Is inclusion of Sabouraud dextrose agar essential for the laboratory diagnosis of fungal keratitis?

<b<Purpose:</b< To determine whether the inclusion of Sabouraud dextrose agar (SDA) is essential in the diagnosis of fungal keratitis. <b< Materials and Methods:</b< Corneal scrapings of 141 patients with microbial keratitis were smeared and cultured. Sheep blood agar (BA),...
Ausführliche Beschreibung

<b<Purpose:</b< To determine whether the inclusion of Sabouraud dextrose agar (SDA) is essential in the diagnosis of fungal keratitis. <b< Materials and Methods:</b< Corneal scrapings of 141 patients with microbial keratitis were smeared and cultured. Sheep blood agar (BA), chocolate agar (CA), SDA, non-nutrient agar (NNA) with <i<Escherichia coli </i<overlay, and brain heart infusion broth (BHI) were evaluated for time taken for growth and cost. The media were also evaluated experimentally for rate of growth and time taken for identification. <b< Results:</b< Twenty-six of 39 patients positive for fungus in corneal scrapings by microscopy were culture-positive. Fungus grew on BA in 22/39, on CA in 18/39, on SDA in 17/39, on NNA in 17/39, and on BHI in 13/39 cases. Growth on SDA was higher in ulcers with larger infiltrate (6/18 versus 9/13, <i<P</i< = 0.04). Estimated saving with inclusion of only BA/CA was Rs. 600 per patient. Performance of all media was similar in <i<in vitro</i< experiment although the characteristic spores and color were seen earlier on SDA. <b< Conclusion:</b< Fungal keratitis can be reliably confirmed on BA or CA, which support growth of both bacteria and fungus. Ausführliche Beschreibung