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Yoo K, Oliveira NK, Bhattacharya S, Fries BC. Achieving Resilience in Aging: How Mitochondrial Modulation Drives Age-associated Fluconazole Tolerance in Cryptococcus neoformans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586817. [PMID: 38585804 PMCID: PMC10996610 DOI: 10.1101/2024.03.26.586817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Cryptococcus neoformans ( Cn ) is an opportunistic fungal microorganism that causes life-threatening meningoencephalitis. During the infection, the microbial population is heterogeneously composed of cells with varying generational ages, with older cells accumulating during chronic infections. This is attributed to their enhanced resistance to phagocytic killing and tolerance of antifungals like fluconazole (FLC). In this study, we investigated the role of ergosterol synthesis, ATP-binding cassette (ABC) transporters, and mitochondrial metabolism in the regulation of age-dependent FLC tolerance. We find that old Cn cells increase the production of ergosterol and exhibit upregulation of ABC transporters. Old cells also show transcriptional and phenotypic characteristics consistent with increased metabolic activity, leading to increased ATP production. This is accompanied by increased production of reactive oxygen species (ROS), which results in mitochondrial fragmentation. This study demonstrates that the metabolic changes occurring in the mitochondria of old cells drive the increase in ergosterol synthesis and the upregulation of ABC transporters, leading to FLC tolerance. IMPORTANCE Infections caused by Cryptococcus neoformans cause more than 180,000 deaths annually. Estimated one-year mortality for patients receiving care ranges from 20% in developed countries to 70% in developing countries, suggesting that current treatments are inadequate. Some fungal cells can persist and replicate despite the usage of current antifungal regimens, leading to death or treatment failure. In replicative aging, older cells display a resilient phenotype, characterized by their enhanced tolerance against antifungals and resistance to killing by host cells. This study shows that age-dependent increase in mitochondrial reactive oxygen species drive changes in ABC transporters and ergosterol synthesis, ultimately leading to the heightened tolerance against fluconazole in old C. neoformans cells. Understanding the underlying molecular mechanisms of this age-associated antifungal tolerance will enable more targeted antifungal therapies for cryptococcal infections.
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Ke W, Xie Y, Chen Y, Ding H, Ye L, Qiu H, Li H, Zhang L, Chen L, Tian X, Shen Z, Song Z, Fan X, Zong JF, Guo Z, Ma X, Xiao M, Liao G, Liu CH, Yin WB, Dong Z, Yang F, Jiang YY, Perlin DS, Chen Y, Fu YV, Wang L. Fungicide-tolerant persister formation during cryptococcal pulmonary infection. Cell Host Microbe 2024; 32:276-289.e7. [PMID: 38215741 DOI: 10.1016/j.chom.2023.12.012] [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: 06/08/2023] [Revised: 09/25/2023] [Accepted: 12/14/2023] [Indexed: 01/14/2024]
Abstract
Bacterial persisters, a subpopulation of genetically susceptible cells that are normally dormant and tolerant to bactericides, have been studied extensively because of their clinical importance. In comparison, much less is known about the determinants underlying fungicide-tolerant fungal persister formation in vivo. Here, we report that during mouse lung infection, Cryptococcus neoformans forms persisters that are highly tolerant to amphotericin B (AmB), the standard of care for treating cryptococcosis. By exploring stationary-phase indicator molecules and developing single-cell tracking strategies, we show that in the lung, AmB persisters are enriched in cryptococcal cells that abundantly produce stationary-phase molecules. The antioxidant ergothioneine plays a specific and key role in AmB persistence, which is conserved in phylogenetically distant fungi. Furthermore, the antidepressant sertraline (SRT) shows potent activity specifically against cryptococcal AmB persisters. Our results provide evidence for and the determinant of AmB-tolerant persister formation in pulmonary cryptococcosis, which has potential clinical significance.
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Affiliation(s)
- Weixin Ke
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yuyan Xie
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yingying Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hao Ding
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Leixin Ye
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haoning Qiu
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Hao Li
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Lanyue Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lei Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhenghao Shen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zili Song
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xin Fan
- Department of Infectious Diseases and Clinical Microbiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China
| | - Jian-Fa Zong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Zhengyan Guo
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Xiaoyu Ma
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Meng Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing 100730, China; Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases (BZ0447), Beijing 100730, China
| | - Guojian Liao
- College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, China
| | - Cui Hua Liu
- University of Chinese Academy of Sciences, Beijing 100049, China; CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wen-Bing Yin
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhiyang Dong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Feng Yang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - Yuan-Ying Jiang
- Department of Pharmacy, Shanghai Tenth People's Hospital, Tongji University School of Medicine, Shanghai 200072, China
| | - David S Perlin
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, NJ 07110, USA
| | - Yihua Chen
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yu V Fu
- University of Chinese Academy of Sciences, Beijing 100049, China; State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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3
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Chen L, Tian X, Zhang L, Wang W, Hu P, Ma Z, Li Y, Li S, Shen Z, Fan X, Ye L, Ke W, Wu Y, Shui G, Xiao M, He GJ, Yang Y, Fang W, Bai F, Liao G, Chen M, Lin X, Li C, Wang L. Brain glucose induces tolerance of Cryptococcus neoformans to amphotericin B during meningitis. Nat Microbiol 2024; 9:346-358. [PMID: 38225460 DOI: 10.1038/s41564-023-01561-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 11/15/2023] [Indexed: 01/17/2024]
Abstract
Antibiotic tolerance is the ability of a susceptible population to survive high doses of cidal drugs and has been shown to compromise therapeutic outcomes in bacterial infections. In comparison, whether fungicide tolerance can be induced by host-derived factors during fungal diseases remains largely unknown. Here, through a systematic evaluation of metabolite-drug-fungal interactions in the leading fungal meningitis pathogen, Cryptococcus neoformans, we found that brain glucose induces fungal tolerance to amphotericin B (AmB) in mouse brain tissue and patient cerebrospinal fluid via the fungal glucose repression activator Mig1. Mig1-mediated tolerance limits treatment efficacy for cryptococcal meningitis in mice via inhibiting the synthesis of ergosterol, the target of AmB, and promoting the production of inositolphosphorylceramide, which competes with AmB for ergosterol. Furthermore, AmB combined with an inhibitor of fungal-specific inositolphosphorylceramide synthase, aureobasidin A, shows better efficacy against cryptococcal meningitis in mice than do clinically recommended therapies.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Xiuyun Tian
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Lanyue Zhang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wenzhao Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Pengjie Hu
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhongyi Ma
- Medical Research Institute, College of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Yeqi Li
- Department of Microbiology, University of Georgia, Athens, GA, USA
| | - Shibin Li
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Zhenghao Shen
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xin Fan
- Department of Infectious Diseases and Clinical Microbiology, Beijing Institute of Respiratory Medicine and Beijing Chao-Yang Hospital, Capital Medical University, Beijing, China
| | - Leixin Ye
- Medical Research Institute, College of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Weixin Ke
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Yao Wu
- State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Guanghou Shui
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, China
| | - Meng Xiao
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
- Beijing Key Laboratory for Mechanisms Research and Precision Diagnosis of Invasive Fungal Diseases, Beijing, China
| | - Guang-Jun He
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Ying Yang
- Beijing Key Laboratory of New Molecular Diagnosis Technologies for Infectious Disease, Department of Biotechnology, Beijing Institute of Radiation Medicine, Beijing, China
| | - Wenxia Fang
- Institute of Biological Science and Technology, Guangxi Academy of Sciences, Nanning, Guangxi, China
| | - Fan Bai
- Biomedical Pioneering Innovation Center (BIOPIC), School of Life Sciences, Peking University, Beijing, China
| | - Guojian Liao
- Medical Research Institute, College of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Min Chen
- Department of Dermatology, Shanghai Key Laboratory of Medical Mycology, Changzheng Hospital, Naval Medical University, Shanghai, China
| | - Xiaorong Lin
- Department of Microbiology, University of Georgia, Athens, GA, USA
| | - Chong Li
- Medical Research Institute, College of Pharmaceutical Sciences, Southwest University, Chongqing, China
| | - Linqi Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China.
