Detection and clinical significance of extended-spectrum β-lactamases in a tertiary-care medical center

Christopher Emery, Lisa A. Weymouth

Research output: Contribution to journalArticle

153 Citations (Scopus)

Abstract

The prevalence of extended-spectrum β-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed. We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center. Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 μg/ml were tested for production of ESBLs by the double-disk synergy method. Approximately 1.5% of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2% of patients (23 of 1,844), were found to express ESBLs. ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics. By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39% of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used. However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate. Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin. Seven were cured. The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing. These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae.

Original languageEnglish (US)
Pages (from-to)2061-2067
Number of pages7
JournalJournal of Clinical Microbiology
Volume35
Issue number8
StatePublished - Aug 1997
Externally publishedYes

Fingerprint

Tertiary Care Centers
Enterobacteriaceae
Ceftazidime
cefpodoxime
Guidelines
Hospital Outpatient Clinics
Ceftriaxone
Cephalosporins
Costs and Cost Analysis
Therapeutics

ASJC Scopus subject areas

  • Microbiology (medical)
  • Microbiology

Cite this

Detection and clinical significance of extended-spectrum β-lactamases in a tertiary-care medical center. / Emery, Christopher; Weymouth, Lisa A.

In: Journal of Clinical Microbiology, Vol. 35, No. 8, 08.1997, p. 2061-2067.

Research output: Contribution to journalArticle

@article{5aec9617d351437981d7723446f827db,
title = "Detection and clinical significance of extended-spectrum β-lactamases in a tertiary-care medical center",
abstract = "The prevalence of extended-spectrum β-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed. We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center. Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 μg/ml were tested for production of ESBLs by the double-disk synergy method. Approximately 1.5{\%} of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2{\%} of patients (23 of 1,844), were found to express ESBLs. ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics. By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39{\%} of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used. However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate. Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin. Seven were cured. The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing. These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae.",
author = "Christopher Emery and Weymouth, {Lisa A.}",
year = "1997",
month = "8",
language = "English (US)",
volume = "35",
pages = "2061--2067",
journal = "Journal of Clinical Microbiology",
issn = "0095-1137",
publisher = "American Society for Microbiology",
number = "8",

}

TY - JOUR

T1 - Detection and clinical significance of extended-spectrum β-lactamases in a tertiary-care medical center

AU - Emery, Christopher

AU - Weymouth, Lisa A.

PY - 1997/8

Y1 - 1997/8

N2 - The prevalence of extended-spectrum β-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed. We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center. Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 μg/ml were tested for production of ESBLs by the double-disk synergy method. Approximately 1.5% of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2% of patients (23 of 1,844), were found to express ESBLs. ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics. By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39% of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used. However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate. Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin. Seven were cured. The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing. These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae.

AB - The prevalence of extended-spectrum β-lactamase (ESBL)-mediated resistance remains unknown for most hospitals, and national guidelines for testing and reporting ESBL-mediated resistance have not yet been developed. We undertook a study to determine the prevalence of ESBLs and the clinical need for testing in our tertiary-care medical center. Members of the family Enterobacteriaceae isolated over a 6-month period for which ceftazidime or ceftriaxone MICs were greater than 1 μg/ml were tested for production of ESBLs by the double-disk synergy method. Approximately 1.5% of isolates of the family Enterobacteriaceae (50 of 3,273), which were isolated from 1.2% of patients (23 of 1,844), were found to express ESBLs. ESBL-producing strains included eight different species and were isolated from patients located throughout the hospital, including outpatient clinics. By using the interpretive guidelines of the National Committee for Clinical Laboratory Standards, 26 to 39% of the isolates would have been reported to be susceptible to ceftazidime, depending upon the routine susceptibility method used. However, tests with cefpodoxime found all of the ESBL-producing strains to be resistant or intermediate. Nine patients infected with ESBL-producing isolates were treated with therapy which included an expanded-spectrum cephalosporin. Seven were cured. The deaths of the other two patients were not attributed to bacterial resistance missed by routine susceptibility testing. These observations suggest that in our tertiary-care medical center, it may not be clinically necessary or cost-effective at this time to institute additional testing on a routine basis to detect ESBL production in all clinical isolates of the family Enterobacteriaceae.

UR - http://www.scopus.com/inward/record.url?scp=0030835823&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030835823&partnerID=8YFLogxK

M3 - Article

VL - 35

SP - 2061

EP - 2067

JO - Journal of Clinical Microbiology

JF - Journal of Clinical Microbiology

SN - 0095-1137

IS - 8

ER -