title: Results from a 13-Year Prospective Cohort Study Show Increased Mortality Associated with Bloodstream Infections Caused by Pseudomonas aeruginosa Compared to Other Bacteria.
abstract: The impact of bacterial species on outcome in bloodstream infections (BSI) is incompletely understood. We evaluated the impact of bacterial species on BSI mortality, with adjustment for patient, bacterial, and treatment factors. From 2002 to 2015, all adult inpatients with monomicrobial BSI caused byStaphylococcus aureusor Gram-negative bacteria at Duke University Medical Center were prospectively enrolled. Kaplan-Meier curves and multivariable Cox regression with propensity score models were used to examine species-specific bacterial BSI mortality. Of the 2,659 enrolled patients, 999 (38%) were infected withS. aureus, and 1,660 (62%) were infected with Gram-negative bacteria. Among patients with Gram-negative BSI,Enterobacteriaceae(81% [1,343/1,660]) were most commonly isolated, followed by non-lactose-fermenting Gram-negative bacteria (16% [262/1,660]). Of the 999S. aureusBSI isolates, 507 (51%) were methicillin resistant. Of the 1,660 Gram-negative BSI isolates, 500 (30%) were multidrug resistant. The unadjusted time-to-mortality among patients with Gram-negative BSI was shorter than that of patients withS. aureusBSI (P= 0.003), due to increased mortality in patients with non-lactose-fermenting Gram-negative BSI generally (P< 0.0001) andPseudomonas aeruginosaBSI (n= 158) in particular (P< 0.0001). After adjustment for patient demographics, medical comorbidities, bacterial antibiotic resistance, timing of appropriate antibiotic therapy, and source control in patients with line-associated BSI,P. aeruginosaBSI remained significantly associated with increased mortality (hazard ratio = 1.435; 95% confidence interval = 1.043 to 1.933;P= 0.02).P. aeruginosaBSI was associated with increased mortality relative toS. aureusor other Gram-negative BSI. This effect persisted after adjustment for patient, bacterial, and treatment factors.
authors.affiliation: Duke University Division of Infectious Diseases, Durham, North Carolina, USA.
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Thaden
authors.affiliation: Duke University Division of Infectious Diseases, Durham, North Carolina, USA.
authors.forename: Lawrence P
authors.initials: LP
authors.lastname: Park
authors.affiliation: Duke University Division of Infectious Diseases, Durham, North Carolina, USA.
authors.forename: Stacey A
authors.initials: SA
authors.lastname: Maskarinec
authors.affiliation: Duke University Division of Infectious Diseases, Durham, North Carolina, USA.
authors.forename: Felicia
authors.initials: F
authors.lastname: Ruffin
authors.affiliation: Duke University Division of Infectious Diseases, Durham, North Carolina, USA vance.fowler@duke.edu.
authors.forename: Vance G
authors.initials: VG
authors.lastname: Fowler
authors.affiliation: University of North Carolina Chapel Hill Division of Infectious Diseases, Chapel Hill, North Carolina, USA.
authors.forename: David
authors.initials: D
authors.lastname: van Duin
mesh_terms: D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology; D004755:Enterobacteriaceae / Q000187:drug effects / Q000472:pathogenicity; D006090:Gram-Negative Bacteria / Q000187:drug effects / Q000472:pathogenicity; D006801:Humans; D011446:Prospective Studies; D011552:Pseudomonas Infections / Q000188:drug therapy* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000472:pathogenicity*; D013211:Staphylococcus aureus / Q000187:drug effects / Q000472:pathogenicity
keywords: Gram negative; Pseudomonas aeruginosa; Staphylococcus aureus; bloodstream infections