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Tan XT, Mohd Shuhairi NB, Mohd Tap R, Amran F. Comparative study of antifungal susceptibility testing methods for clinical Candida albicans isolates. Indian J Med Microbiol 2024; 50:100663. [PMID: 38964501 DOI: 10.1016/j.ijmmb.2024.100663] [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: 03/13/2024] [Revised: 07/01/2024] [Accepted: 07/02/2024] [Indexed: 07/06/2024]
Abstract
PURPOSE Candida albicans is the second most common cause of candidemia in Malaysia. The Clinical and Laboratory Standards Institute (CLSI) broth microdilution method is the gold standard for determining its minimum inhibitory concentration (MIC); however, it is laborious and time-consuming. This study was conducted to evaluate the usefulness of alternative methods, namely Sensititre YeastOne (SYO), VITEK 2 system, and E-test for determining the MIC of clinical C. albicans isolates. MATERIALS AND METHODS The susceptibilities of 95 C. albicans isolates were compared between SYO, VITEK 2 system, and E-test with CLSI broth microdilution method. The categorical agreement (CA), essential agreement (EA), very major errors (VME), major errors (ME) and minor errors (MiE) were calculated. RESULTS Our finding showed the CA varied for SYO from 96.8% to 100%, while the EA ranged from 91.6% to 100%. The SYO method showed 1.1% of VME and ME, and up to 3.2% of MiE. Next, the CA and EA ranges for the VITEK 2 system were 97.8%-100% and 23.2%-100%, respectively. In the VITEK 2 technique, 1.1% of VME were found. For the E-test, the CA varied from 83.2% to 100% while the EA ranged from 64.2% to 98.9%. The E-test method showed 1.1% of VME and up to 16.8% of MiE. CONCLUSIONS In conclusion, SYO and VITEK 2 (except flucytosine) could be potential alternatives to the CLSI broth microdilution method in determining the MIC of C. albicans.
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Affiliation(s)
- Xue Ting Tan
- Mycology Laboratory, Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, 40170, Shah Alam, Selangor, Malaysia.
| | - Nurliyana Binti Mohd Shuhairi
- Mycology Laboratory, Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, 40170, Shah Alam, Selangor, Malaysia.
| | - Ratna Mohd Tap
- Mycology Laboratory, Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, 40170, Shah Alam, Selangor, Malaysia.
| | - Fairuz Amran
- Mycology Laboratory, Bacteriology Unit, Infectious Diseases Research Centre, Institute for Medical Research, National Institute of Health, Ministry of Health Malaysia, Setia Alam, 40170, Shah Alam, Selangor, Malaysia.
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Jarungsirawat R, Kajthunyakarn W, Siriwachirachai C, Pongjanyakul T. Formulation Development of Fluconazole-Loaded Lactose Agglomerate Tablets as a Disinfectant for Candida-Associated Dentures. Pharmaceutics 2022; 14:pharmaceutics14081723. [PMID: 36015349 PMCID: PMC9414907 DOI: 10.3390/pharmaceutics14081723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 08/13/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022] Open
Abstract
Denture stomatitis is induced by irritation or an inflammatory response when wearing a denture for a long time. Candida species are the leading cause of biofilm formation on the surfaces and fissures of dentures. Thus, this study aimed to formulate and evaluate fluconazole tablets for use in preparing a disinfectant mixture with anticandidal activity. For size enlargement of lactose, a tablet diluent, using polyvinylpyrrolidone (PVP) as an agglomerating agent, was developed to enhance the flowability and compactability of the tablet preparation using direct compression. Lactose agglomerates with 6% PVP were used as a diluent for the fluconazole tablets. Furthermore, other excipients were used, such as a buffering agent, disintegrant, surfactant, and lubricant. The fluconazole tablets obtained could be dispersed and dissolved within 10 min in distilled water to achieve a clear mixture, providing a neutral pH and 96% transmittance. Furthermore, the fluconazole mixtures displayed anticandidal efficiency against C. albicans with a similar effect to the standard fluconazole solution. These findings suggest that the fluconazole-loaded lactose agglomerate tablets show strong potential when prepared using direct compression. The fluconazole mixtures made by dispersing the tablets can be used as a disinfectant for Candida-associated dentures, particularly in patients with oral candidiasis.
