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Zhang L, Jiang G, Lu J, Wang L. LINC00844 suppresses tumor progression and predicts survival outcomes through inhibiting miR-19a-5p in cholangiocarcinoma. Clin Transl Oncol 2024; 26:414-423. [PMID: 37400667 DOI: 10.1007/s12094-023-03254-x] [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: 02/01/2023] [Accepted: 06/14/2023] [Indexed: 07/05/2023]
Abstract
BACKGROUND Cholangiocarcinoma (CCA) is a heterogeneous malignancy. The aim of the study was to investigate the regulatory role of long noncoding RNA LINC00844 in CCA progression, explore the underlying molecular mechanisms, and to analyze the potential prognostic value of LINC00844 in CCA patients. METHODS Expression of LINC00844 in CCA cell lines and tissues was examined by reverse transcription-quantitative PCR. Cell counting kit-8 assay was used to assess CCA cell proliferation, and the Transwell assay was used to evaluate tumor cell migration and invasion. miRNAs sponged by LINC00844 were predicted and confirmed using a luciferase reporter assay. Kaplan-Meier survival analysis was performed to evaluate the survival prognosis of CCA patients. RESULTS The expression levels of LINC00844 were decreased in CCA tissues and cells. Overexpression of LINC00844 inhibited cell proliferation, migration and invasion in CCA cells. miR-19a-5p is directly targeted by LINC00844, mediating the inhibitory effects of LINC00844 on the proliferation, migration and invasion of CCA cells. LINC00844 and miR-19a-5p expression were associated with differentiation and tumor node metastasis stage in CCA patients. CCA patients with low LINC00844 expression or overexpression of miR-19a-5p had worse overall survival. CONCLUSION The expression levels of LINC00844 were decreased in both CCA tissues and cells, and high LINC00844 inhibited CCA cell proliferation, migration and invasion through sponging miR-19a-5p. Low LINC00844 and high miR-19a-5p expression were associated with worse overall survival in CCA patients. All the data suggested that the LINC00844/miR-19a-5p axis may provide novel therapeutic targets and prognostic biomarkers for CCA patients.
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Affiliation(s)
- Ling Zhang
- Department of Blood Transfusion, Zibo Central Hospital, Zibo, 255000, Shandong, China
| | - Guohong Jiang
- Department of Clinical Laboratory, Qingdao Chest Hospital, Qingdao, 266043, Shandong, China
| | - Juan Lu
- Department of Clinical Laboratory, The Fifth People's Hospital of Zibo, Zichuan District, No. 102 Zi Mining Bureau, Zibo, 255100, Shandong, China
| | - Lina Wang
- Department of Clinical Laboratory, The Fifth People's Hospital of Zibo, Zichuan District, No. 102 Zi Mining Bureau, Zibo, 255100, Shandong, China.
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Carvajal SK, Melendres J, Escandón P, Firacative C. Reduced Susceptibility to Azoles in Cryptococcus gattii Correlates with the Substitution R258L in a Substrate Recognition Site of the Lanosterol 14-α-Demethylase. Microbiol Spectr 2023; 11:e0140323. [PMID: 37341584 PMCID: PMC10434158 DOI: 10.1128/spectrum.01403-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 06/01/2023] [Indexed: 06/22/2023] Open
Abstract
Cryptococcus neoformans and Cryptococcus gattii cause cryptococcosis, a life-threatening fungal infection affecting mostly immunocompromised patients. In fact, cryptococcal meningitis accounts for about 19% of AIDS-related deaths in the world. Because of long-term azole therapies to treat this mycosis, resistance to fluconazole leading to treatment failure and poor prognosis has long been reported for both fungal species. Among the mechanisms implicated in resistance to azoles, mutations in the ERG11 gene, encoding the azole target enzyme lanosterol 14-α-demethylase, have been described. This study aimed to establish the amino acid composition of ERG11 of Colombian clinical isolates of C. neoformans and C. gattii and to correlate any possible substitution with the in vitro susceptibility profile of the isolates to fluconazole, voriconazole, and itraconazole. Antifungal susceptibility testing results showed that C. gattii isolates are less susceptible to azoles than C. neoformans isolates, which could correlate with differences in the amino acid composition and structure of ERG11 of each species. In addition, in a C. gattii isolate with high MICs for fluconazole (64 μg/mL) and voriconazole (1 μg/mL), a G973T mutation resulting in the substitution R258L, located in substrate recognition site 3 of ERG11, was identified. This finding suggests the association of the newly reported substitution with the azole resistance phenotype in C. gattii. Further investigations are needed to determine the exact role that R258L plays in the decreased susceptibility to fluconazole and voriconazole, as well as to determine the participation of additional mechanisms of resistance to azole drugs. IMPORTANCE The fungal species Cryptococcus neoformans and C. gattii are human pathogens for which drug resistance or other treatment and management challenges exist. Here, we report differential susceptibility to azoles among both species, with some isolates displaying resistant phenotypes. Azoles are among the most commonly used drugs to treat cryptococcal infections. Our findings underscore the necessity of testing antifungal susceptibility in the clinical setting in order to assist patient management and beneficial outcomes. In addition, we report an amino acid change in the sequence of the target protein of azoles, which suggests that this change might be implicated in resistance to these drugs. Identifying and understanding possible mechanisms that affect drug affinity will eventually aid the design of new drugs that overcome the global growing concern of antifungal resistance.
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Affiliation(s)
| | - Javier Melendres
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
| | - Patricia Escandón
- Group of Microbiology, Instituto Nacional de Salud, Bogotá, Colombia
| | - Carolina Firacative
- Studies in Translational Microbiology and Emerging Diseases (MICROS) Research Group, School of Medicine and Health Sciences, Universidad del Rosario, Bogotá, Colombia
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Celik M, Sunnetcioglu M, Guducuoglu H, Arslan Y, Akyuz S, Baran AI. Comparison of Carbapenem Resistance Detected by the BD Phoenix Automated System in Enterobacteriaceae Isolates with E-Test Method. ELECTRONIC JOURNAL OF GENERAL MEDICINE 2022. [DOI: 10.29333/ejgm/11672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Hauzer M, Cohen MJ, Polacheck I, Moses A, Korem M. The prevalence and clinical significance of microcolonies when tested according to contemporary interpretive breakpoints for fluconazole against Candida species using E-test. Med Mycol 2020; 57:718-723. [PMID: 30576514 DOI: 10.1093/mmy/myy130] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 10/28/2018] [Accepted: 11/06/2018] [Indexed: 12/21/2022] Open
Abstract
Changes in the interpretive-breakpoints for antifungals against various Candida species have raised the need to examine the significance of the phenomenon of the growth of microcolonies in agar diffusion inhibition zones, which has generally been considered negligible. The objective was to determine the incidence of cases in which microcolonies demonstrate fluconazole resistance according to current interpretive-breakpoints and whether their growth is associated with therapeutic failure. The fluconazole minimum inhibitory concentrations (MICs) of 100 blood culture isolates of Candida were performed by E-test on Roswell Park Memorial Institute (RPMI) agar and examined for the appearance of microcolonies. Fluconazole MICs of microcolonies were then determined over three generations. The significance of the phenomenon of microcolonies was determined according to clinical data retrieved from electronic files. Microcolonies were a common phenomenon among Candida isolates following incubation on RPMI agar, with a higher frequency among C. albicans isolates as compared to non-albicans Candida across generations (57-93% vs 31-93%, respectively) and a similar fluconazole susceptibility rate over three generations. The rate of microcolonies was similar in both patients with successful and unsuccessful outcome (41% vs 42%, respectively). Microcolonies are a common phenomenon. No increase in MIC was demonstrated throughout three generations of microcolony inoculation on RPMI, and no difference in clinical outcome was observed.
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Affiliation(s)
- Michael Hauzer
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | | | - Itzhack Polacheck
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Allon Moses
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Maya Korem
- Department of Clinical Microbiology and Infectious Diseases, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
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5
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Brito-Santos F, Figueiredo-Carvalho MHG, Coelho RA, de Oliveira JCA, Monteiro RV, da Silva Chaves AL, Almeida-Paes R. Molecular identification and antifungal susceptibility testing of Pucciniomycotina red yeast clinical isolates from Rio de Janeiro, Brazil. Braz J Microbiol 2019; 51:95-98. [PMID: 31776863 DOI: 10.1007/s42770-019-00191-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/13/2019] [Indexed: 11/30/2022] Open
Abstract
Infections caused by Rhodotorula spp. are increasing worldwide. This study identified, through the light of the new taxonomic advances on the subphylum Pucciniomycotina, 16 isolates from blood cultures and compared their antifungal susceptibility on microdilution and gradient diffusion methods. Internal transcriber spacer sequencing identified Rhodotorula mucilaginosa (n = 12), Rhodotorula toruloides (n = 2), Rhodotorula dairenensis (n = 1), and Cystobasidium minutum (n = 1). Amphotericin B was the most effective drug. A good essential agreement was observed on MIC values of amphotericin B and voriconazole determined by the two methods. Therefore, the gradient method is useful for susceptibility tests of R. mucilaginosa against these drugs.
