Anaerobic Culture

Sample type:

Pus, tissue, or other material properly obtained from an abscess, biopsy, aspirate, drainage, exudate, lesion, or wound.

Uses:

Anaerobic cultures are indicated particularly when suspected infections are related to gastrointestinal tract, pelvic organs, associated with malignancy, related to use of aminoglycosides; or occur in a setting in which the diagnosis of gas gangrene or actinomycosis is considered.

Anaerobic culture is especially indicated when an exudate has a foul odor or if the exudate has a grayish discoloration and is hemorrhagic. Frequently, more than one organism is recovered from an anaerobic infection.

Precautions:

1) The only sources for specimens with established validity for meaningful anaerobic culture in patients with pleuropulmonary infections are blood, pleural fluid, transtracheal aspirates, transthoracic pulmonary aspirates, and specimens obtained at thoracotomy.

2) Pleural fluid is preferred for patients with empyema.

3) Bronchoscopically obtained specimens are not ideal as the instrument becomes contaminated by organisms normally contaminating the oropharynx during insertion.

Interfering Factors:

Culture of specimens from sites harboring endogenous anaerobic organisms or contaminated by endogenous organisms may be misleading with regard to etiology and selection of appropriate therapy.

Pre analytical errors:

1) Specimen not received in appropriate anaerobic transport tube.

2) Swab not stored in oxygen-free atmosphere.

3) Refrigeration inhibits viability of certain anaerobic organisms.

4) Unlabeled specimen or name discrepancy between specimen and test request label.

Corrective action:

1) Specimen received in appropriate anaerobic transport tube.

2) Swab stored in oxygen-free atmosphere.

3) No Refrigeration

4) Labeled specimen and no name discrepancy between specimen and test request label.

Post analytical errors:

1) Improper reporting and interpreting.

Corrective action:

1) Proper reporting and interpreting.