- University of Chinese Academy of Sciences, Beijing, China.
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Therapeutic Drug Monitoring of Antifungal Agents in Critically Ill Patients: Is There a Need for Dose Optimisation? Antibiotics (Basel) 2022; 11:antibiotics11050645. [PMID: 35625289 PMCID: PMC9137962 DOI: 10.3390/antibiotics11050645] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Revised: 05/06/2022] [Accepted: 05/07/2022] [Indexed: 02/01/2023] Open
Abstract
Invasive fungal infections are an important cause of morbidity and mortality, especially in critically ill patients. Increasing resistance rates and inadequate antifungal exposure have been documented in these patients, due to clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) alterations, leading to treatment failure. Physiological changes such as third spacing (movement of fluid from the intravascular compartment to the interstitial space), hypoalbuminemia, renal failure and hepatic failure, as well as common interventions in the intensive care unit, such as renal replacement therapy and extracorporeal membrane oxygenation, can lead to these PK and PD alterations. Consequently, a therapeutic target concentration that may be useful for one patient may not be appropriate for another. Regular doses do not take into account the important PK variations in the critically ill, and the need to select an effective dose while minimising toxicity advocates for the use of therapeutic drug monitoring (TDM). This review aims to describe the current evidence regarding optimal PK/PD indices associated with the clinical efficacy of the most commonly used antifungal agents in critically ill patients (azoles, echinocandins, lipid complexes of amphotericin B, and flucytosine), provide a comprehensive understanding of the factors affecting the PK of each agent, document the PK parameters of critically ill patients compared to healthy volunteers, and, finally, make recommendations for therapeutic drug monitoring (TDM) of antifungals in critically ill patients.
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Sixty years of Amphotericin B: An Overview of the Main Antifungal Agent Used to Treat Invasive Fungal Infections. Infect Dis Ther 2021; 10:115-147. [PMID: 33523419 PMCID: PMC7954977 DOI: 10.1007/s40121-020-00382-7] [Citation(s) in RCA: 118] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 12/04/2020] [Indexed: 12/29/2022] Open
Abstract
Introduced in the late 1950s, polyenes represent the oldest family of antifungal drugs. The discovery of amphotericin B and its therapeutic uses is considered one of the most important scientific milestones of the twentieth century . Despite its toxic potential, it remains useful in the treatment of invasive fungal diseases owing to its broad spectrum of activity, low resistance rate, and excellent clinical and pharmacological action. The well-reported and defined toxicity of the conventional drug has meant that much attention has been paid to the development of new products that could minimize this effect. As a result, lipid-based formulations of amphotericin B have emerged and, even keeping the active principle in common, present distinct characteristics that may influence therapeutic results. This study presents an overview of the pharmacological properties of the different formulations for systemic use of amphotericin B available for the treatment of invasive fungal infections, highlighting the characteristics related to their chemical, pharmacokinetic structures, drug–target interactions, stability, and others, and points out the most relevant aspects for clinical practice.
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6
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Alternative therapy to manage otitis media caused by multidrug-resistant fungi. Arch Microbiol 2020; 202:1231-1240. [PMID: 32108246 DOI: 10.1007/s00203-020-01832-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 01/29/2020] [Accepted: 02/07/2020] [Indexed: 10/24/2022]
Abstract
During the last few decades, the increase in the incidence of multidrug-resistant (MDR) fungal infections has become an emerging threat to public health. Therefore, it is important to illuminate the usage of alternative therapy to treat MDR fungal infection. This study was carried out to elucidate the usage of plant extract and essential oil, either alone or with other antifungal drugs to treat otitis media caused by MDR fungi. Medicinal plant is a safe and cheap source when compared with chemical antifungal drugs. Twenty-one fungal isolates out of 104 ear swabs from patients suffering from otitis media were characterized using both phenotypic and genotypic methods. The antibiogram typing was used to determine the MDR isolates. The sensitivity of MDR fungal isolates was tested against several plant extracts and essential oils, either alone or with other antifungal drugs. Thyme oil and clove extracts proved to have synergistic effects suggesting their use in the treatment of fungal infections, especially otitis media caused by MDR fungi. The ultrastructure of MDR fungal isolates exhibited a complete destruction post exposure to the used materials when observed under the transmission microscope (TEM). Thyme oil and clove extract were found to be the most effective agents against MDR fungal isolates and they constitute a promising tool for the management of fungal infection causing the otitis media.