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Affiliation(s)
- Fabio Brito-Santos
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil.
| | - Maria Helena Galdino Figueiredo-Carvalho
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil
| | - Rowena Alves Coelho
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil
| | - Jean Carlos Almeida de Oliveira
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil
| | - Raissa Vieira Monteiro
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil
| | | | - Rodrigo Almeida-Paes
- Mycology Laboratory, Evandro Chagas National Institute of Infectious Diseases, Oswaldo Cruz Foundation, FIOCRUZ, Av. Brazil 4365, Manguinhos, Rio de Janeiro, RJ, 21045-900, Brazil
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Dannaoui E, Espinel-Ingroff A. Antifungal Susceptibly Testing by Concentration Gradient Strip Etest Method for Fungal Isolates: A Review. J Fungi (Basel) 2019; 5:jof5040108. [PMID: 31766762 PMCID: PMC6958406 DOI: 10.3390/jof5040108] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 11/13/2019] [Accepted: 11/16/2019] [Indexed: 12/23/2022] Open
Abstract
Antifungal susceptibility testing is an important tool for managing patients with invasive fungal infections, as well as for epidemiological surveillance of emerging resistance. For routine testing in clinical microbiology laboratories, ready-to-use commercial methods are more practical than homemade reference techniques. Among commercially available methods, the concentration gradient Etest strip technique is widely used. It combines an agar-based diffusion method with a dilution method that determinates a minimal inhibitory concentration (MIC) in µg/mL. Many studies have evaluated the agreement between the gradient strip method and the reference methods for both yeasts and filamentous fungi. This agreement has been variable depending on the antifungal, the species, and the incubation time. It has also been shown that the gradient strip method could be a valuable alternative for detection of emerging resistance (non-wild-type isolates) as Etest epidemiological cutoff values have been recently defined for several drug-species combinations. Furthermore, the Etest could be useful for direct antifungal susceptibility testing on blood samples and basic research studies (e.g., the evaluation of the in vitro activity of antifungal combinations). This review summarizes the available data on the performance and potential use of the gradient strip method.
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Affiliation(s)
- Eric Dannaoui
- Paris-Descartes University, Faculty of Medicine, 75006 Paris, France
- APHP, European Georges Pompidou Hospital, Parasitology-Mycology Unit, Microbiology Department, 75015 Paris, France
- Correspondence: ; Tel.: +33-15-6093-948; Fax: +33-15-6092-446
| | - Ana Espinel-Ingroff
- Virginia Commonwealth University (VCU) Medical Center, Richmond, VA 23219, USA;
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Method-Dependent Epidemiological Cutoff Values for Detection of Triazole Resistance in Candida and Aspergillus Species for the Sensititre YeastOne Colorimetric Broth and Etest Agar Diffusion Methods. Antimicrob Agents Chemother 2018; 63:AAC.01651-18. [PMID: 30323038 DOI: 10.1128/aac.01651-18] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 10/03/2018] [Indexed: 11/20/2022] Open
Abstract
Although the Sensititre Yeast-One (SYO) and Etest methods are widely utilized, interpretive criteria are not available for triazole susceptibility testing of Candida or Aspergillus species. We collected fluconazole, itraconazole, posaconazole, and voriconazole SYO and Etest MICs from 39 laboratories representing all continents for (method/agent-dependent) 11,171 Candida albicans, 215 C. dubliniensis, 4,418 C. glabrata species complex, 157 C. guilliermondii (Meyerozyma guilliermondii), 676 C. krusei (Pichia kudriavzevii), 298 C. lusitaniae (Clavispora lusitaniae), 911 C. parapsilosis sensu stricto, 3,691 C. parapsilosis species complex, 36 C. metapsilosis, 110 C. orthopsilosis, 1,854 C. tropicalis, 244 Saccharomyces cerevisiae, 1,409 Aspergillus fumigatus, 389 A. flavus, 130 A. nidulans, 233 A. niger, and 302 A. terreus complex isolates. SYO/Etest MICs for 282 confirmed non-wild-type (non-WT) isolates were included: ERG11 (C. albicans), ERG11 and MRR1 (C. parapsilosis), cyp51A (A. fumigatus), and CDR2 and CDR1 overexpression (C. albicans and C. glabrata, respectively). Interlaboratory modal agreement was superior by SYO for yeast species and by the Etest for Aspergillus spp. Distributions fulfilling CLSI criteria for epidemiological cutoff value (ECV) definition were pooled, and we proposed SYO ECVs for S. cerevisiae and 9 yeast and 3 Aspergillus species and Etest ECVs for 5 yeast and 4 Aspergillus species. The posaconazole SYO ECV of 0.06 µg/ml for C. albicans and the Etest itraconazole ECV of 2 µg/ml for A. fumigatus were the best predictors of non-WT isolates. These findings support the need for method-dependent ECVs, as, overall, the SYO appears to perform better for susceptibility testing of yeast species and the Etest appears to perform better for susceptibility testing of Aspergillus spp. Further evaluations should be conducted with more Candida mutants.
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8
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Al-Hatmi AMS, Curfs-Breuker I, de Hoog GS, Meis JF, Verweij PE. Antifungal Susceptibility Testing of Fusarium: A Practical Approach. J Fungi (Basel) 2017; 3:jof3020019. [PMID: 29371537 PMCID: PMC5715922 DOI: 10.3390/jof3020019] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Revised: 04/14/2017] [Accepted: 04/19/2017] [Indexed: 12/12/2022] Open
Abstract
In vitro susceptibility testing of Fusarium is becoming increasingly important because of frequency and diversity of infections and because resistance profiles are species-specific. Reference methods for antifungal susceptibility testing (AFST) are those of Clinical and Laboratory Standards Institute (CLSI) and European Committee on Antimicrobial Susceptibility (EUCAST), but breakpoints (BPs) have not yet been established. One of the problems is that phylogenetic distances between Fusarium species are much smaller than between species of, e.g., Candida. Epidemiological cutoff values (ECVs) for some Fusarium species have been determined in order to differentiate wild-type from non-wild-type isolates. In clinical routine, commercially available assays such as Etest, Sensititre or others provide essential agreement with reference methods. Our objective is to summarize antifungal susceptibility testing of Fusarium genus in the clinical laboratory: how to do it, when to do it, and how to interpret it.
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Affiliation(s)
- Abdullah M S Al-Hatmi
- Westerdijk Fungal Biodiversity Institute, PO Box 85167, 3508 AD Utrecht, The Netherlands.
- Centre of Expertise in Mycology Radboud University Medical Centre, Canisius Wilhelmina Hospital, 6500HB Nijmegen, The Netherlands.
- Ministry of Health, Directorate General of Health Services, PO Box 393, 100 Muscat, Oman.
| | - Ilse Curfs-Breuker
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, 6500HB Nijmegen, The Netherlands.
| | - G Sybren de Hoog
- Westerdijk Fungal Biodiversity Institute, PO Box 85167, 3508 AD Utrecht, The Netherlands.
- Basic Pathology Department, Federal University of Paraná State, Curitiba, 81540-970 Paraná, Brazil.
- Biological Sciences Department, Faculty of Science, King Abdulaziz University, PO Box 80203 Jeddah, Saudi Arabia.
| | - Jacques F Meis
- Centre of Expertise in Mycology Radboud University Medical Centre, Canisius Wilhelmina Hospital, 6500HB Nijmegen, The Netherlands.
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, 6500HB Nijmegen, The Netherlands.
| | - Paul E Verweij
- Centre of Expertise in Mycology Radboud University Medical Centre, Canisius Wilhelmina Hospital, 6500HB Nijmegen, The Netherlands.
- Department of Medical Microbiology, Radboud University, Nijmegen Medical Centre, 6500GS Nijmegen, The Netherlands.
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Kumar D, Bhattacharyya S, Gupta P, Banerjee G, Singh M. Comparative Analysis of Disc Diffusion and E-test with Broth Micro-dilution for Susceptibility Testing of Clinical Candida Isolates Against Amphotericin B, Fluconazole, Voriconazole and Caspofungin. J Clin Diagn Res 2015; 9:DC01-4. [PMID: 26675415 DOI: 10.7860/jcdr/2015/14119.6735] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/05/2015] [Indexed: 11/24/2022]
Abstract
BACKGROUND Antifungal susceptibility testing remains an area of intense interest because of the increasing number of clinical isolates resistant to antifungal therapy. Clinical and Laboratory Standards Institute has proposed reference broth micro dilution (BMD) method for susceptibility testing. The reference method is time-consuming and poorly suited for the routine clinical laboratory setting. Agar-based susceptibility testing methods, disk diffusion (DD) method and the E-test method can be an easier, reliable and less time consuming alternative for the BMD method. AIM To compare the results of Amphotericin B, fluconazole, voriconazole, and Caspofungin susceptibility testing by DD, and the E-test method with the CLSI reference method for clinical Candida isolates. MATERIALS AND METHODS Broth Microdilution (BMD), E-test and Disk diffusion testing of the various clinical Candida isolates was performed in accordance with CLSI documents. The results obtained were analysed and compared. RESULTS The categorical agreement for Amphotericin B, fluconazole, voriconazole, and Caspofungin susceptibility results by E-test and DD method was 65.2%, 67.4%; 100%, 82.6%; 100%, 100%; 100%, 97.8% respectively. CONCLUSION The agar-based E-test and disk diffusion methods are reliable alternatives to the BMD method for Candida isolates when test susceptible to fluconazole, voriconazole, and Caspofungin, however the susceptibility testing results must be interpreted with caution in case of Amphotericin B.
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Affiliation(s)
- Deepak Kumar
- Assistant Professor, Department of Microbiology, IMS, BHU Varanasi, U.P., India
| | | | - Prashant Gupta
- Assistant Professor, Department of Microbiology, King George's Medical University , Lucknow, India
| | - Gopa Banerjee
- Professor, Department of Microbiology, King George's Medical University , Lucknow, India
| | - Mastan Singh
- Professor and HOD, Department of Microbiology, King George's Medical University , Lucknow, India
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Lotfi N, Shokohi T, Nouranibaladezaei SZ, Nasrolahi Omran A, Kondori N. High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran. Jundishapur J Microbiol 2015; 8:e22929. [PMID: 26587207 PMCID: PMC4644265 DOI: 10.5812/jjm.22929] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 01/29/2015] [Accepted: 02/24/2015] [Indexed: 12/21/2022] Open
Abstract
Background: Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay. Objectives: Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran. Patients and Methods: We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest. Results: Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candidaparapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp. Conclusions: Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia.
