Infection rates of Borrelia burgdorferi in different instars of Ixodes ricinus ticks from the Dutch North Sea Island of Ameland.
Between 1988 and 1993, a total of 7173 I. ricinus ticks, predominantly, were collected from the vegetation on the Dutch North Sea Island of Ameland. A proportion of the ticks (n = 547) was screened for the presence of Borrelia by immunofluorescence. Infection rates of Borrelia varied, in nymphs (n = 347) from 13% to 46% and in adults, (n = 122) from 20% to 43%. The infection rate in larvae (n = 84) collected in 1993 was 21%, showing that transovarial transmission of B. burgdorferi occurs in the I. ricinus population on Ameland. Two tick-naive sheep seroconverted for B. burgdorferi after field-collected adult or nymphal I. ricinus were allowed to feed on them. Larval progeny (n = 168) of 15 female adult ticks fed on one of these sheep were free from B. burgdorferi. B. burgdorferi was isolated in culture from field-collected adult ticks. Serotyping using monoclonal antibodies against outer surface proteins A and C indicated that both isolated belonged to genospecies B. garinii, and this was confirmed by DraI restriction analysis of the variable DNA sequence between the 5S and 23S rRNA genes.
Rijpkema
S
S
Laboratory of Bacteriology and Antimicrobial Agents, National Institute of Public Health and Environmental Protection, Bilthoven, The Netherlands.
Nieuwenhuijs
J
J
Franssen
F F
FF
Jongejan
F
F
D000818:Animals; D015748:Borrelia burgdorferi Group / Q000302:isolation & purification*; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D008193:Lyme Disease / Q000635:transmission / Q000662:veterinary; D009426:Netherlands; D012756:Sheep; D012757:Sheep Diseases / Q000382:microbiology / Q000469:parasitology / Q000635:transmission; D013987:Ticks / Q000382:microbiology*
D004269:DNA, Bacterial