Print E-mail
Volume 47, Number 4, August 2014

Risk factors for imipenem-nonsusceptible Acinetobacter nosocomialis bloodstream infection 

Lei Huang, Te-Li Chen, Yi-Tzu Lee, Mei-Hui Lee, Shu-Chen Kuo, Kwok-Woon Yu, Horng-Yunn Dou, Chang-Phone Fung

Received: July 18, 2012    Revised: January 5, 2013    Accepted: February 15, 2013   


Corresponding author:

Shu-Chen Kuo, Division of Infectious Diseases, Taipei Veterans General Hospital, Taipei, Taiwan
Institute of Clinical Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan
National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Miaoli County, Taiwan
Corresponding Author InformationCorresponding author. Division of Infectious Diseases, Taipei Veterans General Hospital, No. 201, Section 2, Shih-Pai Road, Taipei 112, Taiwan. 


Background and purpose: 

The emergence of imipenem-nonsusceptible (INS) Acinetobacter baumannii complex has had a great impact on healthcare systems worldwide. Understanding the risk factors related to INS infection is useful for infection control. The risk factors for INS A. baumannii have been well documented; however, the risk factors related to INS Acinetobacter nosocomialis infection lack documentation. The purpose of this study was to identify the risk factors associated with INS A. nosocomialis bacteremia. 



This retrospective 9-year study included 329 adults with A. nosocomialis bacteremia in a tertiary medical center in Taiwan. Acinetobacter nosocomialis was identified using a multiplex polymerase chain reaction method and sequence analysis of a 16S–23S intergenic spacer. 



Among 329 patients with A. nosocomialis bacteremia, 67 had INS isolates (20.4%). Patients with INS isolates tended to have a more severe form of the diseases [with ICU admission and a higher APACHE (Acute Physiology and Chronic Health Evaluation) II score], specific underlying diseases (associated with chronic lung diseases and end-stage renal diseases, but less commonly alcoholism and chemotherapy), multiple invasive procedures, pneumonia as a primary focus of infection, and prior antimicrobial use (sulbactam, antipseudomonal penicillins, aminoglycosides, and carbapenems). Multivariable analysis showed that ICU admission, chronic lung diseases, arterial line catheterization, total parenteral nutrition, and prior use of carbapenems were independent risk factors; prior use of carbapenems was found to be the most influential (odds ratio 6.36, 95% confidence interval 2.00–20.21; p = 0.002).



To our knowledge, this is the first study describing the risk factors associated with INS A. nosocomialis bacteremia. Regulated antibiotic control policy, especially for carbapenem, and infection control measures targeting patients hospitalized in ICU, with chronic lung diseases and multiple invasive procedures, may be helpful in reducing INS A. nosocomialis infection. 


Key words:

Acinetobacter nosocomialis, Bacteremia, Imipenem resistance, Risk factors