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Affiliation(s)
- Nazanin Lotfi
- Department of Medical Mycology, Faculty of Medical Sciences, Tonekabon Branch, Islamic Azad University, Tonekabon, IR Iran
- Department of Medical Mycology and Parasitology, Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran
| | - Tahereh Shokohi
- Department of Medical Mycology and Parasitology, Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, Sari, IR Iran
- Corresponding author: Tahereh Shokohi, Department of Medical Mycology and Parasitology, Invasive Fungi Research Center, School of Medicine, Mazandaran University of Medical Sciences, P. O. Box: 48175-1665, Sari, IR Iran. Tel/Fax: +98-1133543781, E-mail:
| | | | - Ayatollah Nasrolahi Omran
- Department of Medical Mycology, Faculty of Medical Sciences, Tonekabon Branch, Islamic Azad University, Tonekabon, IR Iran
| | - Nahid Kondori
- Department of Infectious Disease, University of Gothenburg, Gothenburg, Sweden
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Chowdhary A, Kathuria S, Singh PK, Sharma B, Dolatabadi S, Hagen F, Meis JF. Molecular characterization andin vitroantifungal susceptibility of 80 clinical isolates of mucormycetes in Delhi, India. Mycoses 2014; 57 Suppl 3:97-107. [DOI: 10.1111/myc.12234] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2014] [Revised: 04/28/2014] [Accepted: 04/28/2014] [Indexed: 11/30/2022]
Affiliation(s)
- Anuradha Chowdhary
- Department of Medical Mycology; Vallabhbhai Patel Chest Institute; University of Delhi; Delhi India
| | - Shallu Kathuria
- Department of Medical Mycology; Vallabhbhai Patel Chest Institute; University of Delhi; Delhi India
| | - Pradeep Kumar Singh
- Department of Medical Mycology; Vallabhbhai Patel Chest Institute; University of Delhi; Delhi India
| | - Brijesh Sharma
- Department of Medicine; Post Graduate Institute of Medical Education and Research; Dr. Ram Manohar Lohia Hospital; Delhi India
| | - Somayeh Dolatabadi
- CBS-KNAW Fungal Biodiversity Center; Utrecht the Netherlands
- Institute for Biodiversity and Ecosystem Dynamics; University of Amsterdam; Amsterdam The Netherlands
| | - Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases; Canisius-Wilhelmina Hospital; Nijmegen the Netherlands
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases; Canisius-Wilhelmina Hospital; Nijmegen the Netherlands
- Department of Medical Microbiology; Radboud University Medical Centre; Nijmegen the Netherlands
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Comparative analysis of the Vitek 2 antifungal susceptibility system and E-test with the CLSI M27-A3 broth microdilution method for susceptibility testing of Indian clinical isolates of Cryptococcus neoformans. Mycopathologia 2012; 173:427-33. [PMID: 22354778 DOI: 10.1007/s11046-012-9528-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2011] [Accepted: 02/03/2012] [Indexed: 10/28/2022]
Abstract
The emergence of antifungal resistance among Cryptococcus neoformans isolates is a matter of great concern. The Clinical and Laboratory Standards Institute (CLSI) broth microdilution reference method (BMD) for antifungal susceptibility testing of C. neoformans is tedious and time-consuming. Consequently, there is a greater need for a reproducible in vitro susceptibility testing method for use in clinical microbiology laboratories. By random amplified polymorphic DNA analysis, the 62 Indian clinical isolates were characterized as Cryptococcus neoformans var. grubii. We evaluated the susceptibilities of these isolates for amphotericin B (AMB) and fluconazole (FLC) by two commercial techniques, i.e., Vitek 2 and E-test against the CLSI M27-A3 BMD. The essential agreement (EA) between the Vitek 2 and E-test with the reference procedure for FLC was similar (82.2%). For AMB, EA of 92 and 76% was obtained with E-test and Vitek 2. Excellent categorical agreement (CA) (98.3% and 100% by Vitek 2 and E-test, respectively) was obtained for AMB. The CA for FLC was 81 and 77.4% by Vitek 2 and E-test. We conclude that both E-test and Vitek 2 system have acceptable levels of accuracy for susceptibility testing of both the drugs. Both of them could identify fluconazole-resistant strains. Vitek 2 could be used for testing susceptibility of voriconazole and 5-flucytosine also at the same time.
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Lester SJ, Malik R, Bartlett KH, Duncan CG. Cryptococcosis: update and emergence of Cryptococcus gattii. Vet Clin Pathol 2011; 40:4-17. [PMID: 21244455 DOI: 10.1111/j.1939-165x.2010.00281.x] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Cryptococcosis is a fungal disease that occurs throughout the world. Recent reclassification of Cryptococcus species along with a change in the distribution pattern has prompted reevaluation of the organism and the diseases caused by this pathogen. This review highlights the emergence of Cryptococcus gattii as a primary pathogen in North America and summarizes our current understanding of the disease in mammals and birds.
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Dannaoui E, Paugam A, Develoux M, Chochillon C, Matheron J, Datry A, Bouges-Michel C, Bonnal C, Dromer F, Bretagne S. Comparison of antifungal MICs for yeasts obtained using the EU-CAST method in a reference laboratory and the Etest in nine different hospital laboratories. Clin Microbiol Infect 2010; 16:863-9. [DOI: 10.1111/j.1469-0691.2009.02997.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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15
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Aktas E, Yigit N. Determination of antifungal susceptibility of Aspergillus spp. responsible for otomycosis by E-test method. J Mycol Med 2009. [DOI: 10.1016/j.mycmed.2009.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Basma R, Barada G, Ojaimi N, Khalaf RA. Susceptibility of Candida albicans to common and novel antifungal drugs, and relationship between the mating type locus and resistance, in Lebanese hospital isolates. Mycoses 2008; 52:141-8. [PMID: 18627469 DOI: 10.1111/j.1439-0507.2008.01559.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The incidence of antifungal resistance is on the increase worldwide and novel drugs are constantly being developed to counter this trend. One hundred and sixteen clinical isolates of Candida albicans were collected from Lebanese hospitals in order to first determine the degree of resistance of Lebanese isolates to four common azoles: fluconazole (FL), itraconazole (IT), ketoconazole (KE), and voriconazole (VO), in addition to amphotericin B (AP) and caspofungin (CS) through the Epsilometer test method and second, determine any relationship between the allelic compositions of the mating type loci (MTLa, MTL alpha, MTLa/alpha) with drug resistance. Results showed that resistance, among C. albicans isolates, was the highest with 12% for IT, followed by 7.7% for VO, 6% for KE, 5% for FL, 1.7% for AP and 0% for CS. Three isolates (2.6%) were resistant to all azoles tested, including one that was resistant to all drugs used except CS. Eleven isolates were homozygous at the MTL locus (9.5%), five of which (45%) were resistant to at least one antifungal drug whereas 14 of the 105 heterozygous strains (13%) exhibited similar resistance (P = 0.02), indicating a strong correlation between MTL locus homozygosity and resistance.
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Affiliation(s)
- Raida Basma
- Natural Sciences Division, Lebanese American University, Byblos, Lebanon
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Ozkutuk A, Ergon C, Metin DY, Yucesoy M, Polat SH. Comparison of disk diffusion, E-test and broth microdilution test in determination of susceptibility of Aspergillus species to amphotericin B, itraconazole and voriconazole. J Chemother 2008; 20:87-92. [PMID: 18343749 DOI: 10.1179/joc.2008.20.1.87] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
In response to the recent increase in Aspergillus infections, new antifungal agents have become available accompanied by studies on antifungal susceptibility tests for epidemiological follow-up. The aim of this study was to compare the efficacy of Clinical Laboratory Standards Institute (CLSI) M 38-A broth microdilution test with the disk diffusion and E-test in determining the susceptibility of Aspergillus spp. to amphotericin B, itraconazole and voriconazole. The study was carried out on 18 A. fumigatus, 7 A. flavus, 5 A. niger and 2 A. versicolor strains isolated from clinical samples. The microdilution method was performed by following the instructions of CLSI M 38-A. The E-test and disk diffusion tests were performed according to the instructions of their manufacturers. The percent agreement between the E-test and CLSI M38-A broth microdilution test at 24 (48) h within +/- 2 dilutions was, respectively, 81% (69%) for amphotericin B, 75% (72%) for itraconazole and 85% (81%) for voriconazole. The disk diffusion test showed good correlation with the E-test but poor correlation with the broth microdilution test for the three antifungal agents we tested. In conclusion, E-test and disk diffusion test have their advantages such as ease of application and interpretation, but their correlation with the broth microdilution should be improved.
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Affiliation(s)
- A Ozkutuk
- Dokuz Eylul University School of Medicine, Department of Infectious Disease and Clinical Microbiology, Izmur, Turkey.