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Affiliation(s)
- Rapee Jarungsirawat
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Wanassnant Kajthunyakarn
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Srinakharinwirot University, Nakhon Nayok 26120, Thailand
| | - Chaipat Siriwachirachai
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Thaned Pongjanyakul
- Division of Pharmaceutical Technology, Faculty of Pharmaceutical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand
- Correspondence: ; Tel.: +66-850-113-176
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Radunovic M, Barac M, Kuzmanovic Pficer J, Pavlica D, Jovanovic A, Pucar A, Petrovic S. Antifungal Susceptibility of Candida albicans Isolated from Tongue and Subgingival Biofilm of Periodontitis Patients. Antibiotics (Basel) 2022; 11:802. [PMID: 35740208 PMCID: PMC9219811 DOI: 10.3390/antibiotics11060802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 05/28/2022] [Accepted: 05/30/2022] [Indexed: 11/18/2022] Open
Abstract
The subgingival biofilm, as the most complex microbial community, has been proven to be reservoir of Candida spp. The main concept of this study was to investigate if there is a difference between the sensitivity of Candida albicans (C. albicans) isolated from tongue and subgingival areas of periodontitis patients to antifungal agents. The aim of the study was to determine: (1) the distribution of different Candida species in the tongue and subgingival samples of periodontitis patients; (2) the susceptibility of Candida albicans strains from tongue and subgingival biofilm to the effects of commonly used antifungal agents: fluconazole, amphotericin B and itraconazole; (3) the correlation between the susceptibility of Candida albicans and clinical periodontal parameters. Tongue and subgingival biofilm samples of periodontitis subjects (N = 163) were examined. Susceptibility was tested when the same Candida species was isolated from both sites (17 subjects). Candida spp. were isolated in 23.3% of tongue and 21.5% of the subgingival samples. All isolates were susceptible to amphotericin B, while 64.71% of tongue and 52.94% of subgingival isolates were susceptible to fluconazole. A low frequency of itraconazole susceptibility was observed for tongue (17.64%) and subgingival isolates (11.76%). The correlations between full-mouth plaque score and Minimal Inhibitory Concentration (MIC) for tongue isolates were strongly positive for all antimycotics. Positive correlation was also observed between moderate periodontal destruction and MICs for tongue and subgingival isolates. The susceptibility of C. albicans to antifungals correlate with oral hygiene and moderate periodontal destruction. There is no difference in antifungal susceptibility between tongue and subgingival isolates.
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Affiliation(s)
- Milena Radunovic
- Department of Microbiology and Immunology, School of Dental Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia;
| | - Milena Barac
- Department of Oral Medicine and Periodontology, School of Dental Medicine, University of Belgrade, Dr Subotica 4, 11000 Belgrade, Serbia; (M.B.); (A.P.)
| | - Jovana Kuzmanovic Pficer
- Department for Medical Statistics and Informatics, School of Dental Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia;
| | - Dusan Pavlica
- Department of Microbiology and Immunology, School of Dental Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia;
| | - Aleksandar Jovanovic
- Clinic of Urology, University Clinical Center of Serbia, Resavska 51, 11000 Belgrade, Serbia;
| | - Ana Pucar
- Department of Oral Medicine and Periodontology, School of Dental Medicine, University of Belgrade, Dr Subotica 4, 11000 Belgrade, Serbia; (M.B.); (A.P.)
| | - Sanja Petrovic
- Department of Microbiology and Immunology, School of Dental Medicine, University of Belgrade, Dr Subotica 1, 11000 Belgrade, Serbia;
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Abstract
Although not as ubiquitous as antibacterial susceptibility testing, antifungal susceptibility testing (AFST) is a tool of increasing importance in clinical microbiology laboratories. The goal of AFST is to reliably produce MIC values that may be used to guide patient therapy, inform epidemiological studies, and track rates of antifungal drug resistance. There are three methods that have been standardized by standards development organizations: broth dilution, disk diffusion, and azole agar screening for Aspergillus Other commonly used methods include gradient diffusion and the use of rapid automated instruments. Novel methodologies for susceptibility testing are in development. It is important for laboratories to consider not only the method of testing but also the interpretation (or lack thereof) of in vitro data.
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Singh R, Kumari A, Kaur K, Sethi P, Chakrabarti A. Relevance of antifungal penetration in biofilm-associated resistance of Candida albicans and non-albicans Candida species. J Med Microbiol 2018; 67:922-926. [DOI: 10.1099/jmm.0.000757] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Rachna Singh
- Department of Microbial Biotechnology, Panjab University, Chandigarh 160014, India
| | - Anjna Kumari
- Department of Microbial Biotechnology, Panjab University, Chandigarh 160014, India
| | - Karminder Kaur
- Department of Microbial Biotechnology, Panjab University, Chandigarh 160014, India
| | - Parul Sethi
- Department of Microbial Biotechnology, Panjab University, Chandigarh 160014, India
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh 160012, India
