Antibiotic resistance: How does antibiotic resistance spread?

Antibiotic resistance is a natural occurrence caused by mutations in bacteria’s genes. However, inappropriate use of antibiotics accelerates the emergence and spread of antibiotic-resistant bacteria. When exposed to antibiotics, susceptible bacteria are killed; while excessive antibiotic use or their use for the wrong reasons can cause bacteria to become resistant and continue to grow and multiply. These resistant bacteria may spread and cause infections in other people.