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Kidd SE, Crawford LC, Halliday CL. Antifungal Susceptibility Testing and Identification. Infect Dis Clin North Am 2021; 35:313-339. [PMID: 34016280 DOI: 10.1016/j.idc.2021.03.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The requirement for antifungal susceptibility testing is increasing given the availability of new drugs, increasing populations of individuals at risk for fungal infection, and emerging multiresistant fungi. Rapid and accurate fungal identification remains at the forefront of laboratory efforts to guide empiric therapy. Antifungal susceptibility testing methods have greatly improved, but are subject to variation in results between methods. Careful standardization, validation, and extensive training of users is essential to ensure susceptibility results are clinically useful and interpreted appropriately. Interpretive criteria for many drugs and species are still lacking, but this will continue to evolve.
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Affiliation(s)
- Sarah E Kidd
- National Mycology Reference Centre, Microbiology & Infectious Diseases, SA Pathology, SA Pathology (Frome Campus), PO Box 14, Rundle Mall, Adelaide, South Australia 5000, Australia; School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia.
| | - Lucy C Crawford
- Microbiology & Infectious Diseases, SA Pathology, PO Box 14, Rundle Mall, Adelaide, South Australia 5000, Australia; Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Catriona L Halliday
- Clinical Mycology Reference Laboratory, Centre for Infectious Diseases and Microbiology Laboratory Services, Institute of Clinical Pathology and Medical Research, NSW Health Pathology, Westmead Hospital, The University of Sydney, Level 3 ICPMR, Darcy Road, Westmead, New South Wales 2145, Australia
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2
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Shamsizadeh F, Ansari S, Zarei Mahmoudabadi A, Hubka V, Čmoková A, Guillot J, Rafiei A, Zomorodian K, Nouripour-Sisakht S, Diba K, Mohammadi T, Zarrinfar H, Rezaei-Matehkolaei A. In vitro antifungal susceptibility patterns of Trichophyton benhamiae complex isolates from diverse origin. Mycoses 2021; 64:1378-1386. [PMID: 33864711 DOI: 10.1111/myc.13287] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 04/07/2021] [Accepted: 04/11/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Species from the Trichophyton benhamiae complex are mostly zoophilic dermatophytes which cause inflammatory dermatophytosis in animals and humans worldwide. OBJECTIVES This study was purposed to (a) to identify 169 reference and clinical dermatophyte strains from the T benhamiae complex species by molecular method and adhering to the newest taxonomy in the complex (b) to evaluate the in vitro antifungal susceptibility profile of these strains against eight common and new antifungal agents that may be used for the treatment of dermatophytosis. METHODS All isolates, mainly originated from Europe but also from Iran, Japan and USA, were subjected to ITS-rDNA sequencing. The in vitro antifungal susceptibility profiles of eight common and new antifungal drugs against the isolates were determined by CLSI M38-A2 protocol and according to microdilution method. RESULTS Based on the ITS-rDNA sequencing, T benhamiae was the dominant species (n = 102), followed by T europaeum (n = 29), T erinacei (n = 23), T japonicum (n = 10), Trichophyton sp (n = 4) and T eriotrephon (n = 1). MIC ranges across all isolates were as follows: luliconazole: 0.0002-0.002 µg/ml, terbinafine: 0.008-0.125 µg/ml, efinaconazole: 0.008-0.125 µg/ml, ciclopirox olamine: 0.03-0.5 µg/ml, itraconazole: 0.06-2 µg/ml, griseofulvin: 0.25-4 µg/ml, amorolfine hydrochloride: 0.125-4 µg/ml and tavaborole: 1-16 µg/ml. CONCLUSION Luliconazole, efinaconazole and terbinafine were the most potent antifungals against T benhamiae complex isolates, regardless of the geographic locations where strains were isolated. These data might help dermatologists to develop effective therapies for successful treatment of infections due to T benhamiae complex species.
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Affiliation(s)
- Forough Shamsizadeh
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Saham Ansari
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Zarei Mahmoudabadi
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Vít Hubka
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.,Laboratory of Fungal Genetics and Metabolism, Institute of Microbiology, Czech Academy of Sciences, Vídeňská, Czech Republic
| | - Adéla Čmoková
- Department of Botany, Faculty of Science, Charles University, Prague, Czech Republic.,Laboratory of Fungal Genetics and Metabolism, Institute of Microbiology, Czech Academy of Sciences, Vídeňská, Czech Republic
| | - Jacques Guillot
- Dynamic Research Group UPEC, EnvA, USC Anses, Ecole Nationale Vétérinaire d'Alfort, Maisons-Alfort, France
| | - Abdollah Rafiei
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Parasitology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Kamiar Zomorodian
- Department of Medical Mycology and Parasitology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | | | - Kambiz Diba
- Department of Medical Mycology and Parasitology, Faculty of Medicine, Urmia University of Medical Sciences, Urmia, Iran
| | - Tooba Mohammadi
- Department of Medical Mycology and Parasitology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hossein Zarrinfar
- Allergy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ali Rezaei-Matehkolaei
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.,Department of Medical Mycology, School of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Jing R, Yang WH, Xiao M, Li Y, Zou GL, Wang CY, Li XW, Xu YC, Hsueh PR. Species identification and antifungal susceptibility testing of Aspergillus strains isolated from patients with otomycosis in northern China. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2021; 55:282-290. [PMID: 33839057 DOI: 10.1016/j.jmii.2021.03.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 03/15/2021] [Accepted: 03/21/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND/PURPOSE There are limited studies on species distribution and susceptibility profiles of Aspergillus strains isolated from patients with otomycosis in China. METHODS A total of 69 confirmed Aspergillus species isolates were obtained from ear swabs of patients diagnosed with otomycosis from 2017 to 2018 in northern China. Identification of these Aspergillus isolates at the species level was performed using conventional morphological methods and MALDI-TOF MS in combination with molecular sequencing, and in vitro susceptibility to nine antifungal agents was evaluated using the Sensititre YeastOne system. RESULTS The Aspergillus section Nigri had the greatest distribution of Aspergillus isolates. A. welwitschiae (n = 25) was the most predominant isolate in section Nigri, followed by A. tubingensis (n = 12) and A. niger (n = 11). Other Aspergillus species were also isolated, including A. terreus (n = 11), A. flavus/A. oryzae (n = 8), and A. fumigatus (n = 2). Amphotericin B, posaconazole, and echinocandins were highly in vitro active against all the isolates tested. 2.9% (2/69) of the isolates were resistant to azoles in our study, including one A. niger isolate with a high MIC value for itraconazole (ITR) (16 mg/L) and one A. tubingensis isolate cross-resistant to both voriconazole (VOR) (MIC >8 mg/L) and ITR (MIC >16 mg/L). One A. welwitschiae and one A. niger isolate both had increased MIC values of 4 mg/L against VOR. CONCLUSIONS A. welwitschiae was the most prevalent Aspergillus species isolated from patients with otomycosis. Our findings also indicated that the azole-resistant Aspergillus section Nigri should be utilized to guide clinical medication for Otomycosis.
