The molecular basis
for virulence in Vibrio
anguillarum, a bacterial pathogen of fish
Vibrio anguillarum
is a highly motile marine bacterium and the causative agent of warm-water
vibriosis in fish. This disease is extremely destructive to fish, causing
major economic losses to the marine aquaculture industry world-wide. My
lab has been examining the molecular basis of virulence in V.
anguillarum with regard to two virulence activities: 1) secreted or
extracellular protease activity and 2) hemolytic/cytotoxic activity
against host cells. We have identified and characterized the functions
and activities of genes responsible for and regulating these virulence
factors. Preliminary data show that V. anguillarum protease
activity degrades host innate immune functions, such as complement
factors. The hemolysins/cytotoxins kill and lyse host cells. It appears
that phagocytic cells are especially vulnerable to these toxins. We
hypothesize that these virulence factors help to promote disease by
disrupting the host immune response to infection. Summer students will
work with my graduate students to examine how the virulence factors
directly affect host cell functions and to further describe how the
virulence factors are regulated. Additionally, we have recently generated
a draft genome sequence for V. anguillarum. Summer students will
have the opportunity to help with our efforts to annotate the genome.
