Table 1. Minimum inhibitory concentration (MIC) of WT, ΔltgAΔltgD double mutant, ltgA+ ltgD+ double complement, and ltgA(E481A)ltgD(E158A) double point mutant Gc to vancomycin and streptomycin.

Lawns of WT, ΔltgAΔltgD double mutant, ltgA+ ltgD+ double complement, and ltgA(E481A)ltgD(E158A) double point mutant Gc on solid medium were exposed to vancomycin or streptomycin Etests to determine MIC after 24 hr incubation at 37°C with 5% CO₂. MIC is represented as a range from 3 biological replicates.

Antibiotic	WT	ΔltgAΔltgD	Double Complement	ltgA(E481A) ltgD(E158A)
Vancomycin	16–24 µg/mL	6–8 µg/mL	16 µg/mL	8 µg/mL
Streptomycin	>1.024 mg/mL	>1.024 mg/mL	>1.024 mg/mL	>1.024 mg/mL