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Affiliation(s)
- Ran Jing
- Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Graduate School, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Wen-Hang Yang
- Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Graduate School, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Meng Xiao
- Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China
| | - Ying Li
- Department of Clinical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Gui-Ling Zou
- The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang, China
| | - Cheng-Ying Wang
- Daqing Oilfield General Hospital, Daqing, Heilongjiang, China
| | - Xiu-Wen Li
- Mudanjiang First People's Hospital, Heilongjiang, Mudanjiang, China
| | - Ying-Chun Xu
- Department of Laboratory Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Graduate School, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing, China.
| | - Po-Ren Hsueh
- Department of Laboratory Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan; Department of Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan.
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Li Y, Wang H, Hou X, Huang JJ, Wang PC, Xu YC. Identification by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry and Antifungal Susceptibility Testing of Non- Aspergillus Molds. Front Microbiol 2020; 11:922. [PMID: 32582045 PMCID: PMC7283379 DOI: 10.3389/fmicb.2020.00922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/17/2020] [Indexed: 12/28/2022] Open
Abstract
Non-Aspergillus molds including Mucorales, Fusarium, and Scedosporium, etc. are emerging pathogens leading to higher mortality in immunocompromised patients. Fifty-two isolates of genetically confirmed non-Aspergillus molds representing 16 species from 8 genera were collected to evaluate the performance of the Bruker matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) in identification of non-Aspergillus molds. Antifungal susceptibilities were determined through the Clinical & Laboratory Standards Institute (CLSI) M38-A2 broth microdilution method and the Sensititre YeastOne colorimetric method. Bruker MALDI-TOF MS identified 57.7% (30/52) of isolates cultured in broth and 15.4% (8/52) of isolates cultured on solid agar media to the species level, respectively, according to standard interpretation criteria. Lowering the species level cut-off value (COV) from ≥2.0 to ≥1.7 could improve the MALDI-TOF MS species-level identification rate to 67.3% (38/52) for isolates cultured on solid media, with a slight increase of false identification rate of 2.6% (1/38). Amphotericin B was the most in vitro fungistatic-active agent for 98.1% (51/52) of the tested non-Aspergillus molds, with minimum inhibitory concentrations (MICs) of ≤2 μg/mL. The susceptibilities to triazoles varied, with MICs of 0.12 to >16 μg/mL among different species of non-Aspergillus molds. The correlation between the CLSI method and Sensititre YeastOne on antifungal susceptibility testing of non-Aspergillus molds was good, with essential agreement (EA) rates of >90% for triazoles and echinocandins except amphotericin B, which had a lower EA rate of 84.6%. In conclusion, a favorable performance of the Bruker MALDI-TOF MS in identification of clinical non-Aspergillus isolates directly inoculated on solid agar media could be achieved with the adoption of alternative interpretation criteria. Antifungal susceptibility testing is important for non-Aspergillus molds, especially when information on triazole susceptibility is required, and the Sensititre YeastOne is a practical and reliable method to determine antifungal susceptibilities of non-Aspergillus molds.
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Affiliation(s)
- Ying Li
- Department of Clinical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China.,Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - He Wang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Xin Hou
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Jing-Jing Huang
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Pei-Chang Wang
- Department of Clinical Laboratory, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ying-Chun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China.,Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
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Li Y, Wang H, Zhao YP, Xu YC, Hsueh PR. Antifungal susceptibility of clinical isolates of 25 genetically confirmed Aspergillus species collected from Taiwan and Mainland China. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2020; 53:125-132. [DOI: 10.1016/j.jmii.2018.04.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 04/15/2018] [Accepted: 04/27/2018] [Indexed: 11/26/2022]
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6
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Lu X, Wang X, Zhang L, Li X, Qi X. Rare Fungal Keratitis Caused by Coprinellus Radians. Mycopathologia 2020; 185:389-394. [PMID: 31915988 DOI: 10.1007/s11046-019-00414-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 12/04/2019] [Indexed: 10/25/2022]
Abstract
A case of fungal keratitis due to Coprinellus radians is reported. To our knowledge, fungal keratitis caused by this species was rare. Fungal hyphae were detected in corneal scrapings, and isolates were identified by morphology and by sequencing the internal transcribed spacer region of ribosomal DNA. The patient was treated with systemic and local antifungal therapy for 5 days, and lamellar keratoplasty was performed after no obvious improvement in symptoms. The in vitro antifungal susceptibilities of the case strain were tested for six antifungal agents. The results showed that 5-fluorouracil was resistant, fluconazole was moderately sensitive, and the other drugs assayed (amphotericin B, posaconazole, itraconazole and voriconazole) were highly effective against this fungus.
