💊 Resistance Evolution

Dosing schedule

Full course

Intermittent

Under-dose

No treatment

Antibiotic dose 1.5 ×MIC Mutation rate 0.5 % Fitness cost of resistance 20 % Initial resistance 0 % Speed 3× Presets

Full course (cure)

Under-dosing

No treatment

Aggressive

Total population—

% resistant—

Generation—

Current dose—

MIC (resistant)—

Outcome—

Bacteria reproduce and randomly mutate to resistance. Antibiotic above the MIC kills susceptible cells; resistant cells survive but pay a fitness cost when no drug is present. Under-dosing (below resistant MIC) kills only the weak and selects for resistance — a full course wipes the colony before resistance can sweep.