H. Bermudez

Karyotype plasticity in Neotropical Leishmania : an index for measuring genomic distance among L. (V.) peruviana and L. (V.) braziliensis populations

A method for phenetic analysis of karyotype data has been developed for Leishmania populations. Measurement of size difference between chromosomes recognized by a given DNA probe in different isolates led to the formulation of a Chromosome Size Difference Index (CSDI). The method was applied to phenetic analysis of 4 sets of chromosomes--each set being recognized by a different probe--in 37 L. (Viannia) peruviana isolates sampled along a North-South transect through the Peruvian Andes and, in 11 L. (V.) braziliensis isolates from the Amazonian forest (Peru, Bolivia and Brazil). Karyotype variability was better accounted for by CSDI than by a method based on disjunctive encoding of karyotype data. CSDI evidenced the nature of relationships between L. braziliensis and L. peruviana and it provided a coherent picture of geographical and genomic differentiation among parasite populations. The latter did cluster according to their geographical origin. L. braziliensis was found karyotypically more homogeneous than L. peruviana. Within L. peruviana, Northern populations were closer to L. braziliensis than to Southern L. peruviana populations. The validity of karyotypic populations, or karyodemes, was sustained.

Leishmaniasis in the Lowlawnds of Bolivia (Leishbol): Part VIII. Characterization and Identification of Bolivian Isolates by PFG Karyotyping

Within the frame of molecular identification of Leishmania species, karyotyping by Pulsed Field Gradient Gel Electrophoresis (PFG) (Schwartz et al., 1983) has been applied (Spithill and Samaras, 1985; Comeau et al., 1986; Garveyand and Santi, 1986; Giannini et al., 1986; Scholler et al., 1986). In this new kind of electrophoresis, the combination of two perpendicular asymetrical electrical fields activated alternatively, induces the resolution of the nuclear genome in chromosome-sized DNA molecules, and makes it possible to obtain a karyotype of the organism being studied.

Leishmaniasis in the Lowlands of Bolivia (Leishbol): Part VII. Preliminary Characterization of Eleven Leishmania Isolates

In the context of the LEISHBOL project in Yapacani in the Lowlands of Bolivia (see Recacoechea et al. (Part 1), in this chapter) a parasitological technique for in vivo isolation was evaluated. Identification of the isolates used exploited biological and molecular characteristics, as well as, parasitological and serological information (eg Recacoechea et al. (Part 3), in this chapter).

Leishmaniasis in the lowlands of Bolivia (LEISHBOL). 1. An overview of the integrated project for the characterization, vigilance and control of leishmaniasis

The republic of Bolivia is located in a central position in South America: it has borders with Brasil, Peru, Chile, Argentina and Paraguay. the country consists of the andean cordillera, of high altitude, in the west, with interandean valleys which, towards the north and east, decrease progressively in altitude to reach the large eastern and subtropical and tropical lowlands that are part of the Amazon region.