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Affiliation(s)
- Xiuhai Lu
- Shandong Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, 372 Jingsi Road, Jinan, 250000, China
| | - Xin Wang
- Shandong Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, 372 Jingsi Road, Jinan, 250000, China
| | - Li Zhang
- Shandong Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, 372 Jingsi Road, Jinan, 250000, China
| | - Xiaofeng Li
- Shandong Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, 372 Jingsi Road, Jinan, 250000, China
| | - Xiaolin Qi
- Shandong Eye Hospital, Shandong Eye Institute, Shandong Academy of Medical Sciences, 372 Jingsi Road, Jinan, 250000, China.
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Ansari S, Ahmadi B, Norouzi M, Ansari Z, Afsarian MH, Lotfali E, Rezaei-Matehkolaei A. Epidermophyton floccosum: nucleotide sequence analysis and antifungal susceptibility testing of 40 clinical isolates. J Med Microbiol 2019; 68:1655-1663. [PMID: 31573466 DOI: 10.1099/jmm.0.001074] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Purpose. Epidermophyton floccosum is an anthropophilic dermatophyte species, which is one of the common causative agents of dermatophytosis in different parts of the world. The aim of the present investigation was to evaluate the genetic diversity of E. floccosum strains isolated from different parts of Iran and to define the in vitro susceptibility profiles of seven antifungal drugs against these clinical isolates.Methodology. Forty clinical strains of E. floccosum isolated from 40 patients with dermatophytosis were subjected to DNA extraction and PCR amplification of the ITS rDNA region using universal primers ITS1 and ITS4. The in vitro activities of griseofulvin, itraconazole, voriconazole, posaconazole, caspofungin, ketoconazole and terbinafine were determined using a broth microdilution method according to the CLSI-M-38A2 protocol.Results. A mean genetic similarity of 99.5 % was found between E. floccosum strains, with intraspecies differences ranging from 0 to 3 nt. The geometric mean (GM) MICs and minimum effective concentrations (MECs) across all isolates were, in increasing order, as follows: terbinafine (GM=0.018 mg l-1), posaconazole (GM=0.022 mg l-1), itraconazole (GM=0.034 mg l-1) and voriconazole (GM=0.045 mg l-1), which had low MICs against all tested strains, whereas caspofungin (GM=0.22 mg l-1), ketoconazole (GM=0.41 mg l-1) and griseofulvin (GM=0.62 mg l-1) demonstrated higher MICs.Conclusion. Our study showed low intraspecies variation within strains of E. floccosum. Furthermore, terbinafine, posaconazole, itraconazole and voriconazole were shown to be the most potent antifungal drugs against E. floccosum strains.
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Affiliation(s)
- Saham Ansari
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahram Ahmadi
- Department of Medical Laboratory Sciences, School of Para-Medicine, Bushehr University of Medical Sciences, Bushehr, Iran
| | - Maryam Norouzi
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Zohreh Ansari
- Department of Chemistry, Shiraz Branch, Islamic Azad University, Shiraz, Iran
| | - Mohammad Hosein Afsarian
- Department of Medical Mycology and Parasitology, School of Medicine, Fasa University of Medical Sciences, Fasa, Iran
| | - Ensieh Lotfali
- Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Ali Rezaei-Matehkolaei
- Infectious and Tropical Diseases Research Center, Health Research Institute, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
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Arendrup MC, Verweij PE, Mouton JW, Lagrou K, Meletiadis J. Multicentre validation of 4-well azole agar plates as a screening method for detection of clinically relevant azole-resistant Aspergillus fumigatus. J Antimicrob Chemother 2018; 72:3325-3333. [PMID: 29029256 DOI: 10.1093/jac/dkx319] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 07/31/2017] [Indexed: 01/02/2023] Open
Abstract
Objectives Azole-resistant Aspergillus fumigatus is emerging worldwide. Reference susceptibility testing methods are technically demanding and no validated commercial susceptibility tests for moulds currently exist. In this multicentre study a 4-well azole-containing screening agar method was evaluated using clinically relevant isolates. Methods Forty WT and 39 cyp51A mutant A. fumigatus [G54 (n = 10), M220 (n = 10), TR34/L98H (n = 9) and TR46/Y121F/T289A (n = 10)] were tested individually and as simulated mixed samples (sampling 4 WT and 1 mutant colonies). EUCAST MICs were determined following E.Def 9.3. In-house and commercial 4-well plates containing agars supplemented with 4 mg/L itraconazole, 1 mg/L voriconazole, 0.5 mg/L posaconazole and no antifungal, respectively, were evaluated. Growth was scored (0-3) by two independent observers in three laboratories. Inter-plate, inter-observer, essential and categorical agreement, sensitivity and specificity were calculated. Results CYP51A genotype and antifungal compound-specific MICs and growth patterns were documented. The inter-observer agreement was excellent with 86%-99% identical scores (range 80%-100%) for both plates. The qualitative agreement (no growth versus growth) was excellent (median 95%-100%, range 87%-100%, overall). The overall sensitivity and specificity for the 4-well plate (no growth versus growth) was 99% (range 97%-100%) and 99% (95%-100%), respectively. The sensitivity for simulated WT/mutant specimens was 94% (range 83%-100%) for the WT-TR34/L98H combination, but 100% for the WT/G54W combination. The performance remained unchanged using only itraconazole- and voriconazole-containing agars, but was lower for the other combinations. Conclusions Implementation of the 4-well screening plate in routine laboratories will allow easy and reliable detection of the most common azole-resistant A. fumigatus.
