Bloodstream infections caused by extended-spectrum-beta-lactamase- producing Escherichia coli: risk factors for inadequate initial antimicrobial therapy.
Extended-spectrum-beta-lactamase (ESBL)-producing strains of Escherichia coli are a significant cause of bloodstream infections (BSI) in hospitalized and nonhospitalized patients. We previously showed that delaying effective antimicrobial therapy in BSI caused by ESBL producers significantly increases mortality. The aim of this retrospective 7-year analysis was to identify risk factors for inadequate initial antimicrobial therapy (IIAT) (i.e., empirical treatment based on a drug to which the isolate had displayed in vitro resistance) for inpatients with BSI caused by ESBL-producing E. coli. Of the 129 patients considered, 56 (43.4%) received IIAT for 48 to 120 h (mean, 72 h). Independent risk factors for IIAT include an unknown BSI source (odds ratios [OR], 4.86; 95% confidence interval [CI], 1.98 to 11.91; P = 0.001), isolate coresistance to >or=3 antimicrobials (OR, 3.73; 95% CI, 1.58 to 8.83; P = 0.003), hospitalization during the 12 months preceding BSI onset (OR, 3.33; 95% CI, 1.42 to 7.79; P = 0.005), and antimicrobial therapy during the 3 months preceding BSI onset (OR, 2.65; 95% CI, 1.11 to 6.29; P = 0.02). IIAT was the strongest risk factor for 21-day mortality and significantly increased the length of hospitalization after BSI onset. Our results underscore the need for a systematic approach to the management of patients with serious infections by ESBL-producing E. coli. Such an approach should be based on sound, updated knowledge of local infectious-disease epidemiology, detailed analysis of the patient's history with emphasis on recent contact with the health care system, and aggressive attempts to identify the infectious focus that has given rise to the BSI.
Tumbarello
Mario
M
Institute of Infectious Diseases, Institute of Microbiology, Catholic University of the Sacred Heart, Rome, Italy. tumbarello@rm.unicatt.it
Sali
Michela
M
Trecarichi
Enrico Maria
EM
Leone
Fiammetta
F
Rossi
Marianna
M
Fiori
Barbara
B
De Pascale
Gennaro
G
D'Inzeo
Tiziana
T
Sanguinetti
Maurizio
M
Fadda
Giovanni
G
Cauda
Roberto
R
Spanu
Teresa
T
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000201:enzymology; D004927:Escherichia coli Infections / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000401:mortality; D005260:Female; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D015999:Multivariate Analysis; D012307:Risk Factors; D017211:Treatment Failure; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000235:genetics
D000900:Anti-Bacterial Agents; D001618:beta-Lactamases