One Bacterial Switch Sets Biofilm Tolerance and β-Lactam Susceptibility in Opposite Directions
One Bacterial Switch Sets Biofilm Tolerance and β-Lactam Susceptibility in Opposite Directions Bioengineer.org The second axis of regulation points in the opposite direction. While the biofilm-deficient mutants lost tolerance to the three matrix-protected drugs, the ΔenvZ and ΔompR mutants displayed increased resistance to eight other β-lactam agents. This inverse phenotype suggested that the wild-type system normally keeps those cells susceptible, and that removing it removes a route of drug entry. Single-gene knockout validation pinpointed the responsible factor: only the ΔompF mutant showed elevated MICs to the same eight antibiotics. Additional EMSA experiments verified that OmpR binds directly to the promoter regions of ompF, meaning the response regulator actively maintains porin expression. In the knockout, that maintenance disappears. Subject of Research: Dual opposing roles of…
