Sputum Culture-Provincial

Overview

Description

• Sputum culture is used to isolate potential respiratory pathogens and can be useful in the diagnosis of respiratory tract infection.

Ordering Recommendations

• Specimens may be collected from patients with signs and symptoms of respiratory tract infection.

 

Specimen Information

Specimen types accepted

• Sputum (induced or expectorated)

Specimen collection container

• Sterile Screw Capped Container

Collection procedure

• Have patient rinse mouth or gargle with sterile water before specimen collection to remove contaminating material and organisms. Patient must cough deeply so that exudative material is obtained from the lung; saliva and nasal drainage are inadequate specimens. Deep coughing may be induced by inhalation of an aerosol of warm, hypertonic (5-15%) saline (label as “Induced” if collected this way).

Required volume

• 5 – 10mL sputum

Transport and stability

• Transport at room temperature, as soon as possible. If delay is anticipated, keep specimen at 4°C.

Testing Information

Relevant clinical history

Patient History

• Underlying diagnosis and history of past/current antimicrobial therapy

Performance

Methodology

• Gram stain and culture for aerobic bacteria and yeast is performed routinely.

Days/times performed

• Specimens will be cultured at the nearest microbiology laboratory.

Maximum laboratory time

• Cultures are incubated for 48 hours.

• Reports of no/non-significant growth are sent at 24 and 48 hours, if applicable.

• Identification and susceptibility results are usually available 24 – 48 hours after an organism is isolated.

Specimen retention time

• Specimens retained for 7 days after culturing.

Other information

NOTE: Repeat specimens for routine culture received within a 3 day period are not routinely processed, unless originating from an intensive care unit.

Last Updated: November 14, 2025