scholarly journals Multicentric Analysis of the Species Distribution and Antifungal Susceptibility of Cryptic Isolates from Aspergillus Section Fumigati

2020 ◽  
Vol 64 (12) ◽  
Author(s):  
S. Imbert ◽  
A. C. Normand ◽  
S. Cassaing ◽  
F. Gabriel ◽  
L. Kristensen ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Amphotericin B ◽  
Species Distribution ◽  
Concentration Gradient ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Content Type ◽  
Species Specific ◽  
High Mics ◽  
Aspergillus Section

ABSTRACT The antifungal susceptibility of Aspergillus cryptic species is poorly known. We assessed 51 isolates, belonging to seven Fumigati cryptic species, by the EUCAST reference method and the concentration gradient strip (CGS) method. Species-specific patterns were observed, with high MICs for azole drugs, except for Aspergillus hiratsukae and Aspergillus tsurutae, and high MICs for amphotericin B for Aspergillus lentulus and Aspergillus udagawae. Essential and categorical agreements between EUCAST and CGS results were between 53.3 and 93.3%.

scholarly journals A Revised Species Concept for OpportunisticMucorSpecies Reveals Species-Specific Antifungal Susceptibility Profiles

2019 ◽  
Vol 63 (8) ◽  
Author(s):  
Lysett Wagner ◽  
Sybren de Hoog ◽  
Ana Alastruey-Izquierdo ◽  
Kerstin Voigt ◽  
Oliver Kurzai ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Susceptibility Testing ◽  
Species Concept ◽  
Antifungal Susceptibility ◽  
Content Type ◽  
Mucor Indicus ◽  
Species Specific ◽  
Susceptibility Profiles ◽  
High Mics

ABSTRACTRecently, the species concept of opportunisticMucor circinelloidesand its relatives has been revised, resulting in the recognition of its classical formae as independent species and the description of new species. In this study, we used isolates of all clinically relevantMucorspecies and performed susceptibility testing using the EUCAST reference method to identify potential species-specific susceptibility patterns.In vitrosusceptibility profiles of 101 mucoralean strains belonging to the genusMucor(72), the closely related speciesCokeromyces recurvatus(3),Rhizopus(12),Lichtheimia(10), andRhizomucor(4) to six antifungals (amphotericin B, natamycin, terbinafine, isavuconazole, itraconazole, and posaconazole) were determined. The most active drug for all Mucorales was amphotericin B. Antifungal susceptibility profiles of pathogenicMucorspecies were specific for isavuconazole, itraconazole, and posaconazole. The species formerly united inM. circinelloidesshowed clear differences in their antifungal susceptibilities.Cokeromyces recurvatus,Mucor ardhlaengiktus,Mucor lusitanicus(M. circinelloidesf.lusitanicus), andMucor ramosissimusexhibited high MICs to all azoles tested.Mucor indicuspresented high MICs for isavuconazole and posaconazole, andMucor amphibiorumandMucor irregularisshowed high MICs for isavuconazole. MIC values ofMucorspp. for posaconazole, isavuconazole, and itraconazole were high compared to those forRhizopusand the Lichtheimiaceae (LichtheimiaandRhizomucor). Molecular identification combined within vitrosusceptibility testing is recommended forMucorspecies, especially if azoles are applied in treatment.

scholarly journals Species Distribution and Comparison between EUCAST and Gradient Concentration Strips Methods for Antifungal Susceptibility Testing of 112 Aspergillus Section Nigri Isolates

2020 ◽  
Vol 64 (7) ◽  
Author(s):  
B. Carrara ◽  
R. Richards ◽  
S. Imbert ◽  
F. Morio ◽  
M. Sasso ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Amphotericin B ◽  
Species Distribution ◽  
Antifungal Susceptibility ◽  
Rank Correlation ◽  
Common Species ◽  
Teaching Hospitals ◽  
Nucleotide Sequence Analysis ◽  
Accurate Identification ◽  
Content Type

