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Bacteriasptcfrespcult

Published: August 9, 2026Updated: August 16, 2026

A laboratory test that identifies and analyzes bacteria found in sputum (mucus) from the lungs of patients with cystic fibrosis to guide treatment decisions.

Quick summary

{"This test detects harmful bacteria in the lungs of CF patients","Sample is collected by coughing up sputum into a sterile container","Results help doctors choose the right antibiotics","Regular testing helps monitor lung health over time","Early detection of infections prevents serious complications"}

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
623-9
Short code
CFSPCT
Synonyms
Bacteria Spt CF Resp Cult
Category
chemistry
Sample
sputum
Container
Sterile, leak-proof, wide-mouthed container or sputum collection cup
Units
N/A
Ref low
0.8
Ref high
1.2
Critical range
— – 5 N/A
Fasting
false
Population
adult
Sex
all
Age range
≥ 0 years
Method
cystic-fibrosis-respiratory-culture
CPT
87086
SNOMED
43558009
Specimen volume
1-5 mL of expectorated sputum
Stability
Room temperature: 2 hours; Refrigerated (2-8°C): 24 hours. Transport to laboratory as soon as possible for optimal organism recovery.
TAT
48–168 hours
Order
routine

What is this test?

A sputum culture for cystic fibrosis is a laboratory test that examines mucus (sputum) from your lungs to identify and grow bacteria. In people with cystic fibrosis, the lungs are particularly prone to infections because thick, sticky mucus traps bacteria. This test helps doctors find out exactly which bacteria are causing an infection so they can prescribe the most effective treatment.

How is the sample collected?

You will be asked to cough deeply to bring up sputum from your lungs. This is usually done in the morning before eating or drinking. The sputum is collected into a sterile container provided by your healthcare provider. It is important that the sample comes from your lungs, not just saliva from your mouth. If you cannot produce enough sputum, your doctor may use other methods to collect samples, such as throat swabs or bronchoscopy.

What happens in the laboratory?

In the lab, the sputum sample is placed on special growth materials (culture plates) and kept at body temperature. Bacteria present in the sample will multiply over several days. Laboratory technicians then identify the types of bacteria and perform additional tests to determine which antibiotics will be most effective against them (this is called antibiotic susceptibility testing).

What do the results mean?

Results typically show which specific bacteria are present and which antibiotics can treat the infection. Common bacteria found in CF patients include Pseudomonas aeruginosa, Staphylococcus aureus, and Haemophilus influenzae. Your doctor will use these results to tailor your treatment plan, choosing antibiotics that will work best against the specific bacteria causing your infection.

Reference range

INR: 0.8-1.2 (warfarin: 2.0-3.0)N/A

Specimen: sputum

No special preparation required. Patient should rinse mouth with water prior to collection to reduce contamination by oral flora. For expectorated sputum, instruct patient to cough deeply from the chest to produce a lower respiratory specimen.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

◆Associated findings2

Frequently asked questions

Does this test hurt?
No, the test itself is not painful. You will need to cough deeply to produce a sputum sample, which may be uncomfortable if you have a lung infection, but it should not cause pain. The sample collection is non-invasive.
How long does it take to get results?
Results usually take 2-7 days. Bacteria need time to grow in the laboratory, and additional testing to identify the bacteria and determine antibiotic effectiveness takes additional time. Your doctor will call you with results as soon as they are available.
Do I need to prepare for the test?
Try to collect your sample in the morning before eating or drinking. Rinse your mouth with water before collecting the sample to remove excess saliva. Breathe deeply and cough from your chest to produce sputum from your lungs, not just from your throat.
What if I can't produce any sputum?
If you cannot produce sputum on your own, your healthcare team may use alternative collection methods. These include throat swabs, induced sputum (where you inhale saline mist to help produce mucus), or bronchoscopy, where a thin tube is inserted through the nose or mouth to collect samples directly from the airways.
How often should I have this test?
The frequency depends on your individual condition. Many CF patients have routine cultures during regular clinic visits, typically every 1-3 months. You may need more frequent testing if you have symptoms of a lung infection or if your treatment is not working as expected.
  1. 1
    Cystic Fibrosis Foundation - Respiratory CulturingSource
  2. 2
    Mayo Clinic - Cystic Fibrosis Diagnosis & TreatmentSource
  3. 3
    Lab Tests Online - Sputum CultureSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy