Abstract

BackgroundInfections due to extensively drug-resistant gram-negative bacteria entail limited treatment options and high mortality and pose an important public health problem. Severe infection causes multiple organ dysfunction through complex mechanisms, which involve either the host, or the pathogenicity of the microorganism. The aims of the present study were the determination of potential risk factors of a fulminant fatal course of bacteremia caused by extensively drug-resistant Klebsiella pneumoniae(XDRKp) and the comparison of fulminantly fatal bacteremias due to XDR-Kp versus XDR Acinetobacter baumannii (XDR-Ab) strains within a 8-years’ period.

Methods:Patients with monomicrobial XDR-Kp (n=60) or XDR-Ab (n=87) bacteremias were divided into three groups, according to ICU outcome (survival, early or late death). Τhe clinical characteristics of patients along with pathogen and treatment-related factors were compared by ANOVA statistics and multinomial logistic regression

Results: Patients with unfavorable outcome revealed higher disease severity at ICU admission and on bacteremia day. Administration of corticosteroids or renal replacement treatment on infection day was significantly higher in the fulminantly fatal group. Pathogens’ resistance pattern and appropriate treatment did not affect outcome. Fulminant bacteremias due to CR-Kp emerged significantly later during ICU hospitalization compared to XDR-Aba. Pathogens’ resistance pattern, regarding colistin and tigecycline, differed between XDR-Kp and XDR-Ab strains. Conclusions: Higher disease severity and administration of corticosteroids and renal replacement therapy posed patients at higher risk for fulminantly fatal course of CR-Kp bacteremia. Receipt of appropriate treatment did not affect outcome.

Keywords:Extensively-drug resistant Klebsiella pneumoniae; Extensively-drug resistant Acinetobacter baumannii; Bacteremia; Risk factors; Fulminant sepsis; ICU mortality