Sputum Culture
Results
A sputum culture is a test to detect and identify bacteria or fungi that are infecting the lungs or breathing passages. Some types of bacteria or fungi grow quickly in a culture and some grow slowly. Test results may take from one day to several weeks, depending on the type of infection suspected. Some organisms (such as Chlamydia pneumoniae and mycoplasma) do not grow in a standard culture and need a special growth medium to be detected in a sputum culture.
Sputum culture Normal: Sputum that has passed through the mouth normally contains several types of harmless bacteria, including some types of strep (streptococcus) and staph (staphylococcus). The culture should not show any harmful bacteria or fungi. Normal culture results are negative.
Abnormal: Harmful bacteria or fungi are present. The most common harmful bacteria in a sputum culture are those that can cause bronchitis or pneumonia (Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, Klebsiella pneumoniae, and Chlamydia pneumoniae) or tuberculosis (Mycobacterium tuberculosis). Mycoplasma, a group of organisms similar to bacteria, can also cause a type of pneumonia. If harmful bacteria or fungi grow, the culture is positive.
If test results indicate an infection, sensitivity testing may be done to determine the best antibiotic to kill the bacteria or fungus.
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| Author: | Maria G. Essig, MS, ELS | Last Updated: March 21, 2007 |
| Medical Review: | Caroline S. Rhoads, MD - Internal Medicine Robert L. Cowie, MB, FCP(SA), MD, MSc, MFOM - Pulmonology | |
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| Topic Contents | |
| Test Overview | |
| Why It Is Done | |
| How To Prepare | |
| How It Is Done | |
| How It Feels | |
| Risks | |
 | Results |
| What Affects the Test | |
| What To Think About | |
| References | |
| Credits | |