Influence of doxycycline resistance on outcome in Acinetobacter baumannii bacteraemia in an intensive care unit

Abstract number: 1734_78

Zaragoza R., Camarena J., Sancho S., González R., Artero A., Navarro J., Nogueira J.

Objective: The aims of this study were to identify the epidemiological and clinical differences between doxycycline resistant Acinetobacter baumannii bacteraemia (ABB) and doxycycline-susceptible episodes, to know their prognosis, and finally to define if doxycycline resistance is a factor independently associated to hospitality and related mortality in critically ill patients with ABB.

Methods: From 1996 to 2006, 341 patients with a clinically significant bacteraemia were prospectively evaluated in an intensive care unit of a university hospital. Doxycycline resistant Acinetobacter baumannii (DR) was defined when MIC was ≥mg/mL (E-test®). Clinical and microbiological variables were studied. A multivariate analysis was performed to determine the factors independently associated to hospitality and related to bacteraemia mortality in critically ill patients with ABB.

Results: Ninety-three (27.2%) of 341 ICU bacteraemias were due to ABB. A sixty-eight percent of them were DR episodes. The mean age of patients with ABB was 60.7 SD 16.2 years and the relation between men/women was 3.3. APACHE II score was 19.2 SD 7.6. The incidence of inadequate empirical antibiotic treatment was 54.7% in ABB patients. The principal origins of ABB were: respiratory (49.5%), unknown (23.2%) and catheter (12.6%). The global and related mortality rate for ABB was 54.7% and 22.1% respectively. There were no differences in presence of severe sepsis or septic shock, APACHE II or SOFA score (admission and at the onset of ABB) between DR and susceptible episodes. Although the incidence of inadequate empirical antimicrobial treatment (48.4% vs 72.4%; p = 0.03) was statistically lower in DR group, related mortality rates (28.1% vs 10.3%; p = 0.04) was significantly higher in DR group. Multivariate analysis confirmed DR (OR 8.2; 95% CI 1.5 – 42.9.9; p = 0.01) as an independent predictor of related mortality to ABB.

Conclusions: The prevalence of ABB is very high among critically ill patients, and majority of them are DR. Although DR did not imply a higher rate of inappropriate empirical antimicrobial treatment, DR was independent associated with an increased related mortality to ABB in critically ill patients.

Session Details

Date: 31/03/2007
Time: 00:00-00:00
Session name: European Society of Clinical Microbiology and Infectious Diseases
Location: ICC, Munich, Germany
Presentation type:
Back to top