ABSTRACT Aspergillus niger, the third species responsible for invasive aspergillosis, has been considered as a homogeneous species until DNA-based identification uncovered many cryptic species. These species have been recently reclassified into the Aspergillus section Nigri. However, little is yet known among the section Nigri about the species distribution and the antifungal susceptibility pattern of each cryptic species. A total of 112 clinical isolates collected from 5 teaching hospitals in France and phenotypically identified as A. niger were analyzed. Identification to the species level was carried out by nucleotide sequence analysis. The MICs of itraconazole, voriconazole, posaconazole, isavuconazole, and amphotericin B were determined by both the EUCAST and gradient concentration strip methods. Aspergillus tubingensis (n = 51, 45.5%) and Aspergillus welwitschiae (n = 50, 44.6%) were the most common species while A. niger accounted for only 6.3% (n = 7). The MICs of azole drugs were higher for A. tubingensis than for A. welwitschiae. The MIC of amphotericin B was 2 mg/liter or less for all isolates. Importantly, MICs determined by EUCAST showed no correlation with those determined by the gradient concentration strip method, with the latter being lower than the former (Spearman’s rank correlation tests ranging from 0.01 to 0.25 depending on the antifungal agent; P > 0.4). In conclusion, A. niger should be considered as a minority species in the section Nigri. The differences in MICs between species for different azoles underline the importance of accurate identification. Significant divergences in the determination of MIC between EUCAST and the gradient concentration strip methods require further investigation.

scholarly journals Comparison of the Sensititre YeastOne and CLSI M38-A2 Microdilution Methods in Determining the Activity of Amphotericin B, Itraconazole, Voriconazole, and Posaconazole against Aspergillus Species

2018 ◽  
Vol 56 (10) ◽  
Author(s):  
Hsuan-Chen Wang ◽  
Ming-I Hsieh ◽  
Pui-Ching Choi ◽  
Chi-Jung Wu
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Antifungal Agents ◽  
Susceptibility Testing ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Aspergillus Species ◽  
Broth Microdilution ◽  
Content Type

ABSTRACT This study compared the YeastOne and reference CLSI M38-A2 broth microdilution methods for antifungal susceptibility testing of Aspergillus species. The MICs of antifungal agents were determined for 100 Aspergillus isolates, including 54 Aspergillus fumigatus (24 TR34/L98H isolates), 23 A. flavus, 13 A. terreus, and 10 A. niger isolates. The overall agreement (within 2 2-fold dilutions) between the two methods was 100%, 95%, 92%, and 90% for voriconazole, posaconazole, itraconazole, and amphotericin B, respectively. The voriconazole geometric mean (GM) MICs were nearly identical for all isolates using both methods, whereas the itraconazole and posaconazole GM MICs obtained using the YeastOne method were approximately 1 dilution lower than those obtained using the reference method. In contrast, the amphotericin B GM MIC obtained using the YeastOne method was 3.3-fold higher than that observed using the reference method. For the 24 A. fumigatus TR34/L98H isolates assayed, the categorical agreement (classified according to the CLSI epidemiological cutoff values) was 100%, 87.5%, and 83.3% for itraconazole, voriconazole, and posaconazole, respectively. For four A. niger isolates, the itraconazole MICs were >8 μg/ml using the M38-A2 method due to trailing growth, whereas the corresponding itraconazole MICs obtained using the YeastOne method were all ≤0.25 μg/ml without trailing growth. These data suggest that the YeastOne method can be used as an alternative for azole susceptibility testing of Aspergillus species and for detecting the A. fumigatus TR34/L98H isolates but that this method fails to detect A. niger isolates exhibiting trailing growth with itraconazole. Additionally, for isolates with azole MICs that approach or that are at susceptibility breakpoints or with high amphotericin B MICs detected using the YeastOne method, further MIC confirmation using the reference CLSI method is needed.

scholarly journals In VitroAntifungal Susceptibility of Clinically Relevant Species Belonging to Aspergillus SectionFlavi

2013 ◽  
Vol 57 (4) ◽  
pp. 1944-1947 ◽  
Author(s):  
Sarah S. Gonçalves ◽  
Alberto M. Stchigel ◽  
Josep Cano ◽  
Josep Guarro ◽  
Arnaldo L. Colombo
Keyword(s):  
Amphotericin B ◽  
Antifungal Agents ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Content Type