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Affiliation(s)
- Maiken Cavling Arendrup
- Unit of Mycology, Statens Serum Institut, Copenhagen, Denmark.,Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Paul E Verweij
- Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands.,Centre of Expertise in Mycology, Radboudumc/CWZ, Nijmegen, The Netherlands
| | - Johan W Mouton
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Katrien Lagrou
- National Reference Center for Mycosis, University Hospitals Leuven, Leuven, Belgium.,Department of Microbiology and Immunology, University of Leuven, Leuven, Belgium
| | - Joseph Meletiadis
- Department of Medical Microbiology and Infectious Diseases, Erasmus Medical Center, Rotterdam, The Netherlands.,Clinical Microbiology Laboratory, Attikon University Hospital, National and Kapodistrian University of Athens, Athens, Greece
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9
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Growth Inhibition and Membrane Permeabilization of Candida lusitaniae Using Varied Pulse Shape Electroporation. BIOMED RESEARCH INTERNATIONAL 2015; 2015:457896. [PMID: 26697485 PMCID: PMC4678064 DOI: 10.1155/2015/457896] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/23/2015] [Indexed: 12/21/2022]
Abstract
Candida lusitaniae is an opportunistic yeast pathogen, which can readily develop resistance to antifungal compounds and result in a complex long-term treatment. The efficient treatment is difficult since structure and metabolic properties of the fungal cells are similar to those of eukaryotic host. One of the potential methods to improve the inhibition rate or the cell permeability to inhibitors is the application of electroporation. In this work we investigated the dynamics of the growth inhibition and membrane permeabilization of C. lusitaniae by utilizing the various pulse shape and duration electric field pulses. Our results indicated that single electroporation procedure using 8 kV/cm electric field may result in up to 51 ± 5% inhibition rate. Also it has been experimentally shown that the electroporation pulse shape may influence the inhibitory effect; however, the amplitude of the electric field and the pulse energy remain the most important parameters for definition of the treatment outcome. The dynamics of the cell membrane permeabilization in the 2–8 kV/cm electric field were overviewed.
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10
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Ansari S, Hedayati MT, Zomorodian K, Pakshir K, Badali H, Rafiei A, Ravandeh M, Seyedmousavi S. Molecular Characterization and In Vitro Antifungal Susceptibility of 316 Clinical Isolates of Dermatophytes in Iran. Mycopathologia 2015; 181:89-95. [PMID: 26369643 DOI: 10.1007/s11046-015-9941-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Accepted: 09/05/2015] [Indexed: 11/29/2022]
Abstract
Dermatophytosis is a common mycotic infection of the skin, nail, and hair, associated with major public health concern worldwide. Various species of dermatophytes show significant differences in susceptibility to antifungals. Here, we present the antifungal susceptibility of a large collection of molecularly identified dermatophyte isolates obtained from tropical region of south of Iran. A total of 9485 patients clinically suspected to have cutaneous fungal infections were examined. Dermatophytosis was confirmed in 1502 cases by direct microscopy and culture. Three hundred and sixteen isolates recovered in culture were identified to species level using PCR sequencing of ITS region and RFLP. Tinea corporis was the most prevalent type of clinical manifestation (35.2 %), followed by tinea cruris (17 %), tinea capitis (12.8 %), tinea pedis (11.3 %), tinea manuum (11 %), tinea unguium (6.9 %), and tinea barbae (5.8 %). Trichophyton interdigitale was the most common isolate (49.36 %), followed by Trichophyton rubrum (18.98 %), Epidermophyton floccosum (13.29 %), Microsporum canis (9.17 %), Arthroderma benhamiae (T. anamorph of A. benhamiae; 5.38 %), and Trichophyton tonsurans (3.79 %). Overall, irrespective of the geographical region, terbinafine was the most potent antifungal against all isolates, with an MIC range of 0.002-0.25 μg/mL, followed by itraconazole (0.004-0.5 μg/mL), griseofulvin (0.125-8 μg/mL), and fluconazole (4-128 μg/mL). Analysis of our data revealed a significant increase in the frequency of A.benhamiae, which definitely warrants further investigation to explore source of this infection in south of Iran. Moreover, terbinafine was the most effective antifungal against all isolates, in vitro.
