A dysflagellar mutant of Leishmania (Viannia) braziliensis isolated from a cutaneous leishmaniasis patient

Parasit Vectors. 2012 Jan 11;5:11. doi: 10.1186/1756-3305-5-11.

Abstract

Background: Parasites of the Leishmania genus alternate between the flagellated extracellular promastigote stage and intracellular amastigotes. Here we report the characterization of a Leishmania isolate, obtained from a cutaneous leishmaniasis patient, which presents peculiar morphological features.

Methods: The parasite was cultured in vitro and characterized morphologically using optical and electron microscopy. Identification was performed based on monoclonal antibodies and internal ribosomal spacer typing. In vitro macrophage cultures, murine experimental models and sand fly infections were used to evaluate infectivity in vitro and in vivo.

Results: The isolate was identified as Leishmania (Viannia) braziliensis. In the atypical promastigotes grown in culture, a short flagellum surrounded or interrupted by a protuberance of disorganized material was observed. A normal axoneme was present close to the basal body but without elongation much further outside the flagellar pocket. A disorganized swelling at the precocious end of the axoneme coincided with the lack of a paraflagellar rod structure. The isolate was able to infect macrophages in vitro, induce lesions in BALB/c mice and infect Lutzomyia longipalpis.

Conclusions: Notwithstanding the lack of an extracellular flagellum, this isolate infects macrophages in vitro and produces lesions when inoculated into mice. Moreover, it is able to colonize phlebotomine sand flies. Considering the importance attributed to the flagellum in the successful infection and survival of Leishmania in the insect midgut and in the invasion of macrophages, these findings may bring new light into the infectious mechanisms of L. (V.) braziliensis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Monoclonal
  • Antiprotozoal Agents / administration & dosage
  • Base Sequence
  • DNA, Protozoan / chemistry
  • DNA, Protozoan / genetics
  • DNA, Ribosomal Spacer / chemistry
  • DNA, Ribosomal Spacer / genetics
  • Female
  • Flagella
  • Humans
  • Leishmania braziliensis / genetics
  • Leishmania braziliensis / isolation & purification*
  • Leishmania braziliensis / ultrastructure
  • Leishmaniasis, Cutaneous / drug therapy
  • Leishmaniasis, Cutaneous / parasitology*
  • Macrophages / parasitology
  • Mice
  • Mice, Inbred BALB C
  • Microscopy, Electron
  • Molecular Sequence Data
  • Mutation
  • Psychodidae / parasitology
  • Sequence Analysis, DNA
  • Treatment Outcome

Substances

  • Antibodies, Monoclonal
  • Antiprotozoal Agents
  • DNA, Protozoan
  • DNA, Ribosomal Spacer

Associated data

  • GENBANK/AJ300483
  • GENBANK/AJ300484