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Resistance of Aspergillus fumigatus to triazoles has been reported increasingly in Europe. As few data are available from Southern France, the objectives of this study were to assess the burden of A. fumigatus isolates with azole resistance from clinical specimens in Lyon, and explore the resistance mechanisms involved. In this retrospective cross-sectional study, 221 consecutive A. fumigatus isolates from respiratory samples were identified from an 8-month period from 195 patients attending the Pulmonary Medicine Departments of Lyon University Hospitals. Morphological identification was confirmed by sequence analysis of the β-tubulin gene. All samples were tested for susceptibilities to itraconazole, voriconazole, posaconazole and isavuconazole using concentration gradient strips, and the results were confirmed using the EUCAST broth microdilution method. Resistance mechanisms were investigated by sequencing the cyp51A gene and its promoter, and by expression analysis of cyp51 and genes encoding several efflux transporters. Four isolates exhibited azole resistance. Three isolates presented with polymorphisms in an intronic region of cyp51A, and one isolate had F46Y, M172V and E427K polymorphisms. No mutations were identified in the cyp51A promoter, but significant induction of cyp51A and cyp51B gene expression was observed for all four and three isolates, respectively. Significant induction of atrF and cdr1B gene expression was observed for two and three isolates, respectively. No significant induction of MDR1/2/3/4, MFS56 and M85 gene expression was observed. To conclude, the observed prevalence of azole resistance was 2.1%. Significant induction of expression of the cyp51 genes and two genes encoding efflux transporters was evidenced, underlying the diversity of resistance mechanisms to be explored., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The in vitro interactions of isavuconazole with colistin were evaluated against 15 clinical Candida auris isolates by a microdilution checkerboard technique based on the EUCAST reference method for antifungal susceptibility testing and by agar diffusion using isavuconazole gradient concentration strips with or without colistin incorporated RPMI agar. Interpretation of the checkerboard results was done by the fractional inhibitory concentration index and by response surface analysis based on the Bliss model. By checkerboard, combination was synergistic for 93% of the isolates when interpretation of the data was done by fractional inhibitory concentration index, and for 80% of the isolates by response surface analysis interpretation. By agar diffusion test, although all MICs in combination decreased compared to isavuconazole alone, only 13% of the isolates met the definition of synergy. Essential agreement of EUCAST and gradient concentration strip MICs at +/- 2 log 2 dilutions was 93.3%. Antagonistic interactions were never observed for any technique or interpretation model used.

MIC values for amphotericin B and three azoles determined by the EUCAST reference technique and by gradient concentration strips were compared for 30 Mucorales isolates belonging to clinically important species. Essential agreement (EA) within ±2 dilution steps at 24 hours between the techniques was 83.3% for isavuconazole. EAs for itraconazole, amphotericin B, and posaconazole were 86.7%, 73.3%, and 56.7%, respectively. A good agreement was obtained between visual and spectrophotometric readings for EUCAST., (Copyright © 2019 American Society for Microbiology.)