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Affiliation(s)
- Saham Ansari
- Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Km 18 Khazarabad Road, P.O. Box 48175-1665, Sari, Iran.,Department of Medical Mycology and Parasitology School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad T Hedayati
- Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Km 18 Khazarabad Road, P.O. Box 48175-1665, Sari, Iran. .,Department of Medical Mycology and Parasitology School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Kamiar Zomorodian
- Department of Parasitology and Mycology, Basic Sciences in Infectious Diseases Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Keyvan Pakshir
- Department of Parasitology and Mycology, Basic Sciences in Infectious Diseases Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Hamid Badali
- Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Km 18 Khazarabad Road, P.O. Box 48175-1665, Sari, Iran.,Department of Medical Mycology and Parasitology School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Abdollah Rafiei
- Department of Parasitology and Mycology/Infectious and Tropical Medicine Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Mostafa Ravandeh
- Department of Parasitology and Mycology, Basic Sciences in Infectious Diseases Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Seyedmojtaba Seyedmousavi
- Invasive Fungi Research Center, Mazandaran University of Medical Sciences, Km 18 Khazarabad Road, P.O. Box 48175-1665, Sari, Iran.,Department of Medical Microbiology and Infectious Diseases, Erasmus University Medical Center, Erasmus, The Netherlands.,Department of Medical Microbiology, Radboud University Medical Centre, Nijmegen, The Netherlands
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11
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Talbot JJ, Kidd SE, Martin P, Beatty JA, Barrs VR. Azole resistance in canine and feline isolates of Aspergillus fumigatus. Comp Immunol Microbiol Infect Dis 2015; 42:37-41. [PMID: 26387063 DOI: 10.1016/j.cimid.2015.08.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 08/13/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
Azole resistance is an emerging cause of treatment failure in humans with aspergillosis. The aim of this study was to determine if azole resistance is emerging in Aspergillus fumigatus isolates from canine and feline sino-nasal aspergillosis cases. Susceptibilities of isolates collected between 1988 and 2014 from 46 dogs and 4 cats to itraconazole, posaconazole, voriconazole, fluconazole and ketoconazole were assessed using Sensititre YeastOne microdilution trays; and to enilconazole and clotrimazole, following the CLSI M38-A2 standard. For the majority of isolates MICs were high for ketoconazole, low for enilconazole and clotrimazole, and less than established epidemiological cut-off values for itraconazole, posaconazole and voriconazole. One canine isolate from 1992 had multiazole resistance and on Cyp51A gene sequencing a mutation associated with azole resistance (F46Y) was detected. There is no evidence of emerging azole resistance among A. fumigatus isolates from dogs and cats and topical azole therapy should be effective against most isolates.
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Affiliation(s)
- Jessica J Talbot
- Valentine Charlton Cat Centre, Faculty of Veterinary Science, University of Sydney, Camperdown 2006, NSW, Australia
| | - Sarah E Kidd
- National Mycology Reference Centre, Microbiology and Infectious Diseases, SA Pathology, Frome Road, Adelaide 5000, SA, Australia
| | - Patricia Martin
- Veterinary Pathology Diagnostic Services, Faculty of Veterinary Science, University of Sydney, Camperdown 2006, NSW, Australia
| | - Julia A Beatty
- Valentine Charlton Cat Centre, Faculty of Veterinary Science, University of Sydney, Camperdown 2006, NSW, Australia
| | - Vanessa R Barrs
- Valentine Charlton Cat Centre, Faculty of Veterinary Science, University of Sydney, Camperdown 2006, NSW, Australia.
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12
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Tortorano AM, Richardson M, Roilides E, van Diepeningen A, Caira M, Munoz P, Johnson E, Meletiadis J, Pana ZD, Lackner M, Verweij P, Freiberger T, Cornely OA, Arikan-Akdagli S, Dannaoui E, Groll AH, Lagrou K, Chakrabarti A, Lanternier F, Pagano L, Skiada A, Akova M, Arendrup MC, Boekhout T, Chowdhary A, Cuenca-Estrella M, Guinea J, Guarro J, de Hoog S, Hope W, Kathuria S, Lortholary O, Meis JF, Ullmann AJ, Petrikkos G, Lass-Flörl C. ESCMID and ECMM joint guidelines on diagnosis and management of hyalohyphomycosis: Fusarium spp., Scedosporium spp. and others. Clin Microbiol Infect 2014; 20 Suppl 3:27-46. [PMID: 24548001 DOI: 10.1111/1469-0691.12465] [Citation(s) in RCA: 316] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 11/18/2013] [Accepted: 11/18/2013] [Indexed: 01/03/2023]
Abstract
Mycoses summarized in the hyalohyphomycosis group are heterogeneous, defined by the presence of hyaline (non-dematiaceous) hyphae. The number of organisms implicated in hyalohyphomycosis is increasing and the most clinically important species belong to the genera Fusarium, Scedosporium, Acremonium, Scopulariopsis, Purpureocillium and Paecilomyces. Severely immunocompromised patients are particularly vulnerable to infection, and clinical manifestations range from colonization to chronic localized lesions to acute invasive and/or disseminated diseases. Diagnosis usually requires isolation and identification of the infecting pathogen. A poor prognosis is associated with fusariosis and early therapy of localized disease is important to prevent progression to a more aggressive or disseminated infection. Therapy should include voriconazole and surgical debridement where possible or posaconazole as salvage treatment. Voriconazole represents the first-line treatment of infections due to members of the genus Scedosporium. For Acremonium spp., Scopulariopsis spp., Purpureocillium spp. and Paecilomyces spp. the optimal antifungal treatment has not been established. Management usually consists of surgery and antifungal treatment, depending on the clinical presentation.
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Affiliation(s)
- A M Tortorano
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milano, Italy
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13
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Cysticidal activity of antifungals against different genotypes of Acanthamoeba. Antimicrob Agents Chemother 2014; 58:5626-8. [PMID: 25001304 DOI: 10.1128/aac.02635-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifungal drugs have been proposed as a novel treatment for Acanthamoeba keratitis. The cysticidal activity of several antifungal compounds was tested against different genotypes of culture collection and clinical isolates of Acanthamoeba. Only voriconazole and posaconazole were found to be cysticidal, with no differences in activity observed between clinical and culture collection isolates.
