Liquid chromatography microspray mass spectrometry for bacterial investigations

Cellular proteins (biomarkers) specific to any individual microorganism, de termined by the direct mass spectral analysis of the corresponding intact c ellular suspension, can be applied for the rapid and specific identificatio n of the organisms present in unknown samples. The components of the bacter ial suspensions, after a rapid separation over a Cls reversed-phase microca pillary column, were directly subjected to on-line electrospray ionization followed by analysis using an ion trap tandem mass spectrometer, This appro ach is equally effective for gram-positive as well as gram-negative bacteri a but has a distinct advantage over our earlier reported method involving m atrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). During electrospray ionitation mass spectrometry (ESI-MS), liquid samples can be directly analyzed and there is the potential for deve loping tandem mass spectral methods for more specific identification of the individual organisms present in crude bacterial mixtures. The total analys is time leading to unambiguous bacterial identification in samples was less than 10 minutes and the results were quite reproducible. Miniaturization o f the instrumentation along with total automation of this simple process co uld have immense impact on field operations. Routine, rapid, cost-effective field monitoring of environmental samples, agricultural products, samples from food processing, industrial sites and health institutions for suspecte d bacterial contamination could be a reality in the near future. Potential utility in biological, medical, bioprocessing, pharmaceutical, and other in dustrial research is also enormous. Copyright (C) 1999 John Wiley & Sons, L td.