Candida dubliniensis

Candida dubliniensis is a fungal opportunistic pathogen originally isolated from AIDS patients. It is also occasionally isolated from immunocompetent individuals. It is of the genus Candida, very closely related to Candida albicans but forming a distinct phylogenetic cluster in DNA fingerprinting. It is most commonly isolated from oral cavities,^[1] and is also occasionally found in other anatomical sites.

Candida dubliniensis
Gram stain of Candida dubliniensis cells (1000-fold magnification)
Scientific classification
Kingdom:	Fungi
Division:	Ascomycota
Class:	Pichiomycetes
Order:	Serinales
Family:	Debaryomycetaceae
Genus:	Candida
Species:	C. dubliniensis
Binomial name
Candida dubliniensis Sullivan et al. (1995)

Prevalence and epidemiology

Candida dubliniensis is cosmopolitan (found around the world), and has been described as a separate species in 1995.^[2] Retrospective studies have shown that previously it had been commonly identified as Candida albicans, with which C. dubliniensis is closely related and shares a number of characteristics.

One test for distinguishing C. dubliniensis from C. albicans, is laboratory culture of the organism at 42 °C. Most C. albicans strains grow at this temperature,^[3] whereas most C. dubliniensis isolates do not.^[2] There are also significant differences in the conditions that lead to the formation of chlamydospores between C. albicans and C. dubliniensis, although they are otherwise phenotypically very similar.^[2]

The Memorial Sloan-Kettering Cancer Center conducted several studies, both retrospective and prospective. In 974 germ-tube positive yeasts, 22 isolates (2.3%) from 16 patients were C. dubliniensis. All individuals were immunologically compromised with either malignancy or AIDS, and the isolates came from a variety of different sites. C. dubliniensis was also isolated from the mouths of 18% of patients with diabetes and who use insulin.^[4]

Antifungal susceptibility

In one study, all 20 C. dubliniensis isolates tested were susceptible to itraconazole, ketoconazole and amphotericin B.^[5]

Fluconazole

Many isolates of C. dubliniensis are sensitive to fluconazole. In one study, sixteen of twenty isolates were sensitive to fluconazole, while four were resistant.^[5] It has been hypothesized that C. dubliniensis possesses the ability to rapidly develop resistance to fluconazole, especially in patients on long-term therapy.^[5]