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:
move from the part of the body where they usually live
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:
fast heartbeat, known as tachycardia
fever with or without chills
low blood pressure
nausea and vomiting
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
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.