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14
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de Melo WCMA, Avci P, de Oliveira MN, Gupta A, Vecchio D, Sadasivam M, Chandran R, Huang YY, Yin R, Perussi LR, Tegos GP, Perussi JR, Dai T, Hamblin MR. Photodynamic inactivation of biofilm: taking a lightly colored approach to stubborn infection. Expert Rev Anti Infect Ther 2014; 11:669-93. [PMID: 23879608 DOI: 10.1586/14787210.2013.811861] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Microbial biofilms are responsible for a variety of microbial infections in different parts of the body, such as urinary tract infections, catheter infections, middle-ear infections, gingivitis, caries, periodontitis, orthopedic implants, and so on. The microbial biofilm cells have properties and gene expression patterns distinct from planktonic cells, including phenotypic variations in enzymic activity, cell wall composition and surface structure, which increase the resistance to antibiotics and other antimicrobial treatments. There is consequently an urgent need for new approaches to attack biofilm-associated microorganisms, and antimicrobial photodynamic therapy (aPDT) may be a promising candidate. aPDT involves the combination of a nontoxic dye and low-intensity visible light which, in the presence of oxygen, produces cytotoxic reactive oxygen species. It has been demonstrated that many biofilms are susceptible to aPDT, particularly in dental disease. This review will focus on aspects of aPDT that are designed to increase efficiency against biofilms modalities to enhance penetration of photosensitizer into biofilm, and a combination of aPDT with biofilm-disrupting agents.
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Affiliation(s)
- Wanessa C M A de Melo
- The Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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15
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Sarver JG, Trendel JA, Bearss NR, Wang L, Luniwal A, Erhardt PW, Viola RE. Early stage efficacy and toxicology screening for antibiotics and enzyme inhibitors. ACTA ACUST UNITED AC 2012; 17:673-82. [PMID: 22460173 DOI: 10.1177/1087057112438769] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The rise in organisms resistant to existing drugs has added urgency to the search for new antimicrobial agents. Aspartate β-semialdehyde dehydrogenase (ASADH) catalyzes a critical step in an essential microbial pathway that is absent in mammals. Our laboratory is using fragment library screening to identify efficient and selective ASADH inhibitors. These preliminary agents are then tested to identify compounds with desired antimicrobial properties for further refinement. Toward this end, we have established a microplate-based, dual-assay approach using a single reagent to evaluate antibiotic activity and mammalian cell toxicity during early stage development. The bacterial assay uses nonpathogenic bacteria to allow efficacy testing without a dedicated microbial laboratory. Toxicity assays are performed with a panel of mammalian cells derived from representative susceptible tissues. These assays can be adapted to target other microbial systems, such as fungi and biofilms, and additional mammalian cell lines can be added as needed. Application of this screening approach to antibiotic standards demonstrates the ability of these assays to identify bacterial selectivity and potential toxicity issues. Tests with selected agents from the ASADH inhibitor fragment library show some compounds with antibiotic activity, but as expected, most of these early agents display higher than desired mammalian cell toxicity.
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Affiliation(s)
- Jeffrey G Sarver
- Center for Drug Design and Development, University of Toledo, Toledo, OH, USA.
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16
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Sardi JCO, Almeida AMF, Mendes Giannini MJS. New antimicrobial therapies used against fungi present in subgingival sites--a brief review. Arch Oral Biol 2011; 56:951-9. [PMID: 21676377 DOI: 10.1016/j.archoralbio.2011.03.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2010] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 01/14/2023]
Abstract
Although the main reservoir of Candida spp. is believed to be the buccal mucosa, these microorganisms can coaggregate with bacteria in subgingival biofilm and adhere to epithelial cells. The treatment of periodontal disease includes scaling and root planning (SRP) associated with proper oral hygiene. However, some patients may have negative responses to different therapeutic procedures, with a continuous loss of insertion, so the use of antimicrobials is needed as an adjuvant to SRP treatment. The use of a broad-spectrum antibiotic, such as tetracycline and metronidazole, as an aid in periodontal treatment has also been a factor for the development of superinfections by resistant bacteria and Candida species, even in patients with HIV. In the dental practice, the most commonly used antifungals are nystatin and fluconazole. However, the introduction of new drugs like the next generation of azoles is essential before the onset of emergent species in periodontal disease. Plants are good options for obtaining a wide variety of drugs. This alternative could benefit a large population that uses plants as a first treatment option. Plants have been used in medicine for a long time and are extensively used in folk medicine, because they represent an economic alternative, are easily accessible and are applicable to various diseases. Herein, we briefly review the literature pertaining the presence of Candida sp. in periodontal pockets, the conventional antifungal resistance and new therapies that include natural antifungal agents are reviewed.
