Robin Patel, M.D., Discusses the Use of MALDI-TOF for Identifying Various Microorganisms
Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) is a powerful analytical mass spectrometry technique that has generated numerous diagnostic and clinical applications, especially for the identification of microorganisms for medical diagnosis. Robin Patel, M.D., Chair of the Division of Clinical Microbiology in the Department of Laboratory Medicine and Pathology at Mayo Clinic in Rochester, Minnesota, was interviewed by Technology Networks for her insight on the technique.
Dr. Patel recognized the potential of MALDI-TOF and procured a machine for her lab. “In just under a week, we convinced ourselves that it worked very well, needed to be implemented into the clinical laboratory, and had generated enough data to submit an abstract to an international scientific meeting,” she recalls. She and her lab have since spearheaded efforts for microbial identification by MALDI-TOF at Mayo Clinic.
According to Dr. Patel, the field may potentially benefit from a central repository of spectra similar to nucleic acids database of genes and mRNA. “It has proven to be more challenging with MALDI-TOF mass spectra than with nucleotide sequences because the data can be affected by details of the conditions used to generate the data, including processing of the sample, alongside individual instruments and their associated software,” she says. If experimental variability can be standardized, it may pave the way for repositories.
Dr. Patel also commented on Mayo's use of MALDI-TOF for positive blood cultures, which are blood samples that have been incubated on instruments that “sense” bacterial growth. These cultures can be plated to solid media and incubated to produce a “film” of growth within hours to a day that is amenable to MALDI-TOF. “This is quick and inexpensive and leverages the remarkable breadth of coverage of MALDI-TOF mass spectrometry,” says Dr. Patel, whose lab performs this on a daily basis.