ABSTRACTThein vitroantifungal susceptibility of 77 isolates belonging to different clinically relevant species ofAspergillussectionFlavi, including those of different phylogenetic clades ofA. flavus, was tested for nine antifungal agents using a microdilution reference method (CLSI, M38-A2). Terbinafine and the echinocandins demonstrated lower MICs/MECs for all species evaluated, followed by posaconazole. Amphotericin B showed MICs ≥ 2 μg/ml for 38 (49.4%) of the 77 isolates tested.

scholarly journals A Multicenter Study of Antifungal Use and Species Distribution and Antifungal usceptibilities of Candida Isolates in South Korea

2020 ◽  
pp. 10-16
Author(s):  
Ju Hyeon Shin ◽  
Eun Jeong Won ◽  
Soo Hyun Kim ◽  
Jong Hee Shin ◽  
Dain Lee ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Species Distribution ◽  
Multicenter Study ◽  
Candida Species ◽  
Antifungal Susceptibility ◽  
Frequent Use ◽  
Defined Daily Doses ◽  
One Year ◽  
Species Specific ◽  
Antifungal Use

Background: Candidiasis control should include monitoring the epidemiology and resistance to various antifungal agents. In this study, the researchers investigated the Candida species recovered from clinical specimens at particular geographic areas or hospitals. Objective: The present study is geared toward the evaluation of antifungal drug usage at Korean hospitals in 2016. It is also essential that species distribution and antifungal susceptibilities of Candida isolates should be looked into to provide important data that can help devise therapeutic strategies to control the disease. Methods: Systemic antifungal agent usage over a one-year period was investigated at 10 Korean hospitals. Identification and antifungal susceptibility tests were performed on clinical isolates of the Candida species, which were collected over a three-month period. Results: The total antifungal usage in each hospital ranged from 7.7 to 158.9 defined daily doses (DDDs) per 1,000 patient days. Fluconazole was most commonly used (37.1%), followed by amphotericin B (30.6%), itraconazole (9.7%), echinocandins (8.8%), voriconazole (7.5%), and posaconazole (6.3%), respectively. Among 274 Candida isolates, C. albicans was the most frequently recovered (51.1%), followed by C. glabrata (15.7%), C. tropicalis (15.0%), and C. parapsilosis (13.5%), respectively. Through the application of either species-specific clinical breakpoints or epidemiological cutoff values to Candida isolates, the non-susceptibility rates to fluconazole, voriconazole, amphotericin B, and micafungin were found in 20.7%, 5.6%, 0%, and 0% of isolates, respectively. Conclusion: This nationwide multicenter study showed that total antifungal use varied considerably according to each hospital. Non-susceptibility to fluconazole should be further monitored, considering the drug's frequent use in Korea.

scholarly journals Species-Specific Antifungal Susceptibility Patterns of Scedosporium and Pseudallescheria Species

2012 ◽  
Vol 56 (5) ◽  
pp. 2635-2642 ◽  
Author(s):  
Michaela Lackner ◽  
G. Sybren de Hoog ◽  
Paul E. Verweij ◽  
Mohammad J. Najafzadeh ◽  
Ilse Curfs-Breuker ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Geometric Mean ◽  
Antifungal Susceptibility ◽  
Moderate Activity ◽  
Significant Activity ◽  
Pseudallescheria Boydii ◽  
Content Type ◽  
Wide Range ◽  
Species Specific ◽  
Susceptibility Patterns

