57
J. Parasitol., 89(1), 2003, pp. 57–61
q American Society of Parasitologists 2003
CHARACTERIZATION OF CARBOHYDRATES OF ADULT ECHINOCOCCUS GRANULOSUS
BY LECTIN-BINDING ANALYSIS
Cecilia Casaravilla, Ramiro Malgor, and Carlos Carmona*
Unidad de Biologı́a Parasitaria, Instituto de Higiene, Av. Alfredo Navarro 3051, CP 11600, Montevideo, Uruguay. e-mail: ccarmona@higiene.edu.uy
ABSTRACT: The identification of lectin-binding structures in adult worms of Echinococcus granulosus was carried out by lectin
fluorescence; the distribution of carbohydrates in parasite glycoconjugates was also studied by lectin blotting. The lectins with
the most ample recognition pattern were ConA, WGA, and PNA. ConA showed widespread reactivity in tegument and paren-
chyma components, including the reproductive system, suggesting that mannose is a highly expressed component of the adult
glycans. Although reproductive structures appeared to be rich in N-acetyl-D-glucosamine (GlcNAc)–N-acetyl neuraminic acid
(NeuAc) and galactose (Gal) as demonstrated by their strong reactivity with WGA and PNA, respectively, some differences were
observed in their labeling patterns. This was very clear in the case of the vagina, which only reacted with WGA. Furthermore,
WGA and ConA both had reactivity with the excretory canals. RCA, the other Gal binding lectin used, only reacted with the
tegument, suggesting that widespread PNA reactivity with the reproductive system is related to the presence of the D-Gal-b-(1,3)-
D-GalNAc terminal structure. UEA I failed to bind to any parasite tissues as determined by lectin fluorescence, whereas DBA
and SBA showed a very faint staining of the tegument. However, in transferred glycans, N-acetyl-D-galactosamine (GalNAc) and
fucose (Fuc) containing glycoproteins were distinctly detected.
Echinococcus granulosus is the causative agent of one of the
most important zoonoses distributed throughout the world
(Rausch, 1995). The domestic life cycle is maintained through
dogs as definitive host and domestic ungulates as interme