a1 Unidade de Parasitologia Médica, Instituto de Higiene e Medicina Tropical (IHMT), Universidade Nova de Lisboa, Rua da Junqueira, 100, 1346-008 Lisboa, Portugal
a2 Centro de Malária e Outras Doenças Tropicais (CMDT)/IHMT, Lisboa, Portugal
a3 Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine (LSHTM), Keppel Street, London WCIE 7HT, UK
Leishmania (Viannia) braziliensis is the main cause of highly disfiguring mucocutaneous leishmaniasis (MCL) in South America. The related species L. (V.) peruviana has only been identified in simple cutaneous lesions (CL). Hybrids between L. braziliensis and L. peruviana have been reported although genetic exchange in Leishmania is considered to be rare. Here we compared growth in vitro, adaptive capacity under thermal and oxidative stress and behaviour in a hamster model, of L. braziliensis, L. peruviana, and their putative hybrids. At 24°C, the optimal temperature for in vitro growth, L. braziliensis had the highest growth rate. In in vitro studies hybrid clones presented heterogeneous phenotypes, from slower growth rates, similar to L. peruviana, to higher growth rates, as observed in L. braziliensis. Hamsters infected with hybrid strains, presented the highest parasite densities and aggressive relapses at a later stage of infection. Hybrids generally presented higher plasticity and phenotypic diversity than the putative parental species, with potential eco-epidemiological implications, including an impact on the success of disease control.
(Received June 20 2011)
(Revised September 23 2011)
(Accepted September 27 2011)
(Online publication November 07 2011)
c1 Corresponding author: Unidade de Parasitologia Médica, Instituto de Higiene e Medicina Tropical, Universidade Nova de Lisboa, Rua da Junqueira, 100, 1346-008 Lisboa, Portugal. Tel: +351 213652600. Fax: +351 213632105. E-mail: firstname.lastname@example.org
p1 Current address: Unidade de Parasitologia Médica, Instituto de Higiene e Medicina Tropical (IHMT)/Unidade de Parasitologia e Microbiologia Médica, Universidade Nova de Lisboa, Portugal.