Automated Identification and Antifungal Susceptibility Testing of Candida Species Using Vitek 2 Compact System in ICUs and Pediatric Oncology Unit, Alexandria, Egypt

Abstract

Background: The epidemiology of candida species has changed over the last two decades. Early species identification and rapid antifungal susceptibility testing (AFST) is mandatory in such critical patients. Objectives: To determine the prevalence of different types of Candida species in ICU and pediatric oncology patients as well as their antifungal susceptibility profile using the Vitek 2 compact system. Methodology: 1023 candida isolates were collected from different clinical samples between May 2014 and February 2017. Identification and antifungal susceptibility testing were performed using Vitek 2 compact system. Results: In the present study fifteen candida species were identified. Non albicans Candida species (NAC) were predominant (65.6%). Candida albicans was the most prevalent species (34.5%). Candida tropicalis (c.tropicalis) was the most common isolated NAC species and the second common isolated species (32.8%), followed by Candida glabrata (C.glabrata) (17.3%), Candida Parapsilosis (C.parapsilosis)(7.5%), accounting for 92.1% of the total number of isolates. Uncommon Candida species were also isolated in this study.C. tropicalis was the most frequent species isolated from urine (50.9%), while C. albicans was the most frequent species isolated (43.3%) & (30.8%) from respiratory and blood samplesrespectively.C. parapsilosis was the most common species isolated from indwelling devices (44.4%). Regarding antifungal susceptibility profile (5.1%) and (2 %) of C.albicans were resistant to fluconazole, and voriconazole repectively. C. tropicalis (24.6%) and (17.5%) were resistant to Fluconazole and voriconazole respectively. (13.9%), (7.2%), (2.4%) of C.glabrata isolates were resistant to fluconazole, voriconazole and amphotericin respectively. All C. parapsilosis isolates were sensitive to fluconazole, voriconazole. Although resistant to fluconazole, all C. krusei isolates were susceptible to voriconazole, while, (84.6%) of isolates were resistant to flucytosine. Conclusions: The increased isolation rates of NAC species and gradual shift in the antifungal susceptibility profile underlines the need of early and accurate diagnosis of infecting Candidaspecies along antifungal susceptibility testing.