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7
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LOTFALI E, KORDBACHEH P, MIRHENDI H, ZAINI F, GHAJARI A, MOHAMMADI R, NOORBAKHSH F, MOAZENI M, FALLAHI A, REZAIE S. Antifungal Susceptibility Analysis of Clinical Isolates of Candida parapsilosis in Iran. IRANIAN JOURNAL OF PUBLIC HEALTH 2016; 45:322-8. [PMID: 27141494 PMCID: PMC4851746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Candida parapsilosis is an emergent agent of invasive fungal infections. This yeast is one of the five most widespread yeasts concerned in invasive candidiasis. C. parapsilosis stands out as the second most common yeast species isolated from patients with bloodstream infections especially in neonates with catheter. Recently several reports suggested that its reduced susceptibility to azoles and polyene might become a cause for clinical concern, although C. parapsilosis is not believed to be intensely prone to the development of antifungal resistance. METHODS In the present report, One hundred and twenty clinical isolates of C. parapsilosis complex were identified and differentiated by using PCR-RFLP analysis. The isolates were then analyzed to determine their susceptibility profile to fluconazole (FLU), itraconazole (ITC) and amphotericin B. The minimum inhibitory concentration (MIC) results were analyzed according to the standard CLSI guide. RESULTS All of isolates were identified as C. parapsilosis. No C. metapsilosis and C. orthopsilosis strains were found. Evaluation of the antifungal susceptibility profile showed that only three (2.5%) C. parapsilosis were resistant to fluconazole, three (2.5%) C. parapsilosis were resistant to itraconazole and two (1.7%) C. parapsilosis were amphotericin B resistant. CONCLUSION Profiles in clinical isolates of C. parapsilosis can provide important information for the control of antifungal resistance as well as distribution and susceptibility profiles in populations.
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Affiliation(s)
- Ensieh LOTFALI
- Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Parivash KORDBACHEH
- Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Hossein MIRHENDI
- Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Farideh ZAINI
- Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali GHAJARI
- Dept. of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul MOHAMMADI
- Dept. of Medical, Parasitology and Mycology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Fatemeh NOORBAKHSH
- Dept. of Biology, Faculty of Science, Islamic Azad University, Varamin-Pishva, Iran
| | - Maryam MOAZENI
- Invasive Fungi Research Center, Dept. of Medical Mycology and Parasitology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Aliakbar FALLAHI
- Dept. of Microbiology & Parasitology & Immunology, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran
| | - Sassan REZAIE
- Dept. of Medical Mycology and Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran,Corresponding Author: Tel: +92-21-5689860
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8
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Ho LK, Nodwell JR. David and Goliath: chemical perturbation of eukaryotes by bacteria. J Ind Microbiol Biotechnol 2015; 43:233-48. [PMID: 26433385 PMCID: PMC4752587 DOI: 10.1007/s10295-015-1686-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2015] [Accepted: 09/09/2015] [Indexed: 12/20/2022]
Abstract
Environmental microbes produce biologically active small molecules that have been mined extensively as antibiotics and a smaller number of drugs that act on eukaryotic cells. It is known that there are additional bioactives to be discovered from this source. While the discovery of new antibiotics is challenged by the frequent discovery of known compounds, we contend that the eukaryote-active compounds may be less saturated. Indeed, despite there being far fewer eukaryotic-active natural products these molecules interact with a far richer diversity of molecular and cellular targets.
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Affiliation(s)
- Louis K Ho
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada
| | - Justin R Nodwell
- Department of Biochemistry, University of Toronto, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.
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9
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Haddadi P, Zareifar S, Badiee P, Alborzi A, Mokhtari M, Zomorodian K, Pakshir K, Jafarian H. Yeast colonization and drug susceptibility pattern in the pediatric patients with neutropenia. Jundishapur J Microbiol 2014; 7:e11858. [PMID: 25485060 PMCID: PMC4255375 DOI: 10.5812/jjm.11858] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 08/10/2013] [Accepted: 11/19/2013] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Pediatric patients with neutropenia are vulnerable to invasive Candida infections. Candida is the primary cause of fungal infections, particularly in immunosuppressed patients. Candida albicans has been the most common etiologic agent of these infections, affecting 48% of patients. OBJECTIVES The aim of this study was to identify Candida spp. isolated from children with neutropenia and determine the antifungal susceptibility pattern of the isolated yeasts. PATIENTS AND METHODS In this study 188 children with neutropenia were recruited, fungal surveillance cultures were carried out on nose, oropharynx, stool, and urine samples. Identification of Candida strains was performed using germ tube and chlamydospore production tests on an API 20 C AUX system. Susceptibility testing on seven antifungal agents was performed using the agar-based E-test method. RESULTS A total of 229 yeasts were isolated. Among those, C. albicans was the most common species followed by C. krusei, C. parapsilosis, C. glabrata, C. tropicalis, C. famata, C. dubliniensis, C. kefyr, and other Candida species. C. glabrata was the most resistant isolated yeasts, which was 70% resistant to fluconazole and 50% to itraconazole, 7.5% to amphotericin B and 14% to ketoconazole. All the tested species were mostly sensitive to caspofungin. CONCLUSIONS Knowledge about the susceptibility patterns of colonized Candida spp. can be helpful for clinicians to manage pediatric patients with neutropenia. In this study, caspofungin was the most effective antifungal agent against the colonized Candida spp. followed by conventional amphotericin B.
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Affiliation(s)
- Pedram Haddadi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Soheila Zareifar
- Hematology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Parisa Badiee
- Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
- Corresponding author: Parisa Badiee, Alborzi Clinical Microbiology Research Center, Namazi Hospital, Zand Ave., Shiraz, IR Iran. Tel: +98-7116474292, Fax: +98-7116474303, E-mail:
| | - Abdolvahab Alborzi
- Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Maral Mokhtari
- Hematology Research Center, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Kamiar Zomorodian
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Keyvan Pakshir
- Department of Parasitology and Mycology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, IR Iran
| | - Hadis Jafarian
- Alborzi Clinical Microbiology Research Center, Shiraz University of Medical Sciences, Shiraz, IR Iran
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10
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Stachowicz J, Krajewska-Kułak E, Łukaszuk C, Niewiadomy A. Relationship between Antifungal Activity against Candida albicans and Electron Parameters of Selected N-Heterocyclic Thioamides. Indian J Pharm Sci 2014; 76:287-98. [PMID: 25284926 PMCID: PMC4171865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 04/25/2014] [Accepted: 05/03/2014] [Indexed: 11/07/2022] Open
Abstract
Due to the increasing demand for new pharmaceuticals showing biological activity against pathogenic microorganisms, there is increasing search for new compounds with predicted biological activity. Variously substituted thioamide derivatives with 1.3 and 1.2 ring of thiazole and 1,3,4-thiadiazole, as well as pyrazole were assessed for their activity against Candida albicans. Activity of majority of tested thioamides was larger as compared with that of the reference drugs. The electron parameters of obtained N-heterocyclic thioamides were determined and dependencies on their biological activity against Candida albicans were studied. The best electron compliance of produced bindings with the activity against Candida albicans was observed for the derivatives containing 1,3,4-thiadiazole ring.
