Identification of Candida dubliniensis in a Prospective Study of Patients in the United States

Abstract

Although Candida albicans remains the fungal species most frequently isolated as an opportunistic oral pathogen, other yeast species are often identified in human immunodeficiency virus (HIV)-seropositive patients. Candida dubliniensisphenotypically resembles C. albicans in many respects, yet it can be identified and differentiated as a unique Candidaspecies by its phenotypic and genetic profiles. The purpose of the present study was to prospectively test for the presence of C. dubliniensis among clinical isolates and to determine the clinical and demographic characteristics of patients harboring C. dubliniensis. Over a 90-day period, isolates from 724 patients that were presumptively identified as C. albicans were screened for C. dubliniensis by use of tests for germ tube and chlamydospore production, by detection of an inability to grow at 45°C, by colony color on CHROMagar Candida medium, and by the results of a sugar assimilation test with the API 20C AUX yeast identification system. Among 699 isolates retrieved from those specimens evaluated, 5 from 25 HIV-seropositive patients and 1 isolate from a patient whose HIV status was unknown were shown to be consistent by phenotyping and by electrophoretic karyotyping with the European reference strain ofC. dubliniensis. One of the C. dubliniensisisolates had dose-dependent susceptibility to fluconazole (MIC, 16 μg/ml). These results confirm the presence of this interesting species in the United States and support the need for further investigations into the prevalence and pathogenesis of C. dubliniensis.

Candida albicans or Candida dubliniensis?

“…In addition, only the C. dubliniensis isolates produced at least one band smaller than 1 mb. This characteristic band was also observed for all C. dubliniensis isolates studied by Diaz-Guerra et al [69] and used by Jabra-Rizk et al [87] to differentiate between C. albicans and C. dubliniensis clinical isolates. It must however be kept in mind that the genomes of both C. albicans and C. dubliniensis contain the Major Repeat Sequence, which is the site for most chromosome reorganisations in both species.…”

Prevalence and phenotypic evaluation of Candida dubliniensis in pregnant women with vulvovaginal candidosis in a university hospital in Ankara

“…Only one isolate (2.43%) (isolate no. 9) did not grow at 42°C, whereas 32 isolates (78.04%) failed to grow at 45°C (six isolates grew weak, three isolates grew well) including the one isolate that did not grow at 42°C (isolates that failed to grow at 45°C: 2, 3, 4, 5, 7, 8,9,10,11,12,13,14,15,16,17,18,20,21,23,24,25,26,27,28,29,31,32,35,36,38,40,41).…”

Current trends of HIV disease of the mouth

“…This trend of increased oral carriage of nonalbicans species has been attributed to the widespread use of fluconazole (63,64). There has been considerable interest in the isolation of C. dubliniensis from the mouth of patients with HIV disease (60,(65)(66)(67)(68)(69)(70)(71)(72)(73)(74). This species does occur in adults (60,(65)(66)(67)(68)(69)(70)(71)(72) and children (60,65,70,73) with HIV disease, but is not ubiquitous in HIV infection (59) nor is C. dublininesis only found in people with HIV disease (60,75).…”