scholarly journals A 20-Year Antifungal Susceptibility Surveillance (From 1999 to 2019) for Aspergillus spp. and Proposed Epidemiological Cutoff Values for Aspergillus fumigatus and Aspergillus flavus: A Study in a Tertiary Hospital in China

2021 ◽  
Vol 12 ◽  
Author(s):  
Xinyu Yang ◽  
Wei Chen ◽  
Tianyu Liang ◽  
JingWen Tan ◽  
Weixia Liu ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Aspergillus Flavus ◽  
Clinical Laboratory ◽  
Dynamic Change ◽  
Antifungal Susceptibility ◽  
Surveillance Period ◽  
Minimum Effective Concentration ◽  
Cutoff Values ◽  
Broth Microdilution Method

The emergence of resistant Aspergillus spp. is increasing worldwide. Long-term susceptibility surveillance for clinically isolated Aspergillus spp. strains is warranted for understanding the dynamic change in susceptibility and monitoring the emergence of resistance. Additionally, neither clinical breakpoints (CBPs) nor epidemiological cutoff values (ECVs) for Aspergillus spp. in China have been established. In this study, we performed a 20-year antifungal susceptibility surveillance for 706 isolates of Aspergillus spp. in a clinical laboratory at Peking University First Hospital from 1999 to 2019; and in vitro antifungal susceptibility to triazoles, caspofungin, and amphotericin B was determined by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. It was observed that Aspergillus fumigatus was the most common species, followed by Aspergillus flavus and Aspergillus terreus. Forty isolates (5.7%), including A. fumigatus, A. flavus, A. terreus, Aspergillus niger, and Aspergillus nidulans, were classified as non-wild type (non-WT). Importantly, multidrug resistance was observed among A. flavus, A. terreus, and A. niger isolates. Cyp51A mutations were characterized for 19 non-WT A. fumigatus isolates, and TR34/L98H/S297T/F495I was the most prevalent mutation during the 20-year surveillance period. The overall resistance trend of A. fumigatus increased over 20 years in China. Furthermore, based on ECV establishment principles, proposed ECVs for A. fumigatus and A. flavus were established using gathered minimum inhibitory concentration (MIC)/minimum effective concentration (MEC) data. Consequently, all the proposed ECVs were identical to the CLSI ECVs, with the exception of itraconazole against A. flavus, resulting in a decrease in the non-WT rate from 6.0 to 0.6%.

Use of spectrophotometric reading for in vitro antifungal susceptibility testing ofAspergillusspp.

1999 ◽  
Vol 45 (10) ◽  
pp. 871-874 ◽  
Author(s):  
Eric Dannaoui ◽  
Florence Persat ◽  
Marie-France Monier ◽  
Elisabeth Borel ◽  
Marie-Antoinette Piens ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Antifungal Susceptibility Testing ◽  
Aspergillus Species ◽  
National Committee ◽  
Broth Microdilution Method

A comparative study of visual and spectrophotometric MIC endpoint determinations for antifungal susceptibility testing of Aspergillus species was performed. A broth microdilution method adapted from the National Committee for Clinical Laboratory Standards (NCCLS) was used for susceptibility testing of 180 clinical isolates of Aspergillus species against amphotericin B and itraconazole. MICs were determined visually and spectrophotometrically at 490 nm after 24, 48, and 72h of incubation, and MIC pairs were compared. The agreement between the two methods was 99% for amphotericin B and ranged from 95 to 98% for itraconazole. It is concluded that spectrophotometric MIC endpoint determination is a valuable alternative to the visual reference method for susceptibility testing of Aspergillus species.Key words: antifungal, susceptibility testing, Aspergillus, spectrophotometric reading.

scholarly journals Genetic Diversity and In Vitro Antifungal Susceptibility of 200 Clinical and Environmental Aspergillus flavus Isolates

