Leishmania mexicana

Leishmania mexicana
Leishmania mexicana in a biopsy specimen from a skin lesion stained with H&E. The amastigotes are lining the walls of two vacuoles, a typical arrangement. The species identification was derived from culture followed by isoenzyme analysis.
Scientific classification
Domain:	Eukaryota
Phylum:	Euglenozoa
Class:	Kinetoplastea
Order:	Trypanosomatida
Genus:	Leishmania
Species:	L. mexicana
Binomial name
Leishmania mexicana Biagi, 1953, emend. Garnham, 1962

False colour SEM micrograph of Promastigote form Leishmania mexicana as found in the sandfly midgut. The cell body is shown in orange and the flagellum is in red. 119 pixels/μm.

Amastigote form Leishmania mexicana as found in mammalian macrophages, 219 pixels/μm.

Leishmania mexicana is a species of obligate intracellular parasites of the protozoan genus Leishmania. In Mexico and Central America, this parasite is the primary cause of cutaneous leishmaniasis.^[1]

Infected sandflies carry L. mexicana in its promastigote form, transmitting it from their salivary glands through their proboscis into the bloodstream of the host. When macrophages phagocytize the parasite, it transitions into its amastigote form, rapidly dividing to break the host cell open and infect other mononuclear phagocytic cells. When uninfected sandflies ingest the blood of an infected animal, they acquire L. mexicana, which returns to the promastigote form to efficiently survive in the insect's midgut.^[2]

Leishmania mexicana can induce the cutaneous and diffuse cutaneous clinical manifestations in humans and certain other mammalian hosts. The cutaneous type develops an ulcer at the bite site, here the amastigotes do not spread and the ulcers become visible either a few days or several months after the initial bite. The diffuse cutaneous type begins when the amastigote diffuses through the skin and metastasize to other tissue. This type does not produce ulcers and there is no treatment.

Treatment of Leishmaniasis caused by L. mexicana consists of pentavalent antimonials as Pentostam or Glucantime injected direct into the ulcer or Intramuscular.

Prevention of L. mexicana infection is principally avoiding the bite of the infected sandfly.

References

1. Majumdar D, Elsayed GA, Buskas T, Boons GJ (March 2005). "Synthesis of proteophosphoglycans of Leishmania major and Leishmania mexicana". J. Org. Chem. 70 (5): 1691–7. doi:10.1021/jo048443z. PMID 15730289.
2. "Leishmaniasis". Centers for Disease Control and Prevention. 14 December 2017. Retrieved 30 October 2023.

• Vinetz JM, Soong L (February 2007). "Leishmania mexicana infection of the eyelid in a traveler to Belize". Braz J Infect Dis. 11 (1): 149–52. doi:10.1590/s1413-86702007000100030. PMID 17625744.
• Robertson CD, Coombs GH (February 1994). "Multiple high activity cysteine proteases of Leishmania mexicana are encoded by the Imcpb gene array". Microbiology. 140 (Pt 2): 417–24. doi:10.1099/13500872-140-2-417. PMID 8180705.
• Ilg T, Etges R, Overath P, et al. (April 1992). "Structure of Leishmania mexicana lipophosphoglycan". J. Biol. Chem. 267 (10): 6834–40. doi:10.1016/S0021-9258(19)50502-6. PMID 1551890.
• Galindo-Sevilla N, Ortiz-Avalos J, Del Angel M, Galvan R, Mancilla-Ramirez J (2003). "Leishmania mexicana Strains Isolated from Both Localized Cutaneous (LCL) and Diffuse Cutaneous (DCL) Lesions in Humans Can Produce DCL in Mice, Being Faster in Males". ASM's Annual Meeting on Infectious Diseases: 43rd annual ICAAC Chicago 2003 : 43rd Interscience Conference on Antimicrobial Agents and Chemotherapy. American Society for Microbiology. ISBN 978-1-55581-284-3.
• Pearson RD, Sousa AQ (1996). "Clinical spectrum of Leishmaniasis". Clin Infect Dis. 22: 1–13. doi:10.1093/clinids/22.1.1. PMID 8824958.
• Sacks D, Noben-Trauth N (2002). "The immunology of susceptibility and resistance to Leishmania major in mice". Nat Rev Immunol. 2 (11): 845–58. doi:10.1038/nri933. PMID 12415308.