Gram Stain and Culture and Sensitivity Tests for Lung Infections
A Gram stain may help identify the type of bacteria that is
causing an infection. For a lung infection, your doctor will take a sample of
mucus and stain it. This makes bacteria easier to see when viewed through a
microscope. The shape and color of the stained bacteria may help identify the
type of bacteria that is causing the infection.
The sample of
mucus then may be cultured in the lab to see if the bacteria grow. If bacteria
from the mucus grow, other tests can be used to predict which antibiotics will
work the best to treat the infection. This is called sensitivity testing
and is done to help prevent bacteria from becoming
These tests may be done
when a doctor needs to identify the organism that is causing the infection. By
doing so, the doctor can choose the antibiotic that is most likely to be
effective. In most cases, unless there is a clear need to identify the
organism, these tests will not be done.
Primary Medical Reviewer
E. Gregory Thompson, MD - Internal Medicine
Specialist Medical Reviewer
Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology
How this information was developed to help you make better health decisions.