RT Journal Article T1 Leishmaniasis in the major endemic region of Plurinational State of Bolivia: Species identification, phylogeography and drug susceptibility implications A1 Bilbao Ramos, Pablo Estanislao A1 Dea Ayuela, María Auxiliadora A1 Cardenas Alegría, Óscar A1 Salamanca, Efraín A1 Santalla Vargas, José Antonio A1 Benito Jimenez, César A1 Flores, Ninoska A1 Bolas Fernández, Francisco AB The Plurinational State of Bolivia is one of the Latin American countries with the highest prevalence of leishmaniasis, highlighting the lowlands of the Department of La Paz where about 50% of the total cases were reported. The control of the disease can be seriously compromised by the intrinsic variability of the circulating species that may limit the efficacy of treatment while favoring the emergence of resistance. Fifty-five isolates of Leishmania from cutaneous and mucocutaneous lesions from patients living in different provinces of the Department of La Paz were tested. Molecular characterization of isolates was carried out by 3 classical markers: the rRNA internal transcribed spacer 1 (ITS-1), the heat shock protein 70 (HSP70) and the mitochondrial cytochrome b (Cyt-b). These markers were amplified by PCR and their products digested by the restriction endonuclease enzymes AseI and HaeIII followed by subsequent sequencing of Cyt-b gene and ITS-1 region for subsequent phylogenetic analysis. The combined use of these 3 markers allowed us to assign 36 isolates (65.5%) to the complex Leishmania (Viannia) braziliensis, 4 isolates (7, 27%) to L. (Viannia) lainsoni. and the remaining 15 isolates (23.7%) to a local variant of L. (Leishmania) mexicana. Concerning in vitro drug susceptibility the amastigotes from all isolates where highly sensitive to Fungizone® (mean IC50between 0.23 and 0.5 μg/mL) whereas against Glucantime® the sensitivity was moderate (mean IC50 ranging from 50.84 μg/mL for L. (V.) braziliensis to 18.23 μg/mL for L. (L.) mexicana. L. (V.) lainsoni was not sensitive to Glucantime®. The susceptibility to miltefosine was highly variable among species isolates, being L. (L.) mexicana the most sensitive, followed by L. (V.) braziliensis and L. (V.) lainsoni (mean IC50 of 8.24 μg/mL, 17.85 μg/mL and 23.28 μg/mL, respectively). PB Elsevier SN 0001-706X YR 2017 FD 2017 LK https://hdl.handle.net/20.500.14352/18446 UL https://hdl.handle.net/20.500.14352/18446 LA eng NO Bilbao Ramos, P. E., Dea Ayuela, M. A., Cardenas Alegría, Ó. et al. «Leishmaniasis in the Major Endemic Region of Plurinational State of Bolivia: Species Identification, Phylogeography and Drug Susceptibility Implications». Acta Tropica, vol. 176, diciembre de 2017, pp. 150-61. DOI.org (Crossref), https://doi.org/10.1016/j.actatropica.2017.07.026. NO Agencia Española de Cooperación Internacional para el Desarrollo DS Docta Complutense RD 17 may 2025