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Clinical and Microbiologic Analysis of a Hospital's Extended‐Spectrum β‐Lactamase‐Producing Isolates Over a 2‐Year Period
Author(s) -
Burgess David S.,
Hall Ronald G.,
Lewis James S.,
Jorgensen James H.,
Patterson Jan E.
Publication year - 2003
Publication title -
pharmacotherapy: the journal of human pharmacology and drug therapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.227
H-Index - 109
eISSN - 1875-9114
pISSN - 0277-0008
DOI - 10.1592/phco.23.12.1232.32706
Subject(s) - piperacillin , nitrofurantoin , medicine , tazobactam , piperacillin/tazobactam , klebsiella pneumoniae , cefepime , microbiology and biotechnology , amikacin , antimicrobial , ertapenem , trimethoprim , sulfamethoxazole , cefotetan , antibiotics , imipenem , antibiotic resistance , biology , escherichia coli , bacteria , biochemistry , genetics , gene , pseudomonas aeruginosa
Study Objective. To evaluate the microbiologic and clinical outcomes of patients with extended‐spectrum β‐lactamase (ESBL)‐producing isolates over a 2‐year period. Design. Retrospective analysis. Setting. Tertiary care teaching hospital. Patients. Twenty‐one patients with cultures of confirmed ESBL‐producing Escherichia coli, Klebsiella pneumoniae , or Klebsiella oxytoca . Measurements and Main Results. Antimicrobial susceptibilities of piperacillin‐tazobactam, cefotetan, carbapenems, aminoglycosides, fluoroquinolones, trimethoprim‐sulfamethoxazole, and nitrofurantoin (nitrofurantoin for urinary isolates only) of confirmed ESBL producers at our institution were determined, as well as clinical outcomes of patients with ESBL‐producing isolates. Microbiologic and medical records were reviewed for patient sex and age, antimicrobial susceptibilities, antimicrobial therapy, and clinical and microbiologic outcomes. From January 2000‐December 2001, 31 isolates were confirmed as ESBL producers (6 E. coli , 11 K. pneumoniae , and 14 K. oxytoca) . A statistically significant increase occurred over the 2‐year period from 9 (0.6%) of 1414 isolates in 2000 to 22 (1.8%) of 1218 isolates in 2001 (p=0.0055). All isolates were susceptible to carbapenems, and more than 88% were susceptible to amikacin, cefotetan, or nitrofurantoin. Less than 70% of isolates were susceptible to gentamicin, fluoroquinolones, piperacillin‐tazobactam, or trimethoprim‐sulfamethoxazole. All patients treated with a carbapenem experienced clinical cure. Piperacillin‐tazobactam alone and in combination resulted in an overall clinical cure rate of 55%, with a 50% cure rate for isolates susceptible to piperacillin‐tazobactam. All patients in whom antibiotic therapy failed had been treated with piperacillin‐tazobactam or cefepime, either alone or in combination with a fluoroquinolone. Conclusion. Carbapenems remain the treatment of choice for ESBL‐producing pathogens. Piperacillin‐tazobactam and cefepime should not be routinely administered for the treatment of these organisms.