1
|
Bhattarai K, Bhattarai K, Kabir ME, Bastola R, Baral B. Fungal natural products galaxy: Biochemistry and molecular genetics toward blockbuster drugs discovery. ADVANCES IN GENETICS 2021; 107:193-284. [PMID: 33641747 DOI: 10.1016/bs.adgen.2020.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Secondary metabolites synthesized by fungi have become a precious source of inspiration for the design of novel drugs. Indeed, fungi are prolific producers of fascinating, diverse, structurally complex, and low-molecular-mass natural products with high therapeutic leads, such as novel antimicrobial compounds, anticancer compounds, immunosuppressive agents, among others. Given that these microorganisms possess the extraordinary capacity to secrete diverse chemical scaffolds, they have been highly exploited by the giant pharma companies to generate small molecules. This has been made possible because the isolation of metabolites from fungal natural sources is feasible and surpasses the organic synthesis of compounds, which otherwise remains a significant bottleneck in the drug discovery process. Here in this comprehensive review, we have discussed recent studies on different fungi (pathogenic, non-pathogenic, commensal, and endophytic/symbiotic) from different habitats (terrestrial and marines), the specialized metabolites they biosynthesize, and the drugs derived from these specialized metabolites. Moreover, we have unveiled the logic behind the biosynthesis of vital chemical scaffolds, such as NRPS, PKS, PKS-NRPS hybrid, RiPPS, terpenoids, indole alkaloids, and their genetic mechanisms. Besides, we have provided a glimpse of the concept behind mycotoxins, virulence factor, and host immune response based on fungal infections.
Collapse
Affiliation(s)
- Keshab Bhattarai
- Pharmaceutical Institute, Department of Pharmaceutical Biology, University of Tübingen, Tübingen, Germany
| | - Keshab Bhattarai
- Central Department of Chemistry, Tribhuvan University, Kirtipur, Kathmandu, Nepal
| | - Md Ehsanul Kabir
- Animal Health Research Division, Bangladesh Livestock Research Institute, Savar, Dhaka, Bangladesh
| | - Rina Bastola
- Spinal Cord Injury Association-Nepal (SCIAN), Pokhara, Nepal
| | - Bikash Baral
- Department of Biochemistry, University of Turku, Turku, Finland.
| |
Collapse
|
2
|
Deacylation of Echinocandin B by Streptomyces species: a novel method for the production of Echinocandin B nucleus. 3 Biotech 2019; 9:412. [PMID: 31696017 DOI: 10.1007/s13205-019-1946-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Accepted: 10/10/2019] [Indexed: 10/25/2022] Open
Abstract
Anidulafungin, a new class of antifungal agent used for the treatment of chronic fungal infections, is derived from Echinocandin B nucleus, an intermediate metabolite of Echinocandin B produced by Aspergillus nidulans. The enzyme acylase plays a key role in the bioconversion of Echinocandin B to Echinocandin B nucleus. In the present study, a rapid screening method was used to select an actinomycete capable of producing Echinocandin B acylase. Out of 140 actinomycetes screened for the production of acylase by preliminary qualitative plate assay, 53 were selected. The selected isolates were subjected to quantitative assay under submerged fermentation for the bioconversion of Echinocandin B to Echinocandin B nucleus. Among 53 strains of actinomycetes, two strains (BICC-8848 and BICC-8547) exhibited higher degree of acylase activity. Various physico-chemical parameters were optimised for maximum bioconversion of ECB to ECB nucleus. It was found that the conditions viz. pH 7.0, temperature 26 °C and substrate concentration of about 4 g/L supported higher degree of bioconversion. It was also observed that, as the medium volume increased to 500 mL, the conversion rate was also increased by more than two-folds.
