Phenotypic identification and antifungal susceptibility patterns of Candida species isolated from various clinical specimens in Suez Canal University Hospitals

Abstract

Background: Candida is the most common cause of fungal infections. Candida species are identified by different phenotypic methods. Accurate identification of Candida species enables appropriate selection of antifungal agents by clinicians. Azoles are the most frequently used antifungal drugs to treat Candida infections. However, resistance among previously susceptible Candida species has emerged which made antifungal susceptibility testing crucial. Aim: This study aimed to phenotypically identify the different Candida species isolated from various clinical specimens in Suez Canal University Hospitals (SCUHs), and to assess their antifungal susceptibility patterns. Method: One hundred and five clinical specimens were collected from different departments in SCUHs. Isolates were identified as Candida by colony morphology on Sabouraud dextrose agar and Gram staining. Candida species were phenotypically identified using germ tube test, hypertonic Sabouraud broth, corn meal agar, chromogenic Candida agar, KB006 HiCandida Identification Kit and Vitek 2 YST-ID system. Antifungal susceptibility to fluconazole, voriconazole and amphotericin B was done by disk diffusion method. Results: Prevalence of Candida was 54.3%. C. tropicalis was the most common species followed by C. albicans, C. dubliniensis, C. glabrata, C. parapsilosis and lastly C. kefyr. Only one strain was resistant to amphotericin B. Eight strains were susceptible dose dependent, and 2 were resistant to fluconazole. No resistance was detected to voriconazole. Conclusions: The prevalence of candidiasis is remarkable. Non-albicans Candida species (NACs) cause most of these infections. Fluconazole and amphotericin B showed low resistance rates. No resistance to voriconazole was reported in this study. Therefore, voriconazole could be more effective as empirical therapy than fluconazole and amphotericin B. Accurate identification of Candida species is essential for therapeutic and prognostic impact, appropriate selection of antifungal agents by clinicians and controlling the increase of resistant Candida strains.

Keywords

• candida
• germ tube
• amphotericin b
• fluconazole
• voriconazole