Fungal culture – Eye/Ear

Alternative Names/Synonyms	Culture-based detection of fungal pathogens in eye and ear specimens
Laboratory	Microbiology
Sub-section	Mycology
Specimen Type	○ Corneal scrapings ○ Conjunctival swab ○ Eye swab ○ Intraocular fluids (e.g. aqueous, vitreous) ○ Lacrimal stone/secretions ○ External ear swab ○ Tympanocentesis fluid (middle ear infections only) ○ Ear/eye devices

Other Information

○ Microscopy will be done if there is sufficient specimen received.

Specimen Requirements (Tube Type)

○ Corneal scrapes: agar plates (IMA [blood, chocolate agars and thioglycollate broth if bacterial culture is being ordered]) and microscope slide (contact the microbiology laboratory to obtain collection supplies)
○ Swabs: Sterile swab in Amies transport medium (eSwab)
○ Lacrimal stone/secretions or tympanocentesis fluid/devices: Clean, sterile container

Collection Requirements

○Corneal Scrapes:
Preferably plant at bedside onto agars and onto microscope slide; otherwise collect in sterile container with small amount of sterile saline. Corneal surfaces should be rinsed thoroughly with sterile normal saline to remove anaesthetic prior to collecting specimen; use a Kimura scalpel to scrape across the ulcer using short firm strokes in one direction; obtain 3 to 5 scrapings per cornea. Avoid contact with eyelids/eyelashes. For agar, plant in rows of C-shaped marks, with each row representing a separate sample.
Conjunctival/eye swab:
○ Conjunctival surfaces should be rinsed thoroughly with normal saline to remove anaesthetic prior to collecting specimen. Roll a sterile pre-moistened swab over the conjunctiva and place in transport medium
○ Collect samples from both affected and unaffected eyes to compare microbial growth using different swabs/transport media for each eye
Intraocular fluids:
○ Collect an aspirate of vitreous fluid or paracentesis of anterior chamber using a needle aspiration technique. Dispense fluid into sterile container.
Lacrimal stone/secretions:
○ For lacrimal stones, collect stones using sterile technique and place into sterile container.
○ For lacrimal secretions, collect visible purulent discharge using a swab or press lacrimal sac to remove exudate for culture. Do not perform a needle aspiration of the lacrimal gland.
External ear swab:
○ Insert clean, sterile swab into ear canal until resistance is met. Rotate swab to collect fluid on swab and place in transport medium.
○ If ear drum is ruptured, collect exudate on swab after inserting through an auditory speculum

Tympanocentesis fluid:
○ Clean external ear canal with mild detergent. Use a syringe to aspirate fluid from the eardrum. Dispense fluid into a sterile container and transport to laboratory.
○ If anaerobic culture required, dispense some of the aspirated fluid into an anaerobic transport medium
Devices:
○ Collect device and place in sterile container using aseptic technique where possible to avoid contamination

Sample Stability

Refer to section Sample Processing / Delivery

Referral Laboratory

In-house

Routine Turnaround Time

○ Up to 28 days

Laboratory Contact Information

416-586-4800 extension 4500

Special Instructions

Approval Required

Sample Processing / Delivery

○ Label specimen container and outer biohazard specimen bag with printed electronic laboratory order sticker. Place specimens in biohazard bag, seal

○ Specimens should be stored at room temperature (20-25˚C) after collection. Transport to the UHN/SH Microbiology Laboratory ASAP after collection. Corneal scrapes should be kept at 35˚C and not refrigerated.