Adherence of different Candida dubliniensis isolates in the presence of fluconazole.
BACKGROUND
The recently described yeast species Candida dubliniensis is closely related to C. albicans and has been recovered predominantly from the oral cavities of HIV-infected individuals and AIDS patients who are often receiving fluconazole as prophylactic or therapeutic treatment for oropharyngeal candidiasis. Like C. albicans, C. dubliniensis secretes aspartic proteinases which in C. albicans have been shown to be involved in adherence.


OBJECTIVE
To explain the increasing prevalence of C. dubliniensis in AIDS patients and to investigate the virulence factors of this yeast.


METHODS
An in vitro assay was developed to compare the adherence to epithelial cells of C. dubliniensis from HIV-patients with that of C. albicans.


RESULTS
All C. albicans isolates adhered better than the 22 C. dubliniensis isolates. In the presence of fluconazole, the C. dubliniensis isolates tested showed increased adherence as compared with controls without fluconazole. In contrast, all C. albicans isolates decreased in adherence to epithelial cells in the presence of fluconazole independently of their in vitro susceptibility to this drug. Proteinase antigens are present on the surface of C. dubliniensis cells adherent to epithelial target cells. In the presence of fluconazole this proteinase antigen was more strongly expressed.


CONCLUSIONS
Increased adherence of C. dubliniensis strains in the presence of fluconazole could explain its high recovery rate from HIV-positive patients in recent years. The induction of proteinase secretion in the presence of fluconazole found for most of the C. dubliniensis isolates could be one of the factors involved in adherence.
Borg-von Zepelin
Margarete
M
Department of Bacteriology, University Clinics, Göttingen, Germany.
Niederhaus
Tatjana
T
Gross
Uwe
U
Seibold
Michael
M
Monod
Michel
M
Tintelnot
Kathrin
K
D017088:AIDS-Related Opportunistic Infections / Q000382:microbiology*; D002175:Candida / Q000145:classification / Q000187:drug effects* / Q000378:metabolism / Q000472:pathogenicity*; D002176:Candida albicans / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000472:pathogenicity; D002180:Candidiasis, Oral / Q000382:microbiology*; D002448:Cell Adhesion; D010450:Endopeptidases / Q000378:metabolism; D004847:Epithelial Cells / Q000382:microbiology; D015725:Fluconazole / Q000494:pharmacology*; D006801:Humans; D009061:Mouth Mucosa / Q000382:microbiology
D015725:Fluconazole; D010450:Endopeptidases