Isolation of Cryptococcus Neoformans from Clinical Samples and Evaluation of Resistance to Antifungal Drugs

Document Type : New and original researches in the field of Microbiology.

Authors

1 College of Health and Medical Technology, Al-Furat Al-Awsat Technical University, Kufa, IRAQ

2 Kufa Technical Institute, Al-Furat Al-Awsat Technical University, Kufa, IRAQ

10.21608/ejmm.2025.381422.1611

Abstract

Background: Cryptococcosis, a severe fungal infection primarily caused by Cryptococcus neoformans, presents substantial risks, particularly to immunocompromised individuals. Objectives: This study aimed to isolate Cryptococcus species from a range of clinical samples and assess their susceptibility to commonly used antifungal agents, containing nystatin, amphotericin B, itraconazole, voriconazole, and fluconazole. Methodology: A total of 240 clinical samples—including sputum, vaginal swabs, bronchoalveolar lavage, and cerebrospinal fluid (CSF)—were collected from patients in hospitals throughout Babylon Governorate, Iraq, during the period between November 2024 and March 2025. Cryptococcus isolates were cultured on Sabouraud dextrose agar (SDA) supplemented with chloramphenicol and were identified through India ink staining, urease testing, and Cryptococcus Differential Agar (CDA)media. Antifungal susceptibility was evaluated using the disk diffusion method, adhering to CLSI standards for accurate and standardized testing. Results: Out of 240 clinical samples, 28 (11.6%) were positive for cryptococcus species. The most common one among these isolates was C. neoformans that accounted for more than 75% of the samples, followed by Cryptococcus gattii (17.8%) and Cryptococcus laurentii (7.1%). Alarmingly, all isolates exhibited complete resistance to nystatin, amphotericin B, itraconazole, voriconazole, and fluconazole. Conclusion: These findings highlight a concerning prevalence of multidrug resistance, especially in Cryptococcus neoformans, underscoring an urgent need for enhanced antifungal stewardship. Furthermore, the results emphasize the importance of molecular surveillance to monitor resistance mechanisms and the necessity for novel antifungal therapies to address emerging challenges in treatment.

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