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Hesstvedt L, Arendrup MC, Poikonen E, Klingpor L, Friman V, Nordøy I. Differences in epidemiology of candidaemia in the Nordic countries - what is to blame? Mycoses 2016; 60:11-19. [DOI: 10.1111/myc.12535] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 06/17/2016] [Accepted: 06/17/2016] [Indexed: 02/04/2023]
Affiliation(s)
- Liv Hesstvedt
- Research institute for Internal Medicine; Oslo University Hospital; Rikshospitalet Norway
- Department of Microbiology; Oslo University Hospital; Rikshospitalet Norway
| | - Maiken C. Arendrup
- Unit of mycology; Department of Microbiology and Research; Statens Serum Institute; Copenhagen Denmark
| | - Eira Poikonen
- Department of Haematology; Helsinki University Central Hospital; Helsinki Finland
| | - Lena Klingpor
- Department of Laboratory Medicine; Karolinska Institute; Stockholm Sweden
| | - Vanda Friman
- Department of Infectious Diseases; Sahlgrenska Academy; University of Gothenburg; Gothenburg Sweden
| | - Ingvild Nordøy
- Research institute for Internal Medicine; Oslo University Hospital; Rikshospitalet Norway
- Section of Clinical Immunology and Infectious Diseases; Oslo University Hospital; Rikshospitalet Norway
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Kamat V, Marathe I, Ghormade V, Bodas D, Paknikar K. Synthesis of Monodisperse Chitosan Nanoparticles and in Situ Drug Loading Using Active Microreactor. ACS APPLIED MATERIALS & INTERFACES 2015; 7:22839-22847. [PMID: 26448128 DOI: 10.1021/acsami.5b05100] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chitosan nanoparticles are promising drug delivery vehicles. However, the conventional method of unregulated mixing during ionic gelation limits their application because of heterogeneity in size and physicochemical properties. Therefore, a detailed theoretical analysis of conventional and active microreactor models was simulated. This led to design and fabrication of a polydimethylsiloxane microreactor with magnetic micro needles for the synthesis of monodisperse chitosan nanoparticles. Chitosan nanoparticles synthesized conventionally, using 0.5 mg/mL chitosan, were 250 ± 27 nm with +29.8 ± 8 mV charge. Using similar parameters, the microreactor yielded small size particles (154 ± 20 nm) at optimized flow rate of 400 μL/min. Further optimization at 0.4 mg/mL chitosan concentration yielded particles (130 ± 9 nm) with higher charge (+39.8 ± 5 mV). The well-controlled microreactor-based mixing generated highly monodisperse particles with tunable properties including antifungal drug entrapment (80%), release rate, and effective activity (MIC, 1 μg/mL) against Candida.
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Affiliation(s)
- Vivek Kamat
- Nanobioscience, Agharkar Research Institute , GG Agarkar Road, Pune 411 004, India
| | - Ila Marathe
- Nanobioscience, Agharkar Research Institute , GG Agarkar Road, Pune 411 004, India
| | - Vandana Ghormade
- Nanobioscience, Agharkar Research Institute , GG Agarkar Road, Pune 411 004, India
| | - Dhananjay Bodas
- Nanobioscience, Agharkar Research Institute , GG Agarkar Road, Pune 411 004, India
| | - Kishore Paknikar
- Nanobioscience, Agharkar Research Institute , GG Agarkar Road, Pune 411 004, India
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Kumari H, Balasubramanian D, Zincke D, Mathee K. Role of Pseudomonas aeruginosa AmpR on β-lactam and non-β-lactam transient cross-resistance upon pre-exposure to subinhibitory concentrations of antibiotics. J Med Microbiol 2014; 63:544-555. [PMID: 24464693 DOI: 10.1099/jmm.0.070185-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Pseudomonas aeruginosa is one of the most dreaded opportunistic pathogens accounting for 10 % of hospital-acquired infections, with a 50 % mortality rate in chronically ill patients. The increased prevalence of drug-resistant isolates is a major cause of concern. Resistance in P. aeruginosa is mediated by various mechanisms, some of which are shared among different classes of antibiotics and which raise the possibility of cross-resistance. The goal of this study was to explore the effect of subinhibitory concentrations (SICs) of clinically relevant antibiotics and the role of a global antibiotic resistance and virulence regulator, AmpR, in developing cross-resistance. We investigated the induction of transient cross-resistance in P. aeruginosa PAO1 upon exposure to SICs of antibiotics. Pre-exposure to carbapenems, specifically imipenem, even at 3 ng ml(-1), adversely affected the efficacy of clinically used penicillins and cephalosporins. The high β-lactam resistance was due to elevated expression of both ampC and ampR, encoding a chromosomal β-lactamase and its regulator, respectively. Differences in the susceptibility of ampR and ampC mutants suggested non-AmpC-mediated regulation of β-lactam resistance by AmpR. The increased susceptibility of P. aeruginosa in the absence of ampR to various antibiotics upon SIC exposure suggests that AmpR plays a major role in the cross-resistance. AmpR was shown previously to be involved in resistance to quinolones by regulating MexEF-OprN efflux pump. The data here further indicate the role of AmpR in cross-resistance between quinolones and aminoglycosides. This was confirmed using quantitative PCR, where expression of the mexEF efflux pump was further induced by ciprofloxacin and tobramycin, its substrate and a non-substrate, respectively, in the absence of ampR. The data presented here highlight the intricate cross-regulation of antibiotic resistance pathways at SICs of antibiotics and the need for careful assessment of the order of antibiotic regimens as this may have dire consequences. Targeting a global regulator such as AmpR that connects diverse pathways is a feasible therapeutic approach to combat P. aeruginosa pathogenesis.