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Affiliation(s)
- Jadwiga Stachowicz
- University of Life Sciences in Lublin, Department of Chemistry, 15 Akademicka Street, 20-950 Lublin, Poland,Address for correspondence E-mail:
| | | | - Cecylia Łukaszuk
- Medical University of Bialystok, Department of General Nursing, Bialystok, Poland
| | - A. Niewiadomy
- University of Life Sciences in Lublin, Department of Chemistry, 15 Akademicka Street, 20-950 Lublin, Poland
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11
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Badiee P, Alborzi A. Susceptibility of clinical Candida species isolates to antifungal agents by E-test, Southern Iran: A five year study. IRANIAN JOURNAL OF MICROBIOLOGY 2011; 3:183-8. [PMID: 22530086 PMCID: PMC3330181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
BACKGROUND AND OBJECTIVES The incidence of fungal infections in immunocompromised patients, especially by Candida species, has increased in recent years. This study was designed to identify Candida species and determine antifungal susceptibility patterns of 595 yeast strains isolated from various clinical specimens. MATERIAL AND METHODS Identification of the isolates were determined by the API 20 C AUX kit and antifungal susceptibilities of the species to fluconazole, amphotericin B, ketoconazole, itraconazole, voriconazole, and caspofungin were determined by the agar-based E-test method. RESULTS Candida albicans (48%) was the most frequently isolated species, followed by Candida kruzei (16.1%), Candida glabrata (13.5%), Candida kefyr (7.4%), Candida parapsilosis (4.8%), Candida tropicalis (1.7%) and other species (8.5%). Resistance varies depending on the species and the respective antifungal agents. Comparing the MIC90 for all the strains, the lower MIC90 was observed for caspofungin (0.5 µg/ml). The MIC90 for all Candida species were 64 µg/ml for fluconazole, 0.75 µg/ml for amphotericin B, 4 µg/ml for ketoconazole, 4 µg/ml for itraconazole, and 2 µg/ml for voriconazole. CONCLUSIONS Species definition and determination of antifungal susceptibility patterns are advised for the proper management and treatment of patients at risk for systemic candidiasis. Resistance to antifungal agents is an alarming sign for the emerging common nosocomial fungal infections.
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Affiliation(s)
- P Badiee
- Corresponding author: Parisa Badiee PhD Address: Prof. Alborzi Clinical Microbiology Research Center, Nemazi Hospital, Zand Ave, Shiraz, Iran. Tel: +98-711-6474292 Fax: +98-711-6474303. E-mail:
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Badiee P, Alborzi A, Joukar M. Molecular assay to detect nosocomial fungal infections in intensive care units. Eur J Intern Med 2011; 22:611-5. [PMID: 22075290 DOI: 10.1016/j.ejim.2011.08.025] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 08/06/2011] [Accepted: 08/25/2011] [Indexed: 11/28/2022]
Abstract
SUMMARY The aims of this study were to determine the incidence of fungal infections in hospital intensive care units and to evaluate a molecular method to detect these infections. MATERIAL AND METHODS The participants in this study were patients admitted to any of the 10 intensive care units at Nemazi Hospital (Shiraz, southern Iran) between March 2009 and January 2010. Oral and rectal swabs, urine, and sputum samples from patients were checked for fungal colonization. If a nosocomial fungal infection was suspected, clinical samples were examined for fungal infection by culture, direct microscopic examination and real-time PCR. Blood samples were cultured by bedside inoculation onto BACTEC medium. Susceptibility of the isolates to antifungal agents was also determined. RESULTS Of 870 patients, 550 (63.2%) had Candida colonization in different body sites and 17 (1.9%) had fungal infections. The mortality rate in patients with fungal infections was 58.8% (10 cases). The etiologic agents were Candida albicans, Candida glabrata, Aspergillus flavus, Aspergillus fumigatus and Aspergillus spp. Three C. albicans were found to be resistant to amphotericin B and itraconazole, and one A. fumigatus and two A. flavus were resistant to amphotericin B, ketoconazole and itraconazole. One A. fumigatus was additionally resistant to caspofungin. CONCLUSIONS Considering the incidence of fungal infections and their high mortality rate, early detection, prompt diagnosis and treatment are critical. Molecular assays can serve as a diagnostic tool to manage patients admitted to the intensive care unit. Antifungal susceptibility testing in different geographical regions can support the choice of prophylaxis and treatment for these patients.
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Affiliation(s)
- Parisa Badiee
- Shiraz University of Medical Sciences, Shiraz, Iran.
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Pitarch A, Nombela C, Gil C. Reliability of antibodies to Candida methionine synthase for diagnosis, prognosis and risk stratification in systemic candidiasis: A generic strategy for the prototype development phase of proteomic markers. Proteomics Clin Appl 2007; 1:1221-42. [PMID: 21136621 DOI: 10.1002/prca.200601036] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2006] [Indexed: 11/10/2022]
Abstract
To be able to diagnose systemic candidiasis (SC) and to predict outcomes in SC patients are still challenging tasks for physicians. Previous proteomic studies suggest that anti-Candida methionine synthase (Met6p) IgG antibodies may be a candidate marker for SC. To evaluate their reliability for diagnosis, prognosis and risk stratification in SC, we developed a generic prototype strategy for their measurement in SC. Receiver-operating-characteristic curve analyses revealed a high diagnostic accuracy for this prototype format, which was slightly better to that for the widely used Western blot assays. Multivariate logistic-regression models showed a positive association between serum anti-Met6p IgG antibody levels and SC risk that was independent from established SC risk factors and other baseline variables. After adjusting for and stratifying according to known prognostic factors, a significant trend toward a lower two-month mortality risk with increasing levels was evidenced in SC patients at presentation. We conclude that these antibodies may be useful in discriminating SC from non-SC patients and determining risk stratification in SC. These may also confer protection against SC and be valuable for the design of future immunotherapies. Furthermore, our prototype format has the potential to make impact on other infectious diseases, cancers, allergies or autoimmune disorders.
