Novel Chromogenic Medium CHROMagarTM Candida Plus for Detection of Candida auris and Other Candida Species from Surveillance and Environmental Samples: A Multicenter Study.

Juan Vicente Mulet Bayona,Carmelo González Padrón,Javier Pemán,Carme Salvador García,Concepción Gimeno Cardona,Amparo Valentín Martín,Javier Colomina Rodríguez,Nuria Tormo Palop

doi:10.3390/jof8030281

Abstract

Epidemiological trends show a dramatic increase in the prevalence of fungal infections, and in the isolation of multidrug-resistant species, such as Candida auris. CHROMagarTM Candida (CC; CHROMagar, Paris, France) and other chromogenic media, which are widely used in the clinical laboratory because they allow a rapid identification of most Candida species. Recently, CHROMagarTM Candida Plus (CC-Plus; CHROMagar, Paris, France) was developed to detect and differentiate C. auris in addition to other major clinical Candida species, such as C. albicans, C. tropicalis, C. glabrata, or C. krusei. C. auris colonies display a differential light blue color with a blue halo. A multicentric study was designed to evaluate the performance of the CC-Plus medium in the detection of Candida species in patients’ surveillance and environmental samples from three Spanish hospitals with active C. auris outbreaks. A total of 364 patients’ surveillance samples and 212 environmental samples were tested. Samples were inoculated in CC and CC-Plus in parallel, and the plates were read at 24 and 48 h. All recovered colonies were presumptively identified according to colony color described by manufacturer, and the definitive identification was performed by mass spectrometry at 48 h. A total of 134 C. auris isolates were obtained (101 from patients’ surveillance samples, and 33 from environmental samples). Sensitivity, specificity, and predictive positive and negative values were 99.5%, 100%, 100%, and 99.1%, respectively, for the main clinical Candida species, showing that CC-Plus is comparable to CC, with the advantage of being able to differentiate C. auris from C. parapsilosis. Furthermore, CC-Plus was able to detect one C. albicans, one C. glabrata, and eight C. auris that did not grow in CC. Additionally, the yeast colonies were generally larger, suggesting that this novel medium could be a richer medium, and suitable for surveillance and environmental cultures of C. auris and other clinically relevant Candida species.

Highlights

Candida species can cause several types of infection, such as oral, esophageal, vulvovaginal, intra-abdominal, and even life-threatening invasive infections, such as candidemia [1,2]
At Consorcio Hospital General Universitario de Valencia (CHGUV) and HUiP, samples were collected at admission of patients in the intensive care units (ICU), once a week until ICU discharge, whereas in other hospital wards, surveillance was performed to contacts of colonized/infected patients with C. auris
All colonies were generally larger on CHROMagarTM Candida (CC)-Plus, and the size was significantly larger with few colonies on the plate

Summary

Introduction

Candida species can cause several types of infection, such as oral, esophageal, vulvovaginal, intra-abdominal, and even life-threatening invasive infections, such as candidemia [1,2]. Some fungal species, such as C. auris, have been shown to display good patient-to-patient transmission and prolonged environmental persistence in clinical settings, causing major outbreaks, especially in intensive care units (ICU) [8–12]. It is useful to study the epidemiology and incidence of Candida spp. colonization and infections in high-risk units, e.g., intensive care units (ICU) or hematology/oncology units, where the patients have more risk to develop IC, if there is an established outbreak of multidrug-resistant species [16]. In the case of C. auris, it is highly recommended to detect colonized patients as a measure of effective infection control practices [9] In this context, environmental sampling may be of interest, since several studies have proven that C. auris can persist on surfaces for days, suggesting that contaminated surfaces may be a relevant source of acquisition [9,17,18]

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Conclusion