Collapse
|
3
|
Bersani I, Piersigilli F, Goffredo BM, Santisi A, Cairoli S, Ronchetti MP, Auriti C. Antifungal Drugs for Invasive Candida Infections (ICI) in Neonates: Future Perspectives. Front Pediatr 2019; 7:375. [PMID: 31616647 PMCID: PMC6764087 DOI: 10.3389/fped.2019.00375] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Accepted: 09/02/2019] [Indexed: 12/26/2022] Open
Abstract
Fungal infections may complicate the neonatal clinical course, and the spectrum of therapies for their treatment in the perinatal period is limited. Polyenes, Azoles and Echinocandins represent the three classes of antifungal drugs commonly used in the neonatal period. The present review provides an overview about the most recent therapeutic strategies for the treatment of fungal infections in neonates.
Collapse
Affiliation(s)
- Iliana Bersani
- Neonatal Intensive Care Unit, Department of Neonatology, Bambino Gesù Children's Hospital, Rome, Italy
| | - Fiammetta Piersigilli
- Neonatal Intensive Care Unit, Department of Neonatology, Bambino Gesù Children's Hospital, Rome, Italy
| | - Bianca Maria Goffredo
- Biochemistry Laboratory, Department of Specialist Pediatrics, Bambino Gesù Children's Hospital, Rome, Italy
| | - Alessandra Santisi
- Neonatal Intensive Care Unit, Department of Neonatology, Bambino Gesù Children's Hospital, Rome, Italy
| | - Sara Cairoli
- Biochemistry Laboratory, Department of Specialist Pediatrics, Bambino Gesù Children's Hospital, Rome, Italy
| | - Maria Paola Ronchetti
- Neonatal Intensive Care Unit, Department of Neonatology, Bambino Gesù Children's Hospital, Rome, Italy
| | - Cinzia Auriti
- Neonatal Intensive Care Unit, Department of Neonatology, Bambino Gesù Children's Hospital, Rome, Italy
| |
Collapse
|
4
|
Targeting the fungal cell wall: current therapies and implications for development of alternative antifungal agents. Future Med Chem 2019; 11:869-883. [PMID: 30994368 DOI: 10.4155/fmc-2018-0465] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Fungal infections are a worldwide problem associated with high morbidity and mortality. There are relatively few antifungal agents, and resistance has emerged within these pathogens for the newest antifungal drugs. As the fungal cell wall is critical for growth and development, it is one of the most important targets for drug development. In this review, the currently available cell wall inhibitors and suitable drug candidates for the treatment of fungal infections are explored. Future studies of the fungal cell wall and compounds that have detrimental effects on this important outer structural layer could aid in antifungal drug discovery and lead to the development of alternative cell wall inhibitors to fill gaps in clinical therapies for difficult-to-treat fungal infections.
Collapse
|
5
|
Ultrashort Self-Assembling Peptide Hydrogel for the Treatment of Fungal Infections. Gels 2018; 4:gels4020048. [PMID: 30674824 PMCID: PMC6209295 DOI: 10.3390/gels4020048] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 05/17/2018] [Accepted: 05/18/2018] [Indexed: 11/16/2022] Open
Abstract
The threat of antimicrobial resistance to society is compounded by a relative lack of new clinically effective licensed therapies reaching patients over the past three decades. This has been particularly problematic within antifungal drug development, leading to a rise in fungal infection rates and associated mortality. This paper highlights the potential of an ultrashort peptide, (naphthalene-2-ly)-acetyl-diphenylalanine-dilysine-OH (NapFFKK-OH), encompassing hydrogel-forming and antifungal properties within a single peptide motif, thus overcoming formulation (e.g., solubility, drug loading) issues associated with many currently employed highly hydrophobic antifungals. A range of fungal susceptibility (colony counts) and cell cytotoxicity (MTS cell viability, LIVE/DEAD staining® with fluorescent microscopy, haemolysis) assays were employed. Scanning electron microscopy confirmed the nanofibrous architecture of our self-assembling peptide, existing as a hydrogel at concentrations of 1% w/v and above. Broad-spectrum activity was demonstrated against a range of fungi clinically relevant to infection (Aspergillus niger, Candida glabrata, Candida albicans, Candida parapsilosis and Candida dubliniensis) with greater than 4 log10 CFU/mL reduction at concentrations of 0.5% w/v and above. We hypothesise antifungal activity is due to targeting of anionic components present within fungal cell membranes resulting in membrane disruption and cell lysis. NapFFKK-OH demonstrated reduced toxicity against mammalian cells (NCTC 929, ARPE-19) suggesting increased selectivity for fungal cells. However, further studies relating to safety for systemic administration is required, given the challenges toxicity has presented in the wider context of antimicrobial peptide drug development. Overall this study highlights the promise of NapFFKK-OH hydrogels, particularly as a topical formulation for the treatment of fungal infections relating to the skin and eyes, or as a hydrogel coating for the prevention of biomaterial related infection.