ABSTRACTSince the separation ofPseudallescheria boydiiandP. apiospermain 2010, limited data on species-specific susceptibility patterns of these and other species ofPseudallescheriaand its anamorphScedosporiumhave been reported. This study presents the antifungal susceptibility patterns of members affiliated with both entities. Clinical and environmental isolates (n= 332) from a wide range of sources and origins were identified down to species level and tested according to CLSI M38-A2 against eight antifungal compounds. WhereasP. apiosperma(geometric mean MIC/minimal effective concentration [MEC] values of 0.9, 2.4, 7.4, 16.2, 0.2, 0.8, 1.5, and 6.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) andP. boydii(geometric mean MIC/MEC values of 0.7, 1.3, 5.7, 13.8, 0.5, 1.4, 2.3, and 11.8 μg/ml for voriconazole, posaconazole, isavuconazole, itraconazole, micafungin, anidulafungin, caspofungin, and amphotericin B, respectively) had similar susceptibility patterns, those forS. aurantiacum,S. prolificans, andS. dehoogiiwere different from each other. Voriconazole was the only drug with significant activity againstS. aurantiacumisolates. The MIC distributions of all drugs except voriconazole did not show a normal distribution and often showed two subpopulations, making a species-based prediction of antifungal susceptibility difficult. Therefore, antifungal susceptibility testing of all clinical isolates remains essential for targeted antifungal therapy. Voriconazole was the only compound with low MIC values (MIC90of ≤2 μg/ml) forP. apiospermaandP. boydii. Micafungin and posaconazole showed moderate activity against the majority ofScedosporiumstrains.

scholarly journals Etest and Sensititre YeastOne Susceptibility Testing of Echinocandins against Candida Species from a Single Center in Austria

2017 ◽  
Vol 61 (8) ◽  
Author(s):  
Maria Aigner ◽  
Thomas Erbeznik ◽  
Martin Gschwentner ◽  
Cornelia Lass-Flörl
Keyword(s):  
Susceptibility Testing ◽  
Antifungal Susceptibility ◽  
Reference Method ◽  
Broth Microdilution ◽  
Content Type ◽  
Testing Susceptibility ◽  
Clinical Breakpoints ◽  
Echinocandin Resistance ◽  
Species Specific

ABSTRACT Candida species were tested for susceptibility to caspofungin, anidulafungin, and micafungin in order to evaluate the roles of Etest and Sensititre YeastOne in antifungal susceptibility testing for daily routines and to survey resistance. A total of 104 Candida species isolates detected from blood cultures were investigated. With EUCAST broth microdilution as the reference method, essential agreement (EA), categorical agreement (CA), very major errors (VME), major errors (ME), and minor (MIN) errors were assessed by reading MICs at 18, 24, and 48 h. By use of EUCAST broth microdilution and species-specific clinical breakpoints (CBPs), echinocandin resistance was not detected during the study period. Using EUCAST CBPs, MIC readings at 24 h for the Etest and Sensititre YeastOne resulted in CA levels of 99% and 93% for anidulafungin and 99% and 97% for micafungin. Using revised CLSI CBPs for caspofungin, CA levels were 92% and 99% for Etest and Sensititre YeastOne. The Etest proved an excellent, easy-to-handle alternative method for testing susceptibility to anidulafungin and micafungin. Due to misclassifications, the Etest is less suitable for testing susceptibility to caspofungin (8% of isolates falsely tested resistant). The CA levels of Sensititre YeastOne were 93% and 97% for anidulafungin and micafungin (24 h) by use of EUCAST CBPs and increased to 100% for both antifungals if CLSI CBPs were applied and to 100% and 99% if Sensititre YeastOne epidemiological cutoff values (ECOFFs) were applied. No one echinocandin could be demonstrated to be superior to another in vitro. Since resistance was lacking among our Candida isolates, we cannot derive any recommendation from accurate resistance detection by the Etest and Sensititre YeastOne.

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 Trends in Antifungal Drug Susceptibility of Cryptococcus neoformans Isolates Obtained through Population-Based Surveillance in South Africa in 2002-2003 and 2007-2008

2011 ◽  
Vol 55 (6) ◽  
pp. 2606-2611 ◽  
Author(s):  
Nelesh P. Govender ◽  
Jaymati Patel ◽  
Marelize van Wyk ◽  
Tom M. Chiller ◽  
Shawn R. Lockhart ◽  
...  
Keyword(s):  
South Africa ◽  
Cryptococcus Neoformans ◽  
Amphotericin B ◽  
Fungal Infections ◽  
Antifungal Susceptibility ◽  
Drug Susceptibility ◽  
Population Based ◽  
Content Type ◽  
Microdilution Method ◽  
Broth Microdilution Method

