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Updated: Mar 31, 2026

Platelet Adhesion and Aggregation Under Flow using Microfluidic Flow Cells
Published on: October 27, 2009
Group G streptococci mediate fibrinogen-dependent platelet aggregation leading to transient entrapment in platelet
Lisbeth Svensson1, Inga-Maria Frick1, Oonagh Shannon1
1Division of Infection Medicine, Department of Clinical Sciences, Lund University, Lund, SE-22184 Lund, Sweden.
Abstract:
Platelets have been reported to become activated in response to bacteria and this is proposed to contribute to the acute response to bacterial infection. In the present study, we investigated platelet aggregation in response to group G streptococci (GGS) in vitro in healthy human donors and in vivo in a mouse model of streptococcal sepsis. Platelet aggregation by GGS was dependent on the bacterial surface protein FOG and engagement of the platelet fibrinogen receptor; however, it was independent of IgG and the platelet Fc receptor. Platelets exerted no antibacterial effects on the bacteria, and aggregates formed were markedly unstable, allowing bacteria to rapidly return to the plasma and grow post-aggregation. Thrombocytopenia and platelet activation occurred during invasive infection with GGS, and platelets were demonstrated to contribute to bacterial dissemination during infection. These findings reveal an important role for bacteria-platelet interactions during the pathogenesis of streptococcal infection.
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