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    Sputum Culture

    How It Feels continued...

    During bronchoscopy or collection of a sputum sample using a catheter, you may feel a strong urge to cough. This can happen as the bronchoscope or catheter passes into the back of your throat. You may also feel as if you can't breathe. Try to relax. Breathe slowly.

    If you are given medicine to numb your throat and nose, you may feel as if your tongue and throat are swollen. You may find it hard to swallow.


    Your throat may feel sore after bronchoscopy or collection of a sputum sample using a nasotracheal catheter.

    If you have severe asthma or bronchitis, you may find it hard to breathe during collection of a sputum sample using a nasotracheal catheter.


    A sputum culture is a test to find bacteria or fungi that are infecting the lungs or airways. Some types of bacteria or fungi grow quickly in a culture, and some grow slowly. Test results may take from 1 day to several weeks. How long your results take depends on the type of infection your doctor thinks you may have. Some organisms do not grow in a standard culture and need a special growth medium to be found in a sputum culture. (Examples are Chlamydophila pneumoniae and mycoplasma.)

    Sputum culture

    Sputum that has passed through the mouth normally contains several types of harmless bacteria. These include some types of strep (Streptococcus) and staph (Staphylococcus). The culture should not show any harmful bacteria or fungi. Normal culture results are negative.


    Harmful bacteria or fungi are present. The most common harmful bacteria in a sputum culture are those that can cause bronchitis, pneumonia, or tuberculosis. If harmful bacteria or fungi grow, the culture is positive.

    If test results point to an infection, sensitivity testing may be done. This testing helps to find the best antibiotic to kill the bacteria or fungus.

    What Affects the Test

    You may not be able to have the test, or the results may not be helpful, if:

    • You used antibiotics recently. They may prevent the growth of bacteria or fungi in the culture.
    • The sputum sample is contaminated.
    • There is not enough sputum sample.
    • You wait too long to take the sample to the lab.
    • You use mouthwash before you collect your sputum sample.

    WebMD Medical Reference from Healthwise

    Last Updated: May 22, 2015
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.

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