Evolved bacterial siderophore-mediated antibiotic cross-protection

• Published in: Research square
• Main Authors: Galdino, Anna Clara M, Vaillancourt, Mylene, Celedonio, Diana, Huse, Kara, Doi, Yohei, Lee, Janet S, Jorth, Peter
• Format: Journal Article
• Language: English
• Published: United States 18.05.2023

Antibiotic cross-protection enables resistant bacteria to protect other bacteria that would be otherwise susceptible to the drug. Cefiderocol is the first siderophore cephalosporin antibiotic approved for treating Gram-negative bacterial infections, including carbapenem-resistant strains. While highly effective, CFDC resistance has been detected clinically, and mechanisms of resistance and cross-protection are not completely understood. In this study, we used experimental evolution and whole genome sequencing to identify cefiderocol resistance mechanisms and evaluated the trade-offs of evolving resistance. We found some cefiderocol-resistant populations evolved cross-protective social behavior, preventing cefiderocol killing of susceptible siblings. Notably, cross-protection was driven by increased secretion of bacterial iron-binding siderophores, which is unique from previously described antibiotic degradation mediated cross-protection. While concerning, we also showed that resistance can be selected against in drug-free environments. Deciphering the costs associated with antibiotic resistance might aid the development of evolution-informed therapeutic approaches to delay the evolution of antibiotic resistance.