Leishmania parasites exchange drug-resistance genes through extracellular vesicles

Leishmania are ancient eukaryotes that have retained the ability to produce extracellular vesicles (EVs) through evolution. Until date, it was unclear if different DNA entities could be associated to Leishmania EVs, and whether these could constitute a novel mechanism of horizontal gene transfer (HGT). Herein, we investigated the DNA content of EVs derived from drug-resistant parasites, as well as the potential of EVs as shuttles for DNA transfer. Next-generation sequencing, and PCR assays confirmed the enrichment of amplicons carrying drug-resistance genes associated to EVs. Transfer assays of drug-resistant EVs highlighted a significant impact in the phenotype of recipient parasites induced by the expression of the transferred DNA. Recipient parasites displayed an enhanced growth and better control of oxidative stress. We provide the first evidence that eukaryotic EVs function as efficient mediators in HGT, thereby facilitating the transmission of drug-resistance genes and increasing the fitness of cells when encountering stressful environments. Overall design: Extracellular vesicles (EVs) were isolated from the wild type (WT) and the antimony (Sb) resistant Leishmania infantum and their DNA content was analyzed using DNA sequencing (Illumina NovaSeq 6000).