Fingerprint matching of E. coli strains with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry of whole cells using a modified correlation approach.
We have developed a mathematical algorithm to compare and distinguish matrix-assisted laser desorption/ionization (MALDI) mass spectra of whole bacteria cells. This fingerprint matching technique eliminates the subjectivity involved in visually comparing two spectra to determine whether they match and it provides a quantitative measure of spectral similarity. Using it, we have distinguished twenty five different strains of a single bacteria species, E. coli. Cells are grown in culture, samples are prepared, and MALDI-TOF mass spectra are recorded for each strain. Pairs of spectra are compared by a modified cross-correlation procedure. This modified approach increases the sensitivity of correlation analysis to small spectral differences. The technique can be fine-tuned by varying the number of intervals into which spectra are divided.
Arnold
R J
RJ
Department of Chemistry, Indiana University, Bloomington 47405, USA.
Reilly
J P
JP
D016172:DNA Fingerprinting / Q000379:methods*; D053938:DNA Fragmentation; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics*; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D004269:DNA, Bacterial