Collapse
|
6
|
Epidemiology of Invasive Candidiasis and Challenges for the Mycology Laboratory: Specificities of Candida glabrata. CURRENT CLINICAL MICROBIOLOGY REPORTS 2014. [DOI: 10.1007/s40588-014-0002-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
7
|
Fernández-Ruiz M, Silva JT, San-Juan R, de Dios B, García-Luján R, López-Medrano F, Lizasoain M, Aguado JM. Aspergillus tracheobronchitis: report of 8 cases and review of the literature. Medicine (Baltimore) 2012; 91:261-273. [PMID: 22932790 DOI: 10.1097/md.0b013e31826c2ccf] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Aspergillus tracheobronchitis (AT) is an infrequent but severe form of invasive pulmonary aspergillosis in which the fungal infection is entirely or predominantly confined to the tracheobronchial tree. We reviewed 8 cases of AT diagnosed in our tertiary care center during an 18-year period, as well as 148 cases previously reported in the English literature from 1985 to July 2011. The demographic, clinical, imaging, bronchoscopic, and outcome characteristics of every eligible patient were excerpted, and predictors of inhospital mortality were identified by logistic regression. Solid organ transplantation (SOT) (44.2%), hematologic malignancy (21.2%), neutropenia (18.7%), and chronic obstructive pulmonary disease (15.4%) were the most common underlying conditions reported. Most cases occurred in patients receiving long-term corticosteroid treatment (71.8%) or chemotherapy (25.0%). Fever and respiratory complaints (cough, dyspnea, stridor, or wheezing) were the most frequent symptoms; one-third of patients developed acute respiratory distress at presentation, and 15.1% were asymptomatic at the time of diagnosis. Initial imaging studies were not informative in 47.4% of the cases. Aspergillus fumigatus was the predominant species (74.4%). The pseudomembranous form was the most commonly observed (31.9% of cases) and was more frequent in neutropenic patients (p = 0.007), whereas ulcerative AT (31.2%) was associated with SOT (p = 0.001). The most frequent antifungal monotherapy regimens were amphotericin B deoxycholate (23.1%) and itraconazole (18.6%), whereas combined therapy was administered in 35.9% of the cases. Overall inhospital mortality was 39.1%, with neutropenia (odds ratio [OR], 20.47; p < 0.001) and acute respiratory distress at presentation (OR, 9.54; p = 0.002) as independent prognostic factors. Our pooled analysis of the literature shows that AT remains a rare opportunistic infection with a nonspecific presentation and a variable course depending on the nature of the predisposing factor.