Objectives: To evaluate the in vitro interactions of isavuconazole with immune suppressors (tacrolimus, cyclosporin A or sirolimus) against 30 Mucorales isolates belonging to the most common species responsible for mucormycosis in humans (Rhizopus arrhizus, Rhizopus delemar, Rhizopus microsporus, Lichtheimia corymbifera, Lichtheimia ramosa, Mucor circinelloides and Rhizomucor pusillus)., Methods: In vitro interaction was evaluated by a microdilution chequerboard technique., Results: Combination of isavuconazole with tacrolimus, cyclosporin A or sirolimus, was synergistic for 50%, 46% and 7% of the isolates, respectively. Antagonistic interaction was observed for 4% of the isolates for the combination with cyclosporin A (one R. arrhizus isolate) and for 32% of the isolates for the combination with sirolimus (six R. arrhizus isolates and three R. pusillus isolates)., Conclusions: These in vitro data show that calcineurin inhibitors are more likely than inhibitors of the mTOR pathway to enhance the activity of isavuconazole against Mucorales. These in vitro results warrant further animal experiments., (© The Author(s) 2019. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Although the Sensititre Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole, and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method/agent-dependent) 11,171 Candida albicans , 215  C. dubliniensis , 4,418  C. glabrata species complex, 157  C. guilliermondii ( Meyerozyma guilliermondii ), 676  C. krusei ( Pichia kudriavzevii ), 298  C. lusitaniae ( Clavispora lusitaniae ), 911  C. parapsilosis sensu stricto , 3,691  C. parapsilosis species complex, 36  C. metapsilosis , 110  C. orthopsilosis , 1,854  C. tropicalis , 244 Saccharomyces cerevisiae , 1,409 Aspergillus fumigatus , 389  A. flavus , 130  A. nidulans , 233  A. niger , and 302  A. terreus complex isolates. SYO/Etest MICs for 282 confirmed non-wild-type (non-WT) isolates were included: ERG11 ( C. albicans ), ERG11 and MRR1 ( C. parapsilosis ), cyp51A ( A. fumigatus ), and CDR2 and CDR1 overexpression ( C. albicans and C. glabrata , respectively). Interlaboratory modal agreement was superior by SYO for yeast species and by the Etest for Aspergillus spp. Distributions fulfilling CLSI criteria for epidemiological cutoff value (ECV) definition were pooled, and we proposed SYO ECVs for S. cerevisiae and 9 yeast and 3 Aspergillus species and Etest ECVs for 5 yeast and 4 Aspergillus species. The posaconazole SYO ECV of 0.06 µg/ml for C. albicans and the Etest itraconazole ECV of 2 µg/ml for A. fumigatus were the best predictors of non-WT isolates. These findings support the need for method-dependent ECVs, as, overall, the SYO appears to perform better for susceptibility testing of yeast species and the Etest appears to perform better for susceptibility testing of Aspergillus spp. Further evaluations should be conducted with more Candida mutants., (Copyright © 2018 American Society for Microbiology.)

Estimating epidemiological cutoff endpoints (ECVs/ECOFFS) may be hindered by the overlap of MICs for mutant and nonmutant strains (strains harboring or not harboring mutations, respectively). Posaconazole MIC distributions for the Aspergillus fumigatus species complex were collected from 26 laboratories (in Australia, Canada, Europe, India, South and North America, and Taiwan) and published studies. Distributions that fulfilled CLSI criteria were pooled and ECVs were estimated. The sensitivity of three ECV analytical techniques (the ECOFFinder, normalized resistance interpretation [NRI], derivatization methods) to the inclusion of MICs for mutants was examined for three susceptibility testing methods (the CLSI, EUCAST, and Etest methods). The totals of posaconazole MICs for nonmutant isolates (isolates with no known cyp51A mutations) and mutant A. fumigatus isolates were as follows: by the CLSI method, 2,223 and 274, respectively; by the EUCAST method, 556 and 52, respectively; and by Etest, 1,365 and 29, respectively. MICs for 381 isolates with unknown mutational status were also evaluated with the Sensititre YeastOne system (SYO). We observed an overlap in posaconazole MICs among nonmutants and cyp51A mutants. At the commonly chosen percentage of the modeled wild-type population (97.5%), almost all ECVs remained the same when the MICs for nonmutant and mutant distributions were merged: ECOFFinder ECVs, 0.5 μg/ml for the CLSI method and 0.25 μg/ml for the EUCAST method and Etest; NRI ECVs, 0.5 μg/ml for all three methods. However, the ECOFFinder ECV for 95% of the nonmutant population by the CLSI method was 0.25 μg/ml. The tentative ECOFFinder ECV with SYO was 0.06 μg/ml (data from 3/8 laboratories). Derivatization ECVs with or without mutant inclusion were either 0.25 μg/ml (CLSI, EUCAST, Etest) or 0.06 μg/ml (SYO). It appears that ECV analytical techniques may not be vulnerable to overlap between presumptive wild-type isolates and cyp51A mutants when up to 11.6% of the estimated wild-type population includes mutants., (Copyright © 2018 American Society for Microbiology.)

In vitro combinations of isavuconazole with echinocandins were evaluated against 30 Aspergillus strains with a two-dimensional checkerboard microdilution method and an agar-based diffusion method. With the checkerboard method, the three combinations showed indifferent interactions for all strains. With the agar-based method, indifferent interactions were found for all strains for isavuconazole-micafungin and isavuconazole-anidulafungin. For the isavuconazole-caspofungin combination, indifference was found in 24/30 strains, synergism in 4/30 strains, and antagonism in 2/30 strains., (Copyright © 2017 American Society for Microbiology.)

