Rapid discrimination between strains of beta haemolytic streptococci by intact cell mass spectrometry.
OBJECTIVE
Beta haemolytic streptococci belonging to Lancefield group A, B, C and G cause a wide spectrum of clinical diseases. Hence there is a need for rapid and accurate typing of these strains. The present study was undertaken to evaluate the use of intact cell matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) for rapid discrimination between strains of beta haemolytic streptococci.


METHODS
Colonies of beta haemolytic streptococci were emulsified with chemical matrix on the sample slide, dried and analyzed by MALDI-TOF-MS.


RESULTS
The reproducibility of results for all groups of beta haemolytic streptococci was good and spectra obtained for Lancefield group A, C and G streptococci showed discrimination between the groups on visual comparison. A finer difference in spectrum was observed among group A streptococci isolated from different locations at different periods of time.


CONCLUSIONS
MALDI-TOF-MS may be a potential tool in discriminating between strains of beta haemolytic streptococci, and also in the characterisation of untypable strains of group A streptococci.
Kumar
M Palani
MP
Department of Microbiology, Dr ALM Postgraduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai, India.
Vairamani
M
M
Raju
Raju Prasada
RP
Lobo
Charmaine
C
Anbumani
N
N
Kumar
C P Girish
CP
Menon
Thangam
T
Shanmugasundaram
S
S
D000293:Adolescent; D002648:Child; D004926:Escherichia coli / Q000378:metabolism; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013290:Streptococcal Infections / Q000175:diagnosis* / Q000382:microbiology; D013291:Streptococcus / Q000235:genetics / Q000378:metabolism*