Specimen Collection for Microbiology Studies PDF

Specimen Collection for Microbiological Studies Dr. Basma Samir (MD) Abscess (Pus) Decontaminate the surface with 70-95% alcohol and 1-2% tincture of iodine. Collect purulent material aseptically from an undrained abscess using a sterile needle and syringe. Open miliary abscesses w...

Specimen Collection for Microbiological Studies Dr. Basma Samir (MD) Abscess (Pus) Decontaminate the surface with 70-95% alcohol and 1-2% tincture of iodine. Collect purulent material aseptically from an undrained abscess using a sterile needle and syringe. Open miliary abscesses with a sterile scalpel and collect the expressed material with a sterile needle and syringe. Transfer 5-10 ml of the aspirated material to sterile container. Transport immediately.  Anaerobic transport media are not recommended for AFB culture. If requesting AFB culture, transfer at least 1 ml of the aspirated material into a sterile container. Swabs are a poor choice because they dry easily (limited amount of material obtained). Swabs are not optimal for fungal, anaerobe cultures. Swabs are not accepted for mycobacterial cultures, perirectal abscesses, oral abscesses. Gram stains cannot be provided from a single swab. If a Gram stain is needed, collect two swabs. Bullae, Vesicles Cleanse the skin as for blood cultures. Aspirate the fluid/purulent material using a sterile needle and syringe. If an aspirate is obtained, place in appropriate bacterial transport tube or sterile container. If no material is obtained, unroof vesicle or bullous lesion and use a Dacron swab to collect cells from the base of the lesion. Place in appropriate bacterial transport media. Cellulitis Swabs and leading-edge aspirates with or without injection of saline fail to yield etiologic agents in the majority of cases. If an unusual organism is suspected, a leading-edge (advancing margin) punch biopsy is the recommended specimen of choice. Place biopsy specimen in a sterile container with small volume of non-bacteriostatic saline. Wounds For closed wounds, refer to Abscess and Bullae, Cellulitis and Vesicles. For open wounds: Clean the sinus tract opening of the wound surface mechanically, without using a germicidal agent, to remove as much of the superficial flora as possible. Attempt to culture the base or edges of the wound to avoid collecting "normal flora" organisms. Preferred specimens for sinus tracts: Aspirates of material obtained by needle or catheterization. Curettings from the lining of the sinus tract. Swabs are less acceptable unless is difficult to obtain specimens by aspirates or curettings. For open wounds: Swabs of sinus tracts may not accurately reflect the underlying disease process. Do not submit cultures of superficial lesions for anaerobic culture. Biopsy of advancing margin of wound is the preferred specimen for anaerobes, mycobacteria and fungi. Tissue Tissue collection is an invasive procedure and requires surgery by a trained physician. Collect tissue aseptically. Include material from both the center and the edge of the lesion. Place the specimen in a sterile container on sterile gauze moistened with sterile nonbacteriostatic saline. Transport in less than an hour at ambient temperature, in a manner to ensure recovery of anaerobic organisms. Do not submit tissue in formalin. Do not jam the tissue into a Culturette using the swab; this is not an acceptable transport device.