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18
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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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Khan ZU, Randhawa HS, Kowshik T, Chowdhary A, Chandy R. Antifungal susceptibility of Cryptococcus neoformans and Cryptococcus gattii isolates from decayed wood of trunk hollows of Ficus religiosa and Syzygium cumini trees in north-western India. J Antimicrob Chemother 2007; 60:312-6. [PMID: 17553813 DOI: 10.1093/jac/dkm192] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND We present antifungal susceptibility data on environmental isolates of Cryptococcus neoformans (serotype A, n=117) and Cryptococcus gattii (serotype B, n=65) cultured from decayed wood of trunk hollows of Ficus religiosa and Syzygium cumini trees. METHODS Susceptibilities to amphotericin B, fluconazole, ketoconazole, itraconazole and voriconazole were determined by using Etest. The MICs were read after 48 h as per the guidelines provided by the manufacturer. RESULTS The MIC90s and susceptibility ranges for C. neoformans isolates were as follows: 0.094 (0.004-0.25) mg/L for amphotericin B, 4 (0.032-12) mg/L for fluconazole, 0.094 (0.004-0.75) mg/L for itraconazole, 0.064 (0.002-0.19) mg/L for ketoconazole, and 0.047 (0.006-0.125) mg/L for voriconazole, whereas for C. gattii isolates these were 0.125 (0.023-0.5) mg/L for amphotericin B, 8 (0.032-16) mg/L for fluconazole, 0.75 (0.006-2) mg/L for itraconazole, 0.125 (0.003-0.19) mg/L for ketoconazole, and 0.094 (0.004-0.125) mg/L for voriconazole. A comparison of the geometric means of MICs (mg/L) revealed that C. gattii was less susceptible than C. neoformans to amphotericin B (0.075 versus 0.051, P=0.0003), fluconazole (2.912 versus 2.316, P=0.003), itraconazole (0.198 versus 0.0344, P<0.0001), ketoconazole (0.072 versus 0.037, P<0.0001), and voriconazole (0.045 versus 0.023, P<0.0001). CONCLUSIONS The antifungal susceptibility data obtained in this study indicate that the occurrence of primary resistance among environmental isolates of C. neoformans serotype A and C. gattii serotype B is rare, and serotype B isolates are less susceptible than serotype A isolates.
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Affiliation(s)
- Zia U Khan
- Mycology Reference Laboratory, Department of Microbiology, Faculty of Medicine, Kuwait University, Kuwait.
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20
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Dias ALT, Matsumoto FE, Melhem MSC, da Silva EG, Auler ME, de Siqueira AM, Paula CR. Comparative analysis of Etest and broth microdilution method (AFST-EUCAST) for trends in antifungal drug susceptibility testing of Brazilian Cryptococcus neoformans isolates. J Med Microbiol 2006; 55:1693-1699. [PMID: 17108273 DOI: 10.1099/jmm.0.46789-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A prospective study was performed to evaluate the correlation between the proposed standard of the Antifungal Susceptibility Testing Subcommittee of the European Committee on Antibiotic Susceptibility Testing (AFST-EUCAST) (document 7.1) and the commercial system Etest for determining the MICs of flucytosine, amphotericin B, fluconazole, itraconazole and voriconazole for a collection of 100 clinical and environmental isolates of Cryptococcus neoformans. The agreements among Etest MICs within +/-2 log2 dilutions of AFST-EUCAST standard MICs were greater for flucytosine, fluconazole and voriconazole (76, 78 and 88 %, respectively) than for amphotericin B (5 %), the lowest agreement, and itraconazole (67 %). Overall, the correlation coefficients were statistically significant (P<0.05), and it is suggested that the Etest and AFST-EUCAST method are reliable alternatives and present good correlation for all drugs evaluated except amphotericin B. However, the observed differences related to MICs for susceptible, susceptible dose dependent and resistant strains between the methods suggest that it will be necessary to carry out further studies, including assessment of interlaboratory agreement and correlation of MICs by different methods with in vivo response.
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Affiliation(s)
- Amanda L T Dias
- Departamento de Ciências Biológicas, Laboratório de Microbiologia, Universidade Federal de Alfenas-MG, Alfenas-MG, Brazil
- Departamento de Microbiologia, Laboratório de Micologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo (USP), São Paulo-SP, Brazil
| | - Flavia E Matsumoto
- Departamento de Microbiologia, Laboratório de Micologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo (USP), São Paulo-SP, Brazil
| | | | - Eriques G da Silva
- Departamento de Microbiologia, Laboratório de Micologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo (USP), São Paulo-SP, Brazil
| | - Marcos E Auler
- Departamento de Microbiologia, Laboratório de Micologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo (USP), São Paulo-SP, Brazil
| | - Antonio M de Siqueira
- Departamento de Ciências Biológicas, Laboratório de Microbiologia, Universidade Federal de Alfenas-MG, Alfenas-MG, Brazil
| | - Claudete R Paula
- Departamento de Microbiologia, Laboratório de Micologia, Instituto de Ciências Biomédicas II, Universidade de São Paulo (USP), São Paulo-SP, Brazil
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21
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Abstract
The yeasts, being favorite eukaryotic microorganisms used in food industry and biotechnologies for production of biomass and various substances, are also used as model organisms in genetic manipulation, molecular and biological research. In this respect, Saccharomyces cerevisiae is the best-known species but current situation in medicine and industry requires the use of other species. Here we summarize the basic taxonomic, morphological, physiological, genetic, etc. information about the pathogenic yeast Candida glabrata that is evolutionarily very closely related to baker's yeast.
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Affiliation(s)
- A Bialková
- Department of Microbiology and Virology, Faculty of Science, Comenius University, Bratislava, Slovakia
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22
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Dannaoui E, Abdul M, Arpin M, Michel-Nguyen A, Piens MA, Favel A, Lortholary O, Dromer F. Results obtained with various antifungal susceptibility testing methods do not predict early clinical outcome in patients with cryptococcosis. Antimicrob Agents Chemother 2006; 50:2464-70. [PMID: 16801427 PMCID: PMC1489793 DOI: 10.1128/aac.01520-05] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The in vitro susceptibilities of Cryptococcus neoformans isolates from consecutive human immunodeficiency virus-positive and -negative patients to the antifungal agents fluconazole, amphotericin B, and flucytosine were determined by different techniques, including the CLSI method, Etest, and broth microdilution in yeast nitrogen base (YNB) medium, during a multicenter prospective study in France. The relationship between the in vitro data and the clinical outcome 2 weeks after the initiation of antifungal therapy was assessed. In addition, the correlation between the strain serotype and the in vitro activities of the antifungals was determined, and the susceptibility results obtained with the different techniques were also compared. Thirty-seven patients received a combination of amphotericin B with flucytosine as first-line therapy, 22 were treated with amphotericin B alone, and 15 received fluconazole alone. Whatever the antifungal tested, there was no trend toward higher MICs for strains isolated from patients who failed to respond to a given therapy compared to those from patients who did not with either the CLSI method, Etest, or broth microdilution in YNB medium. The MICs obtained by the CLSI or Etest method were significantly lower for serotype D strains than for serotype A strains for both fluconazole and amphotericin B, while flucytosine MICs were not different according to serotype. These findings suggest that the in vitro antifungal susceptibility of C. neoformans, as determined with the techniques used, is not able to predict the early clinical outcome in patients with cryptococcosis.
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Affiliation(s)
- E Dannaoui
- Centre National de Référence Mycologie et Antifongiques, Unité de Mycologie Moléculaire, CNRS FRE2849, Institut Pasteur, 25, rue du Dr. Roux, 75724 Paris Cedex 15, France.
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23
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Tay ST, Tanty Haryanty T, Ng KP, Rohani MY, Hamimah H. In vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and Cryptococcus gattii to five antifungal drugs. Mycoses 2006; 49:324-30. [PMID: 16784448 DOI: 10.1111/j.1439-0507.2006.01242.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The in vitro susceptibilities of Malaysian clinical isolates of Cryptococcus neoformans var. grubii and C . gattii to five antifungal drugs (amphotericin B, flucytosine, fluconazole, itraconazole and ketoconazole) were determined using the Etest method. None of the Malaysian isolates was resistant to amphotericin B and ketoconazole. Isolates resistant to flucytosine, fluconazole and itraconazole were observed in this study. Minimum inhibition concentrations (MICs) of > or = 32 microg ml(-1) against flucytosine, > or = 64 microg ml(-1) against fluconazole and > or = 1 microg ml(-1) against itraconazole were noted in four (8.3%), two (4.2%) and one (2.1%) isolates respectively. There was no significant difference in the MICs for both Cryptococcus species (P > 0.05), indicating that C. gattii was as susceptible as var. grubii to all the antifungal drugs tested. No significant difference in the MICs for both Cryptococcus species collected from 1980 to 1990 and 2002 to 2004 were observed (P > 0.05).
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Affiliation(s)
- S T Tay
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, Kuala Lumpur.
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24
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Singh J, Rimek D, Kappe R. Intrinsic in vitro susceptibility of primary clinical isolates of Aspergillus fumigatus, Aspergillus terreus, Aspergillus nidulans, Candida albicans and Candida lusitaniae against amphotericin B. Mycoses 2006; 49:96-103. [PMID: 16466441 DOI: 10.1111/j.1439-0507.2006.01197.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A total of 60 clinical fungal isolates from patients without prior amphotericin B treatment and three control strains were evaluated for their intrinsic susceptibility to amphotericin B (AmB) using microdilution, Etest and disc diffusion assays, on three media each, Roswell Park Memorial Institute (RPMI) 1640, Antibiotic Medium 3 (AM3) and High Resolution Medium. The fungal strains included isolates of Aspergillus fumigatus (n = 10), Aspergillus terreus (n = 12), Aspergillus nidulans (n = 9), Candida albicans (n = 6) and Candida lusitaniae (n = 23). The A. terreus strains were significantly less susceptible to AmB than the A. fumigatus strains in all nine experimental settings (P-values ranging from 0.009 to <0.00001). The A. nidulans strains were equally susceptible to AmB as the A. fumigatus strains in seven of nine experimental settings and less susceptible in two (microdilution performed on RPMI and AM3, P = 0.01 and 0.007). The C. lusitaniae strains were equally susceptible to AmB as the C. albicans strains in seven of nine experimental settings and more susceptible in two (microdilution and Etest, both performed on AM3, P = 0.01 and 0.0002). Thus, we confirmed that A. terreus is intrinsically less susceptible to AmB than A. fumigatus. In contrast, nine German clinical isolates of Aspergillus nidulans were found equally susceptible to AmB as 10 isolates of A. fumigatus. Furthermore, we found 23 German clinical isolates of C. lusitaniae from patients without prior treatment with AmB equally susceptible to AmB as C. albicans.
