Usefulness of Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry in the Characterization of Leishmania Strains Causing Tegumentary Leishmaniasis in Bolivia versus hsp70 Gene Sequencing

Abstract

Matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) is a proteomic technique with proven efficiency in the identification of microorganisms, such as bacteria, fungi, and parasites. The present study aimed to evaluate the usefulness of MALDI-TOF MS for the characterization of Leishmania species circulating in Bolivia using hsp70 gene sequencing as a reference technique. 55 Leishmania strains that were isolated from patients with tegumentary leishmaniasis were analyzed. MALDI-TOF MS identified two species of the L. braziliensis complex (L. braziliensis, n = 26; L. braziliensis outlier, n = 18), one species of the L. guyanensis complex (L. guyanensis, n = 1), one species of the L. lainsoni complex (L. lainsoni, n = 2), and two species of the L. mexicana complex (L. amazonensis, n = 5; and L. garnhami, n = 3). All of the strains were correctly identified at the subgenus, genus, and complex level, but 10 of them (18%) were misidentified as other species within the same complex by the hsp70 gene sequencing, with 7 of these corresponding to possible hybrids. Thus, one L. braziliensis corresponded to L. peruviana, two L. braziliensis corresponded to L. braziliensis/L. peruviana possible hybrids, two L. amazonensis corresponded to L. mexicana, and three L. garnhami and two L. amazonensis corresponded to L. mexicana/L. amazonensis possible hybrids. Accordingly, MALDI-TOF MS could be used as an alternative to molecular techniques for the identification of Leishmania spp., as it is low cost, simple to apply, and able to quickly produce results. In Bolivia, its application would allow for the improvement of the management of patient follow-ups, the updating of the epidemiological data of the Leishmania species, and a contribution to the control of tegumentary leishmaniasis

The work carried out in Bolivia was supported by AECID (14-CO1-558). The participating UB and ISGlobal investigators are part of the GREPIMER group (Grup de Recerca en Patología Importada i Malaties Emergents i Re-emergents), which received support from the Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR, 2017 SGR 924). ISGlobal research was supported by the Tropical Disease Cooperative Research Network (RICET) (RD12/0018/0010) and by the Consorcio Centro de Investigación Biomédica en Red (CIBER) (CB 2021), Instituto de Salud Carlos III, Ministerio de Ciencia e Innovación and Unión Europea – NextGenerationEU. We acknowledge support from the Spanish Ministry of Science and Innovation and State Research Agency through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program