scholarly journals Comparison of two alternative microdilution procedures with the National Committee for Clinical Laboratory Standards reference macrodilution method M27-P for in vitro testing of fluconazole-resistant and -susceptible isolates of Candida albicans.

1995 ◽  
Vol 33 (12) ◽  
pp. 3154-3158 ◽  
Author(s):  
A Espinel-Ingroff ◽  
J L Rodríguez-Tudela ◽  
J V Martínez-Suárez
Keyword(s):  
Candida Albicans ◽  
Clinical Laboratory ◽  
National Committee ◽  
In Vitro Testing ◽  
Fluconazole Resistant

scholarly journals In vitro activities of semisynthetic pneumocandin L-733,560 against fluconazole-resistant and -susceptible Candida albicans isolates.

1996 ◽  
Vol 40 (5) ◽  
pp. 1277-1279 ◽  
Author(s):  
J V Martinez-Suarez ◽  
J L Rodriguez-Tudela
Keyword(s):  
Candida Albicans ◽  
Clinical Laboratory ◽  
Active Agent ◽  
Water Soluble ◽  
National Committee ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Fluconazole Resistant ◽  
Reference Strains

Lipopeptide L-733,560 is a water-soluble derivative of pneumocandin B0 that exhibits enhanced anti-Candida activity. We investigated the in vitro activity of L-733,560 compared with those of amphotericin B, flucytosine, and itraconazole, against fluconazole-resistant (n = 44) and fluconazole-susceptible (n = 46) Candida albicans isolates. Tests were performed with a photometer-read broth microdilution method with RPMI-2% glucose and National Committee for Clinical Laboratory Standards reference strains. Except for those of itraconazole, MICs were not significantly different between the two groups of isolates, as expected for agents with different mechanisms of action. L-733,560 was the most active agent against C.albicans, with MICs for 50 and 90% of the strains tested of 0.01 and 0.06 microgram/ml, respectively.

scholarly journals In Vitro Susceptibilities of Candida dubliniensisIsolates Tested against the New Triazole and Echinocandin Antifungal Agents

1999 ◽  
Vol 37 (3) ◽  
pp. 870-872 ◽  
Author(s):  
M. A. Pfaller ◽  
S. A. Messer ◽  
S. Gee ◽  
S. Joly ◽  
C. Pujol ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Clinical Laboratory ◽  
National Committee ◽  
Mucosal Disease ◽  
Fluconazole Resistant ◽  
Resistant Strains ◽  
Investigational Agents ◽  
Multidrug Resistance Transporters

Candida dubliniensis is a newly recognized fungal pathogen causing mucosal disease in AIDS patients. Although preliminary studies indicate that most strains of C. dubliniensis are susceptible to established antifungal agents, fluconazole-resistant strains have been detected. Furthermore, fluconazole-resistant strains are easily derived in vitro, and these strains exhibit increased expression of multidrug resistance transporters, especially MDR1. Because of the potential for the development of resistant strains of C. dubliniensis, it is prudent to explore the in vitro activities of several of the newer triazole and echinocandin antifungals against isolates of C. dubliniensis. In this study we tested 71 isolates of C. dubliniensis against the triazoles BMS-207147, Sch 56592, and voriconazole and a representative of the echinocandin class of antifungal agents, MK-0991. We compared the activities of these agents with those of the established antifungal agents fluconazole, itraconazole, amphotericin B, and 5-fluorocytosine (5FC) by using National Committee for Clinical Laboratory Standards microdilution reference methods. Our findings indicate that the vast majority of clinical isolates of C. dubliniensis are highly susceptible to both new and established antifungal agents. Strains with decreased susceptibilities to fluconazole remained susceptible to the investigational agents as well as to amphotericin B and 5FC. The increased potencies of the new triazole and echinocandin antifungal agents may provide effective therapeutic options for the treatment of infections due to C. dubliniensis.

scholarly journals In vitro effects of glycyrrhetinic acid and hyaluronic acid on the growth of vulvovaginal Candida albicans and other yeasts

2017 ◽  
Vol 32 (4) ◽  
Author(s):  
Martina Stevan ◽  
Eleonora Fusato ◽  
Decio Armanini ◽  
Giulio Bertoloni ◽  
Francesco De Seta ◽  
...  
Keyword(s):  
Candida Albicans ◽  
Hyaluronic Acid ◽  
Growth Inhibition ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Vulvovaginal Candidiasis ◽  
Glycyrrhetinic Acid ◽  
National Committee ◽  
In Vitro Effects

