Amino acid competition shapes Acinetobacter baumannii gut carriage.

ABSTRACT: Asymptomatic colonization is often critical for persistence of antimicrobial-resistant pathogens, such as Acinetobacter baumannii, and can increase the risk of clinical infections. However, the ecological factors shaping A. baumannii gut colonization remain unclear. We show that A. baumannii and other pathogenic Acinetobacter evolved to utilize the amino acid ornithine, a non-preferred carbon source, to compete with resident microbiota and persist in the gut in mice. A. baumannii encodes ornithine succinyltransferase (AstO) necessary for catabolizing ornithine, especially in conditions of increased microbial diversity. Supplemental dietary ornithine promotes long-term fecal shedding of A. baumannii. By contrast, supplementation of preferred carbon sources-monosodium glutamate or histidine-

SUBMITTER: Ren X 

PROVIDER: S-EPMC12375414 | biostudies-literature | 2025 Aug

REPOSITORIES: biostudies-literature