5.10 - Antibiotics

Antibiotics

• An antibiotic is a medicine that cures a bacterial disease by killing the bacteria inside the body, or by stopping them from growing and dividing.
• It does this without killing the body's own cells, because it interferes with processes found in bacterial cells but not in human cells - for example building the bacterial cell wall, which human cells don't have.
• Many antibiotics are made naturally by fungi and other microorganisms - penicillin, the best-known antibiotic, is made by the mould Penicillium.
• Drug companies grow these organisms on a large scale and extract the antibiotic from them.
• Antibiotics have greatly reduced deaths from bacterial diseases.

Using antibiotics correctly

• A particular antibiotic only kills particular types of bacteria, so it's important to be treated with the right one for the infection.
• It's also important to finish the whole course, even once you start to feel better, so the infection is fully cleared rather than left to flare up again.
• Bacteria can become resistant to antibiotics, which is a growing problem for treatment.

Antibiotics don't work on viruses

• Antibiotics have no effect on viruses, such as those that cause flu and colds, because viruses are not cells and have none of the processes, such as building a cell wall, that antibiotics interfere with.
• Viruses reproduce inside the body's own cells, so it's very difficult to develop a drug that destroys the virus without also damaging the cells it's hiding in.
• This makes antiviral drugs much harder to make than antibiotics.