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Affiliation(s)
- Hansi Kumari
- Department of Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Deepak Balasubramanian
- Department of Biological Sciences, College of Arts and Sciences, Florida International University, Miami, FL, USA.,Department of Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Diansy Zincke
- Department of Biological Sciences, College of Arts and Sciences, Florida International University, Miami, FL, USA.,Department of Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
| | - Kalai Mathee
- Department of Molecular Genetics, Herbert Wertheim College of Medicine, Florida International University, Miami, FL, USA
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9
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Carvalhinho S, Costa AM, Coelho AC, Martins E, Sampaio A. Susceptibilities of Candida albicans mouth isolates to antifungal agents, essentials oils and mouth rinses. Mycopathologia 2012; 174:69-76. [PMID: 22246961 DOI: 10.1007/s11046-012-9520-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2011] [Accepted: 01/02/2012] [Indexed: 10/14/2022]
Abstract
Forty Candida albicans strains isolated from patient's mouth with fixed orthodontic appliances were analyzed to their susceptibilities to antifungal agents, mouth rinses and essential oils. Susceptibility to fluconazole, econazole, miconazole and ketoconazole, amphotericin B and nystatin was assessed by the disk diffusion (DD) method based on the Clinical and Laboratory Standards Institute M44-A protocol, and by Etest (fluconazole and amphotericin B). The susceptibilities to mouth rinses and essential oils were also determined by the DD technique. All isolates tested were susceptible (S) to amphotericin B, nystatin and fluconazole. The overall concordance between the DD and the Etest was 100% for amphotericin and fluconazole. One isolate was resistant to econazole (2.5%) and the other to ketoconazole (2.5%). Econazole and ketoconazole had the highest percentages of susceptible dose dependent (SDD), 55 and 95%, respectively. Regarding to the susceptibility isolates profile, seven phenotypes were detected, and the 3 more represented (90% of the isolates) of them were SDD to one, two or three azoles. The study of mouth rinses showed a high variability of efficacy against C. albicans. The results showed that the isolates susceptibility to essential oils differed (P < 0.05). The profile activity was: cinnamon > laurel > mint > eucalyptus > rosemary > lemon > myrrh > tangerine. The main finding was that the susceptibility to cinnamon and laurel varied among the three more representative antifungal phenotypes (P < 0.05). The susceptibility of econazole-SDD isolates to cinnamon and lemon was higher than those of the econazole-S yeasts (P < 0.05). In contrast, econazole-SDD isolates were less affected by laurel than econazole-S counterparts (P < 0.05).
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Affiliation(s)
- Sara Carvalhinho
- Department of Biology and Environment, University of Trás-os-Montes and Alto Douro (UTAD), PO Box 1013, 5001-911, Vila Real, Portugal
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Arendrup MC, Bille J, Dannaoui E, Ruhnke M, Heussel CP, Kibbler C. ECIL-3 classical diagnostic procedures for the diagnosis of invasive fungal diseases in patients with leukaemia. Bone Marrow Transplant 2012; 47:1030-45. [DOI: 10.1038/bmt.2011.246] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Siikala E, Bowyer P, Richardson M, Saxen H, Sanglard D, Rautemaa R. ADH1 expression inversely correlates with CDR1 and CDR2 in Candida albicans from chronic oral candidosis in APECED (APS-I) patients. FEMS Yeast Res 2011; 11:494-8. [DOI: 10.1111/j.1567-1364.2011.00739.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Galgóczy L, Bácsi A, Homa M, Virágh M, Papp T, Vágvölgyi C. In vitro antifungal activity of phenothiazines and their combination with amphotericin B against different Candida species. Mycoses 2011; 54:e737-43. [PMID: 21605196 DOI: 10.1111/j.1439-0507.2010.02010.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Candidiosis is a mycosis that is currently increasingly affecting the population in consequence of its frequency and the severity of its complications, especially among immunocompromised hosts. In this work, the in vitro anticandidal activities of two phenothiazines (PTZs), chlorpromazine (CPZ) and trifluoperazine (TFP), and their combinations with amphotericin B (AMB) were tested against 12 different Candida strains representing 12 species (Candida albicans, Candida glabrata, Candida guillermondii, Candida inconspicua, Candida krusei, Candida lusitaniae, Candida lypolitica, Candida norvegica, Candida parapsilosis, Candida pulcherrima, Candida tropicalis and Candida zeylanoides). When used alone, both tested PTZs exerted antifungal effects against these strains. In their combinations, these PTZs and AMB mainly acted antagonistically at higher concentrations, but additively and synergistically at lower concentrations as concerns the clinically most important species (C. albicans and C. parapsilosis). For C. albicans, only synergistic interactions were revealed between CPZ and AMB. Synergistic, additive or no interactions were demonstrated between the investigated compounds for the most PTZ-susceptible (C. glabrata to TFP and C. krusei to CPZ) and insusceptible strains (C. glabrata to CPZ and C. lypolitica to TFP).
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Affiliation(s)
- László Galgóczy
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary.