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Mojtaba Taghizadeh-Armaki ◽  
Mohammad Taghi Hedayati ◽  
Saham Ansari ◽  
Saeed Mahdavi Omran ◽  
Sasan Saber ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Aspergillus Flavus ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Content Type ◽  
Microdilution Method ◽  
Microsatellite Genotype ◽  
Broth Microdilution Method ◽  
In Vitro Antifungal Susceptibility

ABSTRACT Aspergillus flavus has been frequently reported as the leading cause of invasive aspergillosis in certain tropical and subtropical countries. Two hundred A. flavus strains originating from clinical and environmental sources and collected between 2008 and 2015 were phylogenetically identified at the species level by analyzing partial β-tubulin and calmodulin genes. In vitro antifungal susceptibility testing was performed against antifungals using the European Committee on Antimicrobial Susceptibility Testing (EUCAST) broth microdilution method. In addition, genotyping was performed using a short-tandem-repeat (STR) assay of a panel of six microsatellite markers (A. flavus 2A, 2B, 2C, 3A, 3B, and 3C), in order to determine the genetic variation and the potential relationship between clinical and environmental isolates. The geometric means of the minimum inhibitory concentrations/minimum effective concentrations (MICs/MECs) of the antifungals across all isolates were (in increasing order): posaconazole, 0.13 mg/liter; anidulafungin, 0.16 mg/liter; itraconazole, 0.29 mg/liter; caspofungin, 0.42 mg/liter; voriconazole, 0.64 mg/liter; isavuconazole, 1.10 mg/liter; amphotericin B, 3.35 mg/liter; and flucytosine, 62.97 mg/liter. All of the clinical isolates were genetically different. However, an identical microsatellite genotype was found between a clinical isolate and two environmental strains. In conclusion, posaconazole and anidulafungin showed the greatest in vitro activity among systemic azoles and echinocandins, respectively. However, the majority of the A. flavus isolates showed reduced susceptibility to amphotericin B. Antifungal susceptibility of A. flavus was not linked with the clinical or environmental source of isolation. Microsatellite genotyping may suggest an association between clinical and environmental strains, although this requires further investigation.

scholarly journals In vitro antifungal susceptibility of clinical and environmental isolates of Aspergillus fumigatus and Aspergillus flavus in Brazil

2018 ◽  
Vol 22 (1) ◽  
pp. 30-36 ◽  
Author(s):  
Laura Bedin Denardi ◽  
Bianca Hoch Dalla-Lana ◽  
Francielli Pantella Kunz de Jesus ◽  
Cecília Bittencourt Severo ◽  
Janio Morais Santurio ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Aspergillus Flavus ◽  
Antifungal Susceptibility ◽  
Environmental Isolates ◽  
In Vitro Antifungal Susceptibility

scholarly journals Correlation between Antifungal Susceptibilities ofCoccidioides immitis In Vitro and Antifungal Treatment with Caspofungin in a Mouse Model

2001 ◽  
Vol 45 (6) ◽  
pp. 1854-1859 ◽  
Author(s):  
Gloria M. González ◽  
Rolando Tijerina ◽  
Laura K. Najvar ◽  
Rosie Bocanegra ◽  
Michael Luther ◽  
...  
Keyword(s):  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
National Committee ◽  
In Vitro Susceptibility ◽  
Minimum Effective Concentration ◽  
Study Results ◽  
Significant Difference

ABSTRACT Caspofungin (Merck Pharmaceuticals) was tested in vitro against 25 clinical isolates of Coccidoides immitis. In vitro susceptibility testing was performed in accordance with the National Committee for Clinical Laboratory Standards document M38-P guidelines. Two C. immitis isolates for which the caspofungin MICs were different were selected for determination of the minimum effective concentration (MEC), and these same strains were used for animal studies. Survival and tissue burdens of the spleens, livers, and lungs were used as antifungal response markers. Mice infected with strain 98-449 (48-h MIC, 8 μg/ml; 48-h MEC, 0.125 μg/ml) showed 100% survival to day 50 when treated with caspofungin at ≥1 mg/kg. Mice infected with strain 98-571 (48-h MIC, 64 μg/ml; 48-h MEC, 0.125 μg/ml) displayed ≥80% survival when the treatment was caspofungin at ≥5 mg/kg. Treatment with caspofungin at 0.5, 1, 5, or 10 mg/kg was effective in reducing the tissue fungal burdens of mice infected with either isolate. When tissue fungal burden study results were compared between strains, caspofungin showed no statistically significant difference in efficacy in the organs of the mice treated with both strains. A better in vitro-in vivo correlation was noted when we used the MEC instead of the MIC as the endpoint for antifungal susceptibility testing. Caspofungin may have a role in the treatment of coccidioidomycosis.

