Aerobic Culture + Gram Stain
•Anaerobic Culture, Abscess
•Anaerobic Culture, Body Fluid
•Anaerobic Culture, Wound
•Wound Anaerobic Culture
Identify and determine susceptibility of acid-fast bacteria referred from another laboratory that has performed the culture of the clinical sample
Additional Test information:
In open wounds, anaerobic organisms may play an etiologic role, whereas aerobes may represent superficial contamination. Serious anaerobic infections are often due to mixed flora that are pathologic synergists. Anaerobes frequently recovered from closed postoperative wound infections include Bacteroides fragilis, approximately 50%; Prevotella melaninogenica, approximately 25%; Peptostreptococcus prevotii, approximately 15%; and Fusobacterium sp, approximately 25%. Anaerobes are seldom recovered in pure culture (10% to 15% of cultures). Aerobes and facultative bacteria when present are frequently found in lesser numbers than the anaerobes. Anaerobic infection is most commonly associated with operations involving opening or manipulating the bowel or a hollow viscus (eg, appendectomy, cholecystectomy, colectomy, gastrectomy, bile duct exploration, etc). The ratio of anaerobes to facultative species is normally about 10:1 in the mouth, vagina, and sebaceous glands and at least 1000:1 in the colon. Biopsy culture is particularly useful in establishing the diagnosis of anaerobic osteomyelitis,2 clostridial myonecrosis, intracranial actinomycosis, and pleuropulmonary infections. Anaerobic infections of soft tissue include anaerobic cellulitis, necrotizing fasciitis, clostridial myonecrosis (gas gangrene), anaerobic streptococcal myositis or myonecrosis, synergistic nonclostridial anaerobic myonecrosis, and infected vascular gangrene. These infections, particularly clostridial myonecrosis, necrotizing fasciitis, and nonclostridial anaerobic myonecrosis, may be fulminant and are frequently characterized by the presence of gas and foul-smelling necrotic tissue.3 Empiric therapy based on likely pathogens should be instituted as soon as appropriate cultures are collected.
Pus, tissue, or other material properly obtained from an abscess, biopsy, aspirate, drainage, exudate, lesion, or wound. To ensure proper growth of organisms place swabs/specimen in anaerobic transporter. Do not refrigerate.
Swab(s) in aerobic/anaerobic swab transport or 0.5 mL pus, other fluid, or tissue from aspirated site in anaerobic transporter and one thin smear
Aerobic/anaerobic bacterial swab transport containing gel preservative or anaerobic transporter and one prepared smear in slide carrier.
Sterile preparation of the aspiration site is imperative
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 the 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.
Specimens for anaerobic culture should be maintained at room temperature. Under these conditions, aerobes and anaerobes will survive 24 to 72 hours when properly collected in the anaerobic transport tube.
Unlabeled specimen or name discrepancy between specimen and test request label; specimen not received in appropriate anaerobic transport tube; swab not in gel transport medium; ESwab™; swab not stored in oxygen-free atmosphere; specimen refrigerated; specimen received after prolonged delay in transport (usually more than 72 hours). Note: Refrigeration inhibits viability of certain anaerobic organisms. Specimens from sites that have anaerobic bacteria as indigenous flora will not be cultured anaerobically (eg, throat, feces, colostomy stoma, rectal swabs, bronchial washes, cervical-vaginal mucosal swabs, sputa, skin and superficial wounds, voided or catheterized urine, ulcer surfaces, drainages onto contaminated surfaces).