scholarly journals In Vitro Activities of Pentamidine, Pyrimethamine, Trimethoprim, and Sulfonamides against Aspergillus Species

2002 ◽  
Vol 46 (6) ◽  
pp. 2029-2031 ◽  
Author(s):  
Javier Afeltra ◽  
Jacques F. G. M. Meis ◽  
Roxana G. Vitale ◽  
Johan W. Mouton ◽  
Paul E. Verweij
Keyword(s):  
Aspergillus Species ◽  
Yeast Nitrogen Base ◽  
Sulfa Drugs ◽  
Nitrogen Base ◽  
Microdilution Method

ABSTRACT The susceptibilities of 70 strains of Aspergillus species were tested against seven different sulfa drugs and pentamidine by a microdilution method with RPMI 1640 and yeast nitrogen base media. Sulfamethoxazole, sulfadiazine, and pentamidine were active in vitro. The MICs obtained with RPMI 1640 were significantly higher than those with yeast nitrogen base. More studies are needed to further elucidate the action of these drugs.

scholarly journals Correlation of Fluconazole MICs with Clinical Outcome in Cryptococcal Infection

2000 ◽  
Vol 44 (6) ◽  
pp. 1544-1548 ◽  
Author(s):  
A. I. Aller ◽  
E. Martin-Mazuelos ◽  
F. Lozano ◽  
J. Gomez-Mateos ◽  
L. Steele-Moore ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Maintenance Therapy ◽  
National Committee ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Cryptococcal Infection ◽  
Microdilution Method ◽  
Cryptococcal Disease ◽  
Fluconazole Therapy

ABSTRACT We have correlated the in vitro results of testing the susceptibility of Cryptococcus neoformans to fluconazole with the clinical outcome after fluconazole maintenance therapy in patients with AIDS-associated cryptococcal disease. A total of 28 isolates of C. neoformans from 25 patients (24 AIDS patients) were tested. The MICs were determined by the broth microdilution technique by following the modified guidelines described in National Committee for Clinical Standards (NCCLS) document M27-A, e.g., use of yeast nitrogen base medium and a final inoculum of 104 CFU/ml. The fluconazole MIC at which 50% of isolates are inhibited (MIC50) and MIC90, obtained spectrophotometrically after 48 h of incubation, were 4 and 16 μg/ml, respectively. Of the 25 patients studied, 4 died of active cryptococcal disease and 2 died of other causes. Therapeutic failure was observed in five patients who were infected with isolates for which fluconazole MICs were ≥16 μg/ml. Four of these patients had previously had oropharyngeal candidiasis (OPC); three had previously had episodes of cryptococcal infection, and all five treatment failure patients had high cryptococcal antigen titers in either serum or cerebrospinal fluid (titers, >1:4,000). Although 14 of the 18 patients who responded to fluconazole therapy had previously had OPC infections, they each had only a single episode of cryptococcal infection. It appears that the clinical outcome after fluconazole maintenance therapy may be better when the infecting C. neoformans strain is inhibited by lower concentrations of fluconazole for eradication (MICs, <16 μg/ml) than when the patients are infected with strains that require higher fluconazole concentrations (MICs, ≥16 μg/ml). These findings also suggest that the MICs determined by the modified NCCLS microdilution method can be potential predictors of the clinical response to fluconazole therapy and may aid in the identification of patients who will not respond to fluconazole therapy.

scholarly journals Growth Media for Mixed Multispecies Oropharyngeal Biofilm Compositions on Silicone

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Matthias Leonhard ◽  
Beata Zatorska ◽  
Doris Moser ◽  
Berit Schneider-Stickler
Keyword(s):  
Culture Conditions ◽  
Microbial Colonization ◽  
Future Research ◽  
Growth Media ◽  
Yeast Nitrogen Base ◽  
Microbial Composition ◽  
Nitrogen Base ◽  
Voice Prostheses

