A Comparative Analysis of Clinical Outcomes in Hematological Patients Afflicted with Bacteremia Attributable to Carbapenem-Resistant Klebsiella pneumoniae versus Escherichia coli

Jiali Wang¹Jia Liu²Qingsong Lin¹Fengkui Zhang¹Yizhou Zheng¹Zhijian Xiao¹Jianxiang Wang¹Aiming Pang¹Yi He¹Erlie Jiang¹Sizhou Feng¹Mingzhe Han¹Weihua Zhai^1*

• ¹Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, Tianjin Municipality, China
• ²State Key Laboratory of Trauma, Burns and Combined Injury, Medical Center of Hematology, The Second Affiliated Hospital of Army Medical University,, Chongqing, China

Introduction: Carbapenem-resistant Enterobacterales (CRE) bloodstream infections (BSI) represent a frequent and grave complication among hematological patients, whose prevailing culprits are Carbapenem-Resistant Klebsiella pneumoniae (CRKP) and Escherichia coli bacteremia (EC). Nevertheless, there is a paucity of studies that have undertaken a comparative analysis of clinical outcomes in patients afflicted with CRKP and EC.Methods: This study was conducted with the aim of identifying the microbiological and clinical characteristics of hematological patients suffering from bacteremia caused by CRKP and CREC.Results: The cohort included 90 patients with equal proportions of CRKP BSI and CREC BSI from 2017 to 2022. Among the tested CRE strains (n = 45) for carbapenemase (CP) genes, the KPC gene was most commonly found in CP-CRKP isolates (12/21), while the NDM gene predominated among CP-CREC strains (18/24). A comparison of drug susceptibility showed that CREC was significantly more susceptible to tigecycline than CRKP (97.73% vs. 64.86%, P = 0.018). Patients treated with tigecycline-based therapy had a higher survival rate in the CREC group (18/24,75%) compared to the CRKP group (8/14,57.1%). The CRKP group had a significantly lower rate of prior cephalosporin use within 30 days compared to the CREC group (27% vs. 49%, P = 0.03) and a higher incidence of multi-site infections before BSI (44% vs. 8.9%, P<0.001). Multivariate analysis showed that BSI caused by CRKP was an independent risk factor for survival (P = 0.029), while CAZ-AVI-based therapy emerged as an independent factor improving patient prognosis (P =0.013).Conclusions: Our results found that bacteremia instigated by CRKP was associated with a less favorable prognosis when compared to cases induced by CREC. Moreover, treatment regimens incorporating CAZ-AVI have the potential to enhance the prognosis of patients grappling with CRE BSI.