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Arendrup MC, Guinea J, Meletiadis J. Twenty Years in EUCAST Anti-Fungal Susceptibility Testing: Progress & Remaining Challenges. Mycopathologia 2024; 189:64. [PMID: 38990395 DOI: 10.1007/s11046-024-00861-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Accepted: 05/15/2024] [Indexed: 07/12/2024]
Abstract
Since its inception in 2002, the EUCAST Antifungal Susceptibility Testing Subcommittee (AFST) has developed and refined susceptibility testing methods for yeast, moulds and dermatophytes, and established epidemiological cut-off values and breakpoints for antifungals. For yeast, three challenges have been addressed. Interpretation of trailing growth in fluconazole susceptibility testing, which has been proven without impact on efficacy if below the 50% endpoint. Variability in rezafungin MIC testing due to laboratory conditions, which has been solved by the addition of Tween 20 to the growth medium in E.Def 7.4. And third, interpretation of MICs for rare yeast with no breakpoints, where recommendations have been established for MIC-based clinical advice. For moulds, refinements include the validation of spectrophotometer reading for A. fumigatus to facilitate objective MIC determination, and for dermatophytes the establishment of a microdilution method with automated reading and a selective medium to minimise the risk of contaminations. Recent initiatives involve development and validation of agar-based screening assays for detection of potential azole and echinocandin resistance in A. fumigatus and Aspergillus species, respectively, and of terbinafine resistance in Trichophyton species. Moreover, the development of a EUCAST guidance document for molecular resistance testing represents an advancement, particularly for identifying target gene alterations associated with resistance. In summary, EUCAST AFST continues to play a pivotal role in standardizing AFST and facilitating accurate interpretation of susceptibility data for clinical decision-making. Adoption of EUCAST breakpoints for commercial test methods, however, requires thorough validation to ensure concordance with EUCAST reference testing species-specific MIC distributions.
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Affiliation(s)
- Maiken Cavling Arendrup
- Unit for Mycology, Statens Serum Institut, Building 45/112, Artillerivej 5, 2300, Copenhagen, Denmark.
- Department Clinical Microbiology, Rigshospitalet, Copenhagen University, Copenhagen, Denmark.
| | - Jesus Guinea
- Clinical Microbiology and Infectious Diseases, Hospital General Universitario Gregorio Marañón, 28007, Madrid, Spain
- Faculty of Health Sciences-HM Hospitals, Universidad Camilo José Cela, Madrid, Spain
| | - Joseph Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
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Vaseghi N, Piramoon M, Khojasteh S, Abbasi K, Mohseni S, Javidnia J, Naghili B, Aslani N. Post-antifungal effect of the combination of anidulafungin with amphotericin B and fluconazole against fluconazole-susceptible and -resistant Candida albicans. Curr Med Mycol 2022; 8:8-15. [PMID: 36654787 PMCID: PMC9825794 DOI: 10.18502/cmm.8.2.10327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 04/25/2022] [Accepted: 05/11/2022] [Indexed: 11/15/2022] Open
Abstract
Background and Purpose Invasive candidiasis is a life-threatening condition that kills a large number of immunocompromised patients each year worldwide. We used post-antifungal effect studies to analyze the activities of anidulafungin (AFG), as a clinically crucial antifungal drug, amphotericin B (AMB), and fluconazole (alone and in combinations) against FLC-susceptible and -resistant Candida albicans (C. albicans) isolates obtained from the cancer patients. Materials and Methods We tested the phenomenon of post antifungal effects of FLC, AMB, AFG, and combinations of FLC+AFG, AFG+AMB, and FLC+AMB against 17 C. albicans isolates obtained from the oral cavity of cancer patients. Isolates that had not been exposed to antifungals, served as a control group. Colony counts were performed at 0, 2, 4, 6, and 24 h after a brief (1 h) exposure to antifungal. Results The FLC had no detectable post-antifungal effect independent of antifungal concentration and resembled drug-free FLC (control). Significant variations in the post-antifungal effect were observed when all AMB and AFG were compared to FLC. The combination of AFG and AMB with FLC resulted in effective activity compared to FLC alone. Combination regimens were rated as indifferent in general. Interestingly, low dosages of the AFG displayed increasing fungistatic action as it approached a fungistatic endpoint against C. albicans isolates (n=17). Conclusion Our findings suggested that brief exposure to AFG, in combination with FLC and AMB, at low concentrations of the medicines utilized, could be effective in the evaluation and optimization of new dosage regimens to manage candidiasis. However, future studies will determine the clinical utility of our findings.
