Malik M, Javed I, Mushtaq S, Anwar M S, Akhtar F K.
Comparison Of Different Staining Techniques And Culture Media Used For Diagnosis Of Infective Keratitis.
Biomedica Jan ;34(1):48-52.

Background and Objectives: Corneal scraping is ideal diagnostic procedure for infective keratitis. It is needed to find simple and proper microbiological investigative modalities for corneal scrapings by using direct microscopic methods, which are easily available and worthy in detection of micro-organisms so that eye clinics develop appropriate and well-timed diagnosis, treatment for averting visual loss. The study was designed to evaluate different staining techniques and culture media used for diagnosis of infective keratitis. It is a descriptive study carried out at Lahore General Hospital, Lahore during June, 2016 ? June 2017, and the samples were processed according to SOPs at Microbiological laboratory of PGMI. Methods: Corneal scrapings were collected from fifty patients who were clinically diagnosed as infective keratitis by Ophthalmologist on clinical examination. The corneal scrapings were immediately inoculated on Chocolate agar, Blood agar, MacConkey agar and Sabouraud?s Dextrose agar with antibiotics. The scrapings were stained with Gram?s staining technique, Kinyoun staining, Giemsa stain and KOH wet mount preparation. Identification of bacterial and fungal pathogens was done by Microbiological SOPs in laboratory. Results: Out of 50 cases of corneal scrapings, 9 (18%) cases of bacterial pathogen were confirmed on Grams staining. One (2%) case of Nocardia spp. was confirmed on Kinyoun staining. 17 (34%) cases of fungal pathogens were confirmed on KOH/LPCB wet mount. Gram staining was 87.88% sensitive and 94.12% specific for diagnosing both bacterial and fungal pathogens. KOH/LPCB were 76.19% sensitive and 96.55% specific for only identification of fungal pathogens. 33 (66%) cases were confirmed in laboratory on cultures. Conclusion: Use of direct smear microscopy of corneal scrapings should be endorsed by different techniques and cultures from the patients who are clinically diagnosed as infective keratitis. Although culture is considered the gold standard but direct microscopy of smears provides prompt information of causative microorganisms.

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