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13
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Siikala E, Rautemaa R, Richardson M, Saxen H, Bowyer P, Sanglard D. Persistent Candida albicans colonization and molecular mechanisms of azole resistance in autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) patients. J Antimicrob Chemother 2010; 65:2505-13. [PMID: 20876623 DOI: 10.1093/jac/dkq354] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
OBJECTIVES Patients with autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED, APS-I) suffer from chronic candidosis caused mainly by Candida albicans, and repeated courses of azole antifungals have led to the development of resistance in the APECED patient population in Finland. The aim of our study was to address whether the patients are persistently colonized with the same or genetically closely related strains, whether epidemic strains are present and which molecular mechanisms account for azole resistance. METHODS Sets of C. albicans (n = 19) isolates from nine APECED patients reported with decreased susceptibility to fluconazole isolated up to 9 years apart were included. The strains were typed by multilocus sequence typing. CDR1/2, MDR1 and ERG11 mRNA expression was analysed by northern blotting and Cdr1, Cdr2 and Mdr1 protein expression by western blotting, and TAC1 and ERG11 genes were sequenced. RESULTS All seven patients with multiple C. albicans isolates analysed were persistently colonized with the same or a genetically closely related strain for a mean of 5 years. All patients were colonized with different strains and no epidemic strains were found. The major molecular mechanisms behind the azole resistance were mutations in TAC1 contributing to overexpression of CDR1 and CDR2. Six new TAC1 mutations were found, one of which (N740S) is likely to be a gain-of-function mutation. Most isolates were found to have gained multiple TAC1 and ERG11 point mutations. CONCLUSIONS Despite clinically successful treatment leading to relief of symptoms, colonization by C. albicans strains is persistent within APECED patients. Microevolution and point mutations occur within strains, leading to the development of azole-resistant isolates.
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Affiliation(s)
- Emilia Siikala
- Department of Bacteriology and Immunology, Haartman Institute, University of Helsinki, Helsinki, Finland.
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Correlation between broth microdilution and disk diffusion methods for antifungal susceptibility testing of caspofungin, voriconazole, amphotericin B, itraconazole and fluconazole against Candida glabrata. J Microbiol Methods 2010; 82:136-40. [PMID: 20493911 DOI: 10.1016/j.mimet.2010.05.002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2009] [Revised: 05/04/2010] [Accepted: 05/06/2010] [Indexed: 11/23/2022]
Abstract
Candida glabrata is one of the most frequent organisms isolated from superficial and invasive fungal infections, after Candida albicans. This organism also exhibits intrinsically low susceptibility to azole antifungals and treatment often fails. The microdilution method is not very practical for use in routine susceptibility testing in the clinical laboratory, thus necessitating the use of other methods. In this study, we compared the in vitro activity of five antifungal agents in three different groups (echinocandin, polyene and azole) against 50 C. glabrata isolates by broth microdilution and disk diffusion methods recommended by Clinical Laboratory Standards Institute CLSI M27-A3 and CLSI M44-A, respectively. All the isolates were susceptible to amphotericin B (100%) and 98% of the isolates were susceptible to caspofungin by the broth microdilution method. Within the azole group drugs, voriconazole was the most active followed by fluconazole and itraconazole in vitro. The highest rate of resistance was obtained against itraconazole with a high number of isolates defined as susceptible-dose dependent or resistant. Although the disk diffusion method is easy to use in clinical laboratories, it shows very poor agreement with the reference method for fluconazole and itraconazole against C. glabrata (8% and 14%, respectively).
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Negri M, Henriques M, Svidzinski TIE, Paula CR, Oliveira R. Correlation between Etest, disk diffusion, and microdilution methods for antifungal susceptibility testing of Candida species from infection and colonization. J Clin Lab Anal 2010; 23:324-30. [PMID: 19785043 DOI: 10.1002/jcla.20337] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The correlation between the microdilution (MD), Etest (ET), and disk diffusion (DD) methods was determined for amphotericin B, itraconazole and fluconazole. The minimal inhibitory concentration (MIC) of those antifungal agents was established for a total of 70 Candida spp. isolates from colonization and infection. The species distribution was: Candida albicans (n=27), C. tropicalis (n=17), C. glabrata (n=16), C. parapsilosis (n=8), and C. lusitaniae (n=2). Non-Candida albicans Candida species showed higher MICs for the three antifungal agents when compared with C. albicans isolates. The overall concordance (based on the MIC value obtained within two dilutions) between the ET and the MD method was 83% for amphotericin B, 63% for itraconazole, and 64% for fluconazole. Considering the breakpoint, the agreement between the DD and MD methods was 71% for itraconazole and 67% for fluconazole. The DD zone diameters are highly reproducible and correlate well with the MD method, making agar-based methods a viable alternative to MD for susceptibility testing. However, data on agar-based tests for itraconazole and amphotericin B are yet scarce. Thus, further research must still be carried out to ensure the standardization to other antifungal agents.
