Acta Tropica 91 (2004) 87–93 Genetic identification and host range of the Spanish strains of Echinococcus granulosus K. Daniel Mwambete, F. Ponce-Gordo ∗ , C. Cuesta-Bandera Departamento de Parasitolog´ ıa, Facultad de Farmacia, Universidad Complutense de Madrid. Plaza Ramón y Cajal s/n. 28040 Madrid, Spain Received 3 September 2003; received in revised form 13 April 2004; accepted 14 April 2004 Available online 1 June 2004 Abstract Three strains of Echinococcus granulosus have been previously identified in Spain (namely ‘sheep’, ‘horse’ and ‘pig’), but these Spanish strains have not been properly genotyped yet. The aim of the present research was to identify the genotype to which they correspond to. Cyst isolates were obtained from different host species, and the strain to which each belonged was established by analysis of its random amplified polymorphic DNA (RAPD) banding patterns. These results were compared to those obtained with the analysis of two mitochondrial fragment sequences (cytochrome oxidase 1 (CO1) and NADH dehydrogenase 1 (ND1)) from each isolate. The Spanish ‘sheep’ strain corresponded with the genotype 1 (G1) of the parasite, infecting Spanish sheep, cattle, goat, pig, wild boar and human; the Spanish ‘horse’ strain corresponded with the genotype 4 (G4), only infecting Spanish horses; and the Spanish ‘pig’ strain corresponded with the genotype 7 (G7), infecting Spanish goat, pig and wild boar. Goat, pig and wild boar can be infected by two genotypes, G1 and G7. This circumstance, and especially the possibility of sylvatic intermediate hosts serving as reservoirs of the G1 genotype of the parasite, must be taken into consideration by authorities in order to develop and evaluate effective anti-hydatidosis programmes. © 2004 Elsevier B.V. All rights reserved. Keywords: Echinococcus granulosus; DNA analysis; Strain; Genotype; Host range; Spain 1. Introduction Echinococcus granulosus is one of the smallest tapeworms of the Taeniidae. The adult stage infects dogs and wolves, while the larval stage (hydatid cyst) develops in several species of wild and domesticated mammals and in humans, causing hydatidosis, a ∗ Corresponding author. Tel.: +34-1-394-1817; fax: +34-1-394-1815. E-mail address: pponce@farm.ucm.es (F. Ponce-Gordo). zoonosis of great veterinary and medical importance. This organism shows a great intraspecific variation in relation to host specificity, epidemiology, morphol- ogy, developmental biology, biochemistry, physiol- ogy, biochemistry and genetics (revised by Thompson and Lymbery, 1988). This variability led to the iden- tification of subspecific variants or strains, and some authors have proposed a revision of the taxonomy of the genus Echinococcus (Thompson et al., 1995; Thompson, 2002). Actually, the subspecific variants are identified as 10 different genotypes of the parasite 0001-706X/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.actatropica.2004.04.001