Bacterial PCR-DGGE on 18 individual ticks from three different habitats in the Netherlands. M, marker; E, Ede deSysselt; V, Veldhoven Hoogeind; A, Amsterdam water supply dunes. A specific band co-migrating with Candidatus Neoehrlichia mikurensis is marked with (*) and a band co-migrating with Rickettsia australis with (**).