Aerobic Bacteria, Blood Culture For

Alternate Names : Blood Culture for Aerobic Bacteria

A test called a blood culture is done to see if there is an infection of the blood. There are different types of blood culture tests. One of these tests checks for a type of organism called aerobic bacteria.

Bacteria are tiny organisms that can live in both the human body and our environment. The aerobic type of bacteria can live and grow only where there is oxygen.

Some bacteria cause illness. Others pose no problems to humans or may be helpful. But even harmless bacteria can become harmful if certain conditions allow them to:

Who is a candidate for the test?

This test is done most often with very young or old people or with those who have weakened immune systems. However, it may be used any time a person has a serious infection. This is because most severe infections can spread to the blood. Kidney and lung infections are two of the most common causes of blood infections.

Signs of a blood infection may include:

Other symptoms are often due to the underlying infection that has spread to the blood. For example, a person with a lung infection may have a cough.

How is the test performed?

Blood samples for this test are usually taken from veins in the forearm or the back of the hand. The samples may be taken from two different sites. This increases the chance of detecting bacteria in the blood. This can also help to rule out contamination of the test by bacteria from the skin or from another source. Two or more blood samples may be collected from each site so aerobic and anaerobic bacteria can both be detected. Anaerobic bacteria can live and grow without oxygen, and some may even die when exposed to oxygen.

First, a band is tied around the upper arm to slow the circulation. This enlarges the veins below. A puncture site is selected and cleaned. Next, a needle is inserted into a vein. Blood is collected and placed into a vial. The vial contains special food that helps the bacteria to grow. The needle is removed from the person's arm, and the vial is sent to the lab. A bandage is put on the puncture site to stop any bleeding.

In the lab, the vial is watched to see if bacteria grow. It takes from 24 to 72 hours or longer for aerobic bacteria to grow. If bacteria grow, the lab can identify them using special tests.