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Affiliation(s)
- Janaina Cássia Orlandi Sardi
- Faculty of Pharmaceutical Sciences of Araraquara, Department of Clinical Analysis, Laboratory of Clinical Mycology, Univ Estadual Paulista, UNESP, Araraquara, SP, Brazil
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17
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Lass-Flörl C. In vitro susceptibility testing in Aspergillus species: an update. Future Microbiol 2010; 5:789-99. [PMID: 20441550 DOI: 10.2217/fmb.10.34] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Aspergillus species are the most common causes of invasive mold infections in immunocompromised patients. The introduction of new antifungal agents and recent reports of resistance emerging during treatment of Aspergillus infections have highlighted the need for in vitro susceptibility testing. Various testing procedures have been proposed, including macro- and micro-dilution, disk diffusion, Etest (AB Biodisk, Sweden) and other commercial tests. Although Aspergillus species are generally susceptible to various compounds, intrinsic and acquired resistance has been documented. Amphotericin B has limited activity against Aspergillus terreus and Aspergillus nidulans. Not surprisingly, continued use of azole-based drugs has the undesirable consequence of elevating the resistance of subsequent isolates from these patients. Several species in the Aspergillus fumigatus complex appear to be resistant to azoles; there is evidence of in vitro and in vivo correlation. Each in vitro susceptibility testing method has its own advantages and disadvantages. Etest is easy to perform and use on a daily basis, yet it is expensive. Disk diffusion is the most attractive alternative method to date, yet we lack sufficient data for aspergilli. The European Committee on Antimicrobial Susceptibility Testing (EUCAST) and the Clinical Laboratory Standard Institute (CLSI) have produced reproducible reference testing methods. This article reviews the available methods for antifungal susceptibility testing in Aspergillus spp. as well as the scant data regarding the clinical implications of in vitro testing.
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Affiliation(s)
- Cornelia Lass-Flörl
- Department of Hygiene, Microbiology & Social Medicine, Division of Hygiene & Clinical Microbiology, Innsbruck Medical University, Fritz Pregl Str 3, 6020 Innsbruck, Austria.
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18
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ELKHATIB WALIDF, NOREDDIN AYMANM. A NEW FLUOROGENIC ASSAY FOR MONITORING AND DETERMINING PLANKTONIC AND BIOFILM FORMS OFPSEUDOMONAS AERUGINOSAVIABLE COUNTIN VITRO. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1745-4581.2009.00156.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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19
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Updating Corneofungimetry: A Bioassay Exploring Dermatomycoses and Antifungal Susceptibility. Mycopathologia 2009; 169:27-35. [DOI: 10.1007/s11046-009-9227-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2009] [Accepted: 07/15/2009] [Indexed: 11/26/2022]
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20
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Duarte M, Giordani RB, De Carli GA, Zuanazzi JA, Macedo AJ, Tasca T. A quantitative resazurin assay to determinate the viability of Trichomonas vaginalis and the cytotoxicity of organic solvents and surfactant agents. Exp Parasitol 2009; 123:195-8. [PMID: 19619538 DOI: 10.1016/j.exppara.2009.07.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 03/24/2009] [Accepted: 07/14/2009] [Indexed: 10/20/2022]
Abstract
Trichomonas vaginalis causes trichomonosis, the most common, non-viral sexually transmitted disease. To test anti-Trichomonas agents, usually many with low water solubility, organic solvents and surfactant agents should be used. Therefore, the minimal inhibitory concentration (MIC) of acetone, methanol, ethanol, isopropanol, DMSO, Tween 20, Tween 80, and Triton X-100 was determined against T. vaginalis isolates using the quantitative resazurin method. Our results showed that solvents and surfactant agents can be employed as vehicles to test bioactive compounds at lower concentrations than MIC values and we suggest acetone and DMSO as preferential. Moreover, a new methodology is established to substitute or to complement the counting of viable trophozoites. The amount of resazurin reduced by T. vaginalis can be quantified by fluorescence spectroscopy, making the test a quantitative determination of cell viability. These results contribute for pharmacological investigations of bioactive compounds that need the use of solvents as solubilization vehicles to test anti-Trichomonas activity.
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Affiliation(s)
- Mariana Duarte
- Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
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21
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Araújo CR, Miranda KC, Fernandes ODFL, Soares AJ, Silva MDRR. In vitro susceptibility testing of dermatophytes isolated in Goiania, Brazil, against five antifungal agents by broth microdilution method. Rev Inst Med Trop Sao Paulo 2009; 51:9-12. [DOI: 10.1590/s0036-46652009000100002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Accepted: 11/03/2008] [Indexed: 11/22/2022] Open
Abstract
The antifungal activities of fluconazole, itraconazole, ketoconazole, terbinafine and griseofulvin were tested by broth microdilution technique, against 60 dermatophytes isolated from nail or skin specimens from Goiania city patients, Brazil. In this study, the microtiter plates were incubated at 28 ºC allowing a reading of the minimal inhibitory concentration (MIC) after four days of incubation for Trichophyton mentagrophytes and five days for T. rubrum and Microsporum canis. Most of the dermatophytes had uniform patterns of susceptibility to the antifungal agents tested. Low MIC values as 0.03 µg/mL were found for 33.3%, 31.6% and 15% of isolates for itraconazole, ketoconazole and terbinafine, respectively.
