eCite Digital Repository

Prevalence and genotypic characteristics of β-lactamase-negative ampicillin-resistant Haemophilus influenzae in Australia

Citation

Witherden, EA and Montgomery, J and Henderson, B and Tristram, SG, Prevalence and genotypic characteristics of β-lactamase-negative ampicillin-resistant Haemophilus influenzae in Australia, Journal of Antimicrobial Chemotherapy, 66, (5) pp. 1013-1015. ISSN 0305-7453 (2011) [Refereed Article]


Preview
PDF
Restricted - Request a copy
116Kb
  

Copyright Statement

The definitive publisher-authenticated version is available online at: http://www.oxfordjournals.org/

DOI: doi:10.1093/jac/dkr035

Abstract

Objectives: To determine the prevalence of β-lactamase-negative ampicillin-resistant (BLNAR) Haemophilus influenzae in Australia and characterize the associated amino acid substitutions in penicillin-binding protein 3.

Methods: Two hundred consecutive non-repeat clinical isolates of H. influenzae were collected and β-lactamase-negative isolates were screened for reduced ampicillin susceptibility using an ampicillin 2 μg disc (breakpoint <17 mm) and Etest (breakpoint ≥0.25 mg/L). All screen-positive isolates had their ampicillin MICs determined by reference broth microdilution and their ftsI genes were sequenced.

Results: No BLNAR strains (MIC ≥4 mg/L) were found, but 5 (2.5%) low BLNAR (L-BLNAR) strains (MIC ≥2 mg/L) and 36 (18%) genetic BLNAR (gBLNAR) strains (R517H or N526K) were found. Of the gBLNAR strains, four had the R517H substitution and the remainder had N526K, while no strains had combined N526K and M377I/S385T/L389F substitutions. A number of strains with neither R517H nor N526K substitutions that did not meet the gBLNAR definition had other BLNAR-associated substitutions.

Conclusions: BLNAR and L-BLNAR strains are uncommon in Australia, while gBLNAR strains are more common than previously recognized.

Item Details

Item Type:Refereed Article
Keywords:BLNAR, ftsI, PBP3
Research Division:Medical and Health Sciences
Research Group:Medical Microbiology
Research Field:Medical Bacteriology
Objective Division:Health
Objective Group:Clinical Health (Organs, Diseases and Abnormal Conditions)
Objective Field:Infectious Diseases
UTAS Author:Witherden, EA (Dr Elizabeth Witherden)
UTAS Author:Tristram, SG (Dr Stephen Tristram)
ID Code:69732
Year Published:2011
Web of Science® Times Cited:12
Deposited By:Health Sciences A
Deposited On:2011-05-16
Last Modified:2014-11-25
Downloads:1 View Download Statistics

Repository Staff Only: item control page