Utility of sunflower agar for laboratory detection of Cryptococcus neoformans

Abstract

Background: Early diagnosis and management of cryptococcal meningitis is associated with good prognosis and long-term survival. Culture methods have been found to be promising and definitive in the diagnosis of many infectious diseases. We look at the sunflower agar (SFA) cultural method for detection Cryptococcus neoformans, the causative agent of cryptococcal meningitis. Materials and Methods: This is a descriptive cross-sectional study carried out at Jos University Teaching Hospital, Jos Nigeria, to find out the performance of SFA for the detection of C. neoformans. Cerebrospinal fluids (CSFs) of the study subjects were collected, subjected to Indian ink microscopy, inoculated on Sabouraud dextrose agar (SDA) and SFA for identification of C. neoformans. Results: A total of 90 CSF samples were analyzed for the identification of C. neoformans. SFA and SDA were able to confirm 8 (50%) and 7 (43%) of the 16 capsulated yeast cells detected by Indian ink microscopy as C. neoformans. Both media were found to have similar sensitivity (100%), specificity (91.3%), positive predictive value (80%), and negative predictive value (100%) in comparison with Indian ink microscopy. In terms of turnaround time, 6 isolates were identified within an average of 48 h (P = 0.017) by SFA, while SDA detects 2 isolates (P = 0.111) at the stipulated period. Conclusion: SFA can be a good routine conventional culture media for laboratory detection of C. neoformans.