Open AccessRaman spectroscopic analysis of skin as a diagnostic tool for Human African Trypanosomiasis
Author(s) -
Alex Girard,
Anneli Cooper,
Samuel Mabbott,
Barbara Bradley,
Steven M. Asiala,
Lauren E. Jamieson,
Caroline Clucas,
Paul Capewell,
Francesco Marchesi,
Matthew P. Gibbins,
Franziska Hentzschel,
Matthias Marti,
Juan F. Quintana,
Paul Garside,
Karen Faulds,
Annette MacLeod,
Duncan Graham
Publication year - 2021
Publication title -
plos pathogens
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.719
H-Index - 206
eISSN - 1553-7374
pISSN - 1553-7366
DOI - 10.1371/journal.ppat.1010060
Subject(s) - trypanosoma brucei , african trypanosomiasis , human skin , ex vivo , raman spectroscopy , biology , virology , trypanosomiasis , in vivo , biochemistry , optics , genetics , physics , microbiology and biotechnology , gene
Human African Trypanosomiasis (HAT) has been responsible for several deadly epidemics throughout the 20th century, but a renewed commitment to disease control has significantly reduced new cases and motivated a target for the elimination of Trypanosoma brucei gambiense -HAT by 2030. However, the recent identification of latent human infections, and the detection of trypanosomes in extravascular tissues hidden from current diagnostic tools, such as the skin, has added new complexity to identifying infected individuals. New and improved diagnostic tests to detect Trypanosoma brucei infection by interrogating the skin are therefore needed. Recent advances have improved the cost, sensitivity and portability of Raman spectroscopy technology for non-invasive medical diagnostics, making it an attractive tool for gambiense -HAT detection. The aim of this work was to assess and develop a new non-invasive diagnostic method for T . brucei through Raman spectroscopy of the skin. Infections were performed in an established murine disease model using the animal-infective Trypanosoma brucei brucei subspecies. The skin of infected and matched control mice was scrutinized ex vivo using a confocal Raman microscope with 532 nm excitation and in situ at 785 nm excitation with a portable field-compatible instrument. Spectral evaluation and Principal Component Analysis confirmed discrimination of T . brucei- infected from uninfected tissue, and a characterisation of biochemical changes in lipids and proteins in parasite-infected skin indicated by prominent Raman peak intensities was performed. This study is the first to demonstrate the application of Raman spectroscopy for the detection of T . brucei by targeting the skin of the host. The technique has significant potential to discriminate between infected and non-infected tissue and could represent a unique, non-invasive diagnostic tool in the goal for elimination of gambiense -HAT as well as for Animal African Trypanosomiasis (AAT).