scholarly journals Hazard of agricultural triazole fungicide: Does cyproconazole induce voriconazole resistance in Aspergillus fumigatus isolates?

2021 ◽  
Author(s):  
Maryam Moazeni ◽  
Elaheh Ghobahi Katomjani ◽  
Iman Haghani ◽  
Mojtaba Nabili ◽  
Hamid Badali ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Homology Model ◽  
In Vitro Activity ◽  
Environmental Isolates ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Resistant Strains

Background and Purpose: The present study aimed to evaluate the effect of cyproconazole, the most used fungicide in Iranian wheat farms, on the induction of voriconazole resistance in Aspergillus fumigatus isolates. Materials and Methods: A collection of 20 clinical and environmental isolates were selected for investigation of the in vitro activity of fungicides. The minimum inhibitory concentrations (MICs) were determined by the documented broth microdilution method M38-A2 (CLSI, 2008). Induction experiments were performed and the possibly induced isolate(s) were subjected to antifungal susceptibility testing, sequencing of the CYP51A promoter, and full coding gene. Furthermore, CYP51-protein homology modeling and docking modes were evaluated using SWISS-MODEL (https://swissmodel.expasy.org/) and SEESAR software (version 9.1). Results: Among 10 susceptible isolates, only one strain showed a high MIC value against voriconazole (MIC=4μg/ml) after 25 passages. Nevertheless, sequencing of the CYP51A promoter and full coding gene did not reveal any mutations. Cyproconazole, which has three nitrogen atoms in the aromatic ring, coordinated to the iron atom of heme through a hydrogen bond contact to residue Lys147 present in the active site of the A. fumigates Cyp51 homology model. Conclusion: Cyproconazole is being applied extensively in wheat farms in Iran. According to the results, cyproconazole may not play a key role in the induction of azole resistance in the isolates through the environmental route. However, the potential ability of the fungicide to induce medically triazole-resistant strains over a long period of application should not be neglected.

UHPLC analysis and in vitro biological activities of Areca triandra Roxb. ex Buch.-Ham.: a substitute of areca nut

2021 ◽  
Vol 16 (12) ◽  
pp. 109-118
Author(s):  
Ashutosh Pathak ◽  
Rahul Das ◽  
Deepu Vijayan ◽  
Nripemo Odyuo ◽  
David L. Baite ◽  
...  
Keyword(s):  
Phenolic Acids ◽  
Clinical Laboratory ◽  
Biological Activities ◽  
Antifungal Susceptibility ◽  
Reducing Power ◽  
Total Phenolic ◽  
Areca Nut ◽  
Chromatography Method ◽  
Minimum Effective Concentration