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Affiliation(s)
- Aida Pitarch
- Department of Microbiology II, Faculty of Pharmacy, Complutense University of Madrid, Madrid, Spain
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Therese KL, Bagyalakshmi R, Madhavan HN, Deepa P. IN-VITRO SUSCEPTIBILITY TESTING BY AGAR DILUTION METHOD TO DETERMINE THE MINIMUM INHIBITORY CONCENTRATIONS OF AMPHOTERICIN B, FLUCONAZOLE AND KETOCONAZOLE AGAINST OCULAR FUNGAL ISOLATES. Indian J Med Microbiol 2006. [DOI: 10.1016/s0255-0857(21)02288-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Kuriyama T, Williams DW, Bagg J, Coulter WA, Ready D, Lewis MAO. In vitro susceptibility of oral Candida to seven antifungal agents. ACTA ACUST UNITED AC 2005; 20:349-53. [PMID: 16238594 DOI: 10.1111/j.1399-302x.2005.00236.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The in vitro susceptibility of 618 Candida isolates to fluconazole, itraconazole, voriconazole, ketoconazole, miconazole, amphotericin B, and nystatin was determined. The isolates were obtained from 559 patients who had attended the UK dental hospital departments in Cardiff, Belfast, Glasgow or London. Antifungal susceptibility was assessed using a broth microdilution method following the National Committee for Clinical Laboratory Standards (NCCLS) M27-A guidelines. The majority of the test strains were C. albicans (n = 521) with few of these being resistant to fluconazole (0.3%). A low incidence of fluconazole resistance (0-6.8%) was similarly evident with all non albicans species (Candida glabrata, 5 of 59 resistant; Candida krusei, 0 of 7 resistant; Candida tropicalis, 0 of 13 resistant; Candida parapsilosis, 0 of 12 resistant; other Candida species, 0 of 6 resistant). Voriconazole, ketoconazole, and miconazole also revealed high activity against both C. albicans and non albicans isolates, and 23.7% of C. glabrata isolates were found to be resistant to itraconazole. There was little difference in the antifungal susceptibilities of Candida isolated from patients who had a history of previous antifungal therapy compared with those who had not received antifungal treatment. In summary, this surveillance study of antifungal susceptibility of oral candidal isolates in the UK, through the collaboration of four dental hospitals, demonstrates that oral Candida species have a high level of susceptibilities to a range of antifungal agents.
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Affiliation(s)
- T Kuriyama
- Department of Oral Surgery, Medicine and Pathology, School of Dentistry, Cardiff University, Cardiff, UK
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Nawrot U, Nowicka J, Juszczak K, Gusin B. Susceptibility to antifungal agents of Candida species isolated from paediatric and adult patients with haematological diseases. Mycoses 2005; 48:385-90. [PMID: 16262874 DOI: 10.1111/j.1439-0507.2005.01154.x] [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: 11/29/2022]
Abstract
Summary The susceptibility to six antifungals: amphotericin B (AMF), 5-fluorocytosine (5-F), miconazole (MIK), ketoconazole (KET), fluconazole (FLU) and itraconazole (ITR) was tested among 206 Candida spp. isolated from paediatric and adult patients with haematological malignancies. To determinate the susceptibility the commercial microdilution method Fungitest (Bio-Rad, France) was used. The strains were classified as susceptible, intermediate susceptible, or resistant on the base of the growth in following breakpoint concentrations of particular drugs: 2 and 8 microg ml(-1) for AMF, 2 and 32 microg ml(-1) for 5-F, 0.5 and 8 microg ml(-1) for MIK, 0.5 and 4 microg ml(-1) for KET and ITR, and 8 and 64 microg ml(-1) for FLU. The highest activity to overall species showed AMF (only one resistant strain) and 5-F (85% susceptible strains). Most of C. albicans isolates were susceptible to tested azoles. The percentages of C. albicans resistant to FLU, ITR, KET and MIK were 4, 11, 8, and 0.8%, respectively. The less susceptible to azoles were C. glabrata and C. krusei (14% and 44% isolates resistant to FLU). A non-albicans Candida isolated from adult patients receiving KET prophylaxis was more frequently resistant to FLU than isolates from patients without previous exposure to azoles (P < 0.05). We did not observe differences in the susceptibility of Candida strains isolated from children compared with those from adults.
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Affiliation(s)
- U Nawrot
- Department of Microbiology, Medical University of Wroclaw, Poland.
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Eloy O, Blanc V, Mallié M, Decousser J, Pina P, Allouch P. Identification et sensibilité aux antifongiques de deux souches de Candida dans 95 hôpitaux français. J Mycol Med 2005. [DOI: 10.1016/j.mycmed.2005.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Sánchez-Vargas LO, Ortiz-López NG, Villar M, Moragues MD, Aguirre JM, Cashat-Cruz M, Lopez-Ribot JL, Gaitán-Cepeda LA, Quindós G. Oral Candida isolates colonizing or infecting human immunodeficiency virus-infected and healthy persons in Mexico. J Clin Microbiol 2005; 43:4159-62. [PMID: 16081965 PMCID: PMC1233912 DOI: 10.1128/jcm.43.8.4159-4162.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Oral yeast carriage was studied in 312 Mexican subjects. Candida albicans was the most frequent species, but other Candida spp. were isolated from 16.5 to 38.5% of patients. Colonization did not correlate with CD4+ number or viral load, but highly active antiretroviral therapy reduced the frequency of candidiasis. Most isolates were susceptible to fluconazole, but 10.8% were resistant to one or more azoles.
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Affiliation(s)
- Luis Octavio Sánchez-Vargas
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Natalia Guadalupe Ortiz-López
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - María Villar
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - María Dolores Moragues
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - José Manuel Aguirre
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Miguel Cashat-Cruz
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Jose Luis Lopez-Ribot
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Luis Alberto Gaitán-Cepeda
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
| | - Guillermo Quindós
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Facultad de Odontología, Universidad Nacional Autónoma de México, México DF, México, Laboratorio de Micología Médica, Departamento de Enfermería I, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Cátedra de Medicina Bucal, Departamento de Estomatología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain, Departamento de Epidemiología, Hospital Infantil de México Dr. Federico Gómez, México DF, Mexico, Department of Medicine, Division of Infectious Diseases, South Texas Centers for Biology in Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, Texas
- Corresponding author. Mailing address: Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain. Phone: 34946012854. Fax:34946013400. E-mail:
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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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Sánchez-Vargas LO, Ortiz-López NG, Villar M, Moragues MD, Aguirre JM, Cashat-Cruz M, Lopez-Ribot JL, Gaitán-Cepeda LA, Quindós G. Point prevalence, microbiology and antifungal susceptibility patterns of oral Candida isolates colonizing or infecting Mexican HIV/AIDS patients and healthy persons. Rev Iberoam Micol 2005; 22:83-92. [PMID: 16107165 DOI: 10.1016/s1130-1406(05)70014-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
We have conducted a longitudinal study over a 3-year period to address the point prevalence, microbiological characteristics and antifungal susceptibility patterns of yeast isolates colonizing or infecting the oral cavities of 111 HIV-infected (51 adults, 60 children) and 201 non HIV-infected (109 adults, 92 children) Mexican persons. Regarding the epidemiology of oral candidiasis, Candida albicans was the most frequent species isolated. Seventy-one out of 85 isolates from colonized persons were C. albicans (83.5%), 27 isolates of them were from HIV-infected children and 44 from non HIV-infected patients. Sixty-two isolates belonged to serotype A which was the most prevalent serotype of C. albicans. Non-albicans species (Candida glabrata, Candida tropicalis and Candida parapsilosis, and Saccharomyces cerevisiae) were isolated from 16.5% of colonized patients and from 38.5% patients with candidiasis or Candida-related lesions. There were nine episodes of infection or colonization by at least 2 different yeast species. In the case of HIV/AIDS patients, it was determined that yeast carriage was not associated with the number of CD4+ cells or the viral load, but HAART reduced the prevalence of oral candidiasis. Overall, most patients harbored strains in vitro susceptible to fluconazole, however 10.8% of the yeasts were resistant to one or more azole antifungal agents and 29% were intermediate susceptible to them. On the contrary, 5-fluorocytosine was very active against all isolates tested, and amphotericin B was active against 97.9% of them.
