2023/08/26 by Madeline L. Sheahan, Michael J. Coyne, K. Flores +6 · 1 voice
Biochemistry, Genetics and Molecular Biology · Environmental Science · #Antibiotic Resistance in Bacteria #Bacteriophages and microbial interactions #Gut microbiota and health
paper · pdf · doi:10.1101/2023.08.25.553775
openalex publication_date 2023/08/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Abstract DNA transfer is ubiquitous in the gut microbiota, especially among species of Bacteroidales. In silico analyses have revealed hundreds of mobile genetic elements shared between these species, yet little is known about the phenotypes they encode, their effects on fitness, or pleiotropic consequences for the recipient’s genome. Here, we show that acquisition of a ubiquitous integrative and conjugative element encoding an antagonistic system shuts down the native contact-dependent antagonistic system of Bacteroides fragilis . Despite inactivating the native antagonism system, mobile element acquisition increases fitness of the B. fragilis transconjugant over its progenitor by arming it with a new weapon. This DNA transfer causes the strain to change allegiances so that it no longer targets ecosystem members containing the same element yet is armed for communal defense.