Aims. Microbial colonization of silicone voice prostheses by bacteria and Candida species limits the device lifetime of modern voice prostheses in laryngectomized patients. Thus, research focuses on biofilm inhibitive properties of novel materials, coatings, and surface enhancements. Goal of this in vitro study was the evaluation of seven commonly used growth media to simulate growth of mixed oropharyngeal species as mesoscale biofilms on prosthetic silicone for future research purposes. Methods and Results. Yeast Peptone Dextrose medium (YPD), Yeast Nitrogen Base medium (YNB), M199 medium, Spider medium, RPMI 1640 medium, Tryptic Soy Broth (TSB), and Fetal Bovine Serum (FBS) were used to culture combined mixed Candida strains and mixed bacterial-fungal compositions on silicone over the period of 22 days. The biofilm surface spread and the microscopic growth showed variations from in vivo biofilms depending on the microbial composition and growth medium. Conclusion. YPD and FBS prove to support continuous in vitro growth of mixed bacterial-fungal oropharyngeal biofilms deposits over weeks as needed for longterm in vitro testing with oropharyngeal biofilm compositions. Significance and Impact of Study. The study provides data on culture conditions for mixed multispecies biofilm compositions that can be used for future prosthesis designs.

scholarly journals Effect of pH on the In Vitro Activities of Amphotericin B, Itraconazole, and Flucytosine against Aspergillus Isolates

2004 ◽  
Vol 48 (8) ◽  
pp. 3147-3150 ◽  
Author(s):  
D. T. A. Te Dorsthorst ◽  
J. W. Mouton ◽  
C. J. P. van den Beukel ◽  
H. A. L. van der Lee ◽  
J. F. G. M. Meis ◽  
...  
Keyword(s):  
Clinical Outcome ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Poor Correlation ◽  
Yeast Nitrogen Base ◽  
Broth Microdilution ◽  
In Vitro Susceptibility ◽  
Nitrogen Base ◽  
The Poor

ABSTRACT The in vitro susceptibilities of 21 Aspergillus isolates were tested against three antifungal agents in RPMI 1640 and yeast nitrogen base at pH 5.0 and 7.0 by a broth microdilution format of the NCCLS method. The MICs of amphotericin B and itraconazole were higher, while those of flucytosine were lower, at pH 5.0 than at pH 7.0. The poor correlation between in vitro results and clinical outcome could be due to a difference in pH between the in vitro susceptibility test and at the site of infection.

scholarly journals Assessment of acid phosphatase enzyme and influence of potassium iodide on its production in the yeast form of Sporothrix schenckii

2019 ◽  
Vol 7 (12) ◽  
pp. 4548
Author(s):  
Rajesh Bareja ◽  
Prem S. Grover ◽  
Sudhir K. Mehra
Keyword(s):  
Acid Phosphatase ◽  
Potassium Iodide ◽  
Sporothrix Schenckii ◽  
Inhibitory Effect ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Yeast Form ◽  
The Mean ◽  
Phosphatase Enzyme

Background: Sporotrichosis is caused by a dimorphic fungal species, Sporothrix schenckii (S. schenckii). The enzyme acid phosphatase is pervasive among yeast and yeast like fungi. It has been studied in various fungi like Aspergillus oryzae, Candida albicans etc. but in S. schenckii little is known about enzyme acid phosphatase. The present study depicts the in-vitro influence of Potassium Iodide (KI) on the enzyme acid phosphatase produced by the S. schenckii (yeast form).Methods: A master culture was prepared by incorporating the standard strain of S. schenckii in YNB (Yeast Nitrogen Base) medium and was incubated at 37ºC. After preparing the increasing concentrations with KI in YNB medium, 1.0 mL suspension of master culture was inoculated into each bottle and incubated at 37ºC for different time period 6th, 12th, 18th day (early, mid, peak of log period) respectively. After centrifuging, a 5% homogenate was prepared, which was used for acid phosphatase enzyme assay.Results: The mean acid phosphatase level of control specimen was 20.9±2.01, 50.0±2.25, 45.0±5.10 μg and test specimens was ranged from 14.9±4.89 to 20.2±3.49, 10.2±4.19 to 40.0±6.39 and 10.0±1.81 to 34.7±6.08 μg on day 6, 12 and 18 respectively. The mean value was lower significantly for all the test concentrations as compared to control (p<0.05).Conclusions: The low activity of the enzyme acid phosphatase indicates that KI has inhibitory effect on the growth of S. schenckii that has led to decrease in the activity of the enzyme.

