Transstadial and transovarial persistence of Babesia divergens DNA in Ixodes ricinus ticks fed on infected blood in a new skin-feeding technique
Although Babesia divergens is the the principal confirmed zoonotic Babesia sp. in Europe, there are gaps in our knowledge of its biology and transmission by the tick Ixodes ricinus. In order to reproduce the part of the parasite cycle that occurs in the vector, an in vitro animal skin feeding technique on blood containing in vitro cultivated B. divergens was developed. Parasite DNA was detected in all samples of salivary glands of nymphs and adults that had fed on parasitized blood as larvae and nymphs, respectively, indicating acquisition as well as a transtadial persistence of B. divergens. PCR performed on eggs and larvae produced by females that had fed on parasitized blood demonstrated the existence of a transovarial transmission of the parasite. Gorging B. divergens infected larvae on non-infected gerbils showed persistance of the parasite over moulting into the resulting nymphs. These results indicate that the parasitic stages infective for the vector (i.e. the sexual stages) can be produced in vitro. To our knowledge, this is the first report of artificial feeding of I. ricinus via membrane as well as in vitro transmission of B. divergens to its vector. The opportunities offered by the use of such a transmission model of a pathogen by I. ricinus are discussed.(Received May 3 2006)
(Revised July 21 2006)
(Accepted July 25 2006)
(Published Online November 1 2006)
Key Words: Babesia divergens; Ixodes ricinus; transmission; ticks; experimental infection.
c1 Ecole Nationale Vétérinaire de Nantes, Service de Parasitologie, UMR ENVN/INRA 1034 Interactions Hôte-Parasite-Milieu, Atlanpole-La Chantrerie, B.P. 40706, 44307 Nantes cedex 03, France. Tel: +33 2 40 68 78 58. Fax: +33 2 40 68 77 51. E-mail: firstname.lastname@example.org.