Molecular typing and antifungal susceptibility of Candida tropicalis, isolated from cancer patients.
S. C. Gagulie 1*, P. N. Dasanayaka1, W.A.S. Wijendra2, R. Ramesh2 , A. G. G. Kaushalya2 and S. Gunasekara 3
1Department of Botany University of Sri Jayewardenepura, Sri Lanka.
2Medical Research Institute, Sri Lanka.
3Department of Microbiology and infection control, Apkesha Hospital, Maharagama, Sri Lanka.
In recent years, the prevalence of Candida species among cancer patients has shifted, with an increasing incidence of non-albicans Candida species, particularly Candida tropicalis. However, the rise in antifungal drug resistance in Candida tropicalis poses challenges to effective cancer patient management. Consequently, there’s a pressing need for a rapid and efficient method to identify Candida tropicalis and assess its susceptibility to antifungal drugs. This study investigated 52 Candida isolates obtained from cancer patients at Apeksha Hospital in Sri Lanka. Molecular identification employed a multiplex PCR technique utilizing specific primer pairs for two strains of C. tropicalis (C. tropicalis I and C. tropicalis II). Furthermore, the antifungal susceptibility of the identified C. tropicalis isolates was evaluated using the disk diffusion method on Mueller-Hinton agar, following CLSI guidelines. The susceptibility testing encompassed six antifungal drugs: Fluconazole, Itraconazole, Clotrimazole, Miconazole, Ketoconazole, and Amphotericin B. Among the 52 isolates, 20 samples (38%) were identified as C. tropicalis II, while C. tropicalis I wasn’t detected. Susceptibility testing revealed Fluconazole as the most effective drug against C. tropicalis II (90%), with Amphotericin B exhibiting the lowest susceptibility (10%). Ketoconazole, Clotrimazole, Itraconazole, and Miconazole displayed varying degrees of susceptibility. Based on these findings, the study advocates for the superior utility of multiplex PCR in clinically and diagnostically identifying C. tropicalis. Additionally, it highlights Fluconazole as the optimal antifungal drug for treating C. tropicalis infections, cautioning against the use of Amphotericin B due to its low susceptibility rates. These results can effectively guide clinicians in managing C. tropicalis infections among cancer patients.