Modification of universal 12S rDNA primers for specific amplification of contaminated Taenia spp. (Cestoda) gDNA enabling phylogenetic studies

The construction of new specific tapeworm primers allowed synthesis of a 31 1-bp fragment of the mitochondrial 12S rDNA of 11 Taenia species and two Ec hinococcus species by PCR. After direct sequencing and construction of an a lignment, the DNA sequences were calculated by three different phylogenetic algorithms. The phylogenetic trees were tested by 1000 bootstrap replicati ons. Reliability of the nodes was tested by splits testing. All three algor ithms revealed a clear monophyletic phylum Taenia, suggesting it may be par aphyletic with respect to the genus Echinococcus. Within the genus Taenia, the first secure group was composed by Taenia saginata, T. solium, T. seria lis, T. ovis and T, hydatigena. A delimited second group was formed by T. m artis, T, taeniaeformis, T. mustelae and T. par va. All of them were oppose d to the genus Echinococcus using other cyclophyllideans as an outgroup. In this study Echinococcus was used as an outgroup, being the closest species against which the ingroup could be routed. The findings of this publicatio n reflect Verster's basic morphologically based grouping of the Taeniidae.