Molecular epidemiology of Candida isolates from AIDS patients showing different fluconazole resistance profiles

Lischewski, A.; Ruhnke, Markus; Tennagen, I; Schönian, Gabriele; Morschhäuser, Joachim; Hacker, Jörg

doi:10.1128/jcm.33.3.769-771.1995

Cited by 34 publications

(23 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fluconazole is a successful antifungal agent for treating all forms of Candida infections, but the repetition and lengthy duration of therapy lead to an increased incidence of FLU resistance following treatment failure. 2,3,21,22 Environmental changes can trigger morphological and physiological differentiation of Candida isolates and induce site-specific infections or systemic disease. This differentiation is mediated by induction of fungal virulence factors enabling C. albicans to spread within the host.…”

Section: Discussionmentioning

confidence: 99%

Difference in virulence between fluconazole‐susceptible and fluconazole‐resistant Candida albicans in a mouse model

Schulz

Weber

Schmidt

et al. 2011

Mycoses

View full text Add to dashboard Cite

Two Candida albicans isolates were collected from a HIV-positive patient with recurrent oropharyngeal candidosis (OPC). One isolate was taken during the first episode of oral candidosis [fluconazole susceptible (FLU-S), minimal inhibitory concentration (MIC) = 0.25 mg l(-1) ] and the second after the patient developed refractory OPC and resistance to fluconazole (FLU-R, MIC = 64 mg l(-1)). Both isolates were clonally identical. Different in vitro studies were carried out to assess putative virulence factors of both isolates. Gene expressions of efflux pumps and CSH1 were determined as well as adherence to human epithelial cells, determination of proteinase secretion and biofilm formation activity. Virulence was studied using a disseminated mouse model. All mice challenged with the FLU-S isolate survived the experiment when FLU was given. However, when FLU was absent, the mortality of the FLU-S isolate was higher than that of the FLU-R isolate with no mice surviving the experiment. In vitro studies showed pronounced growth rates of the FLU-S isolate and a more intense biofilm-building activity compared with the FLU-R isolate. The FLU-R isolate highly up-regulated MDR1 and CSH1. This isolate also adhered stronger to the epithelial cell line. The results showed that FLU-S and FLU-R isolates exhibit different virulence factors, which enable the survival of both isolates in adapted environments.

show abstract

Section: Discussionmentioning

confidence: 99%

Difference in virulence between fluconazole‐susceptible and fluconazole‐resistant Candida albicans in a mouse model

Schulz

Weber

Schmidt

et al. 2011

Mycoses

View full text Add to dashboard Cite

show abstract

“…DNA typing methods based on RAPD, PFGE and RFLP offer potential advantages for characterisation of the relatedness of different isolates of Candida (7, 24). In order to gain a high resolution power in genotyping, one has to combine either independent techniques that differ in their molecular targets, or to use a single technique with several variations, allowing more accurate strain identification within C. albicans (5, 7, 23, 25). In the current study, three independent molecular typing methods were employed, namely, PFGE, RAPD and RFLP, to evaluate the clonal nature amongst geographically related Candida isolates that were either FLZ resistant or sensitive.…”

Section: Discussionmentioning

confidence: 99%

“…Emergence of drug resistance in C. albicans is now a universal problem, especially in patients with immunosuppressive conditions associated with acquired immune deficiency syndrome (AIDS), organ transplantation, and cancer chemotherapy (4–9). A particularly distressing aspect of antifungal therapy is the rapid emergence of C. albicans strains that are resistant to fluconazole (FLZ).…”

mentioning

confidence: 99%

Molecular heterogeneity of fluconazole‐resistant and ‐susceptible oral Candida albicans isolates within a single geographic locale

Dassanayake

Ellepola

Samaranayake

et al. 2002

APMIS

View full text Add to dashboard Cite

The emergence of drug-resistant Candida albicans in immunocompromised patients is common. A disconcerting aspect of this phenomenon is the rapid emergence of C. albicans strains that are resistant to a widely used azole drug, fluconazole (FLZ). To understand the origin of FLZ-resistant yeast isolates, we investigated molecular profiles of 20 geographically related oral C. albicans isolates using three genotyping methods: randomly amplified polymorphic DNA-PCR, with six different primers (OBU1, OBU2, OBU3 RSD6, RSD11 and RSD12); electrophoretic karyotyping by pulsed-field gel electrophoresis; and HinfI restriction fragment analysis. Of the 20 isolates studied, 10 were FLZ- resistant and originated from patients with oral candidosis with a history of FLZ therapy, and the remainder were FLZ susceptible from individuals with oral candidosis, but without a history of FLZ therapy. A composite genotype was generated for each strain by combining molecular types derived from the three independent molecular methods. The composite profiles indicated genetic diversity amongst both the FLZ-resistant as well as -sensitive isolates, and no specific features emerged distinguishing the drug-resistant and -sensitive groups. These observations cast doubt on the theory of a clonal origin of FLZ-resistant C. albicans isolates.

show abstract

“…Almost all of these studies were based on only one molecular technique; however, when more than one molecular typing system has been used to evaluate C. albicans strains, a more accurate strain delineation has been achieved (9). Although comparisons of the usefulness of different DNA-based methods for the delineation of C. albicans strains isolated either from patients with oral candidiasis (7) or from other clinical settings (3) have recently been published, no one method has been defined as the more suitable one.…”

Section: Discussionmentioning

confidence: 99%

Comparison of four molecular typing methods for evaluating genetic diversity among Candida albicans isolates from human immunodeficiency virus-positive patients with oral candidiasis

et al. 1997

View full text Add to dashboard Cite

Candida albicans strain delineation by karyotyping, NotI restriction pattern analysis, hybridization with specific probe 27A, and PCR fingerprinting with the phage M13 core sequence were performed with 30 isolates from the oral cavities of 30 human immunodeficiency virus (HIV)-infected patients and 8 reference strains. Within the panel of clinical isolates, 20 were geographically related, although 10 isolates were susceptible to fluconazole and 10 isolates were resistant to fluconazole. The remaining isolates used in this study were fluconazole resistant and geographically unrelated. A composite DNA type was defined for each of the strains as the combination of types obtained by the four molecular methods. By this procedure, a great diversity of DNA types was found among isolates from the oropharynges of HIV-infected individuals with oral candidiasis. This diversity was not reduced when isolates were evaluated on the basis of whether they came from the same geographical locale and whether they were fluconazole resistant. These data refute the idea of a clonal origin for fluconazole-resistant strains among HIV-positive patients. Karyotyping was the least discriminatory method, yielding 19 DNA types among the 38 strains analyzed. Conversely, hybridization with the 27A probe showed a unique DNA pattern for each of the strains examined in this study. Our results demonstrate that at least two different molecular methods are needed for Candida albicans typing and that there is a great deal of strain variation within the species, irrespective of place of origin or antifungal resistance patterns.

show abstract

Molecular epidemiology of Candida isolates from AIDS patients showing different fluconazole resistance profiles

Cited by 34 publications

References 28 publications

Difference in virulence between fluconazole‐susceptible and fluconazole‐resistant Candida albicans in a mouse model

Difference in virulence between fluconazole‐susceptible and fluconazole‐resistant Candida albicans in a mouse model

Molecular heterogeneity of fluconazole‐resistant and ‐susceptible oral Candida albicans isolates within a single geographic locale

Comparison of four molecular typing methods for evaluating genetic diversity among Candida albicans isolates from human immunodeficiency virus-positive patients with oral candidiasis

Contact Info

Product

Resources

About