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Affiliation(s)
- Luis Octavio Sánchez-Vargas
- Laboratorio de Micología Médica, Departamento de Inmunología, Microbiología y Parasitología, Facultad de Medicina y Odontología, Universidad del País Vasco-Euskal Herriko Unibertsitatea, Bilbao, Spain
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Ozçelik B, Citak S, Cesur S, Abbasoğlu U, Içli F. In Vitro Susceptibility of Candida Species Isolated from Cancer Patients to Some Antifungal Agents. ACTA ACUST UNITED AC 2004; 20:101-8. [PMID: 15283306 DOI: 10.1515/dmdi.2004.20.1-2.101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study was undertaken to study the resistance of Candida species isolated from oropharyngeal swabs of cancer patients to ketoconazole (KET), fluconazole (FLU), amphotericin B (AmpB), and flucytosine (FCU). The most common species identified was C. albicans, followed by C. tropicalis, C. glabrata, C. famata, C. krusei, C. kefyr, and C. gulliermondii. The minimum inhibitory concentration (MIC) of the antifungal agents was evaluated by RPMI 1640 medium with microdilution method. There were no C. albicans strains resistant to KET, FLU and AmpB. All Candida isolates were found highly susceptible to AmpB (MIC AmpB < 1 microg/ml), followed by KET (MIC KET < or =8 microg/ml), FLU (MIC FLU < or =8 microg/ml) and FCU (MIC FCU < or =4 microg/ml). The main conclusion of this study is that prophylactic therapy planned according to typing and antifungal susceptibility will contribute to the prevention of invasive fungal infections in immunosuppressied oncology patients.
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Affiliation(s)
- Berrin Ozçelik
- Department of Pharmaceutical Microbiology, Faculty of Pharmacy, University of Gazi, Ankara, Turkey.
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Willinger B, Engelmann E, Hofmann H, Metzger S, Apfalter P, Hirschl AM, Makristathis A, Rotter M, Raddatz B, Seibold M. Multicenter comparison of Fungitest for susceptibility testing of Candida species. Diagn Microbiol Infect Dis 2002; 44:253-7. [PMID: 12493172 DOI: 10.1016/s0732-8893(02)00452-2] [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: 11/25/2022]
Abstract
In four laboratories the reproducibility of Fungitest, a colorimetric breakpoint method for antifungal susceptibility testing, was examined. The interlaboratory agreement of test results from 50 Candida strains was dependent on the antifungal agents and ranged from 56% to 100%. Itraconazole showed the poorest, amphotericin B and flucytosine (100% and 96%, respectively) the highest concordance. When minor discrepancies were disregarded the agreement increased to 94% to 100% for all agents. In total, major discrepancies were only seen in 2.7%. The overall agreement between concordant results and the NCCLS standard method was high, ranging between 96.4% and 100%. Generally, sensitive strains showed a better agreement with Fungitest. Since the concordance in multisite studies with Fungitest will always depend on the isolates chosen, further studies with this test are necessary.
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Affiliation(s)
- Birgit Willinger
- Division of Clinical Microbiology, Institute of Hygiene and Medical Microbiology, University of Vienna, Vienna, Austria.
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Helmerhorst EJ, Murphy MP, Troxler RF, Oppenheim FG. Characterization of the mitochondrial respiratory pathways in Candida albicans. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1556:73-80. [PMID: 12351220 DOI: 10.1016/s0005-2728(02)00308-0] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Candida albicans is an opportunistic oral pathogen. The flexibility of this microorganism in response to environmental changes includes the expression of a cyanide-resistant alternative respiratory pathway. In the present study, we characterized both conventional and alternative respiratory pathways and determined their ADP/O ratios, inhibitor sensitivity profiles and the impact of the utilization of either pathway on susceptibility to commonly used antimycotics. Oxygen consumption by isolated mitochondria using NADH or malate/pyruvate as respiratory substrates indicated that C. albicans cells express both cytoplasmic and matrix NADH-ubiquinone oxidoreductase activities. The ADP/O ratio was higher for malate/pyruvate (2.2+/-0.1), which generate NADH in the matrix, than for externally added NADH (1.4+/-0.2). In addition, malate/pyruvate respiration was rotenone-sensitive, and an enzyme activity assay further confirmed that C. albicans cells express Complex I activity. Cells grown in the presence of antimycin A expressed the cyanide-insensitive respiratory pathway. Determination of the respiratory control ratio (RCR) and ADP/O ratios of mitochondria from these cells indicated that electron transport from ubiquinone to oxygen via the alternative respiratory pathway was not coupled to ATP production; however, an ADP/O ratio of 0.8 was found for substrates that donate electrons at Complex I. Comparison of antifungal susceptibility of C. albicans cells respiring via the conventional or alternative respiratory pathways showed that respiration via the alternative pathway does not reduce the susceptibility of cells to a series of clinically employed antimycotics (using Fungitest), or to the naturally occurring human salivary antifungal peptide, histatin 5.
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Affiliation(s)
- Eva J Helmerhorst
- Goldman School of Dental Medicine, Boston University, 100 East Newton Street, Boston, MA 02118, USA.
