scholarly journals Detection of Candida dubliniensis in Oropharyngeal Samples from Human Immunodeficiency Virus-Infected Patients in North America by Primary CHROMagar Candida Screening and Susceptibility Testing of Isolates

1998 ◽  
Vol 36 (10) ◽  
pp. 3007-3012 ◽  
Author(s):  
William R. Kirkpatrick ◽  
Sanjay G. Revankar ◽  
Robert K. Mcatee ◽  
Jose L. Lopez-Ribot ◽  
Annette W. Fothergill ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Germ Tube ◽  
Susceptibility Testing ◽  
San Antonio ◽  
Antifungal Susceptibility ◽  
Tube Formation ◽  
Candida Dubliniensis ◽  
Differential Growth ◽  
Immunodeficiency Virus ◽  
Dark Green

Candida dubliniensis has been associated with oropharyngeal candidiasis in patients infected with human immunodeficiency virus (HIV). C. dubliniensis isolates may have been improperly characterized as atypical Candida albicans due to the phenotypic similarity between the two species. Prospective screening of oral rinses from 63 HIV-infected patients detected atypical dark green isolates on CHROMagar Candida compared to typical C. albicans isolates, which are light green. Forty-eight atypical isolates and three control strains were characterized by germ tube formation, differential growth at 37, 42, and 45°C, identification by API 20C, fluorescence, chlamydoconidium production, and fingerprinting by Ca3 probe DNA hybridization patterns. All isolates were germ tube positive. Very poor or no growth occurred at 42°C with 22 of 51 isolates. All 22 poorly growing isolates at 42°C and one isolate with growth at 42°C showed weak hybridization of the Ca3 probe with genomic DNA, consistent with C. dubliniensis identification. No C. dubliniensisisolate but only 18 of 28 C. albicans isolates grew at 45°C. Other phenotypic or morphologic tests were less reliable in differentiating C. dubliniensis from C. albicans. Antifungal susceptibility testing showed fluconazole MICs ranging from ≤0.125 to 64 μg/ml. Two isolates were resistant to fluconazole (MIC, 64 μg/ml) and one strain was dose dependent susceptible (MIC, 16 μg/ml). MICs of other azoles, including voriconazole, itraconazole, and SCH 56592, for these isolates were lower. C. dubliniensis was identified in 11 of 63 (17%) serially evaluated patients. Variability in phenotypic characteristics dictates the use of molecular and biochemical techniques to identifyC. dubliniensis. This study identifies C. dubliniensis in HIV-infected patients from San Antonio, Tex., and shows that C. dubliniensis is frequently detected in those patients by using a primary CHROMagar screen.

scholarly journals Recovery of Candida dubliniensis from Non-Human Immunodeficiency Virus-Infected Patients in Israel

2000 ◽  
Vol 38 (1) ◽  
pp. 170-174
Author(s):  
Itzhack Polacheck ◽  
Jacob Strahilevitz ◽  
Derek Sullivan ◽  
Samantha Donnelly ◽  
Ira F. Salkin ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Pcr Primers ◽  
Candida Dubliniensis ◽  
Upper Respiratory Tract ◽  
Specific Pcr ◽  
Immunodeficiency Virus ◽  
Dark Green ◽  
Green Coloration ◽  
Urine Specimens ◽  
Hiv Negative

ABSTRACT Candida dubliniensis is a recently discovered yeast species principally associated with carriage and disease in the oral cavities of human immunodeficiency virus (HIV)-infected individuals. To date the majority of isolates of this species have been identified in Europe and North America. In this study, five Candida isolates recovered from separate HIV-negative hospitalized patients in Jerusalem, Israel, were presumptively identified as C. dubliniensis on the basis of their dark green coloration when grown on CHROMagar Candida medium. Their identification was confirmed by a variety of techniques, including carbohydrate assimilation profiles, absence of growth at 45°C, positive reaction with C. dubliniensis -specific antibodies as determined by indirect immunofluorescence analysis, and positive amplification with C. dubliniensis -specific PCR primers. All five strains were shown to be susceptible to a range of antifungal agents, including fluconazole. One of the five isolates was recovered from urine specimens, while the remaining four were recovered from upper respiratory tract and oral samples. While none of the patients was HIV positive, all were receiving broad-spectrum antibacterials at the time isolates of C. dubliniensis were obtained from clinical specimens. This study describes the first isolates of C. dubliniensis from the Middle East and confirms that this yeast can be associated with carriage and infection in the absence of HIV infection.