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Affiliation(s)
- Narges Vaseghi
- Department of Pathobiology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Majid Piramoon
- Department of Medicinal Chemistry and Radiopharmacy, School of Pharmacy, Lorestan University of Medical Sciences, Khorramabad, Iran,
Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran
| | - Shaghayegh Khojasteh
- Invasive Fungi Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran,
Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Kiana Abbasi
- Department of Microbiology, Zanjan Branch, Islamic Azad University, Zanjan, Iran
| | - Sahar Mohseni
- Department of Microbiology, Sari Branch, Islamic Azad University, Sari, Iran
| | - Javad Javidnia
- Department of Mycology, School of Medicine, Mazandaran University of Medical Science, Mazandaran, Sari, Iran
| | - Behrooz Naghili
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Narges Aslani
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
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Chowdhary A, Prakash A, Sharma C, Kordalewska M, Kumar A, Sarma S, Tarai B, Singh A, Upadhyaya G, Upadhyay S, Yadav P, Singh PK, Khillan V, Sachdeva N, Perlin DS, Meis JF. A multicentre study of antifungal susceptibility patterns among 350 Candida auris isolates (2009-17) in India: role of the ERG11 and FKS1 genes in azole and echinocandin resistance. J Antimicrob Chemother 2019; 73:891-899. [PMID: 29325167 DOI: 10.1093/jac/dkx480] [Citation(s) in RCA: 338] [Impact Index Per Article: 67.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/18/2017] [Indexed: 11/12/2022] Open
Abstract
Background Candida auris has emerged globally as an MDR nosocomial pathogen in ICU patients. Objectives We studied the antifungal susceptibility of C. auris isolates (n = 350) from 10 hospitals in India collected over a period of 8 years. To investigate azole resistance, ERG11 gene sequencing and expression profiling was conducted. In addition, echinocandin resistance linked to mutations in the C. auris FKS1 gene was analysed. Methods CLSI antifungal susceptibility testing of six azoles, amphotericin B, three echinocandins, terbinafine, 5-flucytosine and nystatin was conducted. Screening for amino acid substitutions in ERG11 and FKS1 was performed. Results Overall, 90% of C. auris were fluconazole resistant (MICs 32 to ≥64 mg/L) and 2% and 8% were resistant to echinocandins (≥8 mg/L) and amphotericin B (≥2 mg/L), respectively. ERG11 sequences of C. auris exhibited amino acid substitutions Y132 and K143 in 77% (n = 34/44) of strains that were fluconazole resistant whereas WT genotypes, i.e. without substitutions at these positions, were observed in isolates with low fluconazole MICs (1-2 mg/L) suggesting that these substitutions confer a phenotype of resistance to fluconazole similar to that described for Candida albicans. No significant expression of ERG11 was observed, although expression was inducible in vitro with fluconazole exposure. Echinocandin resistance was linked to a novel mutation S639F in FKS1 hot spot region I. Conclusions Overall, 25% and 13% of isolates were MDR and multi-azole resistant, respectively. The most common resistance combination was azoles and 5-flucytosine in 14% followed by azoles and amphotericin B in 7% and azoles and echinocandins in 2% of isolates.
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Affiliation(s)
- Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Anupam Prakash
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Cheshta Sharma
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Milena Kordalewska
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, Newark, NJ, USA
| | - Anil Kumar
- Department of Microbiology, Amrita Institute of Medical Sciences and Research Center, Amrita University, Ponekkara, Cochin, India
| | - Smita Sarma
- Department of Microbiology, Medanta-The Medcity, Gurgaon, Haryana, India
| | | | - Ashutosh Singh
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Gargi Upadhyaya
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Shalini Upadhyay
- Department of Microbiology, Medanta-The Medcity, Gurgaon, Haryana, India
| | - Priyanka Yadav
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Pradeep K Singh
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Vikas Khillan
- Department of Microbiology, Institute of Liver & Biliary Sciences, New Delhi, India
| | - Neelam Sachdeva
- Department of Microbiology, Rajiv Gandhi Cancer Institute & Research Center, Delhi, India
| | - David S Perlin
- Public Health Research Institute, Rutgers Biomedical and Health Sciences, Newark, NJ, USA
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital, Nijmegen, The Netherlands.,Centre of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
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4
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Molecular identification and antifungal susceptibility testing of Candida species isolated from dental plaques. J Mycol Med 2018; 28:433-436. [DOI: 10.1016/j.mycmed.2018.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 11/19/2022]
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Mathur P, Hasan F, Singh PK, Malhotra R, Walia K, Chowdhary A. Five-year profile of candidaemia at an Indian trauma centre: High rates of Candida auris blood stream infections. Mycoses 2018; 61:674-680. [PMID: 29738604 DOI: 10.1111/myc.12790] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 04/27/2018] [Accepted: 04/27/2018] [Indexed: 01/16/2023]
Abstract
Candidaemia is a potentially fatal infection with varied distribution of Candida species and their antifungal susceptibility profiles. The recent emergence of Candida auris in invasive candidiasis is a cause for concern. This study describes the profile of candidaemia at an Indian tertiary care hospital and reports the emergence of C. auris. All patients diagnosed with candidaemia between 2012 and 2017 were studied. The isolates were identified using conventional methods, VITEK 2 and MALDI-TOF MS. The isolates not identified by MALDI-TOF were sequenced. Antifungal susceptibility testing was done by the CLSI broth microdilution method and VITEK 2. A total of 114 isolates of Candida species were analysed. Candida tropicalis (39.4%) was the most common species, followed by C. auris (17.5%), C. albicans (14%) and C. parapsilosis (11.4%). Notably, Diutina mesorugosa isolates (n = 10) were not identified by MALDI-TOF and were confirmed by sequencing. Furthermore, 45% (n = 9) C. auris strains exhibited low MICs of FLU (0.05-4 μg/mL) and the remaining 55% (n = 11) isolates had high MICs ≥ 64 μg/mL. Also, D. mesorugosa exhibited high MICs of FLU (32 μg/mL) in 2 isolates. A high rate of errors in antifungal susceptibility was noted with the VITEK 2 as compared to the CLSI method. Candida auris was the second most prevalent species causing candidaemia warranting infection control practices to be strengthened to prevent its spread.
