Clinical characteristics of bloodstream infections due to ampicillin-sulbactam-resistant, non-extended-spectrum-β-lactamase-producing Escherichia coli and the role of TEM-1 hyperproduction

Rebecca I. Waltner-Toews, David L. Paterson, Zubair A. Qureshi, Hanna E. Sidjabat, Jennifer M. Adams-Haduch, Kathleen A. Shutt, Mark Jones, Guo Bao Tian, Anthony W. Pasculle, Yohei Doi

Research output: Contribution to journalArticle

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Abstract

Ampicillin-sulbactam is commonly used as an empirical therapy for invasive infections where Escherichia coli is a potential pathogen. We evaluated the clinical and microbiologic characteristics of bloodstream infection due to E. coli, with focus on cases that were nonsusceptible to ampicillin-sulbactam and not producing extended-spectrum β-lactamase (ESBL). Of a total of 357 unique bacteremic cases identified between 2005 and 2008, 111 (31.1%) were intermediate or resistant to ampicillin-sulbactam by disk testing. In multivariate analysis, a history of liver disease, organ transplant, peptic ulcer disease, and prior use of ampicillin-sulbactam were independent risk factors for bloodstream infection with ampicillin-sulbactam-nonsusceptible E. coli. Among cases that received ampicillin-sulbactam as an empirical therapy, an early clinical response was observed in 65% (22/34) of susceptible cases but in only 20% (1/5) of nonsusceptible cases. Among 50 ampicillin-sulbactam-resistant isolates examined, there was no clonal relatedness and no evidence of production of inhibitor-resistant TEM (IRT). Instead, the resistance was attributed to hyperproduction of TEM-1 β-lactamase in the majority of isolates. However, promoter sequences of bla TEM-1 did not predict resistance to ampicillin-sulbactam. While the plasmid copy number did not differ between representative resistant and susceptible isolates, the relative expression of bla TEM-1 was significantly higher in two of three resistant isolates than in three susceptible isolates. These results suggest high-level bla TEM-1 expression as the predominant cause of ampicillin-sulbactam resistance and also the presence of yet-unidentified factors promoting overexpression of bla TEM-1 in these isolates.

Original languageEnglish
Pages (from-to)495-501
Number of pages7
JournalAntimicrobial agents and chemotherapy
Volume55
Issue number2
DOIs
Publication statusPublished - 01-02-2011

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Escherichia coli
Infection
Ampicillin Resistance
sultamicillin
Escherichia coli Infections
Peptic Ulcer
Liver Diseases
Plasmids
Multivariate Analysis
Transplants
Therapeutics

All Science Journal Classification (ASJC) codes

  • Pharmacology
  • Pharmacology (medical)
  • Infectious Diseases

Cite this

Waltner-Toews, Rebecca I. ; Paterson, David L. ; Qureshi, Zubair A. ; Sidjabat, Hanna E. ; Adams-Haduch, Jennifer M. ; Shutt, Kathleen A. ; Jones, Mark ; Tian, Guo Bao ; Pasculle, Anthony W. ; Doi, Yohei. / Clinical characteristics of bloodstream infections due to ampicillin-sulbactam-resistant, non-extended-spectrum-β-lactamase-producing Escherichia coli and the role of TEM-1 hyperproduction. In: Antimicrobial agents and chemotherapy. 2011 ; Vol. 55, No. 2. pp. 495-501.
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Clinical characteristics of bloodstream infections due to ampicillin-sulbactam-resistant, non-extended-spectrum-β-lactamase-producing Escherichia coli and the role of TEM-1 hyperproduction. / Waltner-Toews, Rebecca I.; Paterson, David L.; Qureshi, Zubair A.; Sidjabat, Hanna E.; Adams-Haduch, Jennifer M.; Shutt, Kathleen A.; Jones, Mark; Tian, Guo Bao; Pasculle, Anthony W.; Doi, Yohei.

In: Antimicrobial agents and chemotherapy, Vol. 55, No. 2, 01.02.2011, p. 495-501.

Research output: Contribution to journalArticle

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AU - Waltner-Toews, Rebecca I.

AU - Paterson, David L.

AU - Qureshi, Zubair A.

AU - Sidjabat, Hanna E.

AU - Adams-Haduch, Jennifer M.

AU - Shutt, Kathleen A.

AU - Jones, Mark

AU - Tian, Guo Bao

AU - Pasculle, Anthony W.

AU - Doi, Yohei

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