Collapse
Affiliation(s)
- Mario Fernández-Ruiz
- From the Unit of Infectious Diseases (MFR, RSJ, BdD, FLM, ML, JMA), Instituto de Investigación Hospital "12 de Octubre" (i+12), and Department of Pneumology (RGL), Hospital Universitario "12 de Octubre," Madrid; and Department of Internal Medicine (JTS), Hospital Infanta Cristina, Complejo Hospitalario Universitario de Badajoz, Badajoz, Spain
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Total synthesis and structure–activity relationships of caspofungin-like macrocyclic antifungal lipopeptides. Tetrahedron 2012. [DOI: 10.1016/j.tet.2012.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
9
|
Yao J, Liu H, Zhou T, Chen H, Miao Z, Sheng C, Zhang W. Total synthesis and structure-activity relationships of new echinocandin-like antifungal cyclolipohexapeptides. Eur J Med Chem 2012; 50:196-208. [PMID: 22348827 DOI: 10.1016/j.ejmech.2012.01.054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2011] [Revised: 01/27/2012] [Accepted: 01/27/2012] [Indexed: 11/30/2022]
Abstract
A series of new echinocandin-like cyclolipohexapeptides were designed and total synthesized via solution phase [3 + 3]-segment coupling strategy with an attempt to improve antifungal activity. The designed compounds showed potent antifungal activities with broad spectrum. In particular, 11 compounds (i.e. 28a-e, 28g, 28i-j, 29a, 29c and 29e) showed better in vitro antifungal activities against Candida albicans or Aspergillus fumigatus than caspofungin. Moreover, the synthesized compounds provided new SAR information for the echinocandins. The findings in this work suggested that the "left" tripeptide segment of cyclolipohexapeptide scaffold might be a hydrophilic structural motif, whereas the "right" lipopeptide segment was preferred as a hydrophobic core. The amino acid component of the cyclolipohexapeptide scaffold could significantly affect the SAR of the side chains.
Collapse
Affiliation(s)
- Jianzhong Yao
- Department of Medicinal Chemistry, School of Pharmacy, Second Military Medical University, Shanghai 200433, China
| | | | | | | | | | | | | |
Collapse
|
10
|
Abstract
The incidence of invasive fungal infections, especially those due to Aspergillus spp. and Candida spp., continues to increase. Despite advances in medical practice, the associated mortality from these infections continues to be substantial. The echinocandin antifungals provide clinicians with another treatment option for serious fungal infections. These agents possess a completely novel mechanism of action, are relatively well-tolerated, and have a low potential for serious drug-drug interactions. At the present time, the echinocandins are an option for the treatment of infections due Candida spp (such as esophageal candidiasis, invasive candidiasis, and candidemia). In addition, caspofungin is a viable option for the treatment of refractory aspergillosis. Although micafungin is not Food and Drug Administration-approved for this indication, recent data suggests that it may also be effective. Finally, caspofungin- or micafungin-containing combination therapy should be a consideration for the treatment of severe infections due to Aspergillus spp. Although the echinocandins share many common properties, data regarding their differences are emerging at a rapid pace. Anidulafungin exhibits a unique pharmacokinetic profile, and limited cases have shown a potential far activity in isolates with increased minimum inhibitory concentrations to caspofungin and micafungin. Caspofungin appears to have a slightly higher incidence of side effects and potential for drug-drug interactions. This, combined with some evidence of decreasing susceptibility among some strains of Candida, may lessen its future utility. However, one must take these findings in the context of substantially more data and use with caspofungin compared with the other agents. Micafungin appears to be very similar to caspofungin, with very few obvious differences between the two agents.
Collapse
Affiliation(s)
- Gregory Eschenauer
- Department of Pharmacy Services, University of Michigan Health System
- Department of Clinical Sciences, College of Pharmacy, University of Michigan
| | - Daryl D DePestel
- Department of Pharmacy Services, University of Michigan Health System
- Department of Clinical Sciences, College of Pharmacy, University of Michigan
| | - Peggy L Carver
- Department of Pharmacy Services, University of Michigan Health System
- Department of Clinical Sciences, College of Pharmacy, University of Michigan
| |
Collapse
|
11
|
Grover ND. Echinocandins: A ray of hope in antifungal drug therapy. Indian J Pharmacol 2011; 42:9-11. [PMID: 20606829 PMCID: PMC2885632 DOI: 10.4103/0253-7613.62396] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 02/06/2009] [Accepted: 03/12/2010] [Indexed: 11/05/2022] Open
Abstract
Invasive fungal infections are on the rise. Amphotericin B and azole antifungals have been the mainstay of antifungal therapy so far. The high incidence of infusion related toxicity and nephrotoxicity with amphotericin B and the emergence of fluconazole resistant strains of Candida glabrata egged on the search for alternatives. Echinocandins are a new class of antifungal drugs that act by inhibition of β (1, 3)-D- glucan synthase, a key enzyme necessary for integrity of the fungal cell wall. Caspofungin was the first drug in this class to be approved. It is indicated for esophageal candidiasis, candidemia, invasive candidiasis, empirical therapy in febrile neutropenia and invasive aspergillosis. Response rates are comparable to those of amphotericin B and fluconazole. Micafungin is presently approved for esophageal candidiasis, for prophylaxis of candida infections in patients undergoing hematopoietic stem cell transplant (HSCT) and in disseminated candidiasis and candidemia. The currently approved indications for anidulafungin are esophageal candidiasis, candidemia and invasive candidiasis. The incidence of infusion related adverse effects and nephrotoxicity is much lower than with amphotericin B. The main adverse effect is hepatotoxicity and derangement of serum transaminases. Liver function may need to be monitored. They are, however, safer in renal impairment. Even though a better pharmacoeconomical choice than amphotericin B, the higher cost of these drugs in comparison to azole antifungals is likely to limit their use to azole resistant cases of candidial infections and as salvage therapy in invasive aspergillosis rather than as first line drugs.