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Affiliation(s)
- Purva Mathur
- Department of Laboratory Medicine, Jai Prakash Narayan Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
| | - Fahmi Hasan
- Department of Laboratory Medicine, Jai Prakash Narayan Apex Trauma Centre, All India Institute of Medical Sciences, New Delhi, India
| | - Pradeep K Singh
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Rajesh Malhotra
- Department of Orthopaedics, All India Institute of Medical Sciences, New Delhi, India.,JaiPrakash Narayan Apex Trauma Centre, AIIMS, New Delhi, India
| | - Kamini Walia
- Division of Epidemiology and Communicable Diseases, Indian Council of Medical Research, New Delhi, India
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
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Abstract
PURPOSE OF REVIEW To describe the epidemiology, strategies for early detection, and clinical management of infections caused by the most commonly found multidrug-resistant (MDR) Candida spp. RECENT FINDINGS Increasing numbers of reports describing invasive infections by MDR Candida auris and Candida glabrata has been reported in medical centers worldwide. SUMMARY We checked all papers published along the last 10 years describing epidemiological, diagnostic, and clinical aspects of infections by MDR Candida spp., with emphasis on C. auris and C. glabrata spp. C. auris has been reported in 15 countries and multidrug resistance rates is usually above 30%. Horizontal transmission is a great concern regarding C. auris. C. glabrata ranks the second most reported Candida spp. in deep-seated infections from United States and some European Centers, although multidrug resistance rates above 10% are restricted to some US centers. Candida haemulonii complex isolates with poor susceptibility to azoles and amphotericin B have been isolated in superficial and deep-seated infections, whereas Candida guilliiermondii complex isolates with poor susceptibility to azoles and echinocandins have been recovered from catheter-related bloodstream infections. Other potential MDR Candida species are Candida krusei, Candida lusitaniae, Candida kefyr, Yarrowia (Candida) lypolitica, and Candida rugosa.
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Aslani N, Janbabaei G, Abastabar M, Meis JF, Babaeian M, Khodavaisy S, Boekhout T, Badali H. Identification of uncommon oral yeasts from cancer patients by MALDI-TOF mass spectrometry. BMC Infect Dis 2018; 18:24. [PMID: 29310582 PMCID: PMC5759378 DOI: 10.1186/s12879-017-2916-5] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 12/13/2017] [Indexed: 11/29/2022] Open
Abstract
Background Opportunistic infections due to Candida species occur frequently in cancer patients because of their inherent immunosuppression. The aim of the present study was to investigate the epidemiology of yeast species from the oral cavity of patients during treatment for oncological and haematological malignancies. Methods MALDI-TOF was performed to identify yeasts isolated from the oral cavity of 350 cancer patients. Moreover, antifungal susceptibility testing was performed in according to CLSI guidelines (M27-A3). Results Among 162 yeasts and yeast-like fungi isolated from the oral cavity of cancer patients, Candida albicans was the most common species (50.6%), followed by Candida glabrata (24.7%), Pichia kudriavzevii (Candida krusei (9.9%)), Candida tropicalis (4.3%), Candida dubliniensis (3.7%), Kluyveromyces marxianus (Candida kefyr (3.7%)) and Candida parapsilosis (1%). In addition, uncommon yeast species i.e., Saprochaete capitata, Saccharomyces cerevisiae, Clavispora lusitaniae (C. lusitaniae) and Pichia kluyveri (C. eremophila) were recovered from oral lesions. Oral colonization by C. albicans, non-albicans Candida species and uncommon yeasts were as follow; 55%, 44% and 1%, whereas oral infection due to C. albicans was 33.3%, non-albicans Candida species 60.6%, and uncommon yeasts 6.1%. Poor oral hygiene and xerostomia were identified as independent risk factors associated with oral yeast colonization. The overall resistance to fluconazole was 11.7% (19/162). Low MIC values were observed for anidulafungin for all Candida and uncommon yeast species. Conclusions This current study provides insight into the prevalence and susceptibility profiles of Candida species, including emerging Candida species and uncommon yeasts, isolated from the oral cavity of Iranian cancer patients. The incidence of oral candidiasis was higher amongst patients with hematological malignancies. The majority of oral infections were caused by non-albicans Candida species which were often more resistant to anti-fungal agents. Our findings suggest that anidulafungin should be used as antifungal of choice for prophylaxis in clinically high-risk patients with documented oral colonization or infection.
