Multidrug-resistant Klebsiella pneumoniae Coinfection with Multiple Microbes: A Retrospective Study on Its Risk Factors and Clinical Outcomes
Authors: Song Xixi , Xu Chonghe , Zhu Zhongqi , Zhang Chenchen , Qin Chao , Liu Juan , Kong Xiaoli , Zhu Zhijun , Xu Wei , Zhu Mei 
Published: November 2024

Background: The prevalence of multidrug-resistant Klebsiella pneumoniae (MDR-KP) is rising globally. The aim of this study was to investigate the epidemiology, risk factors and clinical outcomes of MDR-KP coinfections and infections with carbapenem-resistant Klebsiella pneumoniae (CRKP) among patients in a tertiary hospital in China, and to establish an individualized linear prediction model.
Methods:In this retrospective study,patients admitted between January 2021 and March 2024 with a diagnosis of MDR-KP infection were included. Werecorded demographics, comorbidities, laboratory indicators, therapeutic interventions, antibiotic susceptibility results (AST) and analyzed clinical outcomes.Logistic regression models were employed to evaluate the risk factors associated with MDR-KP coinfections andinfections with CRKP.
Results: A total of 164 patients with MDR-KP infection were included. Of these patients, 78 (47.6%) were infected with MDR-KP only and 86 (52.4%) were coinfected with other microbes; 115 (70.1%) were infected with extended-spectrum beta-lactamase producing Klebsiella pneumoniae (ESBL-KP), and 49 (29.9%) were infected with CRKP. The most common source of infection in patients with MDR-KP infection was the respiratory tract (96/164, 58.5%), followed by the urinary tract (31/164, 18.9%). Multivariate logistic regression analysis showed that nasogastric catheters (OR 5.351, 95% CI 1.437-19.926, P= 0.012),as well as venous and arterial catheters (OR 5.182, 95% CI 1.272-21.113, P = 0.022) were independent risk factors for coinfection. The total risk score for all factors was 143.3, with a predicted risk rate ranging from 0.25 to 0.85. In the ROC curve analysis, the area under the curve (AUC) for predicting coinfection using the total risk score was 0.773 (95% CI: 0.7054-0.8405). Tracheostomy (OR 4.673, 95% CI 1.153-18.937, P = 0.031) and fiberoptic bronchoscopy (OR 4.041, 95% CI 1.305-12.516, P = 0.015) were independent risk factors for infecting with CRKP, witha total risk score for all factors of 193.9, and a predicted risk rate ranging from 0.15 ~ 0.85. In the ROC curve analysis, the area under the curve (AUC) for predicting CRKP using the total risk score was 0.752 (95% CI: 0.6739-0.8306). Analysis on the calibration curve indicated good agreement between the observed and predicted values. The log-rank test was used to compare all-cause mortality between the two groups, and 30-day mortality was higher in the coinfected group than in the MDR-KP alone group (P = 0.03). There was no significant difference in 30-day mortality between the CRKP group and ESBL-KP group (P = 0.09).
Conclusion: This study successfully established a model based on risk factors, which has good predictive value for both patients with coinfections and those with CRKP. Coinfections and CRKP infections significantly increased overall mortality and economic burden, while leading to poor prognosis in patients. These findings provided a basis for further clinical research and refinement of strategies for managing MDR-KP coinfections and CRKP infections.