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Morace G, Amato G, Bistoni F, Fadda G, Marone P, Montagna MT, Oliveri S, Polonelli L, Rigoli R, Mancuso I, La Face S, Masucci L, Romano L, Napoli C, Tatò D, Buscema MG, Belli CMC, Piccirillo MM, Conti S, Covan S, Fanti F, Cavanna C, D'Alò F, Pitzurra L. Multicenter comparative evaluation of six commercial systems and the national committee for clinical laboratory standards m27-a broth microdilution method for fluconazole susceptibility testing of Candida species. J Clin Microbiol 2002; 40:2953-8. [PMID: 12149358 PMCID: PMC120637 DOI: 10.1128/jcm.40.8.2953-2958.2002] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2002] [Revised: 04/18/2002] [Accepted: 05/27/2002] [Indexed: 11/20/2022] Open
Abstract
Fluconazole susceptibility among 800 clinical Candida isolates (60% C. albicans) and two control strains (C. krusei ATCC 6258 and C. parapsilosis ATCC 22019) was tested with the NCCLS M27-A method (gold standard) and six commercial products (Candifast, disk, Etest, Fungitest, Integral System Yeasts, and Sensititre YeastOne). Results were classified as susceptible, susceptible-dose dependent, or resistant using M27-A breakpoints or, for Fungitest, Integral System Yeasts, and Candifast, as susceptible, intermediate, or resistant, according to the manufacturers' instructions. Concordance with NCCLS M27-A results was analyzed with the chi(2) test. Intra- and interlaboratory reproducibility was also evaluated. NCCLS M27-A (90.1%), Etest (93.1%), Sensititre YeastOne (93.1%), disk (96.7%), Fungitest (92.6%), Integral System Yeasts (40.6%), and Candifast (6.0%) classified the indicated percentages of C. albicans isolates as susceptible. Among non-C. albicans strains, the percentages of susceptible isolates were as follows: NCCLS M27-A, 74.0%; Etest, 83.8%; Sensititre YeastOne, 64.1%; disk, 60.6%; Fungitest, 76.6%; Integral System Yeasts, 28.3%; and Candifast, 27.4%. All methods except Candifast and Integral System Yeasts showed good agreement with NCCLS M27-A results for both C albicans and non-C. albicans isolates. Intralaboratory reproducibility was excellent for NCCLS M27-A, Etest, Sensititre YeastOne, disk, and Fungitest (88 to 91%). Similar results emerged from the interlaboratory reproducibility evaluation. Our findings indicate that some commercial methods can be useful for fluconazole susceptibility testing of clinical Candida isolates. Those characterized by a lack of medium standardization and/or objective interpretative criteria should be avoided. Particular caution is necessary when testing is being done for clinical and epidemiological purposes.
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Affiliation(s)
- G Morace
- Istituto di Microbiologia, Università degli Studi di Milano, Italy.
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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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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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Ghannoum MA. Yeast susceptibility testing: reference methods and commercial test systems. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0196-4399(01)99001-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Alves SH, Oliveira LT, Costa JM, Lubeck I, Casali AK, Vainstein MH. In vitro susceptibility to antifungal agents of clinical and environmental Cryptococcus neoformans isolated in Southern of Brazil. Rev Inst Med Trop Sao Paulo 2001; 43:267-70. [PMID: 11696849 DOI: 10.1590/s0036-46652001000500006] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The purpose of the present study was to compare the susceptibility to four antifungal agents of 69 Cryptococcus neoformans strains isolated from AIDS patients with that of 13 C. neoformans strains isolated from the environment. Based on the NCCLS M27-A methodology the Minimal Inhibitory Concentrations (MICs) obtained for amphotericin B, itraconazole and ketoconazole were very similar for clinical and environmental isolates. Clinical isolates were less susceptible to fluconazole than environmental isolates. The significance of these findings and aspects concerning the importance, role and difficulties of C. neoformans susceptibility testing are also discussed.
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Affiliation(s)
- S H Alves
- Departamento Análises Clínicas e Toxicológicas, Laboratório de Pesquisas Micológicas, Universidade Federal de Santa Maria, Santa Maria, RS, Brasil.
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Posteraro B, Romano L, Sanguinetti M, Masucci L, Morace G, Fadda G. Commercial systems for fluconazole susceptibility testing of yeasts: comparison with the broth microdilution method. Diagn Microbiol Infect Dis 2000; 38:29-36. [PMID: 11025181 DOI: 10.1016/s0732-8893(00)00174-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Fluconazole susceptibility was tested in 100 clinical yeast isolates (65 Candida albicans, 13 C. glabrata, 8 C. tropicalis, 7 C. parapsilosis, 3 Saccharomyces cerevisiae, 1 each of C. krusei, C. lusitaniae, Cryptococcus neoformans, Rhodotorula glutinis) and two control strains (Candida krusei ATCC 6258, C. parapsilosis ATCC 22019) using broth microdilution (reference method), disk diffusion, Etest strips, Sensititre YeastOne, Candifast, Integral System Yeasts. Using M27-A breakpoints, isolates were classified as susceptible (81%), susceptible-dose dependent or Resistant with broth dilution. Rates of concordance with the reference method were good for Sensititre YeastOne, Etest and disc-diffusion (81.2%-94.7%) but very low for the Candifast (3.1%) and Integral System (16.6%), which classified most susceptible isolates as resistant. Lack of standardisation (inoculum, medium composition) and non-objective interpretation schemes may be the cause of their poor performance. Sensititre YeastOne, Etest and disc-diffusion are potentially useful for fluconazole antifungal susceptibility testing of yeasts in clinical laboratories.
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Affiliation(s)
- B Posteraro
- Istituto di Microbiologia, Università Cattolica del Sacro Cuore, Rome, Italy
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Willinger B, Apfalter P, Hirschl AM, Makristathis A, Rotter M, Seibold M. Susceptibility testing of Candida species: comparison of NCCLS microdilution method with Fungitest. Diagn Microbiol Infect Dis 2000; 38:11-5. [PMID: 11025178 DOI: 10.1016/s0732-8893(00)00172-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Fungitest is a new commercially available and easy-to-perform breakpoint test system using six antifungal agents. We compared this test with a modified standard method described by the National Committee for Clinical Laboratory Standards (NCCLS). One hundred isolates of Candida species were tested with both methods. Based on the same breakpoints, the correlation of qualitative results between the reference method and Fungitest was high. Best results were obtained after incubation of Fungitest for 48 h. Overall agreement was high, an excellent correlation was given with amphotericin B and flucytosine (100% and 99%, respectively), whereas itraconazole showed only 86% concordance. When Fungitest was read after 24 h the agreement was lower ranging from 100% to 75%. Some of the breakpoints used with Fungitest differ from the breakpoints recommended by NCCLS, whereas others have not been elaborated by the NCCLS. The adaptation of Fungitest breakpoints to NCCLS and determination of further breakpoints have to be discussed before Fungitest can be recommended for routine use.
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Affiliation(s)
- B Willinger
- Dept. of Clinical Microbiology, Hygiene-Institute of University of Vienna, Austria.