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Affiliation(s)
- Melyssa Negri
- Centre of Biological Engineering, Institute for Biotechnology and Bioengineering, Universidade do Minho, Braga, Portugal
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Arendrup MC, Chryssanthou E, Gaustad P, Koskela M, Sandven P, Fernandez V. Diagnostics of fungal infections in the Nordic countries: We still need to improve! ACTA ACUST UNITED AC 2009; 39:337-43. [PMID: 17454898 DOI: 10.1080/00365540601071859] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
A Nordic External Quality Assessment programme in medical mycology was established in 2005. In order to monitor not 'best practice' but the level of routine diagnostics, specimens were designed to resemble clinical samples and laboratories were asked to handle the samples like routine samples. Five simulated clinical samples were distributed to 59 participating Nordic laboratories of clinical microbiology. The specimens contained the following microorganisms: 1) Candida glabrata and C. albicans in a ratio of 1:20; 2) Cryptococcus neoformans; 3) Aspergillus fumigatus, C. albicans and Enterobacter cloacae; 4) C. tropicalis, Klebsiella pneumonia and Enterococcus faecium; 5) None. 66% of the laboratories failed to detect the C. glabrata isolate in sample no. 1. 34% of the laboratories reporting susceptibility results incorrectly reported the Cryptococcus neoformans isolate as fluconazole susceptible. 24% of the laboratories failed to detect Aspergillus fumigatus in specimen no. 3 despite the accompanying clinical information notifying that it was a BAL sample from a neutropenic patient in an ICU. In conclusion, this distribution of simulated clinical samples illustrates that the traditional quality assessment programmes may give a false sense of satisfactory performance, that mycological diagnosis is difficult, and that there is a need of further improvement and attention.
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Abstract
The polyene macrolides nystatin A1 and amphotericin B are effective but toxic antifungal antibiotics that are also active against enveloped viruses, protozoan parasites and pathogenic prion proteins. This chapter describes methods for genetic manipulation of the amphotericin and nystatin producers, Streptomyces nodosus and Streptomyces noursei. These techniques have been used to engineer the biosynthesis of several analogues of both polyenes. Methods for production, identification, purification and characterization of new analogues are also discussed.
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Affiliation(s)
- Sergey Zotchev
- Department of Biotechnology, Norwegian University of Science and Technology, Trondheim, Norway
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18
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Park JY, Shin JH, Uh Y, Kim EC, Kee SJ, Kim SH, Shin MG, Suh SP, Ryang DW. In Vitro Amphotericin B Susceptibility of Korean Bloodstream Yeast Isolates Assessed by the CLSI Broth Microdilution Method, Etest, and Minimum Fungicidal Concentration Test. Ann Lab Med 2008; 28:346-52. [PMID: 18971615 DOI: 10.3343/kjlm.2008.28.5.346] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Ji Young Park
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Jong Hee Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Young Uh
- Department of Laboratory Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea
| | - Eui Chong Kim
- Department of Laboratory Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Seung Jung Kee
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Soo Hyun Kim
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Myung Geun Shin
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Soon Pal Suh
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
| | - Dong Wook Ryang
- Department of Laboratory Medicine, Chonnam National University Medical School, Gwangju, Korea
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19
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Koga-Ito CY, Lyon JP, Resende MAD. Comparison between E-test and CLSI broth microdilution method for antifungal susceptibility testing of Candida albicans oral isolates. Rev Inst Med Trop Sao Paulo 2008; 50:7-10. [DOI: 10.1590/s0036-46652008000100002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2006] [Accepted: 09/24/2007] [Indexed: 11/22/2022] Open
Abstract
Thirty Candida albicans isolated from oral candidosis patients and 30 C. albicans isolated from control individuals were studied. In vitro susceptibility tests were performed for amphotericin B, fluconazole, 5-flucytosine and itraconazole through the Clinical and Laboratorial Standards Institute (CLSI) reference method and E test system. The results obtained were analyzed and compared. MIC values were similar for the strains isolated from oral candidosis patients and control individuals. The agreement rate for the two methods was 66.67% for amphotericin B, 53.33% for fluconazole, 65% for flucytosine and 45% for itraconazole. According to our data, E test method could be an alternative to trial routine susceptibility testing due to its simplicity. However, it can not be considered a substitute for the CLSI reference method.
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Abstract
The current increase in the number and significance of fungal infections, the expanding armamentarium of antifungal agents, and the emergence of the problem of antifungal drug resistance have been intensifying the importance of antifungal susceptibility testing (AST). The Clinical and Laboratory Standards Institute (CLSI, formerly NCCLS) in the United States and the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antimicrobial Susceptibility Testing (AFST-EUCAST) published standard methodologies in order to achieve higher reproducibility and allow direct inter-laboratory comparison of the susceptibility results. Nevertheless, several problems remain unresolved and the methods depend on long incubation periods of a minimum of 24 h (EUCAST) or even 48 h (CLSI). Over the last 15 years, successful applications of flow cytometric techniques to AST of both yeast and moulds have been reported. These techniques are based on the analysis of a great number of fungal cells individually and frequently rely on short incubation times of no more than a few hours. Considering these attributes, flow cytometry (FC) seems to have the potential to achieve clinical usefulness in the near future. The collection of data on the reproducibility of the results and on the correlation with clinical outcomes has barely started, however. Practical validation of the experimental methodologies is not granted before a significant amount of data addressing those questions is available.
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Affiliation(s)
- Luís André Vale-Silva
- Department of Biological and Medical Sciences, Faculty of Pharmacy, Charles University, Hradec Králové, Czech Republic.