We determined the in vitro interactions between echinocandins and azoles against 10 multidrug-resistant Candida auris strains by use of a microdilution checkerboard technique. Our results suggest synergistic interactions between micafungin and voriconazole with fractional inhibitory concentration index (FICI) values of 0.15 to 0.5, and we observed indifferent interactions when micafungin was combined with fluconazole (FICI, 0.62 to 1.5). Combinations of caspofungin with fluconazole or voriconazole exhibited indifferent interactions. No antagonism was observed for any combination., (Copyright © 2017 American Society for Microbiology.)

A new analytical method was developed for the routine Therapeutic Drug Monitoring of 8 antifungals compounds in 50μL of plasma: isavuconazole (ISZ), voriconazole (VRZ), posaconazole (PSZ), fluconazole (FCZ), caspofungin (CSF), flucytosine (5FC), itraconazole (ITZ) and its metabolite OH-itraconazole (OH-ITZ). After adding 50μL of the internal standard, which consisted in a mixture of the deuterated isotopes of the quantified compounds, the sample treatment consisted in a simple protein precipitation with 400μL of acetonitrile. Five microliters of the supernatant were directly injected into the chromatographic system. The chromatographic separation was performed with a Waters C18-BEH column and a mobile phase consisting in a mixture of water and acetonitrile, both containing 0.1% of formic acid. The total run time was 3min and the detection of the analytes was performed by electrospray ionization in a positive mode using selected reaction monitoring. Intra and inter-day precision and inaccuracy were <15% over the calibration ranges that were determined according to their clinical relevance: 0.20-20.0mg/L for ISZ, VRZ, PSZ, ITZ, and OH-ITZ; 0.50-50.0mg/L for FCZ and CSF; 2.00-200mg/L for 5FC. This simple and fast method was found suitable for routine therapeutic drug monitoring., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Clinical breakpoints (CBPs) have not been established for the Mucorales and any antifungal agent. In lieu of CBPs, epidemiologic cutoff values (ECVs) are proposed for amphotericin B, posaconazole, and itraconazole and four Mucorales species. Wild-type (WT) MIC distributions (organisms in a species-drug combination with no detectable acquired resistance mechanisms) were defined with available pooled CLSI MICs from 14 laboratories (Argentina, Australia, Canada, Europe, India, Mexico, and the United States) as follows: 10 Apophysomyces variabilis, 32 Cunninghamella bertholletiae, 136 Lichtheimia corymbifera, 10 Mucor indicus, 123 M. circinelloides, 19 M. ramosissimus, 349 Rhizopus arrhizus, 146 R. microsporus, 33 Rhizomucor pusillus, and 36 Syncephalastrum racemosum isolates. CLSI broth microdilution MICs were aggregated for the analyses. ECVs comprising ≥95% and ≥97.5% of the modeled populations were as follows: amphotericin B ECVs for L. corymbifera were 1 and 2 μg/ml, those for M. circinelloides were 1 and 2 μg/ml, those for R. arrhizus were 2 and 4 μg/ml, and those for R. microsporus were 2 and 2 μg/ml, respectively; posaconazole ECVs for L. corymbifera were 1 and 2, those for M. circinelloides were 4 and 4, those for R. arrhizus were 1 and 2, and those for R. microsporus were 1 and 2, respectively; both itraconazole ECVs for R. arrhizus were 2 μg/ml. ECVs may aid in detecting emerging resistance or isolates with reduced susceptibility (non-WT MICs) to the agents evaluated., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

A patient with aplastic anaemia, successively treated with caspofungin then liposomal amphotericin, developed a disseminated infection due to Acremonium, further confirmed as resistant in vitro to these drugs. Successful treatment was achieved with voriconazole. Multiple antifungal treatments may expose to the risk of breakthrough of multi-resistant pathogens in haematology patients., (© 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.)

In vitro interaction of anidulafungin with voriconazole was tested by a microdilution broth checkerboard technique and an agar diffusion method against 30 Aspergillus clinical isolates belonging to five different species. By using a complete inhibition endpoint, indifferent interactions were observed for 97% of the isolates by the checkerboard technique (FIC index from 0.5 to 2) and for 100% of the isolates by the agar diffusion method (variation of -2 to +1 log(2) dilutions).

