Key Findings

The study characterizes mutations in the TEM beta-lactamase gene, specifically R164S and R244S, which confer resistance to clavulanic acid and BLIP. The R164S mutation enhances activity against ceftazidime, while the R244S mutation increases resistance to clavulanic acid. The R164S/R244S double mutant retains resistance to clavulanic acid but loses the ability to hydrolyze ceftazidime.