scholarly journals Reversible fluconazole resistance in Candida albicans: a potential in vitro model.

1997 ◽  
Vol 41 (3) ◽  
pp. 535-539 ◽  
Author(s):  
H M Calvet ◽  
M R Yeaman ◽  
S G Filler
Keyword(s):  
Candida Albicans ◽  
Molecular Mechanisms ◽  
Rabbit Model ◽  
Serial Passage ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Fluconazole Resistance ◽  
Karyotypic Analysis

To study the development and potential mechanisms of antifungal resistance in relation to antifungal exposure, reversible fluconazole resistance was examined in vitro. Candida albicans ATCC 36082 blastospores were passed in liquid yeast nitrogen base medium containing either 4, 8, 16, or 128 micrograms of fluconazole per ml, and susceptibility testing was performed after each passage. High-level fluconazole resistance (50% inhibitory concentration, > 256 micrograms/ml) developed in the isolates after serial passage in medium containing 8, 16, or 128 micrograms of fluconazole per ml, but not in isolates passed in 4 micrograms of fluconazole per ml. Reduced susceptibility was noted within four to seven passages, which was equivalent to 14 to 19 days of exposure to the drug. However, all isolates returned to the susceptible phenotype after 8 to 15 passages in medium lacking the drug; thus, fluconazole resistance was reversible in vitro. In vivo, organisms retained the resistant phenotype after a single passage in the rabbit model of infective endocarditis. Restriction digest profiles and karyotypic analysis of the parent strain and selected fluconazole-resistant and -susceptible isolates from each group were identical. Investigations into the molecular mechanisms of this reversible resistance failed to reveal increased accumulation of mRNA for 14 alpha-demethylase, the target enzyme for fluconazole, or for the candidal multidrug transporters CDR1 and BENr. This process of continuous in vitro exposure to antifungal drug may be useful as a model for studying the effects of different antifungal agents and dosing regimens on the development of resistance and for defining the mechanism(s) of reversible resistance.

In Vitro Inhibitory Effect of Vanillin on Candida Biofilm

2017 ◽  
Vol 909 ◽  
pp. 177-181 ◽  
Author(s):  
Sroisiri Thaweboon ◽  
Boonyanit Thaweboon ◽  
Rattiporn Kaypetch
Keyword(s):  
Ethyl Alcohol ◽  
Antimicrobial Properties ◽  
Inhibitory Effect ◽  
Major Constituent ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Spoilage Bacteria ◽  
Yeasts And Molds ◽  
Candida Biofilm

Vanillin is a major constituent of vanilla seeds which is used as a flavoring agent in both food and non-food industries. Previous reports have showed that vanillin had antimicrobial properties against food spoilage bacteria, yeasts, and molds. However, investigations about its effect on oral pathogenic yeasts are scarcely found. Objective: This study aims to determine the effect of vanillin on candida biofilm formation in vitro. Method: Vanillin (Sigma-Aldrich, UK) was prepared in 99.7% ethyl alcohol and diluted to concentrations of 0.5-20 mM. Biofilms of Candida albicans (ATCC 10231 and 2 clinical strains) were grown on the bottom of 96-well plate with Yeast Nitrogen Base (YNB) medium supplemented with 100 mM glucose in a shaking incubator at 37oC for 24 h. After washing, each concentration of vanillin was added with YNB supplemented with 200 mM glucose. The plate was incubated in shaking incubator for another 24 h at 37oC. Evaluation of biofilm was assessed through the XTT reduction assay. A solution of 0.2% chlorhexidine gluconate solution and 99.7% ethyl alcohol were used as positive and negative controls respectively. Result: It was found that 75-80% candida biofilm reduction was demonstrated at concentrations of 10.5-20 mM vanillin whereas chlorhexidine exhibited 94% biofilm reduction. Conclusion: Our results indicate that vanillin is a promising agent that can be used to cure candida infection in the oral cavity. Further studies are required to evaluate its effect on other yeast strains and cytotoxicity before consideration for usage in patients.

