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Bacterial Infections

Sample taken from the throat

Bacteria grow in your body causing an infection, making you feel ill or in pain. A very common bacterial infection is strep throat, caused by a group A streptococcal infection.

Your doctor or nurse will take a throat swab to get a sample of the bacteria cells in your throat. Then the sample is sent to the lab to grow the bacteria to determine the type, in order to know the treatment.

A medical laboratory professional will take a very small part of the sample and touch it to a petri dish that has been treated to enable bacteria growth. They will then use a small, sterile instrument to spread the cells around the dish, this is called streaking. It helps to separate as many cells as possible.

Once the bacteria begins to grow it may look like this in the petri dish.

courtesy of bacteriainphotos.com

The medical laboratory professional will then take a small part of the growing bacteria and process it, including staining (or adding colour) in order to view the cells under a microscope. This helps determine what strain or type of bacteria is present and which antibiotic will treat it.