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Affiliation(s)
- Jagpal Singh
- Department of Microbiology and Infectious Diseases, Haema Institute of Laboratory Medicine at the Helios Medical Center, Erfurt, Germany
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25
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Pina-Vaz C, Costa-de-Oliveira S, Rodrigues AG, Espinel-Ingroff A. Comparison of two probes for testing susceptibilities of pathogenic yeasts to voriconazole, itraconazole, and caspofungin by flow cytometry. J Clin Microbiol 2005; 43:4674-9. [PMID: 16145125 PMCID: PMC1234075 DOI: 10.1128/jcm.43.9.4674-4679.2005] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A cytometric approach to determine the susceptibilities of Candida spp. and Cryptococcus neoformans to voriconazole, itraconazole, and caspofungin is described. A total of 63 clinical isolates with different susceptibility patterns were exposed for 1, 2, 4, and 6 h to serial concentrations of each antifungal agent, followed by staining with two fluorescent probes: propidium iodide (PI) and FUN-1. FUN-1 was able to identify the susceptibility patterns of the assayed strains to the three agents after 1 h. PI penetrated a maximum of 50% of the cells treated with PI, at the highest concentration of caspofungin, 16 mug/ml, after 6 h of incubation (this percentage varied with the strain and was drug concentration and time of incubation dependent) and did not stain cells treated with high concentrations of either azole after 6 h. The use of FUN-1 appears to be an excellent fast and reliable alternative to the classical dilution method for determining the susceptibility of Candida spp. and C. neoformans to these three antifungal agents.
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Affiliation(s)
- Cidália Pina-Vaz
- Department of Microbiology, Porto School of Medicine, Alameda Prof. Hernani Monteiro, Porto, Portugal.
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26
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Cuenca-Estrella M, Gomez-Lopez A, Mellado E, Rodriguez-Tudela JL. Correlation between the procedure for antifungal susceptibility testing for Candida spp. of the European Committee on Antibiotic Susceptibility Testing (EUCAST) and four commercial techniques. Clin Microbiol Infect 2005; 11:486-92. [PMID: 15882199 DOI: 10.1111/j.1469-0691.2005.01166.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The correlation between results obtained with the European Committee on Antibiotic Susceptibility Testing (EUCAST) antifungal susceptibility testing procedure (document 7.1) and four commercial systems was evaluated for a collection of 93 clinical isolates of Candida spp. Overall, agreement between the EUCAST procedure and the Sensititre YeastOne and Etest methods was 75% and 90.4%, respectively. The correlation indices (p < 0.01) between the EUCAST and commercial methods were 0.92 for Sensititre YeastOne, 0.89 for Etest, - 0.90 for Neo-Sensitabs, and 0.95 for Fungitest. Amphotericin B MICs obtained by Sensititre YeastOne were consistently higher than with the EUCAST method and, although very major errors were not observed, 91% of MICs were misclassified. Amphotericin B- and fluconazole-resistant isolates were identified correctly with Sensititre YeastOne, Etest and Fungitest. Neo-Sensitabs identified amphotericin B-resistant isolates, but misclassified > 5% of fluconazole-resistant isolates as susceptible. The commercial methods, particularly Etest and Fungitest, appeared to be suitable alternatives to the EUCAST procedure for antifungal susceptibility testing of clinical isolates of Candida.
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Affiliation(s)
- M Cuenca-Estrella
- Servicio de Micología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
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27
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Mallié M, Bastide JM, Blancard A, Bonnin A, Bretagne S, Cambon M, Chandenier J, Chauveau V, Couprie B, Datry A, Feuilhade M, Grillot R, Guiguen C, Lavarde V, Letscher V, Linas MD, Michel A, Morin O, Paugam A, Piens MA, Raberin H, Tissot E, Toubas D, Wade A. In vitro susceptibility testing of Candida and Aspergillus spp. to voriconazole and other antifungal agents using Etest®: results of a French multicentre study. Int J Antimicrob Agents 2005; 25:321-8. [PMID: 15784312 DOI: 10.1016/j.ijantimicag.2004.11.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2004] [Accepted: 11/20/2004] [Indexed: 11/23/2022]
Abstract
Minimum inhibitory concentrations (MICs) of the antifungal agent voriconazole were determined using the Etest and compared with those of amphotericin B, itraconazole and fluconazole using 1986 clinical isolates of Candida spp. Voriconazole MICs were also compared with those of amphotericin B and itraconazole using 391 clinical isolates of Aspergillus spp. Voriconazole was found to have more potent activity and lower MIC values than amphotericin B, itraconazole and fluconazole against C. albicans, C. tropicalis, C. parapsilosis and C. kefyr. Against C. glabrata and C. krusei, voriconazole was more active than either of the other two azole antifungals but had similar activity to amphotericin B. For species of Aspergillus, MIC values of voriconazole were lower than those of amphotericin B and itraconazole against A. fumigatus and A. flavus, and were similar to those of amphotericin B against A. niger. Against A. terreus, MIC values for voriconazole and itraconazole were similar. A. terreus is known to be resistant to amphotericin B, and this was reflected in higher MIC values compared with those of voriconazole and itraconazole. Voriconazole therefore compares very favourably with other antifungal agents against a large number of clinical isolates of Candida and Aspergillus spp.
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Affiliation(s)
- M Mallié
- Laboratoire de Parasitologie-Mycologie Médicale, Faculté de Pharmacie, BP 14491, 15, Avenue Charles Flahault, 34093 Montpellier Cedex 5, France.
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28
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Lester SJ, Kowalewich NJ, Bartlett KH, Krockenberger MB, Fairfax TM, Malik R. Clinicopathologic features of an unusual outbreak of cryptococcosis in dogs, cats, ferrets, and a bird: 38 cases (January to July 2003). J Am Vet Med Assoc 2004; 225:1716-22. [PMID: 15626222 DOI: 10.2460/javma.2004.225.1716] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine clinical and pathologic findings associated with an outbreak of cryptococcosis in an unusual geographic location (British Columbia, Canada). DESIGN Retrospective study. ANIMALS 1 pink-fronted cockatoo, 2 ferrets, 20 cats, and 15 dogs. PROCEDURE A presumptive diagnosis of cryptococcosis was made on the basis of serologic, histopathologic, or cytologic findings, and a definitive diagnosis was made on the basis of culture or immunohistochemical staining. RESULTS No breed or sex predilections were detected in affected dogs or cats. Eleven cats had neurologic signs, 7 had skin lesions, and 5 had respiratory tract signs. None of 17 cats tested serologically for FeLV yielded positive results; 1 of 17 cats yielded positive results for FIV (western blot). Nine of 15 dogs had neurologic signs, 2 had periorbital swellings, and only 3 had respiratory tract signs initially. Microbiologic culture in 15 cases yielded 2 isolates of Cryptococcus neoformans var grubii (serotype A) and 13 isolates of C. neoformans var gattii (serotype B); all organisms were susceptible to amphotericin B and ketoconazole. Serologic testing had sensitivity of 92% and specificity of 98%. CONCLUSIONS AND CLINICAL RELEVANCE Serologic titers were beneficial in identifying infection in animals with nonspecific signs, but routine serum biochemical or hematologic parameters were of little value in diagnosis. Most animals had nonspecific CNS signs and represented a diagnostic challenge. Animals that travel to or live in this region and have nonspecific malaise or unusual neurologic signs should be evaluated for cryptococcosis.
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Affiliation(s)
- Sally J Lester
- Central Laboratory for Veterinarians, 5645 199th St, Langley, BC V3A 1H9, Canada
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29
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Espinel-Ingroff A, Pfaller M, Messer SA, Knapp CC, Holliday N, Killian SB. Multicenter comparison of the Sensititre YeastOne colorimetric antifungal panel with the NCCLS M27-A2 reference method for testing new antifungal agents against clinical isolates of Candida spp. J Clin Microbiol 2004; 42:718-21. [PMID: 14766842 PMCID: PMC344524 DOI: 10.1128/jcm.42.2.718-721.2004] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A multicenter (three centers) study compared MICs obtained by the Sensititre YeastOne Colorimetric Antifungal plate to reference microdilution broth (NCCLS M27-A2 document) MICs of three new triazoles (posaconazole, ravuconazole, and voriconazole) and the echinocandin caspofungin acetate for 100 isolates of Candida spp. In addition, amphotericin B and fluconazole were tested as control drugs. Colorimetric MICs of caspofungin and amphotericin B corresponded to the first blue well (no growth), and MICs of the other agents corresponded to the first slightly purple or blue well. Two comparisons of MIC pairs by the two methods were evaluated: 24-h colorimetric MICs were compared to NCCLS MICs at 24 and at 48 h. The interlaboratory reproducibility of YeastOne and reference MICs was also examined. The best performance of the YeastOne plate was with 24-h MICs (overall, 95 to 99% agreement) for all the species and antifungal agents. These results suggest the potential value of the YeastOne plate for use in the clinical laboratory for the four new antifungal agents evaluated.
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30
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de F L Fernandes O, Passos XS, Souza LKH, Miranda ATB, Cerqueira CHPV, Silva MDRR. In vitro susceptibility characteristics of Cryptococcus neoformans varieties from AIDS patients in Goiânia, Brazil. Mem Inst Oswaldo Cruz 2003; 98:839-41. [PMID: 14595465 DOI: 10.1590/s0074-02762003000600022] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Sixty clinical isolates of Cryptococcus neoformans from AIDS from Goiânia, state of Goiás, Brazil, were characterized according to varieties, serotypes and tested for antifungal susceptibility. To differentiate the two varieties was used L-canavanine-glycine-bromothymol blue medium and to separate the serotypes was used slide agglutination test with Crypto Check Iatron. The Minimal Inhibitory Concentration (MIC) of fluconazole, itraconazole, and amphotericin B were determined by the National Committee for Clinical Laboratory Standards macrodilution method. Our results identified 56 isolates as C. neoformans var. neoformans serotype A and 4 isolates as C. neoformans var. gattii serotype B. MIC values for C. neoformans var. gattii were higher than C. neoformans var. neoformans. We verified that none isolate was resistant to itraconazole and to amphotericin B, but one C. neoformans var. neoformans and three C. neoformans var. gattii isolates were resistant to fluconazole. The presence of C. neoformans var. gattii fluconazole resistant indicates the importance of determining not only the variety of C. neoformans infecting the patients but also measuring the MIC of the isolate in order to properly orient treatment.