Aims. The present study aimed to test the in vitro activity against Candida albicans and non-albicans strains of 18-β glycyrrhetinic acid (18-β GA) and hyaluronic acid (HA), both alone and in combination. This antimicrobial activity was assessed using the National Committee for Clinical Laboratory Standards (NCCLS) method on Candida strains that were isolated from patients with recurrent vulvovaginal candidiasis (RVVC). Results. Our results demonstrate that the anti-Candida activity is independent from antifungal susceptibility level and the fact that the growth inhibition is stronger at acidic pH level makes the two drugs a promising biological alternative for the topical treatment of vulvovaginal candidiasis (VVC) and RVVC. Conclusions. Furthermore, the reduction of both budding cells formation and germ tube elongation, on mammalian cell monolayers, may explain the observed growth inhibition and suggest a decreased virulence, respectively.

scholarly journals In Vitro Activities of Terbinafine against Cutaneous Isolates of Candida albicans and Other Pathogenic Yeasts

1998 ◽  
Vol 42 (5) ◽  
pp. 1057-1061 ◽  
Author(s):  
Neil S. Ryder ◽  
Sonja Wagner ◽  
Ingrid Leitner
Keyword(s):  
Candida Albicans ◽  
Clinical Laboratory ◽  
Pathogenic Fungi ◽  
Clinical Isolates ◽  
National Committee ◽  
Cryptococcus Laurentii ◽  
Dimorphic Fungi ◽  
Cutaneous Infections ◽  
Wide Range

ABSTRACT Terbinafine is active in vitro against a wide range of pathogenic fungi, including dermatophytes, molds, dimorphic fungi, and some yeasts, but earlier studies indicated that the drug had little activity against Candida albicans. In contrast, clinical studies have shown topical and oral terbinafine to be active in cutaneous candidiasis and Candida nail infections. In order to define the anti-Candida activity of terbinafine, we tested the drug against 350 fresh clinical isolates and additional strains by using a broth dilution assay standardized according to the guidelines of the National Committee for Clinical Laboratory Standards (NCCLS) M27-A assay. Terbinafine was found to have an MIC of 1 μg/ml for reference C. albicans strains. For 259 clinical isolates, the MIC at which 50% of the isolates are inhibited (MIC50) of terbinafine was 1 μg/ml (fluconazole, 0.5 μg/ml), and the MIC90 was 4 μg/ml (fluconazole, 1 μg/ml). Terbinafine was highly active against Candida parapsilosis(MIC90, 0.125 μg/ml) and showed potentially interesting activity against isolates of Candida dubliniensis,Candida guilliermondii, Candida humicola, andCandida lusitaniae. It was not active against theCandida glabrata, Candida krusei, andCandida tropicalis isolates in this assay.Cryptococcus laurentii and Cryptococcus neoformans were highly susceptible to terbinafine, with MICs of 0.06 to 0.25 μg/ml. The NCCLS macrodilution assay provides reproducible in vitro data for terbinafine against Candidaand other yeasts. The MICs for C. albicans and C. parapsilosis are compatible with the known clinical efficacy of terbinafine in cutaneous infections, while the clinical relevance of its activities against the other species has yet to be determined.

scholarly journals Successful Treatment of Fluconazole-Resistant Oropharyngeal Candidiasis by a Combination of Fluconazole and Terbinafine

1999 ◽  
Vol 6 (6) ◽  
pp. 921-923 ◽  
Author(s):  
Mahmoud A. Ghannoum ◽  
Boni Elewski
Keyword(s):  
Candida Albicans ◽  
Clinical Symptoms ◽  
In Vitro Testing ◽  
Fungal Culture ◽  
Novel Therapies ◽  
Oropharyngeal Candidiasis ◽  
Therapy Failure ◽  
Fluconazole Therapy ◽  
Fluconazole Resistant

ABSTRACT Increasing incidence of resistance to conventional antifungal therapy has demanded that novel therapies be introduced. Recent in vitro studies have shown that combinations involving azoles and allylamines may be effective in inhibiting fluconazole-resistant fungi. In this report, we describe the case of a 39-year-old woman who presented with white patches on her buccal mucosa, tongue, and palate with a bright erythematous erosive base. A fungal culture revealedCandida albicans. The patient failed to respond to the initially prescribed fluconazole therapy. Failure of therapy can be attributed to a developed resistance to fluconazole from the patient’s intermittent use of this antifungal agent at varying dosages for the preceding 2 years due to a diagnosis of onychomycosis. In vitro testing of the culture from the patient showed elevated MICs of fluconazole, itraconzole, and terbinafine (MICs were 32, 0.5, and 64 μg/ml, respectively). Our goal was to combine therapies of fluconazole and terbinafine in an attempt to clear the fungal infection. Impressively, this combination resulted in the clearing of the clinical symptoms and the patient has successfully been asymptomatic for more than 12 months posttreatment.

