Oral Presentation Australasian Plant Pathology Society Conference 2025

Coupling MALDI-ToF mass spectrometry diagnostics with reference collections  (119790)

Chris Nellessen 1 , David Nehl 1
  1. DAFF, Mascot, NSW, Australia

Matrix assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI-TOF MS) is a mature technology, deployed globally for bacterial identification in human and veterinary disease diagnostics, and food testing. In recent years, it has been formally adopted by DAFF as a part of the plant pathology border diagnostic workflow, as an easy, rapid, inexpensive technology that can provide detailed taxonomic information at multiple stages of an investigation. Underpinning this adoption is a national, collaborative MALDI-ToF steering group under the Subcommittee on Plant Health Diagnostics (SPHD) and an ongoing partnership among its members to further the capacity of MALDI-ToF and its coverage of plant pests and disease. The steering committee recently published national standards guiding the proper process to add new data to a library of MALDI-ToF reference fingerprints, including the accepted method of evaluation of new fingerprint data and a link to an easy-to-use automated Excel template that facilitates this data assessment. Importantly, the fingerprint standard requires samples to be vouchered in accessible collections, whenever possible, paving the way for a future state wherein collection samples are routinely coupled with accessible MALDI-ToF fingerprints. DAFF is partnering with state culture collections, including NSW DPI’s culture collection at Orange Agricultural Institute, to facilitate vouchering, and an expansion in both the collection and MALDI-ToF coverage is expected. Furthermore, fingerprint data can be used for simple population analyses, potentially enabling point-of-origin investigation. Thanks to these promising advantages, DAFF is committed to expanding its MALDI-ToF diagnostic libraries into the future and predicts that MALDI-ToF fingerprint data collection will become a more regular part of its ongoing biosecurity mission at its border laboratories.