Incidence and impact on clinical outcome of infections with piperacillin/tazobactam resistant Escherichia coli in ICU: a retrospective study.
BACKGROUND
Escherichia coli infections are frequent in ICU patients. The increased resistance to fluoroquinolones and amoxicillin/clavulanate of this pathogen mandates the prescription of broad-spectrum antibiotics such as piperacillin/tazobactam (PIP-TAZ) or third generation cephalosporins (3GC).


METHODS
To assess incidence and impact on clinical outcome of infections with PIP-TAZ resistant E. coli in ICU patients, we conducted a retrospective cohort study with infections due to PIP-TAZ resistant (PIP-TAZ R) or to PIP-TAZ susceptible strains (PIP-TAZ S) between 1 January 2002 and 30 June 2004.


RESULTS
Of 83 strains, 13 were PIP-TAZ R: 2 strains produced an extended-spectrum beta-lactamase (2%), 11 produced a high level penicillinase (13%). Prior amoxicillin or amoxicillin/clavulanate prescription was reported in 7 cases (54%) of infections with PIP-TAZ R isolates and in 15 cases (21%) of infections with PIP-TAZ S isolates (p = 0.03). Time of onset of the infection from hospital admission was longer in case of infections with PIP-TAZ R than with PIP-TAZ S isolates (22 +/- 32 vs 10 +/- 21 days, p = 0.01). The overall ICU mortality rate was 38%. Mortality and length of stay in ICU were similar in case of infections with PIP-TAZ R isolates and with PIP-TAZ S isolates.


CONCLUSIONS
Infections with PIP-TAZ R E. coli are frequent in ICU patients. No prognostic impact of this pattern of resistance was found. Prescription of PIP-TAZ for empirical treatment of E. coli infections in ICU however exposes to inappropriate therapy.
Meybeck
Agnès
A
Service de Réanimation, Hôpital Louis-Mourier, 178 rue des Renouillers 92701 Colombes Cedex, France. agnes.meybeck@caramail.com
Ricard
Jean-Damien
JD
Barnaud
Guilène
G
Eveillard
Mathieu
M
Chevrel
Guillaume
G
Mounier
Roman
R
Dreyfuss
Didier
D
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D015331:Cohort Studies; D003428:Cross Infection / Q000188:drug therapy* / Q000382:microbiology / Q000401:mortality; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli / Q000187:drug effects* / Q000302:isolation & purification; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000401:mortality; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010397:Penicillanic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D010878:Piperacillin / Q000494:pharmacology; D012189:Retrospective Studies; D000078142:Tazobactam; D016896:Treatment Outcome; D001618:beta-Lactamases / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D010397:Penicillanic Acid; D001618:beta-Lactamases; D000078142:Tazobactam; D010878:Piperacillin