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Affiliation(s)
- Orionalda de F L Fernandes
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, 74605-050 Goiânia, GO, Brasil.
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31
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Gökahmetoglu S, Nedret Koç A, Patiroglu T. Antifungal susceptibility testing of Candida albicans by flow cytometry. Mycoses 2003; 46:307-11. [PMID: 12950899 DOI: 10.1046/j.1439-0507.2003.00903.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Antifungal susceptibilities of 28 Candida albicans isolates and two quality control strains to amphotericin B and fluconazole were determined by flow cytometry and microdilution method. Minimum inhibitory concentrations (MICs) obtained by flow cytometry were compared with the results obtained by The National Committee for Clinical Laboratory Standards Subcommittee (NCCLS) broth microdilution method. The agreement of results (within two dilution) obtained was found as 96 and 93% for amphotericin B and fluconazole, respectively. At least 24 h incubation was required for reading the microdilution assays. Four hours of incubation was required for fluconazole, whereas 2-h incubation was sufficient for amphotericin B to provide MIC by flow cytometry. Results of this study show that flow cytometry provides a rapid and sensitive in vitro method for antifungal susceptibility testing of Candida albicans isolates.
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Affiliation(s)
- Selma Gökahmetoglu
- Department of Microbiology, Erciyes University Medical Faculty, TR-38039 Kayseri, Turkey.
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32
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Matar MJ, Ostrosky-Zeichner L, Paetznick VL, Rodriguez JR, Chen E, Rex JH. Correlation between E-test, disk diffusion, and microdilution methods for antifungal susceptibility testing of fluconazole and voriconazole. Antimicrob Agents Chemother 2003; 47:1647-51. [PMID: 12709335 PMCID: PMC153338 DOI: 10.1128/aac.47.5.1647-1651.2003] [Citation(s) in RCA: 189] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The activities of fluconazole and voriconazole against isolates of Candida spp. (n = 400) were tested by the E-test, disk diffusion, and the National Committee for Clinical Laboratory Standards (NCCLS) M27-A2 broth microdilution-based reference methods. More than 96% of isolates found to be susceptible to fluconazole by the reference method were identified as susceptible by the agar-based methods. Lesser degrees of correlation with the reference method were seen for isolates identified as resistant by the agar-based methods. Interpretive categories are not available for voriconazole, but results qualitatively similar to those for fluconazole were seen. The agar-based E-test and disk diffusion methods are reliable alternatives to the NCCLS M27-A2 reference microdilution method for isolates that test susceptible to fluconazole.
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Affiliation(s)
- Madonna J Matar
- Laboratory of Mycology Research, Division of Infectious Diseases, University of Texas-Houston Medical School, Houston, Texas 77030
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33
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Fernández-Torres B, Carrillo-Muñoz A, Ortoneda M, Pujol I, Pastor FJ, Guarro J. Interlaboratory evaluation of the Etest for antifungal susceptibility testing of dermatophytes. Med Mycol 2003; 41:125-30. [PMID: 12964844 DOI: 10.1080/mmy.41.2.125.130] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
A three-site interlaboratory reproducibility evaluation of the Etest concentration gradient strip method for testing antifungal susceptibilities was conducted using 30 strains of dermatophytes exposed to strips loaded with ketoconazole (KTZ), itraconazole (ITZ), amphotericin B (AMB) and fluconazole (FCZ). Etest minimal inhibitory concentrations were compared with those obtained using a broth microdilution method. All isolates produced clearly detectable growth at 28 degrees C within 72-96 h for reading with the Etest method. The highest interlaboratory agreement between Etest and the microdilution method was shown with FCZ (94%), and the lowest was seen with KTZ (60%). Overall, agreement between the Etest and microdilution method was variable. It was excellent for AMB (97%), good for ITZ (80%) and KTZ (77%), and low for fluconazole (27%).
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Affiliation(s)
- B Fernández-Torres
- Unitat de Microbiologia, Facultat de Medicine, Institut d'Estudis Avançats, Universitat Rovira i Virgili, 43201 Reus, Tarragona, Spain
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34
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Ramani R, Chaturvedi V. Proficiency testing program for clinical laboratories performing antifungal susceptibility testing of pathogenic yeast species. J Clin Microbiol 2003; 41:1143-6. [PMID: 12624043 PMCID: PMC150294 DOI: 10.1128/jcm.41.3.1143-1146.2003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Antifungal susceptibility testing is expected to facilitate the selection of adequate therapy for fungal infections. The general availability of antifungal susceptibility testing in clinical laboratories is low, even though a number of standard methods are now available. The objective of the present study was to develop and evaluate a proficiency testing program (PTP) for the antifungal susceptibility testing of pathogenic yeasts in laboratories licensed by the New York State Department of Health. A number of quality control standards, and methods for documenting laboratory performance, were developed in consultation with the laboratory directors. The participating laboratories were provided with five American Type Culture Collection strains of pathogenic yeasts for which the minimum inhibitory concentrations (MICs) of amphotericin B and fluconazole were well defined. A majority of laboratories (14 of 17) used broth microdilution, and these were evenly split between the NCCLS M-27A protocol and the Sensititre YeastOne method. The other three laboratories performed susceptibility testing with Etest. Overall, the levels of agreement between MIC reference ranges and the reported MICs were 85 and 74% for amphotericin B and for fluconazole, respectively. All laboratories except one successfully detected fluconazole resistance in a Candida krusei strain. However, amphotericin B resistance in a Candida lusitaniae strain was not detected by any of the participating labs. It is concluded that a suitably designed PTP could adequately monitor the competence of clinical laboratories performing antifungal susceptibility testing.
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Affiliation(s)
- Rama Ramani
- Mycology Laboratory, Wadsworth Center, New York State Department of Health, School of Public Health, State University of New York at Albany, Albany, New York 12201-2002, USA
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35
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Pfaller JB, Messer SA, Hollis RJ, Diekema DJ, Pfaller MA. In vitro susceptibility testing of Aspergillus spp.: comparison of Etest and reference microdilution methods for determining voriconazole and itraconazole MICs. J Clin Microbiol 2003; 41:1126-9. [PMID: 12624040 PMCID: PMC150323 DOI: 10.1128/jcm.41.3.1126-1129.2003] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of the Etest for voriconazole and for itraconazole susceptibility testing of 376 isolates of Aspergillus spp. was assessed in comparison with the National Committee for Clinical Laboratory Standards (NCCLS) proposed standard microdilution broth 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 included A. fumigatus, A. flavus, A. niger, A. terreus, A. versicolor, A. glaucus, A. nidulans, A. ustus, and A. sydowii. Overall agreement percentages between the Etest and microdilution MICs were 97.6% for voriconazole and 95.8% for itraconazole. Where a discrepancy was observed between Etest and the reference method, the Etest tended to give lower values with voriconazole and higher values with itraconazole. The Etest method using RPMI agar appears to be a useful method for determining the voriconazole and itraconazole susceptibilities of Aspergillus spp.
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Affiliation(s)
- J B Pfaller
- 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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36
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Yamazumi T, Pfaller MA, Messer SA, Houston AK, Boyken L, Hollis RJ, Furuta I, Jones RN. Characterization of heteroresistance to fluconazole among clinical isolates of Cryptococcus neoformans. J Clin Microbiol 2003; 41:267-72. [PMID: 12517859 PMCID: PMC149577 DOI: 10.1128/jcm.41.1.267-272.2003] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Strains of Cryptococcus neoformans expressing heteroresistance to fluconazole have been described previously. The present study was conducted to investigate the prevalence of heteroresistance among clinical isolates of C. neoformans and to characterize the heteroresistant phenotypes. A total of 107 clinical isolates of C. neoformans for which the MICs of fluconazole ranged from 0.25 to 32 microg/ml were selected. The isolates were chosen to represent a broad geographic distribution. Of the 107 C. neoformans isolates tested, 4 grew on medium containing fluconazole at concentrations that were four to eight times higher than the MICs for each strain. A fifth isolate, for which the fluconazole MIC was 32 microg/ml, grew on agar with 64 microg of fluconazole per ml. These five isolates (4.7% of the total number) were confirmed to exhibit heteroresistant compositions by population analysis. The degree and frequency of resistance varied among the isolates. Stepwise selection by exposure to fluconazole resulted in subclones of all five strains for which the fluconazole MIC was >64 microg/ml. Subclones of three strains demonstrated a homogeneous population of resistant cells on medium containing 64 microg of fluconazole/ml. The resistance was sensitive to incubation temperature, that is, heteroresistance was demonstrable only at 30 degrees C by agar-based tests, and was reversible through serial transfers on fluconazole-free medium over a period of 8 days. These results suggest that the fluconazole-heteroresistant phenotype of C. neoformans exists in a significant proportion of clinical isolates and that fluconazole resistance can be developed by selection from heteroresistant clones and induction by exposure to fluconazole.
