Transstadial and transovarial persistence ofBabesia divergensDNA inIxodes ricinusticks fed on infected blood in a new skin-feeding technique

Abstract

AlthoughBabesia divergensis the the principal confirmed zoonoticBabesia sp. in Europe, there are gaps in our knowledge of its biology and transmission by the tickIxodes ricinus. In order to reproduce the part of the parasite cycle that occurs in the vector, anin vitroanimal skin feeding technique on blood containingin vitrocultivatedB. divergenswas 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 ofB. 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. GorgingB. divergensinfected 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 producedin vitro. To our knowledge, this is the first report of artificial feeding ofI. ricinusvia membrane as well asin vitrotransmission ofB. divergensto its vector. The opportunities offered by the use of such a transmission model of a pathogen byI. ricinusare discussed.