Antibiotics

Antibiotics are substances that kill bacteriabacteria: Single-celled microorganisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium. or stop their growth. They do not work against virusesviruses: ultramicroscopic non-cellular organisms that replicate themselves inside the cells of living hosts: it is difficult to develop drugs that kill viruses without also damaging the body’s tissues.

How some common antibiotics work

Penicillin

A bacterium damaged and distorted by penicillin

The first antibiotic - penicillin - was discovered in 1928 by Alexander Fleming. He noticed that some bacteria he had left in a petri dish had been killed by naturally occurring penicillium mould.

Since the discovery of penicillin, many other antibiotics have been discovered or developed. Most antibiotics used in medicine have been altered chemically to make them more effective and safer for humans.

Resistance

Bacterial strains can develop resistance to antibiotics. This happens because of natural selection. In a large population of bacteriabacteria: Single-celled microorganisms, some of which are pathogenic in humans, animals and plants. Singular is bacterium., there may be some cells that are not affected by the antibiotic. These cells survive and reproduce, producing even more bacteria that are not affected by the antibiotic.

MRSA is methicillin-resistant staphylococcus aureus. It is very dangerous because it is resistant to most antibiotics. It is important to avoid over-use of antibiotics, so we can slow down, or stop, the development of other strains of resistant bacteria.

Cleanliness

One simple way to reduce the risk of infection is to maintain personal hygiene and to keep hospitals clean. In the 19th century, Ignaz Semmelweis realised the importance of cleanliness in hospitals. However, although his ideas were successful, they were ignored at the time because people did not know that diseases were caused by pathogens that could be killed.

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