Hidatidosis en la República Argentina: análisis de uno de los principales antígenos que componen el líquido hidatídico de las diferentes cepas de Echinococcus granulosus presentes en nuestro país y su aplicación en el diagnóstico de la hidatidosis humana

KAMENETZKY L.; MUZULIN P.M; GUTIERREZ A.M; ROSENZVIT M.C

Anales de la Fundación Alberto J. Roemmers

Prensa Médica Argentina

Lugar: Buenos Aires; Año: 2006 vol. XVII p. 235 - 249

Echinococcus granulosus, the causative agent of cystic hydatid disease, exists as a number of intra-specific variants that differ in biological characters, such as intermediate host specificity and infectivity to humans. One of the major antigens of the larval stage of the parasite, the heterodimeric antigen B (AgB), is widely used in diagnosis and has been involved in the evasion of host immune response. We used PCR-SSCP followed by sequencing to evaluate the intra-specific variation and expression of genes of the AgB family. Forty two genomic sequences were isolated and clustered in five genes (B1 to 5) by maximum parsimony analysis. Differential distribution and frequency of AgB variants among strains were found. The level of nucleotide and amino acid variation observed is higher than the reported so far for coding genes of other helmynth parasites. Differential expression of AgB variants between protoscoleces of sheep and pig strains was detected by RT-PCR. ELISA assays for anti-Echinococcus granulosus IgG detection showed that two recombinant AgB subunits seem to differ in their respective antigenicities. These assays also showed that cyst hydatid fluid is the antigen displaying the best diagnosis efficiency. This result was corroborated by those obtained by the inter-laboratory study of the South American Network of Hydatid Serology.