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Affiliation(s)
- Narges Aslani
- Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran.,Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ghasem Janbabaei
- Gastrointestinal Cancer Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mahdi Abastabar
- Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital (CWZ), Nijmegen, The Netherlands.,Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Mahasti Babaeian
- Gastrointestinal Cancer Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Sadegh Khodavaisy
- Department of Medical Mycology and Parasitology, Tehran University of Medical Sciences, Tehran, Iran
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands.,Institute of Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands
| | - Hamid Badali
- Department of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran. .,Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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Shokohi T, Aslani N, Ahangarkani F, Meyabadi MF, Hagen F, Meis JF, Boekhout T, Kolecka A, Badali H. Candida infanticola and Candida spencermartinsiae yeasts: Possible emerging species in cancer patients. Microb Pathog 2017; 115:353-357. [PMID: 29292174 DOI: 10.1016/j.micpath.2017.12.069] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2017] [Revised: 11/22/2017] [Accepted: 12/28/2017] [Indexed: 02/05/2023]
Abstract
Opportunistic infections due to Candida species occur frequently in intensive care settings. We investigated the prevalence of Candida species among 65 clinical specimens obtained from 200 cancer patients by phenotypic and molecular (ITS sequencing and AFLP) methods. Among the 65 yeast isolates, Candida albicans was the most commonly isolated species (n = 34, 52.3%), whereas other Candida species comprised 47.7% (n = 31) and consisted of Candida glabrata (n = 14, 21.5%), Candida tropicalis (n = 5, 7.7%) and uncommon Candida species (n = 12, 18.5%) such as Candida pelliculosa (n = 3, 4.6%), Pichia kudriavzevii (= Candida krusei, n = 2, 3.1%), Candida orthopsilosis (n = 2, 3.1%), Candida parapsilosis (n = 1, 1.5%), Candida infanticola (n = 2, 3.1%), Candida spencermartinsiae (n = 1, 1.5%), and Kluyveromyces marxianus (=Candida kefyr, n = 1, 1.5%). Candida infanticola and Candida spencermartinsiae were recovered from oral lesions of cancer patients. Matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) easily confirmed these isolates as less common Candida isolates (4.6%). The in vitro antifungal susceptibilities of C. spencermartinsiae and the two strains of C. infanticola were determined according to CLSI guidelines (M27-A3). MIC results among these isolates showed they were susceptible to isavuconazole, posaconazole and voriconazole, however, fluconazole and caspofungin had high MIC values. These Candida species that may occur more commonly in infections remain unnoticed using commonly used phenotypical methods in routine microbiology laboratories. MALDI-TOF MS proved to be a more fast and robust diagnostic technique for identification of the yeasts isolated from different clinical specimens of cancer patients.
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Affiliation(s)
- Tahereh Shokohi
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Narges Aslani
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Fatemeh Ahangarkani
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran; Student Research Committee, Mazandaran University of Medical Sciences, Sari, Iran
| | - Masoumeh Fatahi Meyabadi
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ferry Hagen
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands; Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital (CWZ), and Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius-Wilhelmina Hospital (CWZ), and Center of Expertise in Mycology Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Teun Boekhout
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands; Institute for Biodiversity and Ecosystem Dynamics (IBED), University of Amsterdam, Amsterdam, The Netherlands; Shanghai Key Laboratory of Molecular Medical Mycology, Shanghai Institute of Medical Mycology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Anna Kolecka
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - Hamid Badali
- Department of Medical Mycology and Parasitology/Invasive Fungi Research Center (IFRC), School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
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Comparison of EUCAST and CLSI Reference Microdilution MICs of Eight Antifungal Compounds for Candida auris and Associated Tentative Epidemiological Cutoff Values. Antimicrob Agents Chemother 2017; 61:AAC.00485-17. [PMID: 28416539 DOI: 10.1128/aac.00485-17] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 04/08/2017] [Indexed: 01/30/2023] Open
Abstract
Candida auris is an emerging multidrug-resistant yeast. So far, all but two susceptibility testing studies have examined ≤50 isolates, mostly with the CLSI method. We investigated CLSI and EUCAST MICs for 123 C. auris isolates and eight antifungals and evaluated various methods for epidemiological cutoff (ECOFF) determinations. MICs (in milligrams per liter) were determined using CLSI method M27-A3, and the EUCAST E.Def 7.3. ANOVA analysis of variance with Bonferroni's multiple-comparison test and Pearson analysis were used on log2 MICs (significance at P values of <0.05). The percent agreement (within ±0 to ±2 2-fold dilutions) between the methods was calculated. ECOFFs were determined visually, statistically (using the ECOFF Finder program and MicDat1.23 software with 95% to 99% endpoints), and via the derivatization method (dECOFFs). The CLSI and EUCAST MIC distributions were wide, with several peaks for all compounds except amphotericin B, suggesting possible acquired resistance. Modal MIC, geometric MIC, MIC50, and MIC90 values were ≤1 2-fold dilutions apart, and no significant differences were found. The quantitative agreement was best for amphotericin B (80%/97% within ±1/±2 dilutions) and lowest for isavuconazole and anidulafungin (58%/76% to 75% within ±1/±2 dilutions). We found that 90.2%/100% of the isolates were amphotericin B susceptible based on CLSI/EUCAST methods, respectively (i.e., with MICs of ≤1 mg/liter), and 100%/97.6% were fluconazole nonsusceptible by CLSI/EUCAST (MICs > 2). The ECOFFs (in milligrams per liter) were similar across the three different methods for itraconazole (ranges for CLSI/EUCAST, 0.25 to 0.5/0.5 to 1), posaconazole (0.125/0.125 to 0.25), amphotericin B (0.25 to 0.5/1 to 2), micafungin (0.25 to 0.5), and anidulafungin (0.25 to 0.5/0.25 to 1). In contrast, the estimated ECOFFs were dependent on the method applied for voriconazole (1 to 32) and isavuconazole (0.125 to 4). CLSI and EUCAST MICs were remarkably similar and confirmed uniform fluconazole resistance and variable acquired resistance to the other agents.