scholarly journals Molecular Mechanisms of Fluconazole Resistance in Candida dubliniensis Isolates from Human Immunodeficiency Virus-Infected Patients with Oropharyngeal Candidiasis

2002 ◽  
Vol 46 (6) ◽  
pp. 1695-1703 ◽  
Author(s):  
Sofia Perea ◽  
José L. López-Ribot ◽  
Brian L. Wickes ◽  
William R. Kirkpatrick ◽  
Olga P. Dib ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Molecular Mechanisms ◽  
Systemic Disease ◽  
Antifungal Susceptibility ◽  
Point Mutations ◽  
Candida Dubliniensis ◽  
Clinical Isolates ◽  
Oropharyngeal Candidiasis ◽  
Mechanisms Of Resistance ◽  
Immunodeficiency Virus

ABSTRACT Candida dubliniensis is a newly identified species of Candida that is phenotypically similar to but genetically distinct from C. albicans. This organism has been recovered with increasing frequency from the oral cavities of human immunodeficiency virus (HIV)-infected and AIDS patients and has been implicated as a causative agent of oral candidiasis and systemic disease. In the present study we characterized the molecular mechanisms of resistance to fluconazole (FLC) in C. dubliniensis clinical isolates from two different HIV-infected patients with oropharyngeal candidiasis. Isolates were identified to the species level by phenotypic and genotypic tests. DNA-typing techniques were used to assess strain identity. Antifungal susceptibility testing was performed by NCCLS techniques. Northern blotting analysis was used to monitor the expression of genes encoding lanosterol demethylase (ERG11) and efflux transporters (CDR and MDR1) in matched sets of C. dubliniensis-susceptible and -resistant isolates by using probes generated from their homologous C. albicans sequences. In addition, ERG11 genes were amplified by PCR, and their nucleotide sequences were determined in order to detect point mutations with a possible effect in the affinity for azoles. Decreasing susceptibilities to FLC were detected in C. dubliniensis isolates recovered from both patients during the course of treatment. FLC-resistant C. dubliniensis isolates from one patient demonstrated combined upregulation of the MDR1, CDR1, and ERG11 genes. Among the isolates from the second patient, all isolates showing decreased susceptibility to FLC demonstrated upregulation of MDR1, whereas the levels of mRNA for the ERG11 genes remained constant and the expression of CDR genes was negligible. Fourteen point mutations were found in the ERG11 genes of the isolates with decreased susceptibility to FLC. These data demonstrate that the development of azole resistance in C. dublinensis clinical isolates from HIV-infected patients treated with FLC is mediated by multiple molecular mechanisms of resistance, similar to the observations found in the case of C. albicans.

scholarly journals Further Characterization of Human Salivary Anticandidal Activities in a Human Immunodeficiency Virus-Positive Cohort by Use of Microassays

1999 ◽  
Vol 6 (6) ◽  
pp. 851-855 ◽  
Author(s):  
Alan L. Lin ◽  
Qinghong Shi ◽  
Dorthea A. Johnson ◽  
Thomas F. Patterson ◽  
Michael G. Rinaldi ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Healthy Subjects ◽  
Germ Tube ◽  
Tube Formation ◽  
Strong Inhibition ◽  
Whole Saliva ◽  
Immunodeficiency Virus ◽  
Anticandidal Activity ◽  
Saliva Flow

