In vitro infectivity of species of Leishmania (Viannia) responsible for American cutaneous leishmaniasis.
There is little available information regarding the infectivity of New World Leishmania species, particularly those from the Amazonian Brazil, where there are six species of the subgenus Viannia causing American cutaneous leishmaniasis (ACL). The aim of this study was to compare, in vitro, the potential infectivity of the following Leishmania (Viannia) spp.: L. (V.) braziliensis from localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL) patients, L. (V.) guyanensis, L. (V.) shawi, L. (V.) lainsoni and L. (V.) naiffi from LCL patients only, in cultured BALB/c mice peritoneal macrophage, as well as the production of NO by the infected cells. The infectivity of parasites was expressed by the infection index and, the nitric oxide (NO) production in the macrophage culture supernatant was measured by the Griess method. It was found that L. (V.) braziliensis from MCL, the more severe form of disease, showed the highest (p<or=0.05) infection index (397), as well as the lowest NO production (2.15 microM) compared with those of other species. In contrast, L. (V.) naiffi which is less pathogenic for the human showed the lowest infection index (301) and the highest NO production (4.11 microM). These results demonstrated a negative correlation between the infectivity and the ability of these parasites to escape from the microbicidal activity of the host cell.
Evandro Chagas Institute (Surveillance Secretary of Health, Ministry of Health), Belém, Pará State, Brazil. marlianecampos@iec.pa.gov.br
Marliane Batista
MB
Campos
Cláudia Maria
CM
De Castro Gomes
Adelson Alcimar Almeida
AA
de Souza
Ralph
R
Lainson
Carlos Eduardo Pereira
CE
Corbett
Fernando Tobias
FT
Silveira
D000818:Animals; D002478:Cells, Cultured; D003470:Culture Media / Q000737:chemistry; D005260:Female; D006801:Humans; D007891:Leishmania / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity*; D016773:Leishmaniasis, Cutaneous / Q000276:immunology / Q000469:parasitology*; D017737:Macrophages, Peritoneal / Q000276:immunology* / Q000469:parasitology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009569:Nitric Oxide / Q000096:biosynthesis
D003470:Culture Media; D009569:Nitric Oxide