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Evidence of genotypic diversity among Candida auris isolates by multilocus sequence typing, matrix-assisted laser desorption ionization time-of-flight mass spectrometry and amplified fragment length polymorphism. Clin Microbiol Infect 2015; 22:277.e1-9. [PMID: 26548511 DOI: 10.1016/j.cmi.2015.10.022] [Citation(s) in RCA: 112] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Revised: 10/23/2015] [Accepted: 10/27/2015] [Indexed: 02/03/2023]
Abstract
Candida auris is a multidrug-resistant nosocomial bloodstream pathogen that has been reported from Asian countries and South Africa. Herein, we studied the population structure and genetic relatedness among 104 global C. auris isolates from India, South Africa and Brazil using multilocus sequence typing (MLST), amplified fragment length polymorphism (AFLP) fingerprinting and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). RPB1, RPB2 and internal transcribed spacer (ITS) and D1/D2 regions of the ribosomal DNA were sequenced for MLST. Further, genetic variation and proteomic assessment was carried out using AFLP and MALDI-TOF MS, respectively. Both MLST and AFLP typing clearly demarcated two major clusters comprising Indian and Brazilian isolates. However, the South African isolates were randomly distributed, suggesting different genotypes. MALDI-TOF MS spectral profiling also revealed evidence of geographical clustering but did not correlate fully with the genotyping methods. Notably, overall the population structure of C. auris showed evidence of geographical clustering by all the three techniques analysed. Antifungal susceptibility testing by the CLSI microbroth dilution method revealed that fluconazole had limited activity against 87% of isolates (MIC90, 64 mg/L). Also, MIC90 of AMB was 4 mg/L. Candida auris is emerging as an important yeast pathogen globally and requires reproducible laboratory methods for identification and typing. Evaluation of MALDI-TOF MS as a typing method for this yeast is warranted.
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Multidrug-Resistant Candida auris Misidentified as Candida haemulonii: Characterization by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and DNA Sequencing and Its Antifungal Susceptibility Profile Variability by Vitek 2, CLSI Broth Microdilution, and Etest Method. J Clin Microbiol 2015; 53:1823-30. [PMID: 25809970 DOI: 10.1128/jcm.00367-15] [Citation(s) in RCA: 358] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Accepted: 03/17/2015] [Indexed: 01/18/2023] Open
Abstract
Candida auris is a multidrug-resistant yeast that causes a wide spectrum of infections, especially in intensive care settings. We investigated C. auris prevalence among 102 clinical isolates previously identified as Candida haemulonii or Candida famata by the Vitek 2 system. Internal transcribed spacer region (ITS) sequencing confirmed 88.2% of the isolates as C. auris, and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) easily separated all related species, viz., C. auris (n = 90), C. haemulonii (n = 6), C. haemulonii var. vulnera (n = 1), and Candida duobushaemulonii (n = 5). The in vitro antifungal susceptibility was determined using CLSI broth microdilution (CLSI-BMD), the Vitek 2 antifungal susceptibility test, and the Etest method. C. auris isolates revealed uniformly elevated fluconazole MICs (MIC50, 64 μg/ml), and an alarming percentage of isolates (37%) exhibited elevated caspofungin MICs by CLSI-BMD. Notably, 34% of C. auris isolates had coexisting elevated MICs (≥2 μg/ml) for both fluconazole and voriconazole, and 10% of the isolates had elevated coexisting MICs (≥2 μg/ml) to two additional azoles, i.e., posaconazole and isavuconazole. In contrast to reduced amphotericin B MICs by CLSI-BMD (MIC50, 1 μg/ml) for C. auris, elevated MICs were noted by Vitek 2 (MIC50, 8 μg/ml), which were statistically significant. Candida auris remains an unnoticed pathogen in routine microbiology laboratories, as 90% of the isolates characterized by commercial identification systems are misidentified as C. haemulonii. MALDI-TOF MS proved to be a more robust diagnostic technique for rapid identification of C. auris. Considering that misleading elevated MICs of amphotericin B by the Vitek AST-YS07 card may lead to the selection of inappropriate therapy, a cautionary approach is recommended for laboratories relying on commercial systems for identification and antifungal susceptibility testing of rare yeasts.
