Several challenges complicate AST in epidemiology: 1. Resistance Mechanisms: Bacteria can acquire resistance through various mechanisms, including gene mutations and horizontal gene transfer, making it difficult to predict susceptibility. 2. Laboratory Variability: Differences in laboratory conditions and methodologies can lead to inconsistent results. 3. Emerging Pathogens: New or re-emerging bacterial pathogens may not have established guidelines for susceptibility testing, complicating treatment decisions.
