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Impact of empirical treatment in extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella spp. bacteremia. A multicentric cohort study

Galo Peralta1*, María Lamelo2, Patricia Álvarez-García2, María Velasco3, Alberto Delgado3, Juan Pablo Horcajada4, María Montero4, María Pía Roiz5, Maria Carmen Fariñas5, Juan Alonso5, Luis Martínez Martínez5, Alfonso Gutiérrez-Macías6, Jose Angel Alava6, Azucena Rodríguez7, Ana Fleites7, Vicente Navarro8, Elia Sirvent8, Jose Antonio Capdevila9 and on behalf of the SEMI- BLEE STUDY GROUP (members of SEMI BLEE group were listed in the acknowledgments section)

Author Affiliations

1 Instituto de Formación e Investigación Marqués de Valdecilla (IFIMAV), 3ª Planta. Edificio IFIMAV. Avda Cardenal Herrera Oria s/n, 39011, Santander, Spain

2 Hospital Montecelo, Pontevedra, Spain

3 Hospital Universitario Fundación Alcorcón, Madrid, Spain

4 Hospital del Mar, Barcelona, Spain

5 Hospital Universitario Marqués de Valdecilla-IFIMAV, Santander, Spain

6 Hospital de Basurto, Bilbao, Spain

7 Hospital Central de Asturias, Oviedo, Spain

8 Hospital de Torrevieja, Torrevieja, Spain

9 Hospital de Mataró, Mataró, Spain

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BMC Infectious Diseases 2012, 12:245  doi:10.1186/1471-2334-12-245

Published: 5 October 2012



The objective of this study is to analyze the factors that are associated with the adequacy of empirical antibiotic therapy and its impact in mortality in a large cohort of patients with extended-spectrum β-lactamase (ESBL) - producing Escherichia coli and Klebsiella spp. bacteremia.


Cases of ESBL producing Enterobacteriaceae (ESBL-E) bacteremia collected from 2003 through 2008 in 19 hospitals in Spain. Statistical analysis was performed using multivariate logistic regression.


We analyzed 387 cases ESBL-E bloodstream infections. The main sources of bacteremia were urinary tract (55.3%), biliary tract (12.7%), intra-abdominal (8.8%) and unknown origin (9.6%). Among all the 387 episodes, E. coli was isolated from blood cultures in 343 and in 45.71% the ESBL-E was multidrug resistant. Empirical antibiotic treatment was adequate in 48.8% of the cases and the in hospital mortality was 20.9%. In a multivariate analysis adequacy was a risk factor for death [adjusted OR (95% CI): 0.39 (0.31-0.97); P = 0.04], but not in patients without severe sepsis or shock. The class of antibiotic used empirically was not associated with prognosis in adequately treated patients.


ESBL-E bacteremia has a relatively high mortality that is partly related with a low adequacy of empirical antibiotic treatment. In selected subgroups the relevance of the adequacy of empirical therapy is limited.

Bacteremia; Extended-spectrum β-lactamase; Gram negative; Antibiotic empirical treatment; Prognosis