A promoted MALDI-TOF-MS platform towards rapid and accurate identifications of bacteria

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) is emerging as the most powerful tool for the identification of bacteria. Herein, we demonstrated that the capability of MALDI-TOF-MS towards the discrimination of clinical bacteria can be further dramatically improved. A cooperative matrix consisting of (E)-propyl α-cyano-4-hydroxylcinnamylate (CHCA-C3) and α-cyano-4-hydroxycinnamic acid (CHCA) was used to replace the commonly used matrix CHCA. As a result, 1.4–3.8 times more fingerprint peaks have been identified by the cooperative matrix in comparison with CHCA when six different bacteria were studied. The peaks distribute in the wider m / z range, and the spectral quality has also been significantly improved. As an example of practical applications, the direct and more reliable discrimination between Escherichia coli (E. coli) and Shigella sonnei ( S. sonnei) was achieved based on their protein fingerprints, which was previously claimed to be impossible by CHCA. Thus, a promoted MALDI-TOF-MS platform towards bacterial identification has been established by utilizing the new cooperative matrix, which will exhibit great potential for many applications.