Host-pathogen interaction between macrophage co-cultures with Staphylococcus aureus biofilms

ARCE MIRANDAJULIO E., BARONETTI JOSÉ L AND PARAJE MA. GABRIELA

EUROPEAN JOURNAL OF CLINICAL MICROBIOLOGY & INFECTIOUS DISEASES : OFFICIAL PUBLICATION OF THE EUROPEAN SOCIETY OF CLINICAL MICROBIOLOGY.

SPRINGER

Año: 2021 vol. 40 p. 2563 - 2574

0934-9723

Purpose: The ability of Staphylococcus aureus to form biofilms is an importantvirulence factor. During the infectious process, the interaction between biofilms andimmune cells is determinant; however, the properties that make biofilms resistant to theimmune system are not well characterized. In order to better understand this, weevaluated the in vitro interaction of macrophages during the early stages of S. aureusbiofilm formation.Methods: Biofilm formation was evaluated by Crystal violet staining, light microscopy,and confocal scanning laser microscopy. Furthermore, different activation on L-arginine pathways such as nitric oxide (NO ? ) release and the arginase, theproduction of reactive oxygen species (ROS), the total oxidative stress response(OSR), and levels of cytokine liberation, were determined.Results: Our findings show that the interaction between biofilms and macrophagesresults in stimuli for catabolism of L-arginine via arginase, but not for NO ? , anincrease of ROS production, and activation of the non-enzymatic OSR. We alsoobserved the production of IL-6, but not of TNFα o IL-10 in these co-cultures.Conclusion: These results contribute to a better understanding of host-pathogeninteractions and suggest that biofilms increase resistance against immune cellmechanisms, a phenomenon that could contribute to the ability of S. aureus biofilmsto establish mature biofilms.