Moleculaire detectie van teken-gebonden zoönosen in Ixodes hexagonus teken afkomstig van katten in Nederland
Summary
Ticks are vectors of a great diversity of pathogens, which can be of both veterinary
and human medical interest. Besides the emerging of the number of vector-borne
diseases in humans, the frequency of the number of vector-borne diseases in
companion animals in Europe is also rising. This study has tried to map out the
prevalence of a number of tick-borne zoonoses in I. hexagonus ticks originating
from cats in the Netherlands.
Since the way of life of I. hexagonus is totally different from that of I. ricinus and
because there has only been limited research to I. hexagonus, there has been
chosen to investigate I. hexagonus ticks.
With screening by polymerase chain reaction (PCR) and revere line blot (RLB)
hybridization, 182 ♀ I. hexagonus ticks – collected from July 2005 up to
September 2009 – from the collection of the Utrecht Centre for Tick-borne
Diseases (UCTD), were screened for the presence of Anaplasma spp., Bartonella
spp., Borrelia burgdorferi s.l., Coxiella burnetii, Francisella tularensis and
Rickettsia spp.
The screened I. hexagonus ticks were infected with A. phagocytophilum (2.75%)
and B. schoenbuchensis (2.20%). This is the first time that B. schoenbuchensis is
demonstrated in ticks originating from cats. B. schoenbuchensis is associated with
the zoonosis deer ked dermatitis, although the exact role in the etiology of this
disease remains to be elucidated.
Further, there were positive results for R. helvetica and there was one positive
result for R. massiliae. Because the 16S rRNA sequences of 2 other samples which were positive for Rickettsia spp. by RLB did not match the 16S rRNA sequence of any known Rickettsia spp., these results should be carefully interpreted.
It was remarkable that B. burgdorferi sensu lato was not found in any of the
screened ticks.
On account of – during this investigation – encountered problems with a newly
developed diagnostic RLB test for Francisella and Coxiella, there are no reliable
results concerning the prevalence of these pathogens. At the moment the UCTD is
working to prevent such problems in the future.
To conclude: more research at tick-borne zoonoses is desirable, because not from
all infectious agents it is known whether they are a zoonosis or not and it is not
always known what the role of ticks is in the transmission of these agents.