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Khillan V, Rathore N, Kathuria S, Chowdhary A. A rare case of breakthrough fungal pericarditis due to fluconazole‐resistant Candida auris in a patient with chronic liver disease. JMM Case Rep 2014. [DOI: 10.1099/jmmcr.0.t00018] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Vikas Khillan
- Department of Microbiology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Neha Rathore
- Department of Microbiology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Shallu Kathuria
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
| | - Anuradha Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, India
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Invasive mycosis due to species of Blastobotrys in immunocompromised patients with reduced susceptibility to antifungals. J Clin Microbiol 2014; 52:4094-9. [PMID: 25165080 DOI: 10.1128/jcm.01977-14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cases of invasive mycosis due to Blastobotrys serpentis and B. proliferans identified by sequencing in a preterm patient and a rhabdomyosarcoma patient, respectively, are reported. Both species revealed elevated fluconazole and echinocandin MICs by the CLSI broth microdilution method. Additionally, B. serpentis exhibited high amphotericin B MICs, thus posing serious therapeutic challenges.
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Pfaller MA, Castanheira M, Messer SA, Rhomberg PR, Jones RN. Comparison of EUCAST and CLSI broth microdilution methods for the susceptibility testing of 10 systemically active antifungal agents when tested against Candida spp. Diagn Microbiol Infect Dis 2014; 79:198-204. [PMID: 24736096 DOI: 10.1016/j.diagmicrobio.2014.03.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Revised: 02/27/2014] [Accepted: 03/05/2014] [Indexed: 11/25/2022]
Abstract
The antifungal broth microdilution (BMD) method of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) was compared with Clinical and Laboratory Standards Institute (CLSI) BMD method M27-A3 for amphotericin B, flucytosine, anidulafungin, caspofungin, micafungin, fluconazole, isavuconazole, itraconazole, posaconazole, and voriconazole susceptibility testing of 357 isolates of Candida. The isolates were selected from global surveillance collections to represent both wild-type (WT) and non-WT MIC results for the azoles (12% of fluconazole and voriconazole results were non-WT) and the echinocandins (6% of anidulafungin and micafungin results were non-WT). The study collection included 114 isolates of Candida albicans, 73 of C. glabrata, 76 of C. parapsilosis, 60 of C. tropicalis, and 34 of C. krusei. The overall essential agreement (EA) between EUCAST and CLSI results ranged from 78.9% (posaconazole) to 99.6% (flucytosine). The categorical agreement (CA) between methods and species of Candida was assessed using previously determined CLSI epidemiological cutoff values. The overall CA between methods was 95.0% with 2.5% very major (VM) and major (M) discrepancies. The CA was >93% for all antifungal agents with the exception of caspofungin (84.6%), where 10% of the results were categorized as non-WT by the EUCAST method and WT by the CLSI method. Problem areas with low EA or CA include testing of amphotericin B, anidulafungin, and isavuconazole against C. glabrata, itraconazole, and posaconazole against most species, and caspofungin against C. parapsilosis, C. tropicalis, and C. krusei. We confirm high level EA and CA (>90%) between the 2 methods for testing fluconazole, voriconazole, and micafungin against all 5 species. The results indicate that the EUCAST and CLSI methods produce comparable results for testing the systemically active antifungal agents against the 5 most common species of Candida; however, there are several areas where additional steps toward harmonization are warranted.
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Impact of new antifungal breakpoints on antifungal resistance in Candida species. J Clin Microbiol 2014; 52:994-7. [PMID: 24403302 DOI: 10.1128/jcm.03044-13] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We reviewed our antifungal susceptibility data for micafungin, anidulafungin, fluconazole, and voriconazole against Candida species and compared resistance rates determined by the previous and recently revised CLSI antifungal breakpoints. With the new breakpoints, resistance was significantly increased for micafungin (from 0.8% to 7.6%), anidulafungin (from 0.9% to 7.3%), and voriconazole (from 6.1% to 18.4%) against Candida glabrata. Resistance was also increased for fluconazole against Candida albicans (from 2.1% to 5.7%).
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Chowdhary A, Anil Kumar V, Sharma C, Prakash A, Agarwal K, Babu R, Dinesh KR, Karim S, Singh SK, Hagen F, Meis JF. Multidrug-resistant endemic clonal strain of Candida auris in India. Eur J Clin Microbiol Infect Dis 2013; 33:919-26. [PMID: 24357342 DOI: 10.1007/s10096-013-2027-1] [Citation(s) in RCA: 277] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 11/25/2013] [Indexed: 01/17/2023]
Abstract
Candida auris is a recently described rare agent of fungemia. It is notable for its antifungal resistance. A total of 15 C. auris isolates, originating from seven cases of fungemia, three cases of diabetic gangrenous foot, and one case of bronchopneumonia from a tertiary care hospital in south India, were investigated. All of the 15 isolates were identified by sequencing and 14 of these along with 12 C. auris isolates previously reported from two hospitals in Delhi, north India, two each from Japan and Korea were genotyped by amplified fragment length polymorphism (AFLP). In vitro antifungal susceptibility testing (AFST) was done by the Clinical and Laboratory Standards Institute (CLSI) broth microdilution method. Candida auris isolates were misidentified as Candida haemulonii by VITEK. All were resistant to fluconazole [geometric mean minimum inhibitory concentration (MIC) 64 μg/ml] and 11 isolates were resistant to voriconazole (MIC ≥1 μg/ml). Forty-seven percent of the C. auris isolates were resistant to flucytosine (MIC ≥64 μg/ml) and 40% had high MIC (≥1 μg/ml) of caspofungin. Breakthrough fungemia developed in 28.6% of patients and therapeutic failure in 4 (66.7%) patients. Interestingly, the 26 Indian C. auris isolates from north and south India were clonal and phenotypically and genotypically distinct from Korean and Japanese isolates. The present study demonstrates that C. auris is a potential emerging pathogen that can cause a wide spectrum of human mycotic infections. The prevalence of a C. auris endemic clonal strain resistant to azoles and other antifungals in Indian hospitals with high rates of therapeutic failure in cases of fungemia is worrisome.
