Candiduria-Study of Virulence Factors and Its Antifungal Susceptibility Pattern in Tertiary Care Hospital

Abstract

Background The increased incidence of candiduria in hospitalized patients is due to the use of indwelling devices, long-term antibiotics, parenteral nutrition, and immunocompromised status of the patient. In this study, an attempt was made to speciate, characterize, and determine the antifungal susceptibility pattern of Candida isolated from urinary tract infections (UTIs). Materials and Methods A total of 70 Candida isolates were obtained from urine samples. The isolated Candida species were studied for the production of virulence factors like phospholipase, protease activities, hemolysin, and biofilm production. Antifungal susceptibility testing of the isolated yeasts was done using Mueller-Hinton agar supplemented with 0.5 mg/mL methylene blue by E-test method for amphotericin B, fluconazole, caspofungin, and voriconazole. Results Out of 70 isolates, Candida tropicalis was the most frequently isolated species (65.7%), followed by Candida albicans (14.3%), Candida glabrata (7.1%), Candida krusei (5.7%), Candida parapsilosis (4.3%), and Candida dubliniensis (2.9%). A total of 37.1% were biofilm producers, 62.9% showed proteinase activity, 38.6% were phospholipase positive, and 58.6% isolates showed hemolytic activity. Antifungal susceptibility profile of Candida species showed 38.6, 25.7, 15.7, and 12.9% resistance to amphotericin B, fluconazole, caspofungin, and voriconazole, respectively. Conclusion A rising trend in isolation of non-albicans Candida from urinary isolates was noticed, which was statistically significant when comparing catheterized and noncatheterized urinary isolates from our study. However, there was no statistically significant difference when different virulence factor expressions were compared among Candida spp. isolated from catheterized and noncatheterized urinary samples. Due to this rise in non-albicans Candida species causing UTI that are intrinsically resistant to certain antifungal agents like azoles and increasing incidence of antifungal resistance, it is essential to monitor the antifungal susceptibility profile of Candida species causing candiduria.

Keywords: biofilm; hemolysin; phospholipase; proteinase; virulence.

Fig. 1

Growth of Candida spp. on Hicrome Agar.

Fig. 2

Phospholipase production in Egg yolk agar.

Fig. 3

Hemolysin production of Candida spp. in Blood agar.

Fig. 4

Biofilm formation by tube adherence method.

Fig. 5

Antifungal susceptibility testing by E-test method.