scholarly journals In Vitro Susceptibilities of Candida andCryptococcus neoformans Isolates from Blood Cultures of Neutropenic Patients

1999 ◽  
Vol 43 (6) ◽  
pp. 1463-1464 ◽  
Author(s):  
Daryl J. Hoban ◽  
George G. Zhanel ◽  
James A. Karlowsky
Keyword(s):  
Risk Factors ◽  
Candida Parapsilosis ◽  
Clinical Laboratory ◽  
Blood Cultures ◽  
Weight Basis ◽  
National Committee ◽  
Fluconazole Resistance ◽  
Neutropenic Patients ◽  
Fluconazole Resistant

ABSTRACT Fluconazole-resistant Candida albicans and intrinsically fluconazole-resistant Candida species have been reported as bloodstream isolates. However, an association between the isolation of fluconazole-resistant Candida from the bloodstream and patient risk factors for fungemia has not been established. The purpose of this study was to determine the prevalence of fluconazole resistance in bloodstream isolates ofCandida species and Cryptococcus neoformanscollected from patients with neutropenia, one of the most important risk factors for fungemia. MICs of voriconazole, fluconazole, itraconazole, ketoconazole, amphotericin B, and flucytosine were determined by the National Committee for Clinical Laboratory Standards M27-A method (1997). Voriconazole, on a per-weight basis, was the most active azole tested. Fluconazole resistance (MIC ≥ 64 μg/ml) was not identified in any of the C. albicans(n = 513), Candida parapsilosis(n = 78), Candida tropicalis(n = 62), or C. neoformans(n = 38) isolates tested.

scholarly journals Comparison of a spectrophotometric microdilution method with RPMI-2% glucose with the National Committee for Clinical Laboratory Standards reference macrodilution method M27-P for in vitro susceptibility testing of amphotericin B, flucytosine, and fluconazole against Candida albicans.

1996 ◽  
Vol 40 (9) ◽  
pp. 1998-2003 ◽  
Author(s):  
J L Rodríguez-Tudela ◽  
J Berenguer ◽  
J V Martínez-Suárez ◽  
R Sanchez
Keyword(s):  
Quality Control ◽  
Candida Albicans ◽  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
National Committee ◽  
Microdilution Method ◽  
Reference Strains

The National Committee for Clinical Laboratory Standards has proposed a reference broth macrodilution method for in vitro antifungal susceptibility testing of yeasts (the M27-P method). This method is cumbersome and time-consuming and includes MIC endpoint determination by visual and subjective inspection of growth inhibition after 48 h of incubation. An alternative microdilution procedure was compared with the M27-P method for determination of the amphotericin B, flucytosine, and fluconazole susceptibilities of 8 American Type Culture Collection strains (6 of them were quality control or reference strains) and 50 clinical isolates of candida albicans. This microdilution method uses as culture medium RPMI 1640 supplemented with 18 g of glucose per liter (RPMI-2% glucose). Preparation of drugs, basal medium, and inocula was done by following the recommendations of the National Committee for Clinical Laboratory Standards. The MIC endpoint was calculated objectively from the turbidimetric data read at 24 h. Increased growth of C. albicans in RPMI-2% glucose and its spectrophotometric reading allowed for the rapid (24 h) and objective calculation of MIC endpoints compared with previous microdilution methods with standard RPMI 1640. Nevertheless, good agreement was shown between the M27-P method and this microdilution test. The MICs obtained for the quality control or reference strains by the microdilution method were in the ranges published for those strains. For clinical isolates, the percentages of agreement were 100% for amphotericin B and fluconazole and 98.1% for flucytosine. These data suggest that this microdilution method may serve as a less subjective and more rapid alternative to the M27-P method for antifungal susceptibility testing of yeasts.

scholarly journals In Vitro Testing of Susceptibilities of Filamentous Ascomycetes to Voriconazole, Itraconazole, and Amphotericin B, with Consideration of Phylogenetic Implications

1998 ◽  
Vol 36 (8) ◽  
pp. 2353-2355 ◽  
Author(s):  
Michael R. McGinnis ◽  
Lester Pasarell
Keyword(s):  
Amphotericin B ◽  
Clinical Laboratory ◽  
Reference Method ◽  
Antifungal Drugs ◽  
National Committee ◽  
In Vitro Testing ◽  
Phylogenetic Relatedness ◽  
Phylogenetic Implications ◽  
The Family

