Antifungal Resistance of
            <i>Candida glabrata</i>
            Vaginal Isolates and Development of a Quantitative Reverse Transcription-PCR-Based Azole Susceptibility Assay

Gygax, Scott E.; Vermitsky, John-Paul; Chadwick, Sean G.; Self, Matthew J.; Zimmerman, Jessica; Mordechai, Eli; Adelson, Martin E.; Trama, Jason P.

doi:10.1128/aac.00462-08

Cited by 23 publications

(20 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Specifically, PCR methods for the detection of mutations in the FKS1 gene that confer resistance to echinocandins (211) or of EGR11 mutations or overexpression of pump genes, such as CDR1, CDR2, and MDR1 (212), have recently been described. All these experimental techniques come with the promise of much more rapid identification of resistant Candida infections than the case with traditional broth microdilution methods, thus permitting timely initiation of appropriate treatment and decreasing the rates of treatment failure (213).…”

Section: Pcrmentioning

confidence: 99%

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

et al. 2014

View full text Add to dashboard Cite

SUMMARY Invasive fungal infections constitute a serious threat to an ever-growing population of immunocompromised individuals and other individuals at risk. Traditional diagnostic methods, such as histopathology and culture, which are still considered the gold standards, have low sensitivity, which underscores the need for the development of new means of detecting fungal infectious agents. Indeed, novel serologic and molecular techniques have been developed and are currently under clinical evaluation. Tests like the galactomannan antigen test for aspergillosis and the β-glucan test for invasive Candida spp. and molds, as well as other antigen and antibody tests, for Cryptococcus spp., Pneumocystis spp., and dimorphic fungi, have already been established as important diagnostic approaches and are implemented in routine clinical practice. On the other hand, PCR and other molecular approaches, such as matrix-assisted laser desorption ionization (MALDI) and fluorescence in situ hybridization (FISH), have proved promising in clinical trials but still need to undergo standardization before their clinical use can become widespread. The purpose of this review is to highlight the different diagnostic approaches that are currently utilized or under development for invasive fungal infections and to identify their performance characteristics and the challenges associated with their use.

show abstract

Section: Pcrmentioning

confidence: 99%

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

et al. 2014

View full text Add to dashboard Cite

show abstract

“…RNA was extracted by using hot SDS-phenol followed by ethanol precipitation as described previously (5), suspended in 50 l nuclease-free water, and treated with RQ1 DNase (Promega) as recommended by the manufacturer. RNA (diluted to 50 ng/l) was analyzed by quantitative reverse transcription (qRT)-PCR as described previously (20), using one-step qRT-PCR on the Stratagene Mx3000P QPCR system (Stratagene). Assays (25 l) in triplicate contained 125 ng RNA, 0.6 M each primer (CDR1F and CDR1R or ACT1F and ACT1R), 0.2 M FAMlabeled probe, 12.5 l Quanta one-step master mix (2ϫ) (Quanta Biosciences), 6.5 l water, and 0.5 l Quanta Escript one-step reverse transcriptase.…”

Section: Mediamentioning

confidence: 99%

Flucytosine Antagonism of Azole Activity versus Candida glabrata: Role of Transcription Factor Pdr1 and Multidrug Transporter Cdr1

Steier

Vermitsky

Toner

et al. 2013

Antimicrob Agents Chemother

Self Cite

View full text Add to dashboard Cite

bInfections with the opportunistic yeast Candida glabrata have increased dramatically in recent years. Antifungal therapy of yeast infections commonly employs azoles, such as fluconazole (FLC), but C. glabrata frequently develops resistance to these inhibitors of ergosterol biosynthesis. The pyrimidine analog flucytosine (5-fluorocytosine [5FC]) is highly active versus C. glabrata but is now rarely used clinically due to similar concerns over resistance and, a related concern, the toxicity associated with high doses used to counter resistance. Azole-5FC combination therapy would potentially address these concerns; however, previous studies suggest that 5FC may antagonize azole activity versus C. glabrata. Here, we report that 5FC at subinhibitory concentrations antagonized the activity of FLC 4-to 16-fold versus 8 of 8 C. glabrata isolates tested. 5FC antagonized the activity of other azoles similarly but had only indifferent effects in combination with unrelated antifungals. Since azole resistance in C. glabrata results from transcription factor Pdr1-dependent upregulation of the multidrug transporter gene CDR1, we reasoned that 5FC antagonism might be similarly mediated. Indeed, 5FC-FLC antagonism was abrogated in pdr1⌬ and cdr1⌬ strains. In further support of this hypothesis, 5FC exposure induced CDR1 expression 6-fold, and this upregulation was Pdr1 dependent. In contrast to azoles, 5FC is not a Cdr1 substrate and so its activation of Pdr1 was unexpected. We observed, however, that 5FC exposure readily induced petite mutants, which exhibit Pdr1-dependent CDR1 upregulation. Thus, mitochondrial dysfunction resulting in Pdr1 activation is the likely basis for 5FC antagonism of azole activity versus C. glabrata.

show abstract

“…Surveillance programs performed over the past few decades have demonstrated that although azole resistance is rare in Candida albicans isolates (<1%), it is becoming very common among isolates of non-albican species (up to 15%) [6]. The rise in VVC infections, and more specifically in non-albicans species, could be due to several factors ranging from an increase in over-the-counter antifungal use to an increase in high-risk patient populations (i.e., sexually active young females).…”

Section: Introductionmentioning

confidence: 99%

Isolation and antifungal sensitivity to Candida isolates in young females

Adesiji¹,

Ndukwe

Okanlawon

2011

Open Medicine

View full text Add to dashboard Cite

AbstractA survey of 104 sexually active young females tested on on cervico-vaginal swabs showed that 26 of the females (25%) had vulvovaginal candidiasis with a species distribution of Candida isolates accounting for 13 (50%) with C. albicans, 6 (23%) with C. glabrata, 1 (4%) with C. krusei, and 6 (23%) with C. tropicalis. Of the 26 (25 %) subjects that were positive for VVC, 8 (7.8 %) were symptomatic and 18 (18.8 %) were asymptomatic. However, distribution among different age groups revealed an increase in the 23–27 age group. The comparative analysis of sensitivity of the given fungi to the number of antimycotic preparations used revealed the following: in fluconazole, 2 (7.8%) isolates were sensitive, 5 (19.2%) were susceptible and dose dependent, and 19 (73%) were resistant. For voriconazole, 4 (18.4%) isolates were sensitive, 6 (23.1%) were susceptible and dose dependent, and 16 (61.5%) were resistant. For nystatin, 5 (19.2%) isolates were sensitive, 10 (38.5%) were susceptible and dose dependent, and 11 (42.3%) were resistant. It appears that Candida isolates have a variable resistance response, but 19 (73%) had maximum resistance of the isolated fungi of the genus Candida to fluconazole. Therefore, further studies on the evaluation of combination therapy should be considered for a better outcome in treatment of vulvovaginal candidiasis.

show abstract

Antifungal Resistance of Candida glabrata Vaginal Isolates and Development of a Quantitative Reverse Transcription-PCR-Based Azole Susceptibility Assay

Cited by 23 publications

References 20 publications

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

Molecular and Nonmolecular Diagnostic Methods for Invasive Fungal Infections

Flucytosine Antagonism of Azole Activity versus Candida glabrata: Role of Transcription Factor Pdr1 and Multidrug Transporter Cdr1

Isolation and antifungal sensitivity to Candida isolates in young females

Contact Info

Product

Resources

About