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21
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Park BJ, Arthington-Skaggs BA, Hajjeh RA, Iqbal N, Ciblak MA, Lee-Yang W, Hairston MD, Phelan M, Plikaytis BD, Sofair AN, Harrison LH, Fridkin SK, Warnock DW. Evaluation of amphotericin B interpretive breakpoints for Candida bloodstream isolates by correlation with therapeutic outcome. Antimicrob Agents Chemother 2006; 50:1287-92. [PMID: 16569842 PMCID: PMC1426914 DOI: 10.1128/aac.50.4.1287-1292.2006] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
One hundred seven Candida bloodstream isolates (51 C. albicans, 24 C. glabrata, 13 C. parapsilosis, 13 C. tropicalis, 2 C. dubliniensis, 2 C. krusei, and 2 C. lusitaniae strains) from patients treated with amphotericin B alone underwent in vitro susceptibility testing against amphotericin B using five different methods. Fifty-four isolates were from patients who failed treatment, defined as death 7 to 14 days after the incident candidemia episode, having persistent fever of >or=5 days' duration after the date of the incident candidemia, or the recurrence of fever after two consecutive afebrile days while on antifungal treatment. MICs were determined by using the Clinical Laboratory Standards Institute (formally National Committee for Clinical Laboratory Standards) broth microdilution procedure with two media and by using Etest. Minimum fungicidal concentrations (MFCs) were also measured in two media. Broth microdilution tests with RPMI 1640 medium generated a restricted range of MICs (0.125 to 1 microg/ml); the corresponding MFC values ranged from 0.5 to 4 microg/ml. Broth microdilution tests with antibiotic medium 3 produced a broader distribution of MIC and MFC results (0.015 to 0.25 microg/ml and 0.06 to 2 microg/ml, respectively). Etest produced the widest distribution of MICs (0.094 to 2 microg/ml). However, none of the test formats studied generated results that significantly correlated with therapeutic success or failure.
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Affiliation(s)
- Benjamin J Park
- Mycotic Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, 1600 Clifton Rd., N.E., Mailstop C-09, Atlanta, GA 30333, USA.
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22
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Eloy O, Blanc V, Mallié M, Decousser J, Pina P, Allouch P. Identification et sensibilité aux antifongiques de deux souches de Candida dans 95 hôpitaux français. J Mycol Med 2005. [DOI: 10.1016/j.mycmed.2005.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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23
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Hospenthal DR, Murray CK, Rinaldi MG. The role of antifungal susceptibility testing in the therapy of candidiasis. Diagn Microbiol Infect Dis 2004; 48:153-60. [PMID: 15023422 DOI: 10.1016/j.diagmicrobio.2003.10.003] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2003] [Accepted: 09/23/2003] [Indexed: 11/19/2022]
Abstract
Prior to the introduction of azoles, no real need for antifungal susceptibility testing (AFST) existed, as amphotericin B was the only agent available to treat systemic candidiasis. Introduction of fluconazole and itraconazole provided alternate, less toxic antifungal therapies. Intrinsic resistance of Candida krusei, decreased susceptibility of Candida glabrata, and development of resistance by Candida albicans (in mucosal disease in AIDS) to azoles led to development of our current AFST methodologies. The goal of AFST, like that of antibacterial susceptibility testing, is to predict clinical response, or at least to forecast failure. Although the ability of AFST to predict clinical outcome (clinical correlation) is still being fully elucidated, current methodologies do appear to reliably predict clinical resistance to azoles. Ready access to AFST is currently limited, affecting its timely use, but even with this lack of timeliness, AFST can still play an important role in patient care. Important potential roles include: 1) use in the development of local antibiograms to aid empiric selection of antifungals; 2) testing of isolates from candidemia or deep infection to aid in selection of long-term therapies; and, 3) the testing of isolates from recurrent mucosal disease to aid in selection of alternative regimens.
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Affiliation(s)
- Duane R Hospenthal
- Infectious Disease Service, Department of Medicine, Brooke Army Medical Center, Fort Sam Houston, TX 78234-6200, USA.
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24
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Pfaller MA, Diekema DJ, Boyken L, Messer SA, Tendolkar S, Hollis RJ. Evaluation of the Etest and disk diffusion methods for determining susceptibilities of 235 bloodstream isolates of Candida glabrata to fluconazole and voriconazole. J Clin Microbiol 2003; 41:1875-80. [PMID: 12734220 PMCID: PMC154736 DOI: 10.1128/jcm.41.5.1875-1880.2003] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performances of the Etest and the disk diffusion methods for testing of the susceptibilities of 235 Candida glabrata isolates to fluconazole and voriconazole were compared with that of the National Committee for Clinical Laboratory Standards (NCCLS) approved standard broth microdilution (BMD) method. The NCCLS method used RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35 degrees C. Etest MICs were determined with RPMI 1640 agar containing 2% glucose (RPG agar) and with Mueller-Hinton agar containing 2% glucose and 0.5 microg of methylene blue per ml (MBE agar) and were read after incubation for 48 h at 35 degrees C. Disk diffusion testing was performed with MBE agar, 25-microg fluconazole disks, and 1- microg voriconazole disks and by incubation at 35 degrees C for 24 h. Overall agreements between the Etest and the BMD MICs obtained with RPG and MBE agars were 91 and 96%, respectively, for fluconazole and 93 and 95%, respectively, for voriconazole. Categorical agreements between the agar-based methods and BMD were 52.3 to 64.7% with fluconazole and 94.8 to 97.4% with voriconazole. The vast majority of the discrepancies by the disk diffusion and Etest methods with fluconazole were minor errors. The agar-based methods performed well in identifying isolates with resistance to fluconazole and decreased susceptibility to voriconazole.