scholarly journals In vitro susceptibilities to amphotericin B, itraconazole, and miconazole of filamentous fungi isolated from patients with cystic fibrosis.

1997 ◽  
Vol 41 (9) ◽  
pp. 2064-2066 ◽  
Author(s):  
C Hennequin ◽  
N Benailly ◽  
C Silly ◽  
M Sorin ◽  
P Scheinmann ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Amphotericin B ◽  
Filamentous Fungi ◽  
Antimicrobial Activities ◽  
Aspergillus Species ◽  
Microdilution Method ◽  
Scedosporium Species

The antimicrobial activities of amphotericin B, itraconazole, and miconazole against 101 filamentous fungi from patients with cystic fibrosis were tested by a reproducible microdilution method. Itraconazole was very active against Aspergillus species and Scedosporium species (MIC at which 90% of the isolates were inhibited [MIC90], 0.06 to 0.5 mg/liter), whereas amphotericin B was less effective (MIC90, 0.5 to 8 mg/liter).

In Vitro Evaluation of Candida albicans Biofilm Formation on Denture Base PMMA Resin Incorporated with Silver Nanoparticles and its Effect on Flexural Strength

2014 ◽  
Vol 905 ◽  
pp. 51-55 ◽  
Author(s):  
Sahana Bajracharya ◽  
Sroisiri Thaweboon ◽  
Boonyanit Thaweboon ◽  
Amornrat Wonglamsam ◽  
Theerathavaj Srithavaj
Keyword(s):  
Silver Nanoparticles ◽  
Flexural Strength ◽  
Biofilm Formation ◽  
Base Material ◽  
Bending Test ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Denture Base ◽  
Pmma Resin

The aim of this study is to investigate the candidal biofilm formation on the silver nanoparticles (AgNPs) incorporated denture base heat-polymerized (poly methyl methacrylate), PMMA, resinand its flexural strength.Materials and methods:A total of 36PMMA resin specimens (15×15×2 mm3) were fabricated and divided into 4 groups based on their AgNPs contents (0%,0.5%, 1% and 1.5% w/w of polymer). The biofilm of clinical and reference strainsof C.albicanswere grown on PMMA resin specimens in the presence of yeast nitrogen base broth supplemented with 100 mM glucose at 37oC for 48 h and evaluated by tetrazolium reduction assay. The flexural strength of PMMA resin specimens (65×10×3.3 mm3) were tested by using three-point bending test. Data were analyzed by Kruskal-Wallis and Mann-Whitney U test at p<0.05. result:all="" 3="" groups="" with="" agnps="" showed="" significant="" reduction="" in="" biofilm="" formation="" of="" both="" strains="" i="">C.albicans compared to control (0% AgNPs) (p<0.05). Decreased flexural strength was observed with AgNPs groups compared with the control but within acceptable limit of ISO 20795-1. Conclusion:The reduction of the C. albicans biofilm was observed on the heat-polymerized PMMA resin incorporated with AgNPs. Regarding the flexural strength, the values were within ISO limit. These modified PMMA resin can be developed for the prevention or treatment of the candidal infection associated with the denture base material.