Collapse
Affiliation(s)
- Neeta D Grover
- Department of Pharmacology, Bharati Vidyapeth University Medical College and Hospital, Sangli, Maharashtra, India
| |
Collapse
|
12
|
Clinical breakpoints for the echinocandins and Candida revisited: Integration of molecular, clinical, and microbiological data to arrive at species-specific interpretive criteria. Drug Resist Updat 2011; 14:164-76. [DOI: 10.1016/j.drup.2011.01.004] [Citation(s) in RCA: 276] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 01/17/2011] [Accepted: 01/20/2011] [Indexed: 11/24/2022]
|
13
|
Li J, Li L, Tian Y, Niu G, Tan H. Hybrid antibiotics with the nikkomycin nucleoside and polyoxin peptidyl moieties. Metab Eng 2011; 13:336-44. [DOI: 10.1016/j.ymben.2011.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2010] [Revised: 01/06/2011] [Accepted: 01/10/2011] [Indexed: 10/18/2022]
|
14
|
Definitions and Epidemiology of Candida Species not Susceptible to Echinocandins. CURRENT FUNGAL INFECTION REPORTS 2011. [DOI: 10.1007/s12281-011-0053-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
15
|
|
16
|
FKS mutations and elevated echinocandin MIC values among Candida glabrata isolates from U.S. population-based surveillance. Antimicrob Agents Chemother 2010; 54:5042-7. [PMID: 20837754 DOI: 10.1128/aac.00836-10] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Candida glabrata is the second leading cause of candidemia in the United States. Its high-level resistance to triazole antifungal drugs has led to the increased use of the echinocandin class of antifungal agents for primary therapy of these infections. We monitored C. glabrata bloodstream isolates from a population-based surveillance study for elevated echinocandin MIC values (MICs of ≥0.25 μg/ml). From the 490 C. glabrata isolates that were screened, we identified 16 isolates with an elevated MIC value (2.9% of isolates from Atlanta and 2.0% of isolates from Baltimore) for one or more of the echinocandin drugs caspofungin, anidulafungin, and micafungin. All of the isolates with elevated MIC values had a mutation in the previously identified hot spot 1 of either the glucan synthase FKS1 (n = 2) or FKS2 (n = 14) gene. No mutations were detected in hot spot 2 of either FKS1 or FKS2. The predominant mutation was mutation of FKS2-encoded serine 663 to proline (S663P), found in 10 of the isolates with elevated echinocandin MICs. Two of the mutations, R631G for FKS1 and R665G for FKS2, have not been reported previously for C. glabrata. Multilocus sequence typing indicated that the predominance of the S663P mutation was not due to the clonal spread of a single sequence type. With a rising number of echinocandin therapy failures reported, it is important to continue to monitor rates of elevated echinocandin MIC values and the associated mutations.
Collapse
|
17
|
Fera MT, La Camera E, De Sarro A. New triazoles and echinocandins: mode of action, in vitro activity and mechanisms of resistance. Expert Rev Anti Infect Ther 2010; 7:981-98. [PMID: 19803707 DOI: 10.1586/eri.09.67] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Different types of mycoses, especially invasive mycoses caused by yeasts and molds, are a growing problem in healthcare. The most notable explanation for this increase is a rise in the number of immunocompromised patients owing to advances in transplantation, the emergence of AIDS and a rise in the number of invasive surgical procedures. Despite advances in medical practice, some therapeutic problems remain. In addition, intrinsic or acquired antifungal resistance may pose a serious problem to antifungal therapy. A new generation of triazole agents (voriconazole, posaconazole, isavuconazole, ravuconazole and albaconazole) and the recent class of the echinocandins (caspofungin, micafungin and anidulafungin) have become available, and represent an alternative to conventional antifungals for serious fungal infection management. Currently, only two of the recent triazole generation (voriconazole and posaconazole) and all three echinocandins are available for clinical use. More precisely, voriconazole and posaconazole are indicated for the treatment of invasive fungal infections and the echinocandins for the treatment of specific candidiasis. Voriconazole and posaconazole have a very broad spectrum of antifungal activity that includes Candida species, and filamentous and dimorphic fungi. Their activity extends to both fluconazole- and itraconazole-resistant strains of Candida. A major difference between posaconazole and voriconazole is that posaconazole has activity against Zygomycetes including Mucor spp., Rhizopus spp. and Cunninghamella spp., and voriconazole has no activity against this class of fungi. Ravuconazole, isavuconazole and albaconazole have shown very potent in vitro activity against species of Candida, Cryptococcus and Aspergillus, and they are currently in various stages of development. All three echinocandin agents, caspofungin, micafungin and anidulafungin, are similar in their spectrum of activity. Echinocandins do not possess in vitro activity against important basidiomycetes, including Cryptococcus, Rhodotorula and Trichosporon. This review attempts to deliver the most up-to-date knowledge on the mode of action and mechanisms of resistance to triazoles and echinocandins in fungal pathogens. In addition, the in vitro activity data available on triazoles and echinocandins are reported.
Collapse
Affiliation(s)
- Maria Teresa Fera
- Dipartimento di Patologia e Microbiologia Sperimentale, Università oli Messina, Policlinico Universitario, Torre Biologica II piano, 98125 Messina, Italy.
| | | | | |
Collapse
|
18
|
Sucher AJ, Chahine EB, Balcer HE. Echinocandins: The Newest Class of Antifungals. Ann Pharmacother 2009; 43:1647-57. [DOI: 10.1345/aph.1m237] [Citation(s) in RCA: 137] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Objective: To review the mechanism of action, antifungal spectrum of activity, pharmacodynamics, pharmacokinetics, clinical efficacy, and safety of the echinocandins. Data Sources: A MEDLINE search (1982–May 2009) was conducted for articles published in the English language using the key words caspofungin, micafungin, anidulafungin, and echinocandins. Study Selection and Data Extraction: Medicinal chemistry, in vitro, and animal studies, as well as human trials were reviewed for information on the pharmacodynamics, pharmacokinetics, efficacy, and safety of each echinocandin. Clinical trials were reviewed and included to compare and contrast the available echinocandins. Data Synthesis: Three echinocandin antifungal agents are currently approved for use in the US: caspofungin, micafungin, and anidulafungin. The echinocandins have a unique mechanism of action, inhibiting β-(1,3)-d-glucan synthase, an enzyme that is necessary for the synthesis of an essential component of the cell wall of several fungi. The echinocandins display fungistatic activity against Aspergillus spp. and fungicidal activity against most Candida spp., including strains that are fluconazole-resistant. The echinocandins have been shown to be efficacious for the treatment of esophageal candidiasis, candidemia, and invasive candidiasis. In addition, caspofungin has demonstrated efficacy as empiric treatment of febrile neutropenia and salvage therapy for the treatment of invasive aspergillosis, and it is the only echinocandin approved for use in pediatric patients. Micafungin is the only echinocandin approved for use as prophylaxis against Candida infections in patients undergoing hematopoietic stem cell transplantation. Overall, resistance to echinocandins is still rare, and all agents are well tolerated, with similar adverse effect profiles and few drug–drug interactions. Conclusions: Echinocandins, the newest addition to the arsenal of antifungals, offer potential advantages over other classes of agents. Clinicians should assess their distinguishing characteristics, including route of metabolism, drug interaction profile, and approved indications for use, when determining which agent to include on a formulary.
Collapse
Affiliation(s)
- Allana J Sucher
- Pharmacy Practice, Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University, West Palm Beach, FL, Regis University School of Pharmacy, Denver, CO
| | - Elias B Chahine
- Pharmacy Practice, Lloyd L. Gregory School of Pharmacy, Palm Beach Atlantic University
| | | |
Collapse
|
19
|
Activity of anidulafungin in a murine model of Candida krusei infection: evaluation of mortality and disease burden by quantitative tissue cultures and measurement of serum (1,3)-beta-D-glucan levels. Antimicrob Agents Chemother 2009; 53:1639-41. [PMID: 19139291 DOI: 10.1128/aac.00955-08] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Experience with anidulafungin against Candida krusei is limited. Immunosuppressed mice were injected with 1.3 x 10(7) to 1.5 x 10(7) CFU of C. krusei. Animals were treated with saline, 40 mg/kg fluconazole, 1 mg/kg amphotericin B, or 10 and 20 mg/kg anidulafungin for 5 days. Anidulafungin improved survival and significantly reduced the number of CFU/g in kidneys and serum beta-glucan levels.
Collapse
|
20
|
|
21
|
Correlation of MIC with outcome for Candida species tested against caspofungin, anidulafungin, and micafungin: analysis and proposal for interpretive MIC breakpoints. J Clin Microbiol 2008; 46:2620-9. [PMID: 18579718 DOI: 10.1128/jcm.00566-08] [Citation(s) in RCA: 214] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The CLSI Antifungal Subcommittee followed the M23-A2 "blueprint" to develop interpretive MIC breakpoints for anidulafungin, caspofungin, and micafungin against Candida species. MICs of < or = 2 microg/ml for all three echinocandins encompass 98.8 to 100% of all clinical isolates of Candida spp. without bisecting any species group and represent a concentration that is easily maintained throughout the dosing period. Data from phase III clinical trials demonstrate that the standard dosing regimens for each of these agents may be used to treat infections due to Candida spp. for which MICs are as high as 2 microg/ml. An MIC predictive of resistance to these agents cannot be defined based on the data from clinical trials due to the paucity of isolates for which MICs exceed 2 microg/ml. The clinical data set included only three isolates from patients treated with an echinocandin (caspofungin) for which the MICs were > 2 microg/ml (two C. parapsilosis isolates at 4 microg/ml and one C. rugosa isolate at 8 microg/ml). Based on these data, the CLSI subcommittee has decided to recommend a "susceptible only" breakpoint MIC of < or = 2 microg/ml due to the lack of echinocandin resistance in the population of Candida isolates thus far. Isolates for which MICs exceed 2 microg/ml should be designated "nonsusceptible" (NS). For strains yielding results suggestive of an NS category, the organism identification and antimicrobial-susceptibility test results should be confirmed. Subsequently, the isolates should be submitted to a reference laboratory that will confirm the results by using a CLSI reference dilution method.
