Fucosylation enhances colonization of ticks by Anaplasma phagocytophilum

Fucosylated structures participate in a wide range of pathological processes in eukaryotes and prokaryotes. The impact of fucose on microbial pathogenesis, however, has been less appreciated in arthropods of medical relevance. Thus, we used the tick-borne bacterium Anaplasma phagocytophilum– the agent of human granulocytic anaplasmosis to understand these processes. Here we show that A. phagocytophilum uses ?1,3-fucose to colonize ticks. We demonstrate that A. phagocytophilum modulates the expression of ?1,3-fucosyltransferases and gene silencing significantly reduces colonization of tick cells. Acquisition but not transmission of A. phagocytophilum was affected when ?1,3-fucosyltransferases were silenced during tick feeding. Our results uncover a novel mechanism of pathogen colonization in arthropods. Decoding mechanisms of pathogen invasion in ticks might expedite the development of new strategies to interfere with the life cycle of A. phagocytophilum.