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Arthington-Skaggs BA, Motley M, Warnock DW, Morrison CJ. Comparative evaluation of PASCO and national committee for clinical laboratory standards M27-A broth microdilution methods for antifungal drug susceptibility testing of yeasts. J Clin Microbiol 2000; 38:2254-60. [PMID: 10834985 PMCID: PMC86775 DOI: 10.1128/jcm.38.6.2254-2260.2000] [Citation(s) in RCA: 124] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The PASCO antifungal susceptibility test system, developed in collaboration with a commercial company, is a broth microdilution assay which is faster and easier to use than the reference broth microdilution test performed according to the National Committee for Clinical Laboratory Standards (NCCLS) document M27-A guidelines. Advantages of the PASCO system include the system's inclusion of quality-controlled, premade antifungal panels containing 10, twofold serial dilutions of drugs and a one-step inoculation system whereby all wells are simultaneously inoculated in a single step. For the prototype panel, we chose eight antifungal agents for in vitro testing (amphotericin B, flucytosine, fluconazole, ketoconazole, itraconazole, clotrimazole, miconazole, and terconazole) and compared the results with those of the NCCLS method for testing 74 yeast isolates (14 Candida albicans, 10 Candida glabrata, 10 Candida tropicalis, 10 Candida krusei, 10 Candida dubliniensis, 10 Candida parapsilosis, and 10 Cryptococcus neoformans isolates). The overall agreements between the methods were 91% for fluconazole, 89% for amphotericin B and ketoconazole, 85% for itraconazole, 80% for flucytosine, 77% for terconazole, 66% for miconazole, and 53% for clotrimazole. In contrast to the M27-A reference method, the PASCO method classified as resistant seven itraconazole-susceptible isolates (9%), two fluconazole-susceptible isolates (3%), and three flucytosine-susceptible isolates (4%), representing 12 major errors. In addition, it classified two fluconazole-resistant isolates (3%) and one flucytosine-resistant isolate (1%) as susceptible, representing three very major errors. Overall, the agreement between the methods was greater than or equal to 80% for four of the seven species tested (C. dubliniensis, C. glabrata, C. krusei, and C. neoformans). The lowest agreement between methods was observed for miconazole and clotrimazole and for C. krusei isolates tested against terconazole. When the data for miconazole and clotrimazole were removed from the analysis, agreement was >/=80% for all seven species tested. Therefore, the PASCO method is a suitable alternative procedure for the testing of the antifungal susceptibilities of the medically important Candida spp. and C. neoformans against a range of antifungal agents with the exceptions only of miconazole and clotrimazole and of terconazole against C. krusei isolates.
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Affiliation(s)
- B A Arthington-Skaggs
- Mycotic Diseases Branch, Division of Bacterial and Mycotic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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Rodero L, Córdoba S, Cahn P, Soria M, Lucarini M, Davel G, Kaufman S, Canteros C, Guelfand L. Timed-kill curves for Cryptococcus neoformans isolated from patients with AIDS. Med Mycol 2000; 38:201-7. [PMID: 10892987 DOI: 10.1080/mmy.38.3.201.207] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Infection with Cryptococcus neoformans is an increasing problem in immunocompromised patients, particularly those with acquired immune deficiency syndrome (AIDS). Amphotericin B and fluconazole are currently acceptable therapies for cryptococcal meningitis; however, their effects remain suboptimal and recurrence or treatment failure is still a problem. Antifungal susceptibility testing may be an important tool for guiding therapy, but for C. neoformans, a reliable method is still not available. This retrospective study evaluated minimal inhibitory concentration (MIC) for amphotericin B and fluconazole, and minimal fungicidal concentration (MFC) and timed-kill curves for amphotericin B against 16 clinical isolates of C. neoformans obtained from AIDS patients with cryptococcal meningitis. No correlation between clinical outcome and MIC was observed for amphotericin B. In selected cases, the MFC seemed to be a better predictor of outcome than MIC. In this study, amphotericin B timed-kill curves appeared to show a correlation with clinical outcome of the 16 patients with AIDS-associated cryptococcal meningitis. These in vitro tests must be further evaluated in prospective studies to confirm their potential usefulness for guiding cryptococcal meningitis therapy.
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Affiliation(s)
- L Rodero
- Mycology Department, Instituto Nacional de Enfermedades Infecciosas, ANLIS: Dr. Carlos G. Malbrán, Buenos Aires, Argentina.
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Swinne D, Raes-Wuytack C, Van Looveren K, Desmet P. Comparative evaluation of Fungitest-, Neo-Sensitabs- and M27T-NCCLS broth microdilution methods for antifungal drug susceptibility testing of Candida species and Cryptococcus neoformans. Mycoses 1999; 42:231-7. [PMID: 10424089 DOI: 10.1046/j.1439-0507.1999.00461.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Two commercial antifungal susceptibility testing systems (Fungitest and Neo-Sensitabs) were compared with the M27T-NCCLS reference broth microdilution method using one hundred isolates of Candida sp. and Crptococcus neoformans. Six different antifungal drugs were tested: amphotericin B, 5-fluorocytosine, fluconazole, itraconazole, ketoconazole and miconazole. The overall agreement between the Fungitest and the reference methods was much better than between the Neo-Sensitabs and the reference methods: the agreement for the Fungitest ranged from 100% for amphotericin B to 76.7% for itraconazole whereas for the Neo-Sensitabs, it ranged from 90.4% for amphotericin B to 36% for ketoconazole. For the total number of tests performed with Neo-Sensitabs, there were 37.8% of discrepancies with the reference method whereas for the tests performed with Fungitest, there was only 16.5% of discrepancies. Major discrepancies, defined as results that classified an isolate as susceptible by one method and resistant by another, occurred in 21 cases for the Neo-Sensitabs test and only in four cases with the Fungitest, namely 0.6% of the cases. We conclude that the Fungitest method constitutes a simple and reliable procedure for antifungal drug susceptibility testing.
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Affiliation(s)
- D Swinne
- Institute of Tropical Medicine Prince Leopold, Antwerp, Belgium.
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Witthuhn F, Toubas D, Béguinot I, Aubert D, Rouger C, Remy G, Pinon JM. Evaluation of the fungitest kit by using strains from human immunodeficiency virus-infected patients: study of azole drug susceptibility. J Clin Microbiol 1999; 37:864-6. [PMID: 9986878 PMCID: PMC84589 DOI: 10.1128/jcm.37.3.864-866.1999] [Citation(s) in RCA: 13] [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
One hundred eighteen Candida clinical isolates from human immunodeficiency virus-infected patients were tested for their susceptibilities to fluconazole and itraconazole by Fungitest and the National Committee for Clinical Laboratory Standards MIC method. Fungitest results depended on both yeast species and antifungal agents. This test is able to detect sensitive strains (97% agreement with results of the MIC method in tests with fluconazole and 84% agreement in tests with itraconazole) but has a poor capacity to detect resistant strains (26% agreement in tests with fluconazole and 5% agreement in tests with itraconazole).
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Affiliation(s)
- F Witthuhn
- Laboratoire de Parasitologie-Mycologie, Equipe 4 INSERM U 314, EA 2070, IFR 53, Centre Hospitalier Universitaire de Reims, France
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