Nosocomial bloodstream infections caused by Klebsiella pneumoniae: impact of extended-spectrum beta-lactamase (ESBL) production on clinical outcome in a hospital with high ESBL prevalence.
BACKGROUND
The frequency of ESBL producing Klebsiella pneumoniae bloodstream infections (BSI) is high in Brazilian hospitals, however little is known regarding what role, if any, resistance plays in the expected outcome in hospitals with a high prevalence of these pathogens.


METHODS
From 1996 to 2001, hospital acquired K. pneumoniae BSI were evaluated retrospectively. Each patient was included only once at the time of BSI. ESBL producing strains were identified using the E-test method. The association of variables with the mortality related to bacteremia was included in a stepwise logistic regression model.


RESULTS
One hundred and eight hospital acquired K. pneumoniae BSI met criteria for inclusion. Fifty two percent were due to ESBL producing strains. The overall in-hospital mortality was 40.8%. Variables independently predicting death by multivariate analysis were the following: mechanical ventilation (p = 0.001), number of comorbidities (p = 0.003), antimicrobials prescribed before bacteremia (p = 0.01) and fatal underlying disease (p = 0.025).


CONCLUSIONS
Bacteremia due to ESBL producing K. pneumoniae strains was not an independent predictor for death in patients with BSI. An increased mortality in hospital-acquired BSI by K. pneumoniae was related to the requirement for mechanical ventilation, more than two comorbidities, the previous use of two or more antibiotics, and the presence of a rapidly fatal disease.
Division of Infectious Diseases, Universidade Federal de São Paulo, Brasil (UNIFESP-EPM)/Hospital São Paulo (HSP), Brasil. a.marra@uol.com.br
Alexandre R
AR
Marra
Sérgio B
SB
Wey
Adauto
A
Castelo
Ana Cristina
AC
Gales
Ruy Guilherme R
RG
Cal
José R do Carmo
JR
Filho
Michael B
MB
Edmond
Carlos Alberto P
CA
Pereira
D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D016470:Bacteremia / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality*; D001938:Brazil; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality*; D005260:Female; D006801:Humans; D007223:Infant; D007710:Klebsiella Infections / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality*; D007711:Klebsiella pneumoniae / Q000302:isolation & purification / Q000378:metabolism*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012121:Respiration, Artificial; D012189:Retrospective Studies; D012307:Risk Factors; D018440:beta-Lactam Resistance; D001618:beta-Lactamases / Q000096:biosynthesis*
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases