A newly identified homologous SxtPR efflux system contributes to sulfamethoxazole/trimethoprim susceptibility and pathogenesis in <i>Klebsiella pneumoniae</i>

ABSTRACT Klebsiella pneumoniae is an opportunistic pathogen responsible for a wide range of healthcare-associated infections. In a recent work, we identified a novel Major Facilitator Superfamily efflux system in Acinetobacter baumannii , designated SxtPR, which mediates antimicrobial resistance and pathogenicity (M. Gaona, J. Corral, S. Campoy, J. Barbé, et al, Antimicrob Agents Chemother e0071224, 2024, https://doi.org/10.1128/aac.00712-24 ). Here, we report the identification and characterization of a homologous system in Klebsiella pneumoniae that plays a similar dual role in antimicrobial resistance and virulence.