'In vitro' drug susceptibility of a 'Leishmania' (Leishmania) infantum' isolate from a visceral leishmaniasis pediatric patient after multiple relapses

• Published in: Tropical medicine and infectious disease Vol. 8; no. 7; pp. 1 - 9
• Main Authors: Ferreira, Bianca A., Santos, Gustavo de A., Coser, Elizabeth M., Sousa, Juliana M., Gama, Mônica E. A., Júnior, Leônidas L. B., Pessoa, Fabrício S., Lima, Mayara I. S., Uliana, Silvia R. B., Coelho, Adriano C.
• Format: Journal Article
• Language: English
• Published: Basel, Switzerland MDPI 04.07.2023; MDPI AG
• Subjects: Bone marrow; Brief Report; Control; Diseases; drug susceptibility; Drugs; HIV; Human immunodeficiency virus; Immunological aspects; Infection; Leishmania; Leishmania (Leishmania) infantum; Parasites; Parasitic diseases; Patients; Pediatrics; Penicillin; Risk factors; visceral leishmaniasis; Brazil; visceral leishmaniasis; Leishmania (Leishmania) infantum; drug susceptibility
• ISSN: 2414-6366; 2414-6366
• DOI: 10.3390/tropicalmed8070354

The parasitic protozoan 'Leishmania (Leishmania) infantum' is the etiological agent of human visceral leishmaniasis in South America, an infectious disease associated with malnutrition, anemia, and hepatosplenomegaly. In Brazil alone, around 2700 cases are reported each year. Treatment failure can occur as a result of drug, host, and/or parasite-related factors. Here, we isolated a 'Leishmania' species from a pediatric patient with visceral leishmaniasis that did not respond to chemotherapy, experiencing a total of nine therapeutic relapses and undergoing a splenectomy. The parasite was confirmed as 'L. (L.) infantum' after sequencing of the ribosomal DNA internal transcribed spacer, and the clinical isolate, in both promastigote and amastigote forms, was submitted to 'in vitro' susceptibility assays with all the drugs currently used in the chemotherapy of leishmaniasis. The isolate was susceptible to meglumine antimoniate, amphotericin B, pentamidine, miltefosine, and paromomycin, similarly to another strain of this species that had previously been characterized. These findings indicate that the multiples relapses observed in this pediatric patient were not due to a decrease in the drug susceptibility of this isolate; therefore, immunophysiological aspects of the patient should be further investigated to understand the basis of treatment failure in this case.