BRILLIANCE CANDIDA AGAR  

CODE: CM1002

Brilliance™ Candida Agar (formerly Oxoid Chromogenic Candida Agar (OCCA)) is a selective diffrential medium for the rapid isolation and identification of  clinically important Candida species.

* Adjusted as required to meet performance standards

BRILLIANCE CANDIDA SELECTIVE SUPPLEMENT

Code: SR0231

Directions
Suspend 15.6g in 500ml of distilled water. Add 1 vial of Brilliance Candida Selective Supplement reconstituted as directed. Mix well and bring to the boil with frequent agitation. DO NOT AUTOCLAVE. Cool the medium to 45°C and pour into sterile Petri dishes.

Description
Brilliance Candida Agar allows the differentiation of Candida albicans and Candida tropicalis from other species of Candida within 48 hours. This is important because rapid identification has been shown to have an impact on the morbidity, mortality, and duration of hospitalization. However, conventional identification of Candida spp. is based on a time-consuming and extensive series of tests, e.g. carbohydrate fermentation and assimilation, growth at 37°C and 42°C, colony and cell morphology and the ability to form germ tubes.

Serious infections due to Candida species are becoming increasingly prevalent. This poses particular problems because of the increasing incidence of non-albicans spp. and the emergence of non-albicans isolates resistant to both amphotericin B and the newer azoles¹. Candida species are the fourth most commonly encountered nosocomial pathogens in bloodstream infections in the United States, and candidiasis is associated with mortality rates as high as 60% in immuno-suppressed patients.

Of the Candida spp. encountered in clinical practice, Candida albicans is the most common, and this species is usually susceptible to the azole group of antifungal agents. However, it is the shift toward the isolation of more azole-tolerant species, such as Candida glabrata, Candida tropicalis, and Candida krusei, due to the increasing use of itraconazole and fluconazole as the antifungal drugs of first choice for candidiasis, which is causing greatest concern. Rapid identification of the Candida spp. causing infection is, therefore, critical for the clinician in determining the correct antifungal therapy².

For Candida species involved in bloodstream infections on ICUs, it was shown by Ibrahim et al.³ that initial therapy was inadequate in 95% of the cases because no antifungal agent was administered. Due to this inadequacy in the initial treatment, a mortality rate of about 60% was observed in the patient group with Candida infections. Hence, early recognition of a Candida infection would help a clinician to select proper treatment. Combined with rapid identification of the causative organism, this treatment could be optimized to include a non-azole group anti-fungal agent, if required, at an early stage of the infection.

Brilliance Candida Agar incorporates two chromogens that indicate the presence of the target enzymes:

• X-NAG (5-bromo-4-chloro-3-indolyl N acetyl ß-D-glucosaminide) detects the activity of hexosaminidase.
• BCIP (5-bromo-6-chloro-3-indolyl phosphate p-toluidine salt) detects alkaline phosphatase activity.

The typical enzyme patterns of Candida spp. are shown in Table 1. An opaque agent has been incorporated into the formulation to improve the colour definition on the agar. The broad-spectrum antibacterial agent, chloramphenicol, is added to the agar at 500mg/l to inhibit bacterial growth on the plates.

Technique
Good laboratory practices for the appropriate collection and transport of specimens should be followed. Clinical specimens should be inoculated directly onto the agar. Incubate plates aerobically at 30°C. Inspect for the growth of Candida spp. at 24, 48 and 72 hours.

Table 1: Table of expected reactions on Brilliance Candida Agar

Notes:
‡ The green colour of Candida albicans and Candida dubliniensis is caused by the same chromogenic reaction as the dark blue colour of Candida tropicalis. However, other reactions caused by the medium (the nature of which are subject to a patent application) cause the colonies to appear green.

† Candida glabrata, Candida kefyr, Candida parapsilosis and Candida lusitaniae appear as a variety of beige/brown/yellow colours, due to the mixture of natural pigmentation and some alkaline phosphatase activity. Experienced users may be able to differentiate these species by colour and colony morphology.

For further instructions on the use and interpretation of Brilliance Candida Agar, simply download the data sheet (643KB) in PDF format. Please confirm prepared media codes with your local supplier.

Storage conditions and Shelf Life
Brilliance Candida Agar Base must be stored tightly capped in the original container at 10-30°C. Brilliance Candida Selective Supplement must be stored at 2-8°C. When stored as directed the unopened products will remain stable until the expiry date printed on the containers.
Prepared medium may be stored for up to 2 weeks at 2-8°C.

Appearance
Dehydrated medium: straw coloured, free-flowing powder
Prepared medium: cream coloured opaque gel

Quality control