BEATO, Sílvia Filipa Alves [et al.] (2010) - Apparent dominance of the G1-G3 genetic cluster of echinococcus granulosus strains in the central inland region of Portugal. Parasitology Internacional. ISSN 1383-5769. Vol. 59, nº 4. p. 638-642
1383-5769
Title
Apparent dominance of the G1-G3 genetic cluster of echinococcus granulosus strains in the central inland region of Portugal
Subject
Echinococcus granulosus Hydatic cyst G1-G3 genotypes Portugal Mitochondrial DNA
Infection by the larval stage of the cestode Echinococcus granulosus causes a disease
known as cystic echinococcosis or hydatidosis, which is one of the most widespread
zoonotic infections of veterinary and medical importance. Numerous studies have
shown that E. granulosus exists as a complex of strains differing in a wide variety of
criteria. Ten distinct genotypes (G1-G10) have been identified with potential impact on
the pathology, epidemiology and the effect of the measures implemented for the control
of hydatidosis. Our main objective was to carry out a preliminary analysis of the
genotypes of E. granulosus circulating in the central inland region of Portugal.
Parasite samples (hydatid cysts, n=27) were isolated from the liver and lung of sheep
and cattle. The DNA extracted from protoscoleces isolated from the fertile cysts served
a template for the PCR amplification of part of the mitochondrial cytochrome c oxidase
subunit 1 (cox1), ATP synthase F0 subunit 6 (atp6) as well as the large (rrnL/16S) and
small (rrnS/12S) ribosomal RNA genes. Similarity searches with homologous
sequences in the databanks indicated very high similarity with references assigned to the
G1, G3 and/or G1-G3 complex of Echinococcus strains. Phylogenetic analysis
(Bayesian approach) supported these observations, and confirmed the assignment of all
the analyzed sequences to the G1-G3 genetic cluster.
