Differences in biological characteristics of three Leishmania isolates from patients with espundia

Two recent Leishmania isolates from nasal lesions involving the mucosa, one from an autochthonous case from Texas and one from a case from eastern Peru, were compared with a reference strain of Leishmania braziliensis from Brazil for the biological characteristics which distinguish the L. braziliensis complex from L. mexicana. The characteristics of in vitro growth, pathogenesis in the hamster, and position of the promastigotes in the gut of vector sandflies were determined and compared with the reference strain from Brazil. In spite of the nasal involvement which resembled the clinical picture considered characteristic of L. braziliensis infection, the Texas isolate was clearly L. mexicana. It is considered that the atypical clinical feature was the result of the patient's altered immune state due to neoplastic disease and subsequent radiation therapy. The Peru isolate constitutes the first example of a "fast growing" strain isolated directly from a patient with espundia, but otherwise it demonstrated the characteristics of Leishmania braziliensis.