Outcomes in patients infected with carbapenem-resistant Acinetobacter baumannii and treated with tigecycline alone or in combination therapy

Abstract

Purpose: Acinetobacter baumannii is a non-fermenting aerobic gram-negative bacteria and one of the important nosocomial pathogens, especially in intensive care units (ICUs). In recent years, multidrug-resistant (MDR) isolates have been an emerging problem, with limited therapeutic options. Tigecycline is a novel antimicrobial, with its in vitro activity against most gram-positive and gram-negative pathogens. Methods: This is a retrospective study that was conducted in a tertiary care hospital with 550 beds in Ankara, Turkey, from January 2009 to July 2010. Thirty-three patients who had carbapenem-resistant Acinetobacter spp. infections and received tigecycline alone or in combination with other antibiotics for at least 3 days were included. Results: The median age of the patients was 62 (18-87) years. All of the patients were diagnosed and treated in the ICU. Clinical responses were observed in 23 patients (69.7%). Ten patients (30%) had clinical failure. There was no significant difference between ventilator-associated pneumonia (VAP) and bloodstream infection (BSI) in terms of clinical or microbiological outcome (p > 0.05). The microbiological response rate was 50%. Superinfection was detected in 13 patients (43.3%) and Pseudomonas aeruginosa was the most frequently isolated pathogen. The 30-day overall mortality rate and attributable mortality rates were 57.6 and 24.2%, respectively. The attributable mortality rate was higher in the group in which microbiological eradication was not provided. Conclusions: Although it is approved by the Food and Drug Administration (FDA) for the treatment of complicated intra-abdominal infections, complicated skin and soft tissue infections, and community-acquired bacterial pneumonia, emerged resistance of Acinetobacter spp. and limited therapeutic options left physicians no choice but to use tigecycline for off-label indications. © 2011 Springer-Verlag.