Antibiotics kill bacteria by targeting and disrupting essential structures or processes that bacteria need to survive and multiply. The main mechanisms include:
- Destroying the bacterial cell wall or membrane: Many antibiotics, such as penicillins, block the synthesis of the bacterial cell wall (specifically the peptidoglycan layer), which weakens the wall and causes the bacteria to burst due to osmotic pressure
- Inhibiting protein synthesis: Antibiotics can interfere with the bacterial ribosomes, the machinery that produces proteins essential for bacterial growth and reproduction
- Blocking DNA or RNA synthesis: Some antibiotics prevent bacteria from replicating their DNA or transcribing RNA, stopping bacterial reproduction and survival
There are two main types of antibiotics based on their effect:
- Bactericidal antibiotics kill bacteria directly by causing lethal damage to these essential structures or processes.
- Bacteriostatic antibiotics inhibit bacterial growth and reproduction, allowing the immune system to eliminate the infection
Because these antibiotic targets are either absent or structurally different in human cells, antibiotics selectively harm bacteria without damaging human cells, although side effects can occur
. In summary, antibiotics kill bacteria primarily by disrupting their cell walls, protein production, or genetic material, leading to bacterial death or growth inhibition
