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Identification of Haemophilus influenzae type b isolates by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry

Månsson, Viktor LU ; Resman, Fredrik LU ; Kostrzewa, Markus; Nilson, Bo LU and Riesbeck, Kristian LU (2015) In Journal of Clinical Microbiology 53(7). p.2215-2224
Abstract
Haemophilus influenzae type b (Hib) is, in contrast to non-b H. influenzae, associated with severe invasive disease such as meningitis and epiglottitis in small children. To date accurate H. influenzae capsule typing requires PCR, a time-consuming and cumbersome method. MALDI-TOF MS provides rapid bacterial diagnostics and is increasingly used in clinical microbiology laboratories. Here MALDI-TOF MS was evaluated as a novel approach to separate Hib from other H. influenzae. PCR-verified Hib and non-Hib reference isolates were selected based on genetic and spectral characteristics. Mass spectra of reference isolates were acquired, and used to generate different classification algorithms for Hib/non-Hib separation using both ClinProTools and... (More)
Haemophilus influenzae type b (Hib) is, in contrast to non-b H. influenzae, associated with severe invasive disease such as meningitis and epiglottitis in small children. To date accurate H. influenzae capsule typing requires PCR, a time-consuming and cumbersome method. MALDI-TOF MS provides rapid bacterial diagnostics and is increasingly used in clinical microbiology laboratories. Here MALDI-TOF MS was evaluated as a novel approach to separate Hib from other H. influenzae. PCR-verified Hib and non-Hib reference isolates were selected based on genetic and spectral characteristics. Mass spectra of reference isolates were acquired, and used to generate different classification algorithms for Hib/non-Hib separation using both ClinProTools and MALDI Biotyper software. A test series of mass spectra from 33 Hib and 77 non-Hib isolates, all characterized by PCR, was used to evaluate the algorithms. Several algorithms yielded good results but the two best were a ClinProTools model based on 22 separating peaks and a subtyping main spectra (MSP) model using MALDI Biotyper. The ClinProTools model had a sensitivity of 100%, a specificity of 99% and the results were 98% reproducible using a different MALDI-TOF MS instrument. The Biotyper subtyping MSPs had a sensitivity of 97%, a specificity of 100% and 93% reproducibility. Our results suggest that it is possible to use MALDI-TOF MS to differentiate Hib from other H. influenzae. This is a promising method to rapidly identify Hib in unvaccinated populations, and for screening or surveillance of Hib carriage in vaccinated populations. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Clinical Microbiology
volume
53
issue
7
pages
2215 - 2224
publisher
American Society for Microbiology
external identifiers
  • pmid:25926500
  • wos:000358287700030
  • scopus:84932635228
ISSN
1098-660X
DOI
10.1128/JCM.00137-15
language
English
LU publication?
yes
id
2f11c190-35d2-4edd-9a27-9809cade2792 (old id 5461498)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/25926500?dopt=Abstract
date added to LUP
2015-06-04 12:22:04
date last changed
2017-11-12 03:01:46
@article{2f11c190-35d2-4edd-9a27-9809cade2792,
  abstract     = {Haemophilus influenzae type b (Hib) is, in contrast to non-b H. influenzae, associated with severe invasive disease such as meningitis and epiglottitis in small children. To date accurate H. influenzae capsule typing requires PCR, a time-consuming and cumbersome method. MALDI-TOF MS provides rapid bacterial diagnostics and is increasingly used in clinical microbiology laboratories. Here MALDI-TOF MS was evaluated as a novel approach to separate Hib from other H. influenzae. PCR-verified Hib and non-Hib reference isolates were selected based on genetic and spectral characteristics. Mass spectra of reference isolates were acquired, and used to generate different classification algorithms for Hib/non-Hib separation using both ClinProTools and MALDI Biotyper software. A test series of mass spectra from 33 Hib and 77 non-Hib isolates, all characterized by PCR, was used to evaluate the algorithms. Several algorithms yielded good results but the two best were a ClinProTools model based on 22 separating peaks and a subtyping main spectra (MSP) model using MALDI Biotyper. The ClinProTools model had a sensitivity of 100%, a specificity of 99% and the results were 98% reproducible using a different MALDI-TOF MS instrument. The Biotyper subtyping MSPs had a sensitivity of 97%, a specificity of 100% and 93% reproducibility. Our results suggest that it is possible to use MALDI-TOF MS to differentiate Hib from other H. influenzae. This is a promising method to rapidly identify Hib in unvaccinated populations, and for screening or surveillance of Hib carriage in vaccinated populations.},
  author       = {Månsson, Viktor and Resman, Fredrik and Kostrzewa, Markus and Nilson, Bo and Riesbeck, Kristian},
  issn         = {1098-660X},
  language     = {eng},
  number       = {7},
  pages        = {2215--2224},
  publisher    = {American Society for Microbiology},
  series       = {Journal of Clinical Microbiology},
  title        = {Identification of Haemophilus influenzae type b isolates by use of matrix-assisted laser desorption ionization-time of flight mass spectrometry},
  url          = {http://dx.doi.org/10.1128/JCM.00137-15},
  volume       = {53},
  year         = {2015},
}