The in vitro susceptibilities of three hundred eighty-one isolates representing two classes, five orders, nine families, 30 genera, and 51 species of ascomycetous fungi to voriconazole, itraconazole, and amphotericin B were tested by using a modification of the National Committee for Clinical Laboratory Standards M27-A reference method. For those fungi of known phylogenetic relatedness, drug MICs were consistently low for isolates among all clades, except for members of the family Microascaceae. The highest MICs of all drugs tested were consistently for the Microascaceae, supporting the observation of fungal phylogeny and corresponding susceptibility to antifungal drugs. Itraconazole and voriconazole have a broad range of activity against phylogenetically similar agents of hyalohyphomycosis, phaeohyphomycosis, chromoblastomycosis, and mycetoma.

scholarly journals Comparative Evaluation of FUNGITEST and Broth Microdilution Methods for Antifungal Drug Susceptibility Testing of Candida Species and Cryptococcus neoformans

1998 ◽  
Vol 36 (4) ◽  
pp. 926-930 ◽  
Author(s):  
Kate G. Davey ◽  
Ann D. Holmes ◽  
Elizabeth M. Johnson ◽  
Adrien Szekely ◽  
David W. Warnock
Keyword(s):  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Drug Susceptibility ◽  
Drug Susceptibility Testing ◽  
National Committee ◽  
Broth Microdilution ◽  
Fluconazole Resistant

The FUNGITEST method (Sanofi Diagnostics Pasteur, Paris, France) is a microplate-based procedure for the breakpoint testing of six antifungal agents (amphotericin B, flucytosine, fluconazole, itraconazole, ketoconazole, and miconazole). We compared the FUNGITEST method with a broth microdilution test, performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines, for determining the in vitro susceptibilities of 180 isolates ofCandida spp. (50 C. albicans, 50C. glabrata, 10 C. kefyr, 20C. krusei, 10 C. lusitaniae, 20C. parapsilosis, and 20 C. tropicalisisolates) and 20 isolates of Cryptococcus neoformans. Overall, there was 100% agreement between the methods for amphotericin B, 95% agreement for flucytosine, 84% agreement for miconazole, 83% agreement for itraconazole, 77% agreement for ketoconazole, and 76% agreement for fluconazole. The overall agreement between the methods exceeded 80% for all species tested with the exception ofC. glabrata (71% agreement). The poorest agreement between the results for individual agents was seen with C. glabrata (38% for fluconazole, 44% for ketoconazole, and 56% for itraconazole) and C. tropicalis (50% for miconazole). The FUNGITEST method misclassified as susceptible 2 of 12 (16.6%) fluconazole-resistant isolates, 2 of 10 (20%) itraconazole-resistant isolates, and 4 of 8 (50%) ketoconazole-resistant isolates of several Candida spp. Further development of the FUNGITEST procedure will be required before it can be recommended as an alternative method for the susceptibility testing of Candida spp. or C. neoformans.

In vitro activities of voriconazole (UK-109,496) against fluconazole-susceptible and -resistant Candida albicans isolates from oral cavities of patients with human immunodeficiency virus infection.

1997 ◽  
Vol 41 (3) ◽  
pp. 575-577 ◽  
Author(s):  
M Ruhnke ◽  
A Schmidt-Westhausen ◽  
M Trautmann
Keyword(s):  
Human Immunodeficiency Virus ◽  
Candida Albicans ◽  
Hiv Infection ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
National Committee ◽  
Broth Microdilution ◽  
Esophageal Candidiasis ◽  
Immunodeficiency Virus

The susceptibility of Candida albicans to a new antifungal triazole, voriconazole (UK-109,496), was investigated in 105 isolates obtained from the oral cavities of patients with human immunodeficiency virus (HIV) infection to study this drug's activity against fluconazole-susceptible and -resistant isolates. MICs were determined by a broth microdilution technique according to document M27-T from the National Committee for Clinical Laboratory Standards and by using a broth microdilution technique and a synthetic high-resolution medium. These antifungal susceptibility testing methods showed high levels of agreement (93% for fluconazole and 86% for voriconazole). Data from in vitro studies showed that voriconazole has good activity against fluconazole-susceptible and -resistant C. albicans isolates; the MICs at which 90% of all isolates were inhibited were 0.19 to 0.39 microgram/ml. We found that for isolates for which fluconazole MICs were high, voriconazole MICs were proportionally higher than those for fluconazole-susceptible C.albicans (P < 0.001). Pretreatment isolates from six patients with fluconazole-refractory esophageal candidiasis were included in the study. For these isolates the MICs were < or = 0.39 microgram/ml, and all patients responded to voriconazole. These results suggest that voriconazole is effective even in the treatment of fluconazole-refractory esophageal candidiasis and should be studied further to determine its clinical relevance in patients with HIV infection.

Sign in / Sign up

Export Citation Format

Share Document