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Affiliation(s)
- T Yamazumi
- Medical Microbiology Division, Department of Pathology, University of Iowa College of Medicine, Iowa City, 52242, USA
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37
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Maxwell MJ, Messer SA, Hollis RJ, Diekema DJ, Pfaller MA. Evaluation of Etest method for determining voriconazole and amphotericin B MICs for 162 clinical isolates of Cryptococcus neoformans. J Clin Microbiol 2003; 41:97-9. [PMID: 12517832 PMCID: PMC149576 DOI: 10.1128/jcm.41.1.97-99.2003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of the Etest for voriconazole and amphotericin B susceptibility testing of 162 isolates of Cryptococcus neoformans was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) broth microdilution method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 72 h at 35 degrees C. MICs were determined by Etest for all 162 isolates with RPMI 1640 agar containing 2% glucose (RPG agar) and were read after incubation for 72 h at 35 degrees C. The Etest results for both voriconazole and amphotericin B correlated well with reference MICs. Agreement was 94% for voriconazole and 99% for amphotericin B. When discrepancy was noted between the results obtained by Etest and broth microdilution for voriconazole, the Etest generally provided a higher MIC. The Etest method using RPG agar appears to be a useful method for determining the susceptibility of C. neoformans to voriconazole and amphotericin B.
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Affiliation(s)
- M J Maxwell
- Department of Pathology, University of Iowa College of Medicine and College of Public Health, Iowa City, Iowa 52242, USA
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38
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Espinel-Ingroff A. Evaluation of broth microdilution testing parameters and agar diffusion Etest procedure for testing susceptibilities of Aspergillus spp. to caspofungin acetate (MK-0991). J Clin Microbiol 2003; 41:403-9. [PMID: 12517880 PMCID: PMC149640 DOI: 10.1128/jcm.41.1.403-409.2003] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The NCCLS M38-A document does not describe guidelines for testing caspofungin acetate (MK-0991) and other echinocandins against molds. This study evaluated the susceptibilities of 200 isolates of Aspergillus fumigatus, A. flavus, A. nidulans, A. niger, and A. terreus to caspofungin (MICs and minimum effective concentrations [MECs]) by using standard RPMI 1640 (RPMI) and antibiotic medium 3 (M3), two inoculum sizes (10(3) and 10(4) CFU/ml), and two MIC determination criteria (complete [MICs-0] and prominent growth inhibition [MICs-2]) at 24 and 48 h. Etest MICs were also determined. In general, caspofungin MIC-2 and MEC pairs were comparable with both media and inocula (geometric mean ranges of MECs and MICs, respectively, with larger inoculum: 0.12 to 0.64 microg/ml and 0.12 to 0.44 microg/ml with RPMI versus 0.04 to 0.51 microg/ml and 0.03 to 0.21 microg/ml with M3); however, MEC results were less influenced by testing conditions than MICs, especially with the larger inoculum. Overall, the agreement between caspofungin Etest MICs and broth dilution values was higher with MECs obtained with M3 (>90%) and the large inoculum than under the other testing conditions. Because RPMI is a more stable and chemically defined medium than M3, the determination at 24 h of the easier visual MECs with RPMI and the inoculum recommended in the M38-A document appears to be a suitable procedure at present for in vitro testing of caspofungin against Aspergillus spp. Future in vitro correlations with in vivo outcome of both microdilution and Etest procedures may detect more-relevant testing conditions.
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Affiliation(s)
- Ana Espinel-Ingroff
- Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, Virginia 23298, USA.
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40
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Hahn RC, Fontes CJF, Batista RD, Hamdan JS. In vitro comparison of activities of terbinafine and itraconazole against Paracoccidioides brasiliensis. J Clin Microbiol 2002; 40:2828-31. [PMID: 12149337 PMCID: PMC120660 DOI: 10.1128/jcm.40.8.2828-2831.2002] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2001] [Revised: 12/24/2001] [Accepted: 05/08/2002] [Indexed: 11/20/2022] Open
Abstract
In vitro, terbinafine is highly active against a broad spectrum of pathogenic fungi. We evaluated the activities of terbinafine and itraconazole against 31 isolates of Paracoccidioides brasiliensis. The tests were conducted by using a broth macrodilution procedure. MICs, in micrograms per milliliter, were as follows: terbinafine, 0.015 to 1.0 (geometric mean, 0.1188); itraconazole, 0.007 to 0.5 (geometric mean, 0.03165). The usual therapy for paracoccidioidomycosis is sulfonamides, amphotericin B, and azole derivatives (ketoconazole, itraconazole, and fluconazole). In comparison to amphotericin B, azole derivatives allow shorter treatment courses, can be administered orally, and are equally effective. Itraconazole has as high efficacy as ketoconazole, but with superior tolerance. It is the current drug of choice for treatment of paracoccidioidomycosis. The data obtained in this study indicate that terbinafine is active against P. brasiliensis in vitro and suggest that this allylamine can be considered a new option as drug therapy for paracoccidioidomycosis.
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Affiliation(s)
- R C Hahn
- Department of Microbiology, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil
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41
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Espinel-Ingroff A, Rezusta A. E-test method for testing susceptibilities of Aspergillus spp. to the new triazoles voriconazole and posaconazole and to established antifungal agents: comparison with NCCLS broth microdilution method. J Clin Microbiol 2002; 40:2101-7. [PMID: 12037072 PMCID: PMC130678 DOI: 10.1128/jcm.40.6.2101-2107.2002] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
NCCLS document M38-P describes standard parameters for testing the fungistatic activities (MICs) of established agents against filamentous fungi (molds). This study evaluated the in vitro susceptibilities of 15 Aspergillus flavus isolates, 62 A. fumigatus isolates, and 10 isolates each of A. niger, A. nidulans, and A. terreus to voriconazole, posaconazole, itraconazole, and amphotericin B by the E-test and NCCLS M38-P microdilution methods. The agreement (within 3 dilutions) between methods for voriconazole was independent of the E-test incubation time (93.3 to 100% for four of five species at both incubation times). In contrast, with amphotericin B, itraconazole, and posaconazole, E-test results were more dependent on the incubation time for certain species. For A. fumigatus, posaconazole E-test MICs had better concordance with reference values after 48 h (95.2%) than after 24 h (90%), while the highest agreement for itraconazole MICs was after 24 h (90.3 versus 74.2%) of incubation. Better agreement between the methods was also obtained with 24-h E-test amphotericin B MICs for A. flavus (73.3 versus 26.7%) and A. fumigatus (96.7 versus 64.5%). E-test MICs of the four agents had the lowest percentages of agreement with reference values for A. nidulans (60 to 80%). For isolates for which high MICs were obtained for the four agents by the reference method, high MICs were also obtained by E-test at both 24 and 48 h. The utility of in vitro results of either the E-test or the NCCLS broth microdilution (M38-P) method for Aspergillus spp. needs to be established in clinical trials.
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Affiliation(s)
- Ana Espinel-Ingroff
- Division of Infectious Diseases, Medical College of Virginia Campus of Virginia Commonwealth University, Richmond, Virginia 23298-0049, USA.
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42
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Barry AL, Pfaller MA, Rennie RP, Fuchs PC, Brown SD. Precision and accuracy of fluconazole susceptibility testing by broth microdilution, Etest, and disk diffusion methods. Antimicrob Agents Chemother 2002; 46:1781-4. [PMID: 12019090 PMCID: PMC127270 DOI: 10.1128/aac.46.6.1781-1784.2002] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Interpretive agreements among the results of fluconazole broth microdilution tests, Etests, and disk diffusion tests were documented by evaluating 495 Candida spp. Microdilution reference test results were in agreement with 96% of the Etest results; most discrepancies were minor differences. Fluconazole resistance of Candida krusei strains often required a full 48 h of incubation in order to be observed by the standard method. For the disk diffusion tests that were performed on Mueller-Hinton agar with glucose and methylene blue, 97% of results were in agreement with those of the reference test, especially when zones of inhibition were measured after the first 24 h of incubation. Some Candida glabrata isolates failed to grow satisfactorily until a full 48 h of incubation was completed. Precision was determined by testing 50 selected isolates in triplicate in each of three laboratories. The reproducibility of results of disk diffusion tests was comparable to that of the reference method. With all procedures, determination of test results was particularly challenging with some strains, and new methods are needed in order to improve endpoint definition.
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Affiliation(s)
- A L Barry
- The Clinical Microbiology Institute, Wilsonville, Oregon 97070, USA.
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43
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Silva MDRR, Costa MR, Miranda ATB, Fernandes ODFL, Costa CR, Paula CRD. Evaluation of Etest and macrodilution broth method for antifungal susceptibility testing of Candida sp strains isolated from oral cavities of AIDS patients. Rev Inst Med Trop Sao Paulo 2002; 44:121-5. [PMID: 12163903 DOI: 10.1590/s0036-46652002000300002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
A comparison of the Etest and the reference broth macrodilution susceptibility test for fluconazole, ketoconazole, itraconazole and amphotericin B was performed with 59 of Candida species isolated from the oral cavities of AIDS patients. The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-A guidelines. Our data showed that there was a good correlation between the MICs obtained by the Etest and broth dilution methods. When only the MIC results at +/- 2 dilutions for both methods were considered, the agreement rates were 90.4% for itraconazole, ketoconazole and amphotericin B and 84.6% for fluconazole of the C. albicans tested. In contrast, to the reference method, the Etest method classified as susceptible three fluconazole-resistant isolates and one itraconazole-resistant isolate, representing four very major errors. These results indicate that Etest could be considered useful for antifungal sensitivity evaluation of yeasts in clinical laboratories.
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Affiliation(s)
- Maria do Rosário R Silva
- Instituto de Patologia Tropical e Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, Brasil.
