Xenopsylla /zen′ōsil′ə/ , a genus of parasitic fleas responsible for the transmission of bubonic plague, murine typhus, and other infections. Many of more than 30 species of Xenopsylla are vectors of pathogens, including X. cheopis, a rat flea found worldwide. It is a vector of Yersinia pestis, the bacterial source of murine typhus, as well as of the plague.