ABSTRACT Salivary anticandidal activities play an important role in oral candidal infection. R. P. Santarpia et al. (Oral Microbiol. Immunol. 7:38–43, 1992) developed in vitro anticandidal assays to measure the ability of saliva to inhibit the viability of Candida albicans blastoconidia and the formation of germ tubes byC. albicans. In this report, we describe modifications of these assays for use with small volumes of saliva (50 to 100 μl). For healthy subjects, there is strong inhibition of blastoconidial viability in stimulated parotid (75%), submandibular-sublingual (74%), and whole (97%) saliva, as well as strong inhibition of germ tube formation (>80%) for all three saliva types. The susceptibility of several Candida isolates to inhibition of viability by saliva collected from healthy subjects is independent of body source ofCandida isolation (blood, oral cavity, or vagina) or the susceptibility of the isolate to the antifungal drug fluconazole. Salivary anticandidal activities in human immunodeficiency virus (HIV)-infected patients were significantly lower than those in healthy controls for inhibition of blastoconidial viability (P< 0.05) and germ tube formation (P < 0.001). Stimulated whole-saliva flow rates were also significantly lower (P < 0.05) for HIV-infected patients. These results show that saliva of healthy individuals has anticandidal activity and that this activity is reduced in the saliva of HIV-infected patients. These findings may help explain the greater incidence of oral candidal infections for individuals with AIDS.

scholarly journals Interpretation of Trailing Endpoints in Antifungal Susceptibility Testing by the National Committee for Clinical Laboratory Standards Method

1998 ◽  
Vol 36 (1) ◽  
pp. 153-156 ◽  
Author(s):  
Sanjay G. Revankar ◽  
William R. Kirkpatrick ◽  
Robert K. McAtee ◽  
Annette W. Fothergill ◽  
Spencer W. Redding ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Antifungal Susceptibility Testing ◽  
National Committee ◽  
Oropharyngeal Candidiasis ◽  
Length Polymorphisms ◽  
Immunodeficiency Virus ◽  
Agar Dilution ◽  
Different Strains

Trailing endpoints remain a problem in antifungal susceptibility testing using the National Committee for Clinical Laboratory Standards (NCCLS) method. For isolates for which trailing endpoints are found, MICs of ≤1 μg/ml at 24 h and of >64 μg/ml at 48 h are usually observed. In a study of human immunodeficiency virus (HIV)-infected patients with oropharyngeal candidiasis, we identified three patients with multiple serial isolates for which trailing endpoints were observed with fluconazole. At 24 h, MICs were generally ≤1 μg/ml by both broth macro- and microdilution methods. However, at 48 h, MICs were >64 μg/ml, while the organism remained susceptible by agar dilution testing with fluconazole. Most episodes of oropharyngeal candidiasis with trailing-endpoint isolates responded to doses of fluconazole as low as 100 mg/day. Two patients had both susceptible and trailing-endpoint isolates by NCCLS broth macro- and microdilution testing; these isolates were found to be the same strain by pulsed-field gel electrophoresis using restriction fragment length polymorphisms. Another patient had two different strains, one for which trailing endpoints were observed and one which was susceptible at 48 h. Trailing endpoints may be seen with selected isolates of a strain or may be a characteristic finding for most or all isolates of a strain. In addition, with isolates for which trailing endpoints are observed, reading the endpoint for the NCCLS method at 24 h may be more appropriate.

Multicenter prospective surveillance of oral Candida dubliniensis among adult Brazilian human immunodeficiency virus-positive and AIDS patients

2001 ◽  
Vol 41 (1-2) ◽  
pp. 29-35 ◽  
Author(s):  
Eveline Pı́polo Milan ◽  
Priscilla de Laet Sant’ Ana ◽  
Analy Salles de Azevedo Melo ◽  
Derek J. Sullivan ◽  
David C. Coleman ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Candida Dubliniensis ◽  
Prospective Surveillance ◽  
Aids Patients ◽  
Immunodeficiency Virus ◽  
Oral Candida
Sign in / Sign up

Export Citation Format

Share Document