Newly Named Klebsiella aerogenes (formerly Enterobacter aerogenes) Is Associated with Poor Clinical Outcomes Relative to Other Enterobacter Species in Patients with Bloodstream Infection
- 24 August 2020
- journal article
- research article
- Published by American Society for Microbiology in Journal of Clinical Microbiology
- Vol. 58 (9)
- https://doi.org/10.1128/jcm.00582-20
Abstract
Objectives: Enterobacter aerogenes was recently renamed Klebsiella aerogenes. This study aimed to identify differences in clinical characteristics, outcomes, and bacterial genetics among patients with K. aerogenes versus Enterobacter species bloodstream infections (BSI). Methods: We prospectively enrolled patients with K. aerogenes or Enterobacter cloacae complex (Ecc) BSI from 2002-2015. We performed whole genome sequencing (WGS) and pan-genome analysis on all bacteria. Results: Overall, 150 patients with K. aerogenes (46/150 [31%]) or Ecc (104/150 [69%]) BSI were enrolled. The two groups had similar baseline characteristics. Neither total in-hospital mortality (13/46 [28%] versus 22/104 [21%]; p=0.3) nor attributable in-hospital mortality (9/46 [20%] versus 13/104 [12%]; p=0.3) differed between patients with K. aerogenes versus Ecc BSI, respectively. However, poor clinical outcome (death before discharge, recurrent BSI, and/or BSI complication) was higher for K. aerogenes than Ecc BSI (32/46 [70%] versus 42/104 [40%]; p=0.001). In a multivariable regression model, K. aerogenes BSI, relative to Ecc BSI, was predictive of poor clinical outcome (odds ratio 3.3; 95% confidence interval 1.4-8.1; p=0.008). Pan-genome analysis revealed 983 genes in 323 genomic islands unique to K. aerogenes isolates, including putative virulence genes involved in iron acquisition (n=67), fimbriae/pili/flagella production (n=117), and metal homeostasis (n=34). Antibiotic resistance was largely found in Ecc lineage 1, which had a higher rate of multidrug resistant phenotype (23/54 [43%]) relative to all other bacterial isolates (23/96 [24%]; p=0.03). Conclusions: K. aerogenes BSI was associated with poor clinical outcomes relative to Ecc BSI. Putative virulence factors in K. aerogenes may account for these differences.Keywords
Funding Information
- HHS | NIH | National Institute of Allergy and Infectious Diseases (U19AI110819)
- HHS | National Institutes of Health (1KL2TR002554)
- HHS | National Institutes of Health (K24-AI093969)
This publication has 29 references indexed in Scilit:
- PanOCT: automated clustering of orthologs using conserved gene neighborhood for pan-genomic analysis of bacterial strains and closely related speciesNucleic Acids Research, 2012
- A Multicentre Study of Acute Kidney Injury in Severe Sepsis and Septic Shock: Association with Inflammatory Phenotype and HLA GenotypePLOS ONE, 2012
- Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistanceClinical Microbiology & Infection, 2012
- Clinical outcomes of health-care-associated infections and antimicrobial resistance in patients admitted to European intensive-care units: a cohort studyThe Lancet Infectious Diseases, 2011
- Acute kidney injury in non-severe pneumonia is associated with an increased immune response and lower survivalKidney International, 2010
- Acute lung injury and acute respiratory distress syndromeJournal of Emergencies, Trauma, and Shock, 2010
- Guidelines for the diagnosis and management of disseminated intravascular coagulationBritish Journal of Haematology, 2009
- Serum‐Induced Iron‐Acquisition Systems and TonB Contribute to Virulence inKlebsiella pneumoniaeCausing Primary Pyogenic Liver AbscessThe Journal of Infectious Diseases, 2008
- Evidence for the Role of Reactive Nitrogen Species in Polymicrobial Sepsis-Induced Renal Peritubular Capillary Dysfunction and Tubular InjuryJournal of the American Society of Nephrology, 2007
- Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injuryCritical Care, 2007