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Affiliation(s)
- A Chowdhary
- Department of Medical Mycology, Vallabhbhai Patel Chest Institute, University of Delhi, Delhi, 110 007, India,
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Development of a Luminex-based multiplex assay for detection of mutations conferring resistance to Echinocandins in Candida glabrata. J Clin Microbiol 2013; 52:790-5. [PMID: 24353003 DOI: 10.1128/jcm.03378-13] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Echinocandins are the recommended treatment for invasive candidiasis due to Candida glabrata. Resistance to echinocandins is known to be caused by nonsynonymous mutations in the hot spot-1 (HS1) regions of the FKS1 and FKS2 genes, which encode a subunit of the β-1,3-glucan synthase, the target of echinocandins. Here, we describe the development of a microsphere-based assay using Luminex MagPix technology to identify mutations in the FKS1 HS1 and FKS2 HS1 domains, which confer in vitro echinocandin resistance in C. glabrata isolates. The assay is rapid and can be performed with high throughput. The assay was validated using 102 isolates that had FKS1 HS1 and FKS2 HS1 domains previously characterized by DNA sequencing. The assay was 100% concordant with DNA sequencing results. The assay was then used for high-throughput screening of 1,032 C. glabrata surveillance isolates. Sixteen new isolates with mutations, including a mutation that was new to our collection (del659F), were identified. This assay provides a rapid and cost-effective way to screen C. glabrata isolates for echinocandin resistance.
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Pfaller MA, Diekema DJ, Procop GW, Rinaldi MG. Comparison of the Vitek 2 yeast susceptibility system with CLSI microdilution for antifungal susceptibility testing of fluconazole and voriconazole against Candida spp., using new clinical breakpoints and epidemiological cutoff values. Diagn Microbiol Infect Dis 2013; 77:37-40. [DOI: 10.1016/j.diagmicrobio.2013.05.019] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 05/27/2013] [Accepted: 05/29/2013] [Indexed: 11/26/2022]
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EUCAST and CLSI: Working Together Towards a Harmonized Method for Antifungal Susceptibility Testing. CURRENT FUNGAL INFECTION REPORTS 2013. [DOI: 10.1007/s12281-012-0125-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Lockhart SR, Iqbal N, Cleveland AA, Farley MM, Harrison LH, Bolden CB, Baughman W, Stein B, Hollick R, Park BJ, Chiller T. Species identification and antifungal susceptibility testing of Candida bloodstream isolates from population-based surveillance studies in two U.S. cities from 2008 to 2011. J Clin Microbiol 2012; 50:3435-42. [PMID: 22875889 PMCID: PMC3486211 DOI: 10.1128/jcm.01283-12] [Citation(s) in RCA: 206] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/01/2012] [Indexed: 01/03/2023] Open
Abstract
Between 2008 and 2011, population-based candidemia surveillance was conducted in Atlanta, GA, and Baltimore, MD. Surveillance had been previously performed in Atlanta in 1992 to 1993 and in Baltimore in 1998 to 2000, making this the first population-based candidemia surveillance conducted over multiple time points in the United States. From 2,675 identified cases of candidemia in the current surveillance, 2,329 Candida isolates were collected. Candida albicans no longer comprised the majority of isolates but remained the most frequently isolated species (38%), followed by Candida glabrata (29%), Candida parapsilosis (17%), and Candida tropicalis (10%). The species distribution has changed over time; in both Atlanta and Baltimore the proportion of C. albicans isolates decreased, and the proportion of C. glabrata isolates increased, while the proportion of C. parapsilosis isolates increased in Baltimore only. There were 98 multispecies episodes, with C. albicans and C. glabrata the most frequently encountered combination. The new species-specific CLSI Candida MIC breakpoints were applied to these data. With the exception of C. glabrata (11.9% resistant), resistance to fluconazole was very low (2.3% of isolates for C. albicans, 6.2% for C. tropicalis, and 4.1% for C. parapsilosis). There was no change in the proportion of fluconazole resistance between surveillance periods. Overall echinocandin resistance was low (1% of isolates) but was higher for C. glabrata isolates, ranging from 2.1% isolates resistant to caspofungin in Baltimore to 3.1% isolates resistant to anidulafungin in Atlanta. Given the increase at both sites and the higher echinocandin resistance, C. glabrata should be closely monitored in future surveillance.
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Affiliation(s)
- Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, Georgia, USA.
