Echinococcus granulosus in Portugal: the first report of the G7 genotype in cattle

Although cystic echinococcosis (CE) has been a recognized public health problem in Portugal, molecular data regarding the types and prevalence of infecting strains of its etiological agent (Echinococcus granulosus) are still scarce. Over the last years we have been evaluating the prevalence of CE in the country, and in this report we determined the parasite genotypes infecting sheep, goats, cattle and human in Portugal, based on 209 hydatid cysts recovered from liver (n=96), lung (n=95), pancreas (n=17) and kidney (n=1) samples obtained between 2008 and 2011. Protoscoleces or germinal layers were collected from individual cysts, DNA was extracted, and a part of the mitochondrial DNA encoding the cytochrome c oxidase subunit 1 was amplified by PCR. Overall, the results confirm the overall dominance of the G1-G3 cluster of strains, which are particularly prevalent in southern Portugal in livestock ruminants. Unexpectedly, one parasite sequence with cattle origin was found to correspond to E. granulosus G7 genotype (also known as E. intermedius), here reported for the first time in bovine, in Portugal.