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Affiliation(s)
- M A Pfaller
- Department of Pathology. Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa 52242, USA.
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25
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Maxwell MJ, Messer SA, Hollis RJ, Boyken L, Tendolkar S, Diekema DJ, Pfaller MA. Evaluation of Etest method for determining fluconazole and voriconazole MICs for 279 clinical isolates of Candida species infrequently isolated from blood. J Clin Microbiol 2003; 41:1087-90. [PMID: 12624034 PMCID: PMC150324 DOI: 10.1128/jcm.41.3.1087-1090.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of Etest in fluconazole and voriconazole testing of 279 isolates of uncommon Candida spp. was assessed in comparison with the National Committee for Clinical Laboratory Standards (NCCLS)-approved standard broth microdilution (BMD) method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35 degrees C. Etest MICs were determined with RPMI agar containing 2% glucose and were read after incubation for 48 h at 35 degrees C. The isolates include Candida krusei, C. lusitaniae, C. guilliermondii, C. kefyr, C. rugosa, C. lipolytica, C. pelliculosa, C. dubliniensis, C. famata, C. zeylanoides, C. inconspicua, and C. norvegensis. Overall agreement between Etest and BMD MICs was 96% for fluconazole and 95% for voriconazole. Where a discrepancy was observed between Etest and the reference method, the Etest tended to give lower values with both fluconazole and voriconazole. The Etest method using RPMI agar appears to be a useful method for determining fluconazole and voriconazole susceptibilities of uncommon species of Candida.
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Affiliation(s)
- M J Maxwell
- Departments of Pathology. Medicine. Epidemiology, University of Iowa College of Medicine and College of Public Health, Iowa City, Iowa 52242, USA
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26
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Esen N, Yücesoy M, Yuluğ N. Evaluation of semisolid agar screening tests for determining fluconazole and amphotericin B susceptibilities of Candida strains by using three different media. J Chemother 2003; 15:37-42. [PMID: 12678412 DOI: 10.1179/joc.2003.15.1.37] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
The susceptibilities of 164 Candida isolates against fluconazole and amphotericin B were determined by semisolid agar screening tests and the microdilution method according to NCCLS M27-A standards. The semisolid agar screening tests were performed with three different media containing 0.5% agar and 2, 8, and 40 microg/ml of fluconazole or 0.5 and 2.0 microg/ml of amphotericin B. These media were MOPS buffered RPMI 1640, brain-heart infusion and 1/3 diluted Sabouraud dextrose agar. The results of both methods were interpreted as susceptible, dose dependent susceptible and resistant for fluconazole and susceptible and resistant for amphotericin B. The agreement rates of semisolid agar screening tests using RPMI 1640, brain-heart infusion and Sabouraud dextrose media with the reference microdilution method were found to be 71.4%, 51.2%, and 57.3% for fluconazole and 79.3%, 53.7%, and 56.7% for amphotericin B, respectively. Overall, we conclude that semisolid agar screening tests using RPMI 1640 can be used for determining the susceptibilities of Candida isolates against fluconazole and amphotericin B in clinical microbiology laboratories.
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Affiliation(s)
- N Esen
- Dokuz Eylül University, School of Medicine, Department of Microbiology and Clinical Microbiology, Izmir, Turkey.
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27
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Wolf DG, Falk R, Hacham M, Theelen B, Boekhout T, Scorzetti G, Shapiro M, Block C, Salkin IF, Polacheck I. Multidrug-resistant Trichosporon asahii infection of nongranulocytopenic patients in three intensive care units. J Clin Microbiol 2001; 39:4420-5. [PMID: 11724855 PMCID: PMC88559 DOI: 10.1128/jcm.39.12.4420-4425.2001] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Trichosporon asahii (Trichosporon beigelii) infections are rare but have been associated with a wide spectrum of clinical manifestations, ranging from superficial involvement in immunocompetent individuals to severe systemic disease in immunocompromised patients. We report on the recent recovery of T. asahii isolates with reduced susceptibility in vitro to amphotericin B (AMB), flucytosine, and azoles from six nongranulocytopenic patients who exhibited risk factors and who developed either superficial infections (four individuals) or invasive infections (two individuals) while in intensive care units. The latter two patients responded clinically and microbiologically to AMB treatment. All six isolates were closely related according to random amplified polymorphic DNA studies and showed 71% similarity by amplified fragment length polymorphism analysis, suggesting a common nosocomial origin. We also review the literature pertaining to T. asahii infections and discuss the salient characteristics of this fungus and recent taxonomic proposals for the genus.
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Affiliation(s)
- D G Wolf
- Department of Clinical Microbiology and Infectious Diseases, The Hebrew University-Hadassah Medical Center, Jerusalem, Israel
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