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Kingsbury JM, Heitman J, Pinnell SR. Calcofluor white combination antifungal treatments for Trichophyton rubrum and Candida albicans. PLoS One 2012; 7:e39405. [PMID: 22792174 PMCID: PMC3391284 DOI: 10.1371/journal.pone.0039405] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 05/24/2012] [Indexed: 12/31/2022] Open
Abstract
Superficial mycoses caused by dermatophyte fungi are among the most common infections worldwide, yet treatment is restricted by limited effective drugs available, drug toxicity, and emergence of drug resistance. The stilbene fluorescent brightener calcofluor white (CFW) inhibits fungi by binding chitin in the cell wall, disrupting cell wall integrity, and thus entails a different mechanism of inhibition than currently available antifungal drugs. To identify novel therapeutic options for the treatment of skin infections, we compared the sensitivity of representative strains of the dermatophyte Trichophyton rubrum and Candida albicans to CFW and a panel of fluorescent brighteners and phytoalexin compounds. We identified the structurally related stilbene fluorescent brighteners 71, 85, 113 and 134 as fungicidal to both T. rubrum and C. albicans to a similar degree as CFW, and the stilbene phytoalexins pinosylvan monomethyl ether and pterostilbene inhibited to a lesser degree, allowing us to develop a structure-activity relationship for fungal inhibition. Given the abilities of CFW to absorb UV(365 nm) and bind specifically to fungal cell walls, we tested whether CFW combined with UV(365 nm) irradiation would be synergistic to fungi and provide a novel photodynamic treatment option. However, while both treatments individually were cytocidal, UV(365 nm) irradiation reduced sensitivity to CFW, which we attribute to CFW photoinactivation. We also tested combination treatments of CFW with other fungal inhibitors and identified synergistic interactions between CFW and some ergosterol biosynthesis inhibitors in C. albicans. Therefore, our studies identify novel fungal inhibitors and drug interactions, offering promise for combination topical treatment regimes for superficial mycoses.
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Affiliation(s)
- Joanne M Kingsbury
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America.
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Progress in antifungal susceptibility testing of Candida spp. by use of Clinical and Laboratory Standards Institute broth microdilution methods, 2010 to 2012. J Clin Microbiol 2012; 50:2846-56. [PMID: 22740712 DOI: 10.1128/jcm.00937-12] [Citation(s) in RCA: 357] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifungal susceptibility testing of Candida has been standardized and refined and now may play a useful role in managing Candida infections. Important new developments include validation of 24-h reading times for all antifungal agents and the establishment of species-specific epidemiological cutoff values (ECVs) for the systemically active antifungal agents and both common and uncommon species of Candida. The clinical breakpoints (CBPs) for fluconazole, voriconazole, and the echinocandins have been revised to provide species-specific interpretive criteria for the six most common species. The revised CBPs not only are predictive of clinical outcome but also provide a more sensitive means of identifying those strains with acquired or mutational resistance mechanisms. This brief review serves as an update on the new developments in the antifungal susceptibility testing of Candida spp. using Clinical and Laboratory Standards Institute (CLSI) broth microdilution (BMD) methods.
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Lockhart SR, Iqbal N, Bolden CB, DeBess EE, Marsden-Haug N, Worhle R, Thakur R, Harris JR. Epidemiologic cutoff values for triazole drugs in Cryptococcus gattii: correlation of molecular type and in vitro susceptibility. Diagn Microbiol Infect Dis 2012; 73:144-8. [PMID: 22494557 DOI: 10.1016/j.diagmicrobio.2012.02.018] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Revised: 02/21/2012] [Accepted: 02/21/2012] [Indexed: 01/12/2023]
Abstract
Cryptococcus gattii causes infection in tropical and subtropical regions worldwide but has garnered increased attention since its 1999 emergence in North America. C. gattii can be divided into 4 molecular types that may represent cryptic species. Recent evidence has shown that azole antifungal MIC values differ among these molecular types. We tested a large collection of C. gattii isolates for susceptibility to 4 azole drugs. We found that isolates of molecular type VGII have the highest geometric mean (GM) fluconazole MIC values (8.6 μg/mL), while isolates of molecular type VGI have the lowest (1.7 μg/mL). For fluconazole, itraconazole, and voriconazole GM MIC values, VGI < VGIII < VGIV < VGII. The GM MIC values for posaconazole were similarly represented across molecular types, with the exception that VGII < VGIII and VGIV. We used the MIC values to establish preliminary epidemiologic cutoff values for each azole and molecular type of C. gattii.
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Affiliation(s)
- Shawn R Lockhart
- Mycotic Diseases Branch, Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Validation of 24-hour flucytosine MIC determination by comparison with 48-hour determination by the Clinical and Laboratory Standards Institute M27-A3 broth microdilution reference method. J Clin Microbiol 2011; 49:4322-5. [PMID: 22012016 DOI: 10.1128/jcm.05479-11] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Flucytosine and itraconazole are the only antifungal agents for which the Clinical Laboratory and Standards Institute recommendations include MIC breakpoint readings at 48 h only. Here we show good essential and categorical agreement between the flucytosine MIC readings at 48 and 24 h for Candida species.
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Clinical breakpoints for voriconazole and Candida spp. revisited: review of microbiologic, molecular, pharmacodynamic, and clinical data as they pertain to the development of species-specific interpretive criteria. Diagn Microbiol Infect Dis 2011; 70:330-43. [DOI: 10.1016/j.diagmicrobio.2011.03.002] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Revised: 02/21/2011] [Accepted: 03/07/2011] [Indexed: 11/23/2022]
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