Caracterização genotípica de Leishmania (Leishmania) infantum proveniente de cães naturalmente infectados com leishmaniose visceral americana no Estado de São Paulo

Abstract

 Even though the importance of visceral leishmaniasis (VL) in Brazil is recognized,    the genetic diversity of Leishmania (Leishmania) infantum is still poorly studied.    Thus, the use of microsatellite analysis becomes an importante tool for the study of    genotypes of Leishmania in endemic regions. The aim of this study was to determine    the genotypic profile of isolates of L. infantum from two regions of São Paulo State    (SP) analyzing hypervariable regions of DNA with dinucleotide microsatellite    markers. This study aims to contribute with information about the possible origins    of the parasites, as well as the introduction and spread of VL in this State. Multilocus    microsatellite typing (MLMT) was performed using a set of 17 microsatellite    markers. DNA was extracted from 250 samples collected from dogs diagnosed with    VL and 112 (45%) were genotyped: 67 from the northwest region (NWSP), and 29    from the southeast region (SESP) of SP. The results were correlated with other 16    samples from Mato Grosso do Sul State (MS) (which borders NWSP). Although, a    small portion of samples was genotyped, it was possible to genotype multiple loci    using small amounts of Leishmania DNA extracted directly from dog tissues. Despite    the fact that MLMT analysis defined 33 different genotypes, a low polymorphism    was detected within the parasites studied with 10 loci being polymorphic. There    are two main populations circulating in SP with strong genetic differentiation, one    (POP-A) is composed by samples from SESP and NWSP. The other, belongs to    the same population found in MS (POP-B), which was the main one population.    The majority (93.75%) of MS parasite genotypes belonged to POP-B, with just one    sample (6.25%) grouped in POP-A. POP-B also comprised 10.34% of SESP and    26.87% of NWSP samples. Besides one sample from MS, POP-A is composed by    73.13% of NWSP and 89.66% of SESP samples. All these data together contributed    to the detection of the genetic profile of L. infantum populations in SP State.