ABSTRACTCryptococcus neoformansis the most common cause of meningitis among adult South Africans with HIV infection/AIDS. Widespread use of fluconazole for treatment of cryptococcal meningitis and other HIV-associated opportunistic fungal infections in South Africa may lead to the emergence of isolates with reduced fluconazole susceptibility. MIC testing using a reference broth microdilution method was used to determine if isolates with reduced susceptibility to fluconazole or amphotericin B had emerged among cases of incident disease. Incident isolates were tested from two surveillance periods (2002-2003 and 2007-2008) when population-based surveillance was conducted in Gauteng Province, South Africa. These isolates were also tested for susceptibility to flucytosine, itraconazole, voriconazole, and posaconazole. Serially collected isolate pairs from cases at several large South African hospitals were also tested for susceptibility to fluconazole. Of the 487 incident isolates tested, only 3 (0.6%) demonstrated a fluconazole MIC of ≥16 μg/ml; all of these isolates were from 2002-2003. All incident isolates were inhibited by very low concentrations of amphotericin B and exhibited very low MICs to voriconazole and posaconazole. Of 67 cases with serially collected isolate pairs, only 1 case was detected where the isolate collected more than 30 days later had a fluconazole MIC value significantly higher than the MIC of the corresponding incident isolate. Although routine antifungal susceptibility testing of incident isolates is not currently recommended in clinical settings, it is still clearly important for public health to periodically monitor for the emergence of resistance.

scholarly journals Molecular Identification and Antifungal Susceptibility of Yeast Isolates Causing Fungemia Collected in a Population-Based Study in Spain in 2010 and 2011

2013 ◽  
Vol 58 (3) ◽  
pp. 1529-1537 ◽  
Author(s):  
Jesús Guinea ◽  
Óscar Zaragoza ◽  
Pilar Escribano ◽  
Estrella Martín-Mazuelos ◽  
Javier Pemán ◽  
...  
Keyword(s):  
Hot Spot ◽  
Antifungal Susceptibility ◽  
Point Mutations ◽  
Population Based ◽  
Candida Guilliermondii ◽  
Population Based Study ◽  
Content Type ◽  
Candida Lusitaniae ◽  
Species Specific

ABSTRACTWe report the molecular identifications and antifungal susceptibilities of the isolates causing fungemia collected in the CANDIPOP population-based study conducted in 29 Spanish hospitals. A total of 781 isolates (from 767 patients, 14 of them having mixed fungemia) were collected. The species found most frequently wereCandida albicans(44.6%),Candida parapsilosis(24.5%),Candida glabrata(13.2%),Candida tropicalis(7.6%),Candida krusei(1.9%),Candida guilliermondii(1.7%), andCandida lusitaniae(1.3%). OtherCandidaand non-Candidaspecies accounted for approximately 5% of the isolates. The presence of cryptic species was low. Compared to findings of previous studies conducted in Spain, the frequency ofC. glabratahas increased. Antifungal susceptibility testing was performed by using EUCAST and CLSI M27-A3 reference procedures; the two methods were comparable. The rate of fluconazole-susceptible isolates was 80%, which appears to be a decrease compared to findings of previous studies, explained mainly by the higher frequency ofC. glabrata. Using the species-specific breakpoints and epidemiological cutoff values, the rate of voriconazole and posaconazolein vitroresistance was low (<2%). In the case ofC. tropicalis, using the EUCAST procedure, the rate of azole resistance was around 20%. There was a correlation between the previous use of azoles and the presence of fluconazole-resistant isolates. Resistance to echinocandins was very rare (2%), and resistance to amphotericin B also was very uncommon. The sequencing of the hot spot (HS) regions fromFKS1orFKS2genes in echinocandin-resistant isolates revealed previously described point mutations. The decrease in the susceptibility to fluconazole in Spanish isolates should be closely monitored in future studies.

Sign in / Sign up

Export Citation Format

Share Document