Cystic fibrosis (CF) screen culture (cough swab, cepacia)
Microbiology
Notes
- Sputum is the recommended specimen for routine sampling
- A cough swab should only be used if a patient cannot expectorate as the sensitivity for isolation of key pathogens such as Pseudomonas aeruginosa and Staphylococcus aureus is considerably less than sputum
- Samples are cultured for both routine respiratory and cystic fibrosis (CF) associated pathogens
- Sputum samples may be examined for Mycobacteria on request. Frequency should not be more than once every two months.
- The information given here is intended for use by healthcare professionals. Please see Lab Tests Online-UK for more general advice, links and background.
Sample requirements
Sputum
- Sputum rather than saliva is required
- Expectorate sample directly into the container
- Physiotherapy may be required
Cough swab
Standard charcoal transport swab
- Hold the swab as far back in the throat as possible while the patient coughs
- Place swab into transport medium
Required information
- Current or recent antibiotic therapy
- Antibiotic allergies
Storage/transport
Sputum:
Transport without delay to ensure survival of fastidious organisms. Where transport is difficult, specimens may be cultured up to 48hr after collection. If specimens are not processed on the same day as they are collected, interpretation of results should be made with care.
If transport is delayed, refrigeration is preferable to storage at ambient temperature.
Cough swabs:
Transport without delay, if transport is delayed store at ambient temperature
Turnaround time
Up to 6 days