Resistance is not as black and white as you suggest. https://litfl.com/minimum-inhibitory-concentration/ https://litfl.com/minimum-inhibitory-concentration/ I

Resistance is not as black and white as you suggest. https://litfl.com/minimum-inhibitory-concentration/ https://litfl.com/minimum-inhibitory-concentration/ It’s more of a spectrum of concentrations. A resistant bacteria is one that doesn’t grow above a certain threshold. But longer exposure or higher concentration will change the effectiveness.