳入了耐碳青霉烯类鲍曼不动杆菌（CRAB）的成年患者。采用多因素logistic回归分析确定30天死亡率的预测因子。对所有分离株进行实时聚合酶链反应以检测毒力因子，并使用多位点序列分型进行基因分型。
结果：在153例CRAB菌血症患者中，66%接受了适当的确定性抗生素治疗。住院和30天死亡率分别为58.3和23.5％，分别。最终,我们在分析中纳入了125例CRAB菌血症患者，排除早期死亡病例。所有CRAB分离物携带blaOXA-23和blaOXA-51。临床菌株属于10种序列类型(STs)，主要基因型为ST191、ST195、ST451和ST784。毒力因子的分布包括表面粘附(Ata，84.8%；选择，7.2%），生物膜形成(OmpA，76.8%），杀死宿主细胞(AbeD，99.2%)，毒素（LipA，99.2%)，和共轭(BfmR，90.4%）。在多变量逻辑回归分析中，由于急性肾损伤和中度至重度血小板减少导致的血液透析是与30天死亡率相关的重要危险因素。然而,微生物学因素不是显著的预测因子。
结论：与微生物学因素相比，急性肾损伤导致的血液透析和中重度血小板减少等临床因素对CRAB菌血症死亡率的影响更大。
