Evolution

Have the flu? Don’t take antibiotics.

In 1929 Alexander Fleming discovered that penicillin prohibits bacterial growth. From that one amazing discovery, antibiotics were developed to fight bacterial infections that once killed many people, such as tuberculosis.

Antibiotics work by disrupting key components of bacterial growth, such as formation of the cell wall or DNA replication, and thus preven ts the bacteria from reproducing. Why don’t antibiotics hurt human cells? Antibiotics target very specific components of cells, and the antibiotics we use cannot harm human cell components. Antibiotics do not work on viruses because viruses are not alive outside of a human cell. Viruses use human cells to reproduce, and so antibiotics cannot harm viruses because there is nothing for the antibiotics to work on.

Antibiotics won’t hurt you, so why not take them for the flu? First, antibiotics won’t stop the flu, because it is a virus. Second, when antibiotics are misused, bacteria can become resistant to antibiotics.

There are two common ways to misuse antibiotics. Taking antibiotics for a viral infection is one way. Taking antibiotics when you don’t have a bacterial infection will expose the bacteria present in your body to the antibiotic. Only those bacteria with some resistance will survive. If the bacteria ever begin to grow out of control (as often happens with yeast infections), then the antibiotic may not be effective because the bacteria growing have a resistance to it.

Another way to misuse antibiotics: if a person is prescribed antibiotics and he/she does not finish the prescription, there is a possibility that not all of the bacteria have been killed. By not finishing the prescription, that person has allowed the bacteria with the greatest amount of resistance to survive and reproduce. The next time that person needs to take antibiotics for that bacteria, the antibiotics may not work because the bacteria are resistant.

If the misuse of antibiotics continues, eventually no dose or type of antibiotic may be effective against the bacteria causing the infection. This has already happened to certain types of bacteria. Methicillin-resistant Staphylococcus aureus (MRSA) is a type of staph bacteria that commonly infects the skin and is very difficult to treat. The most common types of antibiotics no longer have an effect on MRSA and an infection of MRSA can be life-threatening.

Photo courtesy of YouthHealthWorld.com
http://youthhealthworld.com/Sneezing_and_Coughing.htm

Sources:

http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Antibiotic_resistant_bacteria

http://evolution.berkeley.edu/evolibrary/article/medicine_03

http://www.news-medical.net/health/What-is-a-Virus.aspx

http://health.howstuffworks.com/medicine/medication/question88.htm

http://www.scientificamerican.com/article.cfm?id=how-do-antibiotics-kill-b

http://www.cdc.gov/mrsa/definition/index.html