Areca triandra Roxb. ex Buch.-Ham. (Arecaceae) distributed in Assam, North Bengal plains, Meghalaya andaman and Nicobar Islands is used as a substitute for A. catechu L. (Areca Nut). A. catechu is widely used as masticator in South Asia. The present study was conducted to find out the phenolic acids present in A. triandra and potential of it in inhibiting the reactive oxygen species (ROS). Plant extracts obtained from leaf and nut were analyzed qualitatively, quantitatively and phenolic acids were identified and quantified using reverse phase chromatography method developed on through Hypersil Gold aQ C18 column in Thermo Scientific Dionex Ultimate 3000 UHPLC. Three antioxidant assays viz. DPPH, ABTS and reducing power assay were performed to assess the potential of A. triandra as an antioxidant. Antifungal susceptibility test was performed by Clinical Laboratory Standard Institute (CLSI) recommended broth microdilution assay and disk diffusion susceptibility assay using Tinidazole as standard. Total catechin content was 19.51% of total phenolic content in NME. The antioxidant property was observed in NME only for DPPH, ABTS and RPA assays. In antifungal activity, minimum effective concentration (MEC) was observed in NME at the concentration of 1.0mg/ml and above whereas in LME, no MEC was observed up to tested concentrations. A. triandra possesses high catechin content and has promising potential as an antioxidant agent.

scholarly journals Quantitation of Candida albicans Ergosterol Content Improves the Correlation between In Vitro Antifungal Susceptibility Test Results and In Vivo Outcome after Fluconazole Treatment in a Murine Model of Invasive Candidiasis

2000 ◽  
Vol 44 (8) ◽  
pp. 2081-2085 ◽  
Author(s):  
Beth A. Arthington-Skaggs ◽  
David W. Warnock ◽  
Christine J. Morrison
Keyword(s):  
Murine Model ◽  
Invasive Candidiasis ◽  
Clinical Laboratory ◽  
Antifungal Susceptibility ◽  
Resistant Isolate ◽  
National Committee ◽  
Ergosterol Content ◽  
In Vitro Antifungal Susceptibility

ABSTRACT MIC end point determination for the most commonly prescribed azole antifungal drug, fluconazole, can be complicated by “trailing” growth of the organism during susceptibility testing by the National Committee for Clinical Laboratory Standards approved M27-A broth macrodilution method and its modified broth microdilution format. To address this problem, we previously developed the sterol quantitation method (SQM) for in vitro determination of fluconazole susceptibility, which measures cellular ergosterol content rather than growth inhibition after exposure to fluconazole. To determine if SQM MICs of fluconazole correlated better with in vivo outcome than M27-A MICs, we used a murine model of invasive candidiasis and analyzed the capacity of fluconazole to treat infections caused by C. albicansisolates which were trailers (M27-A MICs at 24 and 48 h, ≤1.0 and ≥64 μg/ml, respectively; SQM MIC, ≤1.0 μg/ml), as well as those which were fluconazole sensitive (M27-A and SQM MIC, ≤1.0 μg/ml) and fluconazole resistant (M27-A MIC, ≥64 μg/ml; SQM MIC, 54 μg/ml). Compared with the untreated controls, fluconazole therapy increased the survival of mice infected with a sensitive isolate and both trailing isolates but did not increase the survival of mice infected with a resistant isolate. These results indicate that the SQM is more predictive of in vivo outcome than the M27-A method for isolates that give unclear MIC end points due to trailing growth in fluconazole.

scholarly journals In Vitro Activities of the New Antifungal Triazole SCH 56592 against Common and Emerging Yeast Pathogens

2000 ◽  
Vol 44 (1) ◽  
pp. 226-229 ◽  
Author(s):  
Francesco Barchiesi ◽  
Daniela Arzeni ◽  
Annette W. Fothergill ◽  
Luigi Falconi Di Francesco ◽  
Francesca Caselli ◽  
...  
Keyword(s):  
Clinical Laboratory ◽  
Clinical Development ◽  
National Committee ◽  
In Vitro Activity ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Vitro Data ◽  
In Vitro Data

