Not all antibiotics work in the same way. Some antibiotics kill bacteria, these are known as bacteriocidal antibiotics, and others just prevent the bacteria from growing, these are known as bacteriostatic. Different groups, or classes of antibiotics have different actions on bacteria:
- Some will interfere with the making of the bacterial cell wall. All bacteria have a cell wall that protects them from the outside environment and helps to contain the cell contents. When a bacteria multiplies it grows and divides into two, if the cell wall is damaged the bacterial cell will burst when it tries to multiply.
- Some antibiotics stop bacteria from making important chemicals they need to survive
- Others interfere with the genetic material in a bacterial cell and cause it to stop the bacterial cell dividing into two and multiplying.
So, antibiotics act in different ways, but they also act on different bacteria. Some antibiotics will selectively act on a few specific bacteria, these are known as narrow spectrum antibiotics. Others will target a wider range of bacteria, these are known as broad spectrum antibiotics. If you have a bacterial infection is important to know which bacteria is causing it, so that you can take the appropriate antibiotic.