Antifungal susceptibility patterns, in vitro production of virulence factors, and evaluation of diagnostic modalities for the speciation of pathogenic Candida from blood stream infections and vulvovaginal candidiasis.

Chaitanya Tellapragada,Nidhi Malik,Parvati V Bhat,Tushar Shaw,Vandana Kalwaje Eshwara,Ruqaiyah Johar,Chiranjay Mukhopadhyay,Asha Kamath

doi:10.1155/2014/142864

Chaitanya Tellapragada, Nidhi Malik + Show 6 more

Open Access

https://doi.org/10.1155/2014/142864

Copy DOI

Abstract

Candida spp. have emerged as successful pathogens in both invasive and mucosal infections. Varied virulence factors and growing resistance to antifungal agents have contributed to their pathogenicity. We studied diagnostic accuracy of HiCrome Candida Differential Agar and Vitek 2 Compact system for identification of Candida spp. in comparison with species-specific PCR on 110 clinical isolates of Candida from blood stream infections (54, 49%) and vulvovaginal candidiasis (56, 51%). C. albicans (61%) was the leading pathogen in VVC, while C. tropicalis (46%) was prominent among BSIs. HiCrome Agar and Vitek 2 Compact had good measures of agreement (κ) 0.826 and 0.895, respectively, in comparison with PCR. We also tested these isolates for in vitro production of proteinase, esterase, phospholipases, and biofilms. Proteinase production was more among invasive isolates (P = 0.017), while phospholipase production was more among noninvasive isolates (P = 0.001). There was an overall increase in the production of virulence factors among non-albicans Candida. Identification of clinical isolates of Candida up to species level either by chromogenic agar or by Vitek 2 Compact system should be routinely done to choose appropriate therapy.

Highlights

The opportunistic yeasts belonging to the genus Candida have been associated with a wide range of human infections and significant mortality and morbidity
Of the total 110 isolates studied, 54 (49%) were obtained from the blood cultures of patients with candidaemia comprising C. tropicalis (25, 46%), C. parapsilosis (16, 30%), C. albicans (7, 13%), C. glabrata (2, 4%), C. krusei (1, 2%), and other Candida spp. (3, 6%). Another 56 (51%) Candida isolates were from women of reproductive age group diagnosed with VVC involving C. albicans (34, 61%), C. glabrata (11, 20%), C. tropicalis (5, 9%), C. parapsilosis (2, 4%), C. krusei (2, 4%), and other Candida spp. (2, 4%)
As polymerase chain reaction (PCR) did not identify the species of 5 Candida isolates, only 105 Candida were included in the analysis of diagnostic utility of HiCrome Candida Differential Agar and Vitek 2 Compact system

Summary

Introduction

The opportunistic yeasts belonging to the genus Candida have been associated with a wide range of human infections and significant mortality and morbidity. Estimates suggest that Candida spp. have been the third most common nosocomial pathogens associated with blood stream infections (BSIs) [1]. Though C. albicans has been associated mostly with human infections, there has been an increase in the prevalence of infections due to non-albicans Candida in the recent past [3, 4]. Of the many pathogenic non-albicans species known, C. tropicalis, C. parapsilosis, C. kefyr, C. krusei, and C. guilliermondii are mostly associated with human infections. Though non-albicans Candida have proven to be common pathogens in most invasive infections, little attention is given to their virulence attributes. With the increasing rate of infections due to non-albicans Candida and varying susceptibilities to commonly used empirical

Objectives

Methods

Results

Discussion

Conclusion