Epidemiologic, genetic, and clinical associations among phenotypically distinct populations of Leishmania (Viannia) in Colombia.

Abstract

Phenotypic characterization of 511 strains of Leishmania, subgenus Viannia, isolated from Colombian patients was conducted based on electrophoretic polymorphisms of 13 isoenzymes. Ninety-one Colombian strains of L. braziliensis were the most heterogeneous, constituting seven zymodemes while 397 L. panamensis and 22 L. guyanensis strains yielded five and three zymodemes, respectively. Phosphogluconate dehydrogenase, nucleoside hydrolase, and superoxide dismutase were the most polymorphic enzymes in this collection of strains, and together with glucose-6-phosphate dehydrogenase, allowed the discrimination of the three aforementioned species. Hierarchical cluster analysis of the zymodemes using Jaccard's coefficient of similarities revealed two clusters, one constituted by L. braziliensis zymodemes, and another by three subgroups consisting of zymodemes of L. panamensis closely related to the species reference strain, another consisting of L. guyanensis zymodemes, and a third group distinguished by new electromorphs of proline iminopeptidase and aspartate aminotransferase that reacted with the L. panamensisspecific monoclonal antibody B-11. Multiple zymodemes of L. panamensis and L. guyanensis were found to be sympatrically transmitted in foci along the Pacific coast. Leishmania braziliensis variants were ubiquitous throughout the territory of Colombia; L. panamensis was prevalent in the western region and L. guyansis was prevalent in the Orinoco and Amazon river basins in the eastern half of the country. Distinct zymodemes of L. panamensis predominated in the northern and southern regions of the Pacific coast. Nine zymodemes of all three species were isolated from mucosal lesions. Zymodeme 1.1 of L. braziliensis had the highest frequency of mucosal involvement (10% of the cases), and disease caused by this zymodeme had the longest mean time of evolution (31 months; P ϭ 0.002). In addition to being useful in describing epidemiologic relationships, the intraspecific heterogeneity of strains of the Viannia subgenus within and among foci can be used to understand such fundamental questions as the pathogenicity of different populations of parasites, and the induction of cross-protection against related parasites.

Ecology of the Leishmania Species in the Guianan Ecoregion Complex

“…However, isolates from different polymorphic species show plesiomorphic similarities in their enzymatic or genetic profiles, suggesting that they may have originated from one primary sylvatic enzootic form. 80,81 Globally, although L. (V.) braziliensis [82][83][84][85][86][87][88][89][90] and in a lesser extent L. (V.) amazonensis 85,91 were shown to be highly polymorphic, L. (V.) naiffi, 45,82,83 L. (V.) guyanensis, 46,83,88 and L. (L.) deanei 92 were shown to have less diversity. Leishmania (V.) lainsoni was shown to be more invariant.…”

Clinical and Epidemiologic Profile of Cutaneous Leishmaniasis in Colombian Children: Considerations for Local Treatment

“…15,16 Criteria for local therapies. A retrospective clinical assessment was conducted to determine the proportion and epidemiologic characteristics of children meeting WHO and PAHO criteria for management with local treatment using thermotherapy or intralesional injections of pentavalent antimonials.…”

Genetic risk factors for human susceptibility to infections of relevance in dermatology

“…Coupled with the observations from Saravia et al mentioned above, these findings indicate a major role for the intra-species variability among these microorganisms with regard to form of the disease, paralleling the strong relationship between species of Leishmania and form of leishmaniasis. 45,58,59 In the most recent report, a geographic clustering of ATL forms was found in the same Brazilian region. 61 It was remarkable that the distributions of ML and DL overlapped those of the clones of the parasite that were associated with these diseases in that previous study, indicating that the L. brazilliensis genetic content may also influence other complex phenotypes like geographic distribution of form of leishmaniasis within an affected region.…”

“…However, two Colombian reports by Saravia et al were very insightful in this respect. 58,59 In both studies, the authors described an increased frequency of mucosal involvement among human cases caused by particular L. braziliensis zymodemes or strains. Furthermore, the disease evolution in those infected with parasites of the "mucosal-prone" L. braziliensis zymodeme was statistically longer (p=0.002) than that caused by other strains.…”