Leishmania braziliensis: isolation of carbohydrate-containing antigen and possibility of its use in the immunodiagnosis of American cutaneous leishmaniasis.
Leishmania braziliensis is a causative agent of American Cutaneous Leishmaniasis (ACL). The 034-JCG strain, isolated from a patient from the northern region of Paraná State, Brazil, was cultivated in Blood Agar Base medium, lyophilized and submitted to phenol-water extraction. The extract was treated with RNase I. The carbohydrate containing-antigen (Ag-CHO) was immunogenic to rabbits and showed at least a fraction with some negative charge at pH 8.2. This antigen showed cross-reactivity with the phenol-water extract of the growth medium used for the culture of promastigotes and with the surface antigens of promastigotes. Its composition is: 24.3% of total sugars, from which 11.2% of galactose, 7.5% of mannose and 5.6% of ribose. Protein content was 5.4% and phosphate 18.5%. The antigenic activity was maintained after: repeated freezing-thawing; lyophilization; heating at 100 degrees C for 30 minutes; treatment with RNase, trichloroacetic acid and sodium metaperiodate. The precipitin line obtained is Periodic Acid Schiff positive. The application of the Ag-CHO in counterimmunoelectrophoresis reaction for the immunodiagnosis of ACL showed 60% sensitivity, and no cross-reaction with the five sera of Chagas' disease patients tested. The use of this antigen in a more sensitive technique, with more samples of sera, may improve these results.
Departamento de Análises Clínicas, Universidade Estadual de Maringá, Brasil.
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Silveira
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Kemmelmeier
D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000302:isolation & purification; D001938:Brazil; D002241:Carbohydrates / Q000032:analysis; D003124:Colorimetry / Q000379:methods; D000939:Epitopes; D005455:Fluorescent Antibody Technique; D005779:Immunodiffusion; D007892:Leishmania braziliensis / Q000276:immunology / Q000302:isolation & purification*; D016773:Leishmaniasis, Cutaneous / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D011817:Rabbits
D000953:Antigens, Protozoan; D002241:Carbohydrates; D000939:Epitopes