DETECTION OF BORRELIA-BURGDORFERI SENSU-LATO BY PCR IN QUESTING IXODES-RICINUS LARVAE FROM THE DUTCH NORTH-SEA ISLAND OF AMELAND

In May 1995, 61 Ixodes ricinus larvae were collected from vegetation o n the Dutch North Sea island of Ameland. Fifty-seven lysates (94%) wer e analysed for the presence of Borrelia DNA by the polymerase chain re action (PCR), which amplified the intergenic spacer region between the 5S and 23S rRNA genes. Three samples (5%) were positive and hybridiza tion of the PCR product to genomic group-specific probes revealed that two larvae were infected with Borrelia afzelii and group VS 116, resp ectively and one larval tick carried a mixed infection of B. afzelii a nd Borrelia garinii. Previously, we showed that these three genomic gr oups were present in adult and nymphal ticks collected on Ameland. Tra nsovarial transmission may be an important factor in the establishment of these genomic groups in the local tick population.