Background: Aspergillosis is a high-risk complication in cystic fibrosis (CF) lung transplant patients. Azole antifungal drugs inhibit CYP3A4, resulting in significant metabolic drug-drug interactions. Voriconazole (VRZ) was marketed without therapeutic drug monitoring (TDM) recommendations, consistent with favorable pharmacokinetics, but regular determinations of plasma VRZ concentration were introduced in our center to manage interactions with calcineurin inhibitors and to document the achievement of therapeutic levels., Methods: VRZ TDM data analysis for trough concentration (C0) and peak concentration (C2) was carried out, using validated liquid chromatography assay with ultraviolet detection, for 35 CF lung transplant patients (mean age 25 years, mean weight 47 kg, balanced sex ratio) since 2003. Therapeutic range (C0: 1.5 +/- 0.5 - C2 : 4.0 +/- 1.0 mg/L) was expressed relative to pivotal pharmacokinetic trial data., Results: The duration of VRZ treatment ranged from 9 days to 22 months. The recommended standard dose of VRZ (200 mg twice a day, following the loading dose) resulted in significant plasma concentrations (>0.5 mg/L) in 20% of CF lung transplant patients. Therapeutic concentrations were obtained using higher doses (average 570 +/- 160 mg/day, +43%, P<0.01). Despite adaptation, C0 remained <0.5 mg/L (11%), even when the drug was administered intravenously, highlighting the variability of VRZ pharmacokinetics, possibly enhanced by CYP2C19 polymorphism. The risk of inefficacy during periods of underdosage was overcome by treatment with antifungal drug combinations (caspofungin, n=10). The therapeutic index was limited by neurologic effects (14%) and hepatic abnormalities (30%). VRZ concentrations correlated significantly (P<0.01) with aspartate aminotransferase levels but not with bilirubin levels. VRZ acted as a metabolic inhibitor of tacrolimus (C0 to dose ratio 5.8 +/- 2.6, n=31/VRZ versus 1.7 +/- 0.9 alone, P<0.001). Large changes in azole concentration affected the magnitude of the drug-drug interactions and adjustment requirements., Conclusions: TDM is required because VRZ levels are often undetectable in treated CF lung transplant patients, supporting the use of antifungal drug combinations until achievement of VRZ C0 at a steady state between 1 and 2 mg/L. Plasma VRZ concentrations should be determined for the quantitative, individualized management of drug-drug interactions in lung transplant patients, in particular immunosuppressant such as tacrolimus, considering VRZ to be both a target and an inhibitor of CYP3A4.

The posaconazole MIC(90) for 1,903 yeast isolates from France was 1 microg/ml (range, < or =0.015 to 8 microg/ml). Ninety percent of isolates with fluconazole MICs of > or =8 microg/ml (n = 509) and 90% of those with voriconazole MICs of > or =2 microg/ml (n = 80) were inhibited by 2 and 8 microg/ml of posaconazole, respectively.

Fungal mycetoma (or eumycetoma) are endemic diseases in tropical areas that have economic effects because of their chronic and disabling evolution. Classic treatments include surgery and antifungal drugs, but these have multiple side effects. We report a case of black-grain fungal mycetoma successfully treated with voriconazole without side effects. The duration of the treatment remains unclear, but must be prolonged because of the frequency of relapses.

The case is reported of a patient with cavitary sarcoidosis complicated by an aspergilloma caused by an itraconazole-resistant strain of Aspergillus fumigatus, who was treated with voriconazole. The authors suggest that susceptibility testing of A. fumigatus strains is of value during long-term therapy with itraconazole, and that voriconazole may be a good option for treatment of patients infected with itraconazole-resistant strains of A. fumigatus.

Three isolates of zygomycetes were used to produce a disseminated infection in nonimmunocompromised mice. Against all zygomycete strains, amphotericin B significantly prolonged survival. Itraconazole was inactive against Rhizopus microsporus and Rhizopus oryzae but was partially active against Absidia corymbifera. Posaconazole had no beneficial effects against R. oryzae but showed partial activity against A. corymbifera. Posaconazole had a clear dose-response effect against R. microsporus.