ABSTRACT A broth microdilution method performed in accordance with the National Committee for Clinical Laboratory Standards guidelines was used to compare the in vitro activity of the new antifungal triazole SCH 56592 (SCH) to that of fluconazole (FLC), itraconazole (ITC), and ketoconazole (KETO) against 257 clinical yeast isolates. They included 220 isolates belonging to 12 different species of Candida, 15 isolates each of Cryptococcus neoformans andSaccharomyces cerevisiae, and seven isolates ofRhodotorula rubra. The MICs of SCH at which 50% (MIC50) and 90% (MIC90) of the isolates were inhibited were 0.06 and 2.0 μg/ml, respectively. In general, SCH was considerably more active than FLC (MIC50 and MIC90 of 1.0 and 64 μg/ml, respectively) and slightly more active than either ITC (MIC50 and MIC90 of 0.25 and 2.0 μg/ml, respectively) and KETO (MIC50 and MIC90 of 0.125 and 4.0 μg/ml, respectively). Our in vitro data suggest that SCH has significant potential for clinical development.

scholarly journals Evaluation of a Modified EUCAST Fragmented-Mycelium Inoculum Method forIn VitroSusceptibility Testing of Dermatophytes and the Activity of Novel Antifungal Agents

2015 ◽  
Vol 59 (6) ◽  
pp. 3675-3682 ◽  
Author(s):  
B. Risslegger ◽  
C. Lass-Flörl ◽  
G. Blum ◽  
M. Lackner
Keyword(s):  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Preparation Method ◽  
Antifungal Susceptibility ◽  
Broth Microdilution ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Inoculum Preparation ◽  
Minimal Effective Concentration

ABSTRACTFor antifungal susceptibility testing of nonsporulating or poorly sporulating dermatophytes, a fragmented-mycelium inoculum preparation method was established and compared to broth microdilution testing according to CLSI and EUCAST guidelines. Moreover, thein vitroactivity of new antifungal agents against dermatophytes was evaluated. Agreement between the mycelial inoculum method and the CLSI broth microdilution method was high (93% to 100%). Echinocandins (minimal effective concentration [MEC], ≤0.5 mg/liter) and posaconazole (MIC, ≤3.00 mg/liter) showed good activity against all tested dermatophytes.

scholarly journals Antifungal Susceptibility Patterns of Opportunistic Fungi in the Genera Verruconis and Ochroconis

2014 ◽  
Vol 58 (6) ◽  
pp. 3285-3292 ◽  
Author(s):  
S. Seyedmousavi ◽  
K. Samerpitak ◽  
A. J. M. M. Rijs ◽  
W. J. G. Melchers ◽  
J. W. Mouton ◽  
...  
Keyword(s):  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Species Level ◽  
Phylogenetic Distance ◽  
Dematiaceous Fungi ◽  
Opportunistic Fungi ◽  
Content Type ◽  
Broth Microdilution Method ◽  
Susceptibility Patterns

ABSTRACTSpecies ofVerruconisand species ofOchroconisare dematiaceous fungi generally found in the environment but having the ability to infect humans, dogs, cats, poultry, and fish. This study presents the antifungal susceptibility patterns of these fungi at the species level. Forty strains originating from clinical and environmental sources were phylogenetically identified at the species level by using sequences of the ribosomal DNA internal transcribed spacer (rDNA ITS).In vitroantifungal susceptibility testing was performed against eight antifungals, using the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. The geometric mean MICs for amphotericin B (AMB), flucytosine (5FC), fluconazole (FLC), itraconazole (ITC), voriconazole (VRC), and posaconazole (POS) and minimum effective concentrations (MECs) for caspofungin (CAS) and anidulafungin (AFG) across theOchroconisandVerruconisspecies were as follows, in increasing order. ForVerruconisspecies, the values (μg/ml) were as follows: AFG, 0.04; POS, 0.25; ITC, 0.37; AMB, 0.50; CAS, 0.65; VRC, 0.96; 5FC, 10.45; and FLC, 47.25. ForOchroconisspecies, the values (μg/ml) were as follows: AFG, 0.06; POS, 0.11; CAS, 0.67; VRC, 2.76; ITC, 3.94; AMB, 5.68; 5FC, 34.48; and FLC, 61.33. Antifungal susceptibility ofOchroconisandVerruconiswas linked with phylogenetic distance and thermotolerance. Echinocandins and POS showed the greatestin vitroactivity, providing possible treatment options forOchroconisandVerruconisinfections.

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