Resistant strains develop through several mechanisms, including: 1. Genetic Mutations: Microorganisms naturally undergo mutations, some of which may confer resistance to a particular antimicrobial agent. 2. Horizontal Gene Transfer: Bacteria can acquire resistance genes from other bacteria through processes like conjugation, transformation, or transduction. 3. Selective Pressure: Overuse or misuse of antibiotics in humans, animals, and agriculture can create selective pressure, allowing resistant strains to thrive while susceptible ones are eliminated.