scholarly journals Pentamidine Is Active In Vitro against Fusarium Species

2003 ◽  
Vol 47 (10) ◽  
pp. 3252-3259 ◽  
Author(s):  
Michail S. Lionakis ◽  
Russell E. Lewis ◽  
George Samonis ◽  
Dimitrios P. Kontoyiannis
Keyword(s):  
Clinical Laboratory ◽  
Fusarium Species ◽  
Tissue Perfusion ◽  
In Vivo Studies ◽  
National Committee ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Minimum Fungicidal Concentration

ABSTRACT Fusariosis is an emerging opportunistic mycosis against which currently used antifungals have limited activity. Here, we investigated the in vitro activities of pentamidine (PNT) against 10 clinical isolates of Fusarium species (five Fusarium solani isolates and five non-F. solani isolates) by using the National Committee for Clinical Laboratory Standards microdilution method in three different media (RPMI, RPMI-2, and a yeast nitrogen base medium), disk diffusion testing, and viability dye staining. PNT had significant activities against all 10 Fusarium isolates. Non-F. solani isolates were more susceptible than F. solani isolates (P < 0.05). Additionally, PNT was fungicidal against all non-F. solani isolates, whereas it had fungistatic effects against four of the five F. solani isolates. PNT also exhibited greater activity against conidial than against hyphal development of the fungus. This fungicidal activity against non-F. solani Fusarium isolates was confirmed microscopically after staining of PNT-treated Fusarium oxysporum hyphae with the fluorescent viability dyes 5,(6)-carboxyfluorescein diacetate (CFDA) and bis-(1,3-dibutylbarbituric acid) trimethine oxonol (DiBAC). The MICs at which 50% of the isolates were inhibited (2 μg/ml for non-F. solani isolates and 4 μg/ml for F. solani isolates) and the minimum fungicidal concentration at which 50% of the isolates were killed (8 μg/ml for non-F. solani isolates) were much lower than the PNT tissue concentrations previously reported in humans using conventional daily intravenous PNT dosing. Finally, PNT was more active against Fusarium isolates in a hypoxic environment of in vitro growth (P < 0.05). This finding may be clinically significant, because Fusarium, an angiotropic mold, causes tissue infarcts with resultant low tissue perfusion. Our findings suggest that PNT may have a role in the management of Fusarium infections. Future in vivo studies are needed to verify these in vitro findings.

scholarly journals Detection of Resistance to Amphotericin B amongCryptococcus neoformans Clinical Isolates: Performances of Three Different Media Assessed by Using E-Test and National Committee for Clinical Laboratory Standards M27-A Methodologies

1998 ◽  
Vol 36 (10) ◽  
pp. 2817-2822 ◽  
Author(s):  
M. Lozano-Chiu ◽  
V. L. Paetznick ◽  
M. A. Ghannoum ◽  
J. H. Rex
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Diffusion Method ◽  
National Committee ◽  
Yeast Nitrogen Base ◽  
Nitrogen Base ◽  
Agar Diffusion ◽  
Agar Diffusion Method

Although reliable detection of resistance in vitro is critical to the overall performance of any susceptibility testing method, the recently released National Committee for Clinical Laboratory Standards M27-A methodology for susceptibility testing of yeasts discriminates poorly between resistant and susceptible isolates ofCandida spp. We have previously shown that both substitution of antibiotic medium 3 for RPMI 1640 medium in the microdilution variant of the M27-A method and use of the E-test agar diffusion methodology permit detection of amphotericin B-resistantCandida isolates. To determine the relevance of these observations to Cryptococcus neoformans, we have evaluated the performances of both the M27-A and the E-test methodologies with this yeast using three different media (RPMI 1640 medium, antibiotic medium 3, and yeast nitrogen base). As with Candida, we found that only antibiotic medium 3 permitted consistent detection of resistant isolates when testing was performed in broth by the M27-A method. When testing was performed by the E-test agar diffusion method, both RPMI 1640 medium and antibiotic medium 3 agar permitted ready detection of the resistant isolates. Reading of the results after 48 h of incubation was required for testing in broth by the M27-A method, while the MIC could be determined after either 48 or 72 h when the agar diffusion method was used.

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