Microbiology

Ear swabs

  • Swab any pus or exudates.
  • For investigation of fungal infection, scrapings of material from the ear canal are preferred although swabs can also be used.
  • Unless otherwise stated, swabs for bacterial and fungal culture should then be placed in Amies transport medium with charcoal.

Eye swabs

All conjunctival swabs should be placed in transport medium with charcoal. In neonates a separate sample should also be taken for examination for Chlamydia. A kit is available from the Virology Laboratory for the collection of samples for Chlamydia identification.

Ulcer swabs

These swabs should only be taken when there is clinical evidence of cellulitis around the wound. If cellulitis is present, the ulcer should be gently cleaned with sterile water or saline to remove any slough. A specimen should then be collected, a biopsy or, a needle aspiration of the edge of the wound is preferable or a swab from beneath the edge of the ulcer otherwise.

Wound swabs (W/S surgical, W/S trauma)

Specimens of pus and exudates are always preferable to swabs. Collect the pus into a dry sterile bottle, or, only if this is not possible, take a swab. The swab should be taken from the deepest part of the wound trying to avoid the superficial microflora.

  • Use bacterial swabs with transport medium for routine culture.
  • Gently cleanse wound with sterile water or saline to remove any slough before swabbing.
  • If pus is present, draw off using a sterile syringe and transfer into a sterile container.
  • If the wound has very little exudate or if it is dry, then moisten the swab in sterile saline prior to swabbing.
  • Rotate the swab gently across the affected area.
  • Place back into the transport medium and secure lid tightly.
  • Document the exact anatomical site on the swab and request form as this affects processing procedure.

For nasal, pernasal, postnasal and throat swabs, see Respiratory Specimens.