Poster Presentation 15th Lorne Infection and Immunity 2025

Outer Membrane Vesicles as Drivers of Invasive Carbapenem-Resistant Klebsiella pneumoniae Infections: Pyroptosis and Inflammatory Pathways as Key Mechanisms (#356)

Xiaotuan Zhang 1 2 , Yao Sun 1 , Jingchun Kong 1 , Jia Zhang 3 , Ying Zhang 1 , Huale Chen 1 , Zeyu Huang 1 , Tieli Zhou 1 , Jianzhong Ye 1 4
  1. Department of Clinical Laboratory, The First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China
  2. Department of Clinical Laboratory, The Second Affiliated Hospital, Hengyang Medical School, University of South China, Hengyang, Hunan, China
  3. Department of Medical Lab Science, School of Laboratory Medicine and Life Science, Wenzhou Medical University, Wenzhou, Zhejiang, China
  4. Monash University, Clayton, VIC, Australia

Carbapenem-resistant Klebsiella pneumoniae (CRKP) bloodstream infections present significant therapeutic challenges and high mortality rates. Outer membrane vesicles (OMVs), secreted by Gram-negative bacteria, play a pivotal role in modulating host-pathogen interactions. This study investigates the contribution of CRKP OMVs to invasive infections and the impact of antibiotic misuse on OMV dynamics. CRKP OMVs significantly promote bacterial invasion into the bloodstream by inducing excessive pyroptosis via Gasdermin D (GSDMD) cleavage, compromising local immune defenses, and amplifying pro-inflammatory responses. Antibiotic treatments, including carbapenems and aztreonam, exacerbated infections by enhancing OMV production, leading to increased mortality in murine models. The inhibition of GSDMD-mediated pyroptosis using disulfiram markedly improved survival rates, highlighting a potential therapeutic target. These findings underscore the dual role of CRKP OMVs as infection accelerators and inflammatory mediators, offering critical insights into optimizing antimicrobial strategies against multidrug-resistant infections.