TY - JOUR
T1 - Serotype discrimination of encapsulated Streptococcus pneumoniae strains by Fourier-transform infrared spectroscopy and chemometrics
AU - Vaz, M.
AU - Meirinhos-Soares, L.
AU - Sousa, C. C.S.
AU - Ramirez, M.
AU - Melo-Cristino, J.
AU - Lopes, J. A.
N1 - Funding Information:
Autoridade Nacional do Medicamento e Produtos de Saúde I.P. (INFARMED, I.P.) is greatly acknowledged for providing access to the infrared spectrometer and where all the laboratorial work was performed. Clara C. S. Sousa thanks the Fundação para a Ciência e a Tecnologia in Portugal for the award of her post-doctoral scholarship ( BPD/70548/2010 ). This work was also supported by Fundação para a Ciência e a Tecnologia in Portugal through grant no. PEst-C/EQB/LA0006/2011 .
PY - 2013/5
Y1 - 2013/5
N2 - Fourier-transform infrared (FTIR) spectroscopy was evaluated as an alternative method for serotyping encapsulated Streptococcus pneumonia strains. Sixty-nine invasive strains from the Microbiology Laboratory of the Medicine Faculty of University of Lisbon were selected for the analysis. The encapsulated strains used in this work (9N, 9V, 14, 19A, 19F, 23A, 23B and 23F) were serotyped by the standard capsular reaction test using the chessboard method and specific sera. FTIR spectra were analysed with chemometric methods. Results showed that the best spectral region unveiling serotype difference is located at 1185-900cm-1. A partial least squares discriminant analysis model was calibrated using this spectral region against the chessboard method serotyping. FTIR spectroscopy proved to be able to correctly predict 100% of strains according to the serogroups (9, 14, 19, 23). A segregated analysis showed that it was also possible to differentiate serotypes belonging to the same serogroup although spectral differences are less pronounced as was initially expected.
AB - Fourier-transform infrared (FTIR) spectroscopy was evaluated as an alternative method for serotyping encapsulated Streptococcus pneumonia strains. Sixty-nine invasive strains from the Microbiology Laboratory of the Medicine Faculty of University of Lisbon were selected for the analysis. The encapsulated strains used in this work (9N, 9V, 14, 19A, 19F, 23A, 23B and 23F) were serotyped by the standard capsular reaction test using the chessboard method and specific sera. FTIR spectra were analysed with chemometric methods. Results showed that the best spectral region unveiling serotype difference is located at 1185-900cm-1. A partial least squares discriminant analysis model was calibrated using this spectral region against the chessboard method serotyping. FTIR spectroscopy proved to be able to correctly predict 100% of strains according to the serogroups (9, 14, 19, 23). A segregated analysis showed that it was also possible to differentiate serotypes belonging to the same serogroup although spectral differences are less pronounced as was initially expected.
KW - Chemometrics
KW - FTIR spectroscopy
KW - Serogroups
KW - Serotyping
KW - Streptococcus pneumoniae
UR - http://www.scopus.com/inward/record.url?scp=84875617863&partnerID=8YFLogxK
U2 - 10.1016/j.mimet.2013.02.008
DO - 10.1016/j.mimet.2013.02.008
M3 - Article
C2 - 23499920
AN - SCOPUS:84875617863
SN - 0167-7012
VL - 93
SP - 102
EP - 107
JO - Journal of Microbiological Methods
JF - Journal of Microbiological Methods
IS - 2
ER -
