iScience (Jun 2024)

Phagosomal granulocytic ROS in septic patients induce the bacterial SOS response

  • Stecy Chollet,
  • Ana Catalina Hernandez Padilla,
  • Thomas Daix,
  • Margaux Gaschet,
  • Bruno François,
  • Christophe Piguet,
  • Nathalie Gachard,
  • Sandra Da Re,
  • Robin Jeannet,
  • Marie-Cécile Ploy

Journal volume & issue
Vol. 27, no. 6
p. 109825

Abstract

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Summary: Septic patients with worst clinical prognosis have increased circulating immature granulocytes (IG), displaying limited phagocytosis and reactive oxygen species (ROS) production. Here, we developed an ex vivo model of incubation of human granulocytes, from septic patients or healthy donors, with Escherichia coli. We showed that the ROS production in Sepsis-IG is lower due to decreased activation and protein expression of the NADPH oxidase complex. We also demonstrated that the low level of ROS production and lower phagocytosis of IG in sepsis induce the bacterial SOS response, leading to the expression of the SOS-regulated quinolone resistance gene qnrB2. Without antimicrobial pressure, the sepsis immune response alone may promote antibiotic resistance expression.

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