Candida dubliniensis: An update.

The increased incidence of fungal infections during the last decade has been well-documented [1-4]. Given that one of the most important factors contributing to this phenomenon is the increased numbers of immunocompromised individuals, it is perhaps not surprising that species previously not associated with human disease and novel species previously unknown to science have been identified as potential pathogens (e.g., Penicillium marneffei [5], Emmonsia pasteuriana [6] and Candida dubliniensis [7]). C. dubliniensis was first identified as a new species in 1995 [7]. As its name suggests this species was originally described in Dublin, Ireland. While performing an epidemiological investigation of oral candidosis in Irish HIV-infected individuals and AIDS patients in the early 1990s it was discovered that some germ tubeand chlamydospore-positive isolates, which were identified as Candida albicans on the basis of these characteristics, failed to hybridize efficiently with the C. albicans-specific DNA fingerprinting probe 27A [7,8]. Subsequent in-depth analysis of these organisms revealed that they constituted a distinct species clearly separate from, but closely related to, C. albicans [7]. In the intervening four years C. dubliniensis isolates have been identified in a range of clinical settings by many laboratories throughout the world [9-19]. The purpose of this short article is to review briefly the most recent data available on C. dubliniensis. In particular we wish to highlight the advances being made in the development of rapid and accurate tests to allow the discrimination of C. dubliniensis from other Candida species, especially C. albicans. With the introduction of these tests we hope that many other laboratories will be encouraged to search for this species in clinical specimens and culture collections and thus provide further information concerning the epidemiology and the true clinical significance of this newly identified opportunistic pathogen. Phenotypic characteristics