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44
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Cuenca-Estrella M, Rodríguez-Tudela JL. Present status of the detection of antifungal resistance: the perspective from both sides of the ocean. Clin Microbiol Infect 2002; 7 Suppl 2:46-53. [PMID: 11525218 DOI: 10.1111/j.1469-0691.2001.tb00009.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The NCCLS reference methodology for antifungal susceptibility testing is a new milestone of the evolution of medical mycology. The use of this methodology however, is not problem-free. At present, major limitations are a trailing phenomenon with azoles, unreliable detection of resistance to amphotericin B, poor growth of some organisms and unpractical procedures for the clinical laboratory. Herein a overview of NCCLS guidelines for yeasts and filamentous fungi is presented. Likewise, a review of studies conducted trying to overcome the limitations of reference procedures is also included. Several alternative approaches are reviewed as alternative media, inoculum size and incubation time. Modifications of reading procedure and endpoint determination are also evaluated. Agar diffusion methods and other methods for susceptibility testing are cited. Finally, we discuss the data on correlation of the in vitro results with the in vivo activity.
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Affiliation(s)
- M Cuenca-Estrella
- Servicio de Micrología, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain.
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45
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Pfaller MA, Yu WL. Antifungal susceptibility testing. New technology and clinical applications. Infect Dis Clin North Am 2001; 15:1227-61. [PMID: 11780273 DOI: 10.1016/s0891-5520(05)70192-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The state of the art for susceptibility testing of yeasts is comparable with that of bacteria. Standardized methods for performing antifungal susceptibility testing are reproducible, accurate, and available in clinical laboratories. The development of quality control limits and interpretive criteria for a limited number of antifungal agents provides a basis for the application of this testing in the clinical laboratory. A proficiency testing program is available as a quality assurance measure for laboratories and has documented steady improvement among laboratories using the NCCLS method. As with antibacterial agents, surveillance programs are now in place using reference quality testing methods to monitor antifungal resistance trends on a global scale. It is clear that antifungal susceptibility testing can predict outcome in several clinical situations. Susceptibility testing is most helpful in dealing with infection caused by non-albicans species of Candida, and susceptibility testing of azoles is increasingly important in the management of candidiasis in critically ill patients. Susceptibility testing also has been standardized for filamentous fungi that cause invasive infections. Studies are ongoing to further refine this approach and evaluate the in vivo correlation with the in vitro data for molds. Future efforts must be directed toward establishing and validating interpretive break-points for licensed antifungals such as amphotericin B, and for new antifungals that are not yet licensed. Finally, procedures must be optimized for testing non-Candida yeasts (e.g., C. neoformans) and molds.
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Affiliation(s)
- M A Pfaller
- Medical Microbiology Division, Department of Pathology, University of Iowa College of Medicine, Iowa City, Iowa, USA.
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46
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Pfaller MA, Messer SA, Mills K, Bolmström A, Jones RN. Evaluation of Etest method for determining caspofungin (MK-0991) susceptibilities of 726 clinical isolates of Candida species. J Clin Microbiol 2001; 39:4387-9. [PMID: 11724849 PMCID: PMC88553 DOI: 10.1128/jcm.39.12.4387-4389.2001] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of the Etest for testing the susceptibilities to caspofungin (MK-0991) of 726 isolates of Candida spp. was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) microdilution broth method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35 degrees C. MICs were determined by Etest for all 726 isolates with RPMI agar containing 2% glucose (RPG) and were read after incubation for 48 h at 35 degrees C. The Candida isolates included Candida albicans (n = 486), Candida glabrata (n = 96), Candida tropicalis (n = 51), Candida parapsilosis (n = 47), Candida krusei (n = 11), Candida lusitaniae (n = 2), and Candida guilliermondii (n = 33). In addition, a subset of 314 isolates were also tested by Etest using Casitone agar (CAS) and antibiotic medium 3 agar (AM3). The Etest results obtained using RPG correlated well with reference MICs. Overall agreement was 94% with RPG, 82% with CAS, and 79% with AM3. When RPG was used, agreement ranged from 79% for C. parapsilosis to 100% for C. krusei, C. lusitaniae, and C. guilliermondii. When CAS was used, agreement ranged from 0% for C. lusitaniae to 100% for C. glabrata. With AM3, agreement ranged from 0% for C. lusitaniae to 100% for C. guilliermondii. All three media supported growth of each of the Candida species. Etest results were easy to read, with sharp zones of inhibition. In most instances (75%) where a discrepancy was observed between the Etest and the reference method, the Etest MIC was lower. The Etest method using RPG appears to be useful for determining caspofungin susceptibilities of Candida species.
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Affiliation(s)
- M A Pfaller
- CAST Laboratories and Department of Pathology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
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Pfaller MA, Messer SA, Mills K, Bolmström A, Jones RN. Evaluation of Etest method for determining posaconazole MICs for 314 clinical isolates of Candida species. J Clin Microbiol 2001; 39:3952-4. [PMID: 11682513 PMCID: PMC88470 DOI: 10.1128/jcm.39.11.3952-3954.2001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The performance of the Etest for posaconazole (SCH 56592) susceptibility testing of 314 isolates of Candida spp. was assessed against the National Committee for Clinical Laboratory Standards (NCCLS) microdilution broth method. The NCCLS method employed RPMI 1640 broth medium, and MICs were read after incubation for 48 h at 35 degrees C. MICs were determined by Etest for all 314 isolates with RPMI agar containing 2% glucose (RPG agar) and were read after incubation for 48 h at 35 degrees C. The Candida isolates included C. albicans (n = 174), C. glabrata (n = 57), C. tropicalis (n = 31), C. parapsilosis (n = 39), C. krusei (n = 5), C. guilliermondii (n = 6), and C. lusitaniae (n = 2). The Etest results correlated well with reference MICs. Overall agreement was 95%, and agreements for individual species were as follows: C. krusei, 100%; C. albicans, 98%; C. tropicalis, 97%; C. glabrata, 93%; C. parapsilosis, 85%; C. guilliermondii, 83%; and C. lusitaniae, 50%. The problem of trailing end points was minimized with RPG agar, and good agreement with broth dilution MICs was obtained when discernible growth within an established ellipse was ignored. The Etest method using RPG agar appears to be a useful method for determining posaconazole susceptibilities of Candida species.
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Affiliation(s)
- M A Pfaller
- CAST Laboratories and Department of Pathology, University of Iowa College of Medicine, Iowa City, Iowa 52242, USA.
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Rex JH, Pfaller MA, Walsh TJ, Chaturvedi V, Espinel-Ingroff A, Ghannoum MA, Gosey LL, Odds FC, Rinaldi MG, Sheehan DJ, Warnock DW. Antifungal susceptibility testing: practical aspects and current challenges. Clin Microbiol Rev 2001; 14:643-58, table of contents. [PMID: 11585779 PMCID: PMC88997 DOI: 10.1128/cmr.14.4.643-658.2001] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Development of standardized antifungal susceptibility testing methods has been the focus of intensive research for the last 15 years. Reference methods for yeasts (NCCLS M27-A) and molds (M38-P) are now available. The development of these methods provides researchers not only with standardized methods for testing but also with an understanding of the variables that affect interlaboratory reproducibility. With this knowledge, we have now moved into the phase of (i) demonstrating the clinical value (or lack thereof) of standardized methods, (ii) developing modifications to these reference methods that address specific problems, and (iii) developing reliable commercial test kits. Clinically relevant testing is now available for selected fungi and drugs: Candida spp. against fluconazole, itraconazole, flucytosine, and (perhaps) amphotericin B; Cryptococcus neoformans against (perhaps) fluconazole and amphotericin B; and Aspergillus spp. against (perhaps) itraconazole. Expanding the range of useful testing procedures is the current focus of research in this area.
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Affiliation(s)
- J H Rex
- Division of Infectious Diseases, Department of Internal Medicine, Center for the Study of Emerging and Reemerging Pathogens, University of Texas Medical School, Houston, Texas 77030, USA.
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Abstract
With the rising frequency of fungal infections, as well as increasing reports of resistance to antifungal agents, it is imperative that clinically applicable antifungal susceptibility testing be available. In 1997 the National Committee for Clinical Laboratory Standards published standard guidelines for antifungal susceptibility testing of Candida sp and Cryptococcus neoformans with amphotericin B, flucytosine, fluconazole, itraconazole, and ketoconazole. Although the methods are standard, they are time consuming, can be difficult to interpret, and are approved only for testing limited organisms and drugs. Modifications to the methods and alternative approaches have been proposed to make these tests more convenient and efficient, applicable to a greater number of species, and appropriate for performing in the clinical laboratory.
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Affiliation(s)
- H L Hoffman
- College of Pharmacy, University of Iowa, Iowa City 52242, USA
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Milani G, Schereiber AZ, Vercesi AE. Ca(2+) transport into an intracellular acidic compartment of Candida parapsilosis. FEBS Lett 2001; 500:80-4. [PMID: 11434931 DOI: 10.1016/s0014-5793(01)02585-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
In this report, we study Ca2+ transport in permeabilized Candida parapsilosis spheroplasts prepared by a new technique using lyticase. An intracellular non-mitochondrial Ca2+ uptake pathway, insensitive to orthovanadate and sensitive to the V-H(+)-ATPase inhibitor bafilomycin A(1), nigericin and carbonyl cyanide p-trifluoromethoxyphenylhydrazone was characterized. Acidification of the compartment in which Ca2+ accumulated was followed using the fluorescent dye acridine orange. Acidification was stimulated by the Ca2+ chelator EGTA and inhibited by Ca2+. These results, when added to the observation that Ca2+ induces alkalization of a cellular compartment, provide evidence for the presence of a Ca2+/nH(+) antiporter in the acid compartment membrane. Interestingly, like in acidocalcisomes of trypanosomatids, the antioxidant 3,5-dibutyl-4-hydroxytoluene inhibits the V-H(+)-ATPase. In addition, the antifungal agent ketoconazole promoted a fast alkalization of the acidic compartment. Ketoconazole effects were dose-dependent and occurred in a concentration range close to that attained in the plasma of patients treated with this drug.
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Affiliation(s)
- G Milani
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, Campinas 13083 970, SP, Brazil
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