Direct analysis and identification of Helicobacter and Campylobacter species by MALDI-TOF mass spectrometry

Campylobacter jejuni, Campylobacter fetus, and Campylobacter coli were comp ared with Helicobacter pylori and Helicobacter mustelae by direct analysis of individual cultured colonies in 50% methanol-water with a matrix-assiste d laser desorption/ionization time-of-flight mass spectrometer: (MALDI-TOF MS). H. pylori and Campylobacter species from blood agar culture produced u nique, complex spectra with over 25 different ions in mass/charge (m/z) ran ge from 2 000 to 62 000. A biomarker for H. pylori was centered around m/z 58 268, and H. mustelae was distinguished from LT, pylon: by its ions at m/ z 49 608 and 57 231. Campylobacters could be distinguished from Helicobacte rs by their lack of ions around m/z 58 000 and 61 000 as well as distinguis hing biomarkers of lower m/z: 10 074 and 25 478 for C. coli; m/z 10 285 and 12 901 for C. jejuni; m/z 10 726 and 11 289 for C. fetus. MALDI-TOF MS is a rapid and direct method for detection of these potentially pathogenic bac teria from culture.