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22
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Abstract
Antifungal susceptibility testing is a very dynamic field of medical mycology. Standardization of in vitro susceptibility tests by the Clinical and Laboratory Standards Institute (CLSI) and the European Committee for Antimicrobial Susceptibility Testing (EUCAST), and current availability of reference methods constituted the major remarkable steps in the field. Based on the established minimum inhibitory concentration (MIC) breakpoints, it is now possible to determine the susceptibilities of Candida strains to fluconazole, itraconazole, voriconazole, and flucytosine. Moreover, utility of fluconazole antifungal susceptibility tests as an adjunct in optimizing treatment of candidiasis has now been validated. While the MIC breakpoints and clinical significance of susceptibility testing for the remaining fungi and antifungal drugs remain yet unclear, modifications of the available methods as well as other methodologies are being intensively studied to overcome the present drawbacks and limitations. Among the other methods under investigation are Etest, colorimetric microdilution, agar dilution, determination of fungicidal activity, flow cytometry, and ergosterol quantitation. Etest offers the advantage of practical application and favorable agreement rates with the reference methods that are frequently above acceptable limits. However, MIC breakpoints for Etest remain to be evaluated and established. Development of commercially available, standardized colorimetric panels that are based on CLSI method parameters has added more to the antifungal susceptibility testing armamentarium. Flow cytometry, on the other hand, appears to offer rapid susceptibility testing but requires specified equipment and further evaluation for reproducibility and standardization. Ergosterol quantitation is another novel approach, which appears potentially beneficial particularly in discrimination of azole-resistant isolates from heavy trailers. The method is yet investigational and requires to be further studied. Developments in methodology and applications of antifungal susceptibility testing will hopefully provide enhanced utility in clinical guidance of antifungal therapy. However, and particularly in immunosuppressed host, in vitro susceptibility is and will remain only one of several factors that influence clinical outcome.
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Affiliation(s)
- Sevtap Arikan
- Department of Microbiology and Clinical Microbiology, Hacettepe University Medical School, Ankara, Turkey.
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23
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Abstract
Scedosporium spp. are increasingly recognized as causes of resistant life-threatening infections in immunocompromised patients. Scedosporium spp. also cause a wide spectrum of conditions, including mycetoma, saprobic involvement and colonization of the airways, sinopulmonary infections, extrapulmonary localized infections, and disseminated infections. Invasive scedosporium infections are also associated with central nervous infection following near-drowning accidents. The most common sites of infection are the lungs, sinuses, bones, joints, eyes, and brain. Scedosporium apiospermum and Scedosporium prolificans are the two principal medically important species of this genus. Pseudallescheria boydii, the teleomorph of S. apiospermum, is recognized by the presence of cleistothecia. Recent advances in molecular taxonomy have advanced the understanding of the genus Scedosporium and have demonstrated a wider range of species than heretofore recognized. Studies of the pathogenesis of and immune response to Scedosporium spp. underscore the importance of innate host defenses in protection against these organisms. Microbiological diagnosis of Scedosporium spp. currently depends upon culture and morphological characterization. Molecular tools for clinical microbiological detection of Scedosporium spp. are currently investigational. Infections caused by S. apiospermum and P. boydii in patients and animals may respond to antifungal triazoles. By comparison, infections caused by S. prolificans seldom respond to medical therapy alone. Surgery and reversal of immunosuppression may be the only effective therapeutic options for infections caused by S. prolificans.
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24
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Quindós G, Carrillo-Muñoz AJ, Eraso E, Cantón E, Pemán J. [In vitro antifungal activity of voriconazole: New data after the first years of clinical experience]. Rev Iberoam Micol 2007; 24:198-208. [PMID: 17874856 DOI: 10.1016/s1130-1406(07)70043-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Voriconazole has been developed to meet the increasing need for new and useful antifungal agents for the treatment of invasive mycoses. This review describes the spectrum of voriconazole antifungal activity based on data from in vitro studies published during the last three years. This survey demonstrates that voriconazole has a broad antifungal spectrum against the most common fungal pathogens being its action fungistatic for Candida and fungicidal for Aspergillus and other filamentous fungi. Overall, more than 95% of all Candida isolates tested are susceptible to voriconazole and less than 3% are resistant. Similar or even better activity rates have been described for Aspergillus, Cryptococcus and most of yeasts and moulds of medical importance. We also discuss the limitations related to the azole cross-resistance observed in some Candida glabrata isolates, the poor activity of voriconazole against Scedosporium prolificans, its activity against fungal biofilms and the great potential usefulness of combination of voriconazole with other antifungal drugs.
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Affiliation(s)
- Guillermo Quindós
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco, Bilbao, Spain.
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25
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Peeters E, Nelis HJ, Coenye T. Comparison of multiple methods for quantification of microbial biofilms grown in microtiter plates. J Microbiol Methods 2007; 72:157-65. [PMID: 18155789 DOI: 10.1016/j.mimet.2007.11.010] [Citation(s) in RCA: 721] [Impact Index Per Article: 42.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Revised: 10/26/2007] [Accepted: 11/13/2007] [Indexed: 11/28/2022]
Abstract
In the present study six assays for the quantification of biofilms formed in 96-well microtiter plates were optimised and evaluated: the crystal violet (CV) assay, the Syto9 assay, the fluorescein diacetate (FDA) assay, the resazurin assay, the XTT assay and the dimethyl methylene blue (DMMB) assay. Pseudomonas aeruginosa, Burkholderia cenocepacia, Staphylococcus aureus, Propionibacterium acnes and Candida albicans were used as test organisms. In general, these assays showed a broad applicability and a high repeatability for most isolates. In addition, the estimated numbers of CFUs present in the biofilms show limited variations between the different assays. Nevertheless, our data show that some assays are less suitable for the quantification of biofilms of particular isolates (e.g. the CV assay for P. aeruginosa).
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Affiliation(s)
- Elke Peeters
- Laboratory for Pharmaceutical Microbiology, Ghent University, Harelbekestraat 72, Ghent, Belgium
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26
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Righi E, Giacomazzi CG, Bassetti M, Bisio F, Soro O, McDermott JL, Varnier OE, Ratto S, Viscoli C. Soft-tissue infection withAbsidia corymbiferaand kidney complications in an AIDS patient. Med Mycol 2007; 45:637-40. [DOI: 10.1080/13693780701435358] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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