A DNA-PROBE FOR THE DETECTION OF DICROCOELIUM-DENDRITICUM IN ANTS OF FORMICA SPP. AND LASIUS SPP

Repetitive DNA sequences present in the genome of Dicrocoelium dendrit icum were identified by hybridization of genomic DNA that had been dig ested with different restriction enzymes with P-32-labeled genomic D. dendriticum DNA. DNA fragments containing repetitive sequences were is olated from PstI-digested D. dendriticum DNA and were subcloned into a plasmid vector. Plasmids containing repetitive sequences were identif ied by colony hybridization. One of these plasmids, designated Ddr-IV, was isolated and used as a probe in further studies. Ddr-IV is specif ic for D. dendriticum since it does not hybridize to DNA isolated from other trematodes. In addition, Ddr-IV was capable of detecting D. den driticum metacercariae in ants (Formica cunicularia, F. rufibarbis, an d Lasius sp.), which act as second intermediate hosts in the parasite' s life cycle. Since metacercariae constitute the infectious stage of t he parasite for grazing animals, Ddr-IV will provide a useful tool for epidemiology studies of dicrocoeliosis.