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Detection of beta-lactamase-negative ampicillin resistance in Haemophilus influenzae in Belgium. / Schotte, Lise; Wautier, Magali; Martiny, Delphine; Piérard, Denis; Depypere, Melissa.

In: Diagnostic Microbiology and Infectious Disease, Vol. 93, No. 3, 2019, p. 243-249.

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Schotte, Lise ; Wautier, Magali ; Martiny, Delphine ; Piérard, Denis ; Depypere, Melissa. / Detection of beta-lactamase-negative ampicillin resistance in Haemophilus influenzae in Belgium. In: Diagnostic Microbiology and Infectious Disease. 2019 ; Vol. 93, No. 3. pp. 243-249.

BibTeX

@article{dcf2578c555f45dfa91421e9d653befe,
title = "Detection of beta-lactamase-negative ampicillin resistance in Haemophilus influenzae in Belgium",
abstract = "Haemophilus influenzae, a frequent colonizer of the respiratory tract, is the causative agent of several clinically important infections. In cases that require therapeutic intervention, laboratory susceptibility testing can detect beta-lactam antibiotic resistance and guide the best treatment course. In the absence of a beta-lactamase, beta-lactam resistance may be due to an altered form of the PBP3 protein, encoded by the ftsI gene. While these so-called beta-lactamase-negative ampicillin-resistant (BLNAR) strains are of serious clinical interest, identification in the clinical laboratory is not always straightforward. In the current study, the ftsI genes of a set of phenotypic BLNAR H. influenzae isolates taken from samples collected in the UZ Brussel hospital in Belgium were sequenced and re-tested at the National Reference Laboratory (NRC). Non-silent mutations in the ftsI gene were found in 100{\%} of the isolates. Although 30{\%} of the isolates were classified by the NRC as beta-lactamase-negative ampicillin-sensitive (BLNAS) strains based on the EUCAST guidelines on ampicillin minimal inhibitory concentration (MIC), all isolates showed MIC values ≥1 mg/L. These relatively high MIC values indicate a decreased susceptibility to ampicillin, and suggest that sequencing of the ftsI gene should be used as part of an antibiotic susceptibility testing (AST) algorithm in the clinical laboratory. This would allow clinicians to make better informed decisions regarding patient treatment.",
keywords = "Algorithms, Ampicillin/pharmacology, Ampicillin Resistance/genetics, Anti-Bacterial Agents/pharmacology, Bacterial Proteins/genetics, Belgium, Haemophilus Infections/diagnosis, Haemophilus influenzae/drug effects, Humans, Microbial Sensitivity Tests, Mutation, Penicillin-Binding Proteins/genetics, Polymerase Chain Reaction, Sequence Analysis, DNA, beta-Lactam Resistance/genetics, beta-Lactamases/genetics",
author = "Lise Schotte and Magali Wautier and Delphine Martiny and Denis Pi{\'e}rard and Melissa Depypere",
note = "Copyright {\circledC} 2018 Elsevier Inc. All rights reserved.",
year = "2019",
doi = "10.1016/j.diagmicrobio.2018.10.009",
language = "English",
volume = "93",
pages = "243--249",
journal = "Diagnostic Microbiology and Infectious Disease",
issn = "0732-8893",
publisher = "Elsevier Inc.",
number = "3",

}

RIS

TY - JOUR

T1 - Detection of beta-lactamase-negative ampicillin resistance in Haemophilus influenzae in Belgium

AU - Schotte, Lise

AU - Wautier, Magali

AU - Martiny, Delphine

AU - Piérard, Denis

AU - Depypere, Melissa

N1 - Copyright © 2018 Elsevier Inc. All rights reserved.

PY - 2019

Y1 - 2019

N2 - Haemophilus influenzae, a frequent colonizer of the respiratory tract, is the causative agent of several clinically important infections. In cases that require therapeutic intervention, laboratory susceptibility testing can detect beta-lactam antibiotic resistance and guide the best treatment course. In the absence of a beta-lactamase, beta-lactam resistance may be due to an altered form of the PBP3 protein, encoded by the ftsI gene. While these so-called beta-lactamase-negative ampicillin-resistant (BLNAR) strains are of serious clinical interest, identification in the clinical laboratory is not always straightforward. In the current study, the ftsI genes of a set of phenotypic BLNAR H. influenzae isolates taken from samples collected in the UZ Brussel hospital in Belgium were sequenced and re-tested at the National Reference Laboratory (NRC). Non-silent mutations in the ftsI gene were found in 100% of the isolates. Although 30% of the isolates were classified by the NRC as beta-lactamase-negative ampicillin-sensitive (BLNAS) strains based on the EUCAST guidelines on ampicillin minimal inhibitory concentration (MIC), all isolates showed MIC values ≥1 mg/L. These relatively high MIC values indicate a decreased susceptibility to ampicillin, and suggest that sequencing of the ftsI gene should be used as part of an antibiotic susceptibility testing (AST) algorithm in the clinical laboratory. This would allow clinicians to make better informed decisions regarding patient treatment.

AB - Haemophilus influenzae, a frequent colonizer of the respiratory tract, is the causative agent of several clinically important infections. In cases that require therapeutic intervention, laboratory susceptibility testing can detect beta-lactam antibiotic resistance and guide the best treatment course. In the absence of a beta-lactamase, beta-lactam resistance may be due to an altered form of the PBP3 protein, encoded by the ftsI gene. While these so-called beta-lactamase-negative ampicillin-resistant (BLNAR) strains are of serious clinical interest, identification in the clinical laboratory is not always straightforward. In the current study, the ftsI genes of a set of phenotypic BLNAR H. influenzae isolates taken from samples collected in the UZ Brussel hospital in Belgium were sequenced and re-tested at the National Reference Laboratory (NRC). Non-silent mutations in the ftsI gene were found in 100% of the isolates. Although 30% of the isolates were classified by the NRC as beta-lactamase-negative ampicillin-sensitive (BLNAS) strains based on the EUCAST guidelines on ampicillin minimal inhibitory concentration (MIC), all isolates showed MIC values ≥1 mg/L. These relatively high MIC values indicate a decreased susceptibility to ampicillin, and suggest that sequencing of the ftsI gene should be used as part of an antibiotic susceptibility testing (AST) algorithm in the clinical laboratory. This would allow clinicians to make better informed decisions regarding patient treatment.

KW - Algorithms

KW - Ampicillin/pharmacology

KW - Ampicillin Resistance/genetics

KW - Anti-Bacterial Agents/pharmacology

KW - Bacterial Proteins/genetics

KW - Belgium

KW - Haemophilus Infections/diagnosis

KW - Haemophilus influenzae/drug effects

KW - Humans

KW - Microbial Sensitivity Tests

KW - Mutation

KW - Penicillin-Binding Proteins/genetics

KW - Polymerase Chain Reaction

KW - Sequence Analysis, DNA

KW - beta-Lactam Resistance/genetics

KW - beta-Lactamases/genetics

U2 - 10.1016/j.diagmicrobio.2018.10.009

DO - 10.1016/j.diagmicrobio.2018.10.009

M3 - Article

C2 - 30424950

VL - 93

SP - 243

EP - 249

JO - Diagnostic Microbiology and Infectious Disease

JF - Diagnostic Microbiology and Infectious Disease

SN - 0732-8893

IS - 3

ER -

ID: 49086358