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Published: 25 Jan, 2017

Signal protein triggers mechanism allowing bacteria to colonize the tick stomach

NEWS Before infecting humans, the tick-borne bacterium A. phagocytophilum first triggers the expression of a particular protein in the tick’s stomach, altering molecules and allowing the bacteria to enter and colonize the gut microbes. The unexpected finding, made by researchers at Umeå and Yale universities and published recently in the journal PNAS, could help scientists develop strategies to block tick-borne bacteria and viruses.

Felipe Cava and Akhilesh Yadav at the Laboratory for Molecular Infection Medicine Sweden (MIMS). Photo: CavaLab.

“Tick-borne bacteria or viruses that infect humans first have to get past a tick’s defenses and colonize its stomach. How they can manage to do this is still not well understood but this clue could lead to a way to prevent common and sometimes deadly tick-borne infectious diseases,” says Felipe Cava, who is a group leader at the Laboratory for Molecular Infection Medicine Sweden at Umeå University and co-author of the article.

To investigate this trigger mechanism, MIMS research group leader Felipe Cava and Akhilesh Yadav, along with colleagues at Yale University, studied human granulocytic anaplasmosis. The second-most-common tick-borne infection in the United States, human granulocytic anaplasmosis can cause headaches, muscle pain and even death.

The researchers found that the bacterium A. phagocytophilum triggers the expression of an antifreeze glycoprotein (IAFGP) which alters molecules in the tick’s stomach and allows the bacteria to enter and colonize the gut microbes.

“The team here at MIMS continues to investigate the details of the bacterial cell wall. We are currently setting up a new database called Mureinome to collect molecular information on the metabolic and regulatory pathways that could be used to develop new species-specific antimicrobials therapies,” says Felipe Cava.

This research was made possible with funding support from the Laboratory for Molecular Infection Medicine Sweden, Knut and Alice Wallenberg Foundation, Kempe Foundations and the Swedish Research Council (VR). 

Link to the article in Proceedings of the National Academy of Sciences

For more information, please contact:

Felipe Cava, Molecular Infection Medicine Sweden, Umeå UniversityPhone: +46 90 785 6755

More information about Felipe Cava's research group:

About the publication:

Proceedings of the National Academy of Sciences, article: Pathogen-mediated manipulation of arthropod microbiota to promote infection. Authors: Nabil M. Abraham, Lei Liu, Brandon L. Jutras, Akhilesh K. Yadav, Sukanya Narasimhan, Vissagan Gopalakrishnan, Juliana M. Ansari, Kimberly K. Jefferson, Felipe Cava, Christine Jacobs-Wagner and Erol Fikrig. DOI: 10.1073/pnas.1613422114.

Editor: Daniel Harju