screw‑capped container
SWAB
0.5 mL
Transport: Place the swab immediately into the transport medium provided in the collection kit, ensuring the swab tip is submerged and the cap is securely tightened to prevent leakage.
Temperature: Transport the specimen at room temperature to the laboratory as soon as possible, ideally within two hours of collection. If transport is delayed, storage at 4°C (refrigeration) may be necessary, but specific lab protocols should be followed.
Timeliness: Prompt delivery to the lab is crucial to maintain bacterial viability and ensure accurate results.
qPCR
(RML)
Prior Antimicrobial Therapy: Collecting the specimen prior to the administration of antibiotics is essential, as the medication can interfere with bacterial growth in the lab, leading to false-negative results.
Surface Contamination: Swabbing an uncleaned surface or surrounding skin will likely yield normal skin flora, obscuring the actual pathogen causing the infection.
Necrotic Tissue/Eschar: Sampling from dead or non-viable tissue is not recommended, as pus or necrotic material can be toxic to white blood cells and may not yield the true infecting organisms.
Dry Swabs: Submitting a dry swab is a common error and is likely to result in poor or no recovery of bacteria, especially anaerobes.
Improper Transport: Using the wrong transport medium (e.g., an aerobic swab for a potential anaerobic culture) or improper storage/transport temperature can compromise the sample integrity
Preparation: Always perform hand hygiene and don appropriate personal protective equipment (PPE). Remove old dressings and thoroughly irrigate and cleanse the wound with sterile normal saline to remove surface contaminants before sampling.
Technique: Use the recommended Levine Technique: identify a 1 cm² area of clean, viable, granulating wound tissue. Apply enough pressure while rotating the swab for 5 seconds to express fluid from the wound bed into the swab tip.
Avoid: Do not touch the swab to gloves or other non-sterile surfaces before or after collection.
Documentation: Provide detailed clinical information on the requisition form, including the patient’s history of antimicrobial therapy, specific wound location, and a description of the wound’s appearance.
Safety: Dispose of all used materials in appropriate biohazard containers.
