|
Test ID: Ear Culture
|
|
Ear Culture
|
|
Bacterial and fungal culture of ear discharge
|
|
Useful For
|
Infections of the ear either otitis externa or otitis media.
|
|
Method name and description
|
Ear culture by conventional culture technique
|
|
Clinical information
|
Otitis externa resembles infection of skin and soft tissue elsewhere. However, there are some notable differences. The canal is narrow and, as a result, foreign materials and fluid that enter can become trapped, causing irritation and maceration of the superficial tissues. Otitis externa can be subdivided into categories: acute localized; acute diffuse; chronic; and invasive (‘malignant’).
Otitis media can occur when oropharyngeal flora ascends the eustachian tube and are not eliminated by the defense mechanisms of the middle ear. Otitis media is a common disease in children with frequent recurrence of infections. It is important to treat otitis media because possible complications include the loss of hearing.
Organisms usually isolated include:
- Haemophilus influenza
- Streptococcus pneumonia
- Group A Streptococcus
- M. catarrhalis
- Pseudomonas aeruginosa-is a frequent cause otitis media associated with exposure to fresh water.
- Vibrio alginolyticus – is a cause in oceanic swimmers.
- Staphylococcus aureus [in pure growth]
- fungus / yeast
|
|
Aliases
|
- Ear culture
- C Ear
- Culture Ear
- Ear swab culture
|
|
|
Specimen type / Specimen volume / Specimen container
|
Specimen type:
External ear discharge
Mastoid sinus secretions
Middle ear discharge/aspirate
Tympanic membrane aspirate
Specimen container:
Swab in Amies transport medium
|
|
Collection instructions / Special Precautions / Timing of collection
|
Collection instructions / Special Precautions:
Outer ear:
- Remove any debris or crust from the ear canal
- Obtain a sample by firmly rotating the swab in the outer canal
Note: vigorous swabbing is required since surface swabbing may miss Streptococcal cellulitis
Inner ear:
- For ruptured tympanic membrane, collect fluid on the sterile swab via an auditory speculum.
- Rotate swab and allow fluid to collect on swab.
Timing of collection:
Prior to antimicrobial therapy
|
|
Relevant clinical information to be provided
|
- Patient clinical details
- Antibiotic therapy
- Collection site
|
|
Storage and transport instructions
|
≤ 2 hrs. at room temperature
> 2 hrs: store at room temperature (maximum 24 hrs)
|
|
Specimen Rejection Criteria
|
- Wrong container without any transport medium
- Duplicate specimen in 72 hrs.
- Unlabeled/mislabeled specimen
- No relevant clinical details provided with the request. (Please note that where applicable, the relevant clinical details should reflect those on the patient’s electronic record at the time the order was placed).
|
|
|
Biological reference intervals and clinical decision values
|
Microscopy:
- Presence of pus cells, epithelial cells, and organisms with quantitation.
Culture:
Negative:
- “No growth”
- “Normal skin flora”
- “Normal skin flora including coliforms”
Positive culture:
- All significant isolates reported with appropriate susceptibilities.
|
|
Factors affecting test performance and result interpretation
|
- Improper collection technique
- Improper container
- Improper transportation
- Prior antibiotic therapy
|
|
Turnaround time / Days and times test performed / Specimen retention time
|
Turnaround time:
Microscopy: 24 hrs.
Culture: 48-96 hours
Days and times test performed
Daily 24/7. Note: In HGH microbiology laboratory, test timings are from Sun to Fri 7am to 3pm.
Specimen Retention time
48 hrs. after the final report
|
|
|
