Corneal scrapings are collected for the diagnosis of keratitis (inflammation of the cornea) caused by bacterial, fungal, viral, chlamydial or acanthamoeba infection.
The physician usually prepares two or three slides and inoculates the appropriate media at the time of specimen collection. The following media is to be supplied to the physician for each eye: BA, CHOC, SABHI-C. The physician will inoculate the plates in rows of “C” – shaped marks, with each row representing a separate sample.
If a delay in transport or processing is anticipated, the specimen should be kept in the incubator (35°C).
Virus and chlamydia detection require universal transport media (UTM).
If acanthamoeba is requested, recommend collection of specimen into approximately 2 mL sterile water and forward specimen to PHL for processing. Also request the contact lens case and contact lens solution in original container to be submitted. If there is a delay in transport, store the specimen at room temperature.
Direct Examination
Gram stain KOH Calcofluor white stain (if two smears are provided).
Culture
| Media | Incubation |
| Blood Agar (BA) | CO2, 35°C x 48 hours |
| Chocolate Agar (CHOC) | CO2, 35°C x 48 hours |
| SABHI with Chloramphenicol (SABHI-C) | O2, 30°C x 4 weeks |
All organisms should be identified. If a mixture of organisms is present consult with charge technologist or microbiologist.
Gram stain
Report, without quantitation, the presence of pus cells and organisms.
Culture
Negative report
“No growth.”
Positive
Report all isolates with appropriate susceptibilities without quantitation.
H.D. Isenberg, 2004. Wound Cultures – Wound and Soft Tissue Cultures, p. 3.13.1.1 – 3.13.1.16. In Clinical Microbiology Procedures Handbook, 2nd Edition, Vol 1 ASM Press, Washington, D.C.
H.D. Isenberg. 2004. Ocular Cultures p. 3.10.1. – 3.10.8. In Clinical Microbiology Procedures Handbook, 2nd Edition, Vol 1 ASM Press, Washington, D.C.