LPS O-antigen polysaccharide length impacts outer membrane permeability of enteric gram-negative bacteria.

ABSTRACT: The gram-negative outer membrane (OM) forms the bacterial cell surface and acts as a barrier against antibiotic influx. In enteric species, the OM is covered by lipopolysaccharides (LPS) decorated with varying lengths of O-antigen (O-Ag) polysaccharide that protect bacteria against mammalian host defenses. Studies of lab-adapted Escherichia coli K-12 strains have proven instrumental in unraveling the essential processes of LPS synthesis, transport, and assembly into the OM. However, O-Ag synthesis was inactivated in K-12 strains during their lab adaption, and these cells produce a non-native, truncated LPS form. Surprisingly, we found that re-activating O-Ag synthesis in K-12 permeabilizes the OM to diverse antibiotics, causing susceptibility. The O-Ag that modifies LPS is directly

SUBMITTER: May KL 

PROVIDER: S-EPMC12691688 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature