Leishmania braziliensis: Dissemination of panamanian strains in golden hamsters

Abstract

Dissemination of Panamanian strains of Leishmania braziliensis was observed in experimentally infected golden hamsters, Mesocricetus auratus, during the characterization of 164 strains isolated from patients (67), two species of edentates (88), and dogs (9). A total of 614 hamsters was employed in these studies. Hamsters were inoculated intradermally in the nose with 5–10 × 10 6 promastigotes from cultures of strains in their first to third passage in vitro. Parasites were recovered by culture from skin samples, viscera, blood and bone marrow. All strains studied disseminated to various areas of the skin and to the ear pinnae. Highest incidence of dissemination occurred in the skin from the tip of the tail, feet, and ears. Positive cultures obtained from liver and spleen were not considered as evidence for metastasis since they may have been due to the transitory presence in the blood of rare parasitized macrophages. Dissemination of various areas of the body was directly proportional to the length of the postinoculation period of the sloth strains.