Anaerobic Culture, Extended Incubation

Some anaerobes will be killed by contact with molecular oxygen for only a few seconds. Overlying and adjacent areas must be carefully disinfected to eliminate contamination with indigenous flora. Ideally, pus or other fluid obtained by needle aspiration through intact skin or mucosal surface that has been cleaned with antiseptic should be collected. Sampling of open lesions is enhanced by deep aspiration using a sterile plastic catheter. Curettings of base of an open lesion are optimal. If irrigation is necessary, nonbacteriostatic sterile normal saline may be used. Lower respiratory samples must be obtained by transtracheal percutaneous needle aspiration, transbronchial biopsy, transthoracic needle biopsy, or open lung biopsy by physicians trained in these procedures. If swabs must be used, collect two; use one for Gram stain and one for culture. Anaerobic transports must be used for swabs and for aspirates. Specimens are to be collected from a prepared site using sterile technique. Contamination with normal flora from skin, rectum, vaginal tract, or other body surfaces must be avoided.