Before infecting humans, tick-borne bacteria or viruses first have to get past a tick's defenses to colonize it. How this occurs is not well understood. To investigate, Yale researchers studied a model of the second-most-common tick-borne infection in the United States, human granulocytic anaplasmosis, which can cause headaches, muscle pain, and even death.
The
researchers found that in ticks, the bacterium that causes the infection, A.
phagocytophilum, triggers the expression of a particular protein. This protein
alters molecules in the tick's gut, allowing the bacteria to enter and colonize
the gut microbes.
"It's
like a stealth warrior that indirectly changes the tick by using the tick's own
defense system," said Erol Fikrig, M.D., chief of the Infectious Diseases
Section at Yale School of Medicine and senior author of the study.
The
unexpected finding could help scientists develop strategies to block A.
phagocytophilum and other tick-borne agents that cause disease, say the
researchers. Fikrig's team will explore the phenomenon in the bacterium that
causes Lyme disease, and its work could have implications for other
mosquito-borne infections, such as Zika and West Nile.
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