Clinical Characteristics, Risk Factors, and Outcomes of Patients with Polymicrobial <i>Klebsiella pneumoniae</i> Bloodstream Infections
Feizhen Song, Kai Zhang, Jianjiang Huang, Zhenhua Qian, Hongwei Zhou, Jiachang Cai, Cheng Zheng, Feifei Zhou, Wei Cui, Gensheng Zhang
Abstract
Background . Polymicrobial Klebsiella pneumoniae bloodstream infection (KP‐BSI) has been reported to account for more than 10% of all KP‐BSI, but few studies have characterized polymicrobial KP‐BSI. Our study investigated the clinical characteristics, risk factors, and outcomes of polymicrobial KP‐BSI by comparing with monomicrobial KP‐BSI. Methods . We conducted a single‐center retrospective cohort study of patients with KP‐BSI from 1 January 2013 to 31 December 2018 and collected the clinical data by reviewing electronic medical records. Results . Of the 818 patients with KP‐BSI recruited, 13.9% (114/818) were polymicrobial KP‐BSI. The severity of illness in polymicrobial and monomicrobial KP‐BSI was similar, while the rate of resistance to carbapenems was obviously higher in polymicrobial KP‐BSI (78.1% vs. 65.6%, p = 0.009). On multivariate analysis, hospitalization in burn ward (odds ratio (OR) 6.13, 95% confidence interval (CI) 2.00‐18.76, p = 0.001) and intensive care unit (OR 2.39, 95% CI 1.05‐5.43, p = 0.038) was independently associated with polymicrobial KP‐BSI. Gram‐negative bacteria accounted for the highest proportion (68.9%) among copathogens of polymicrobial KP‐BSI, whereas gram‐positive bacteria (22.9%) and Candida (8.2%) ranked the second and the third, respectively, with Acinetobacter baumannii being the most common (23.0%). Patients with polymicrobial KP‐BSI had longer hospital days after BSI onset and total hospital days than patients with monomicrobial KP‐BSI (median (interquartile range (IQR)), 19 (5, 39) vs. 12 (6, 25), 37 (21, 67) vs. 29 (16, 53), respectively, p < 0.05). The mortality did not differ between polymicrobial KP‐BSI and monomicrobial KP‐BSI (all p > 0.05). Conclusions . It was observed that polymicrobial KP‐BSI accounted for a significant proportion among all KP‐BSI in the current study. Hospitalization in burn ward and intensive care unit was an independent risk factor for the development of polymicrobial KP‐BSI. The patients with polymicrobial KP‐BSI had a higher rate of carbapenem‐resistant K. pneumoniae and might have poor outcomes compared to monomicrobial KP‐BSI.