Rapid microbial identifications by MALDI-TOF – Viva la revolution!

Abstract

Although the application of mass spectrometry to bacterial identification was proposed as far back as 1975 by John Anhalt, it was not until 1987 when Professor Franz Hillenkamp and Dr Michael Karas first pioneered Matrix Assisted Laser Desorption/Ionisation Time-of-Flight mass spectrometry (MALDI-TOF MS) for truly rapid microbial identification in diagnostic microbiology laboratories. Conventional phenotypic methods of identifying isolates of bacteria, yeasts and filamentous fungi require hours to several days to complete, depending on the type of organism involved, and may be prone to error due to bias or inexperience. Even the more recent molecular innovations have their limitations that place them outside the scope and budget of many routine laboratories. However, MALDI-TOF MS technology has changed the way we think about microbial identifications and strain differentiation by providing results from plate to name in approximately five minutes for one isolate and around 90 minutes for 60 isolates at under $2 an identification. It is likely to be particularly helpful clinically for identification of species in positive blood culture broths and for organisms that are hard to identify quickly.