title: Evaluation of Genetic Polymorphism of Leishmania (V.) braziliensis Isolates Obtained from the Same Patient before and after Therapeutic Failure or Reactivation of Cutaneous Lesions.
abstract: The aim of this study was to investigate genetic polymorphism in Leishmania braziliensis population previously typed through isoenzyme electrophoresis, isolated from the same patient in two different moments: (A) before the beginning of treatment and (B) after treatment failure to meglumine antimoniate or reactivation after successful initial treatment. Fifteen pairs of isolates were assessed using the polymorphic molecular marker LSSP-PCR and following the phenetic analysis. The genetic profiles of the 30 samples were grouped in four clusters. Only two patients presented total identity in the A and B isolates. Most isolates presented similarity coefficients varying from 0.63 to 0.91. In this group of patients genetic polymorphisms could be observed indicating low similarity between the pairs of isolates. The results demonstrate the existence of genetic polymorphism between the samples isolated before treatment and after reactivation or treatment failure, suggesting a possible differentiation of the structure of the original parasite population which could be involved in the mechanisms of resistance to treatment or reactivation of lesions in the ATL. This phenomenon is important, although other factors also could be involved in this context and are discussed in this paper.
authors.affiliation: Laboratório de Vigilância em Leishmanioses, Instituto de Pesquisa Clínica Evandro Chagas, Fundação Oswaldo Cruz, Avenida Brasil 4365, 21040-900 Rio de Janeiro, RJ, Brazil.
authors.forename: Cibele
authors.initials: C
authors.lastname: Baptista
authors.forename: Armando de Oliveira
authors.initials: Ade O
authors.lastname: Schubach
authors.forename: Maria de Fatima
authors.initials: Mde F
authors.lastname: Madeira
authors.forename: Luciana
authors.initials: L
authors.lastname: de Freitas Campos Miranda
authors.forename: Andressa
authors.initials: A
authors.lastname: Guimarães de Souza Pinto
authors.forename: Juliana
authors.initials: J
authors.lastname: Helena da Silva Barros
authors.forename: Fatima
authors.initials: F
authors.lastname: Conceição-Silva
authors.forename: Maria Ines
authors.initials: MI
authors.lastname: Fernandes Pimentel
authors.forename: Raquel
authors.initials: R
authors.lastname: da Silva Pacheco