MLST approach for the description of genetic diversity of Leishmania spp. in northern Argentina

MARCO JORGE DIEGO; BARROSO PAOLA ; LOCATELLI FABRICIO; CAIMI KARINA; KORENAGA MASATAKA; HASHIGUCHI YOSHIHISA; RUYBAL PAULA

New Orleans

Conferencia; 11th International Conference on Molecular Epidemiology and Evolutionary Genetics of Infectious Diseases; 2012

Leishmaniasis is a vector-borne protozoan infection that includes asymptomatic infection and three main clinical syndromes: cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL) and visceral leishmaniasis (VL). About 21 Leishmania species are known to infect humans and they are transmitted by approximately 30 species of phlebotomine sand flies. According to the National Health Department, in northern Argentina CL is endemic in 9 provinces while VL is spreading from autochthonous transmission foci in 7 provinces. Reference method for the identification and typing of Leishmania is Multilocus Enzyme Electrophoresis (MLEE) which is a time-consuming technique that requires massive cultures of parasites. The application of molecular strategies, particularly Multilocus Sequence Typing (MLST), for the characterization of the parasite diversity represents an improved approach for the description of its variability and population dynamics. Although 4 MLST schemes have been already published, there is a need to include new genes to study the genetic diversity of this parasite. The aim of this study was to perform a first genetic characterization of Argentinean isolates including in the process new candidate genes. Search of gene candidates was performed by genome database website (www.genedb.org) based on genes involved in MLEE typing and metabolic pathways (www.genome.jp/KEGG/pathway.html) and distribution throughout the genome. Seven housekeeping genes were selected as candidates to begin reference strains and Argentinean isolates characterization. Primers were designed in order to amplify Leishmania spp. but to exclude Trypanosoma spp. since both diseases coexist in the country. Phylogenetic relationships were inferred using maximum-likelihood (ML), Kimura-2 parameter, 500 bootstrap replications. In accordance to disease history and wider geographical distribution, L. braziliensis showed higher allele polymorphism than L. infantum. Topological congruence among individual locus dendrograms was obtained and concatenated sequences analysis correlated with species determination and geographical distribution. This study represents the first characterization of genetic variability of Leishmania sp. in Argentina.