Collapse
|
22
|
Cruciani M, Serpelloni G. Management of Candida infections in the adult intensive care unit. Expert Opin Pharmacother 2008; 9:175-91. [PMID: 18201143 DOI: 10.1517/14656566.9.2.175] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
The epidemiology of Candida infection in intensive care units (ICUs) and the management strategies for such infections in non-neutropenic intensive care patients are discussed in this review. Candida species are one of the leading causes of nosocomial bloodstream infections and a significant cause of morbidity in patients admitted to the ICU. Prophylactic, pre-emptive and empiric treatment strategies for Candida infections have been explored in ICU patients. Routine prophylaxis should not be administered to the whole population of ICU patients, because the concerns about the selection of azole-resistant Candida strains or the induction of resistance are justified. Treatment of fungal infections is now possible with newer antifungal agents, including newer azoles (e.g., voriconazole, posaconazole) and echinocandins (e.g., micafungin, anidulafungin). However, there is a critical need for improvement in diagnosis of invasive Candida infection in order to provide clinicians the opportunity to intervene earlier in the diseases course.
Collapse
Affiliation(s)
- Mario Cruciani
- Center of Preventive Medicine & HIV Out-Patient Clinic, V. Germania, 20-37135 Verona, Italy.
| | | |
Collapse
|
23
|
Ostrosky-Zeichner L, Rex JH. Antifungal and Antiviral Therapy. Crit Care Med 2008. [DOI: 10.1016/b978-032304841-5.50055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
24
|
Kim R, Khachikian D, Reboli AC. A comparative evaluation of properties and clinical efficacy of the echinocandins. Expert Opin Pharmacother 2007; 8:1479-92. [PMID: 17661730 DOI: 10.1517/14656566.8.10.1479] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
With the increase in prevalence of fungal infections, newer antifungal agents are needed to effectively treat invasive disease, and at the same time minimize adverse effects from therapy. The echinocandins comprise a novel class of antifungals; their mechanism of action involves inhibiting 1,3-beta-D-glucan synthase, which is essential in cell wall synthesis for certain fungi. All three echinocandins are US FDA-approved for the treatment of esophageal candidiasis. Caspofungin and anidulafungin are licensed for the treatment of candidemia, and other select forms of invasive candidiasis. Micafungin is at present the only echinocandin approved for prophylaxis of fungal infections in hematopoietic stem cell transplants; whereas caspofungin is approved for empiric therapy of febrile neutropenia. Although all three echinocandins are active against Aspergillus, only caspofungin is presently approved for salvage therapy in invasive aspergillosis. Combination therapy with echinocandins plus other licensed antifungal therapy shows promise in treating invasive aspergillosis. This article will explore the similarities and differences among the echinocandins.
Collapse
Affiliation(s)
- Rose Kim
- Cooper University Hospital/UMDNJ-Robert Wood Johnson Medical School Education and Research Building, Division of Infectious Diseases, Department of Medicine, Camden, NJ 08103, USA.
| | | | | |
Collapse
|
25
|
How to diagnose and treat fungal infections in chronic prostatitis. CURRENT FUNGAL INFECTION REPORTS 2007. [DOI: 10.1007/s12281-007-0006-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
26
|
Yadav V, Mandhan R, Pasha Q, Pasha S, Katyal A, Chhillar AK, Gupta J, Dabur R, Sharma GL. An antifungal protein from Escherichia coli. J Med Microbiol 2007; 56:637-644. [PMID: 17446286 DOI: 10.1099/jmm.0.46973-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A cytosolic protein was purified fromEscherichia coliBL21 that demonstrated potent antifungal activity against pathogenic strains ofAspergillus fumigatus,Aspergillus flavus,Aspergillus nigerandCandida albicans. The MIC of purified protein fromE. coliBL21 (PPEBL21) againstAspergillusspecies andC. albicanswas 1.95–3.98 and 15.62 μg ml−1, respectively.In vitrotoxicity tests demonstrated no cytotoxicity of PPEBL21 to human erythrocytes up to the tested concentrations of 1250 μg ml−1. Amphotericin B was lethal to 100 % of human erythrocytes at a concentration of 37.5 μg ml−1. The N-terminal amino acid sequence of PPEBL21 was found to be DLAEVASR, which showed 75 % sequence similarity with alcohol dehydrogenase of yeast. Mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also substantiated these observations. The results suggested thatE. coliBL21 might be an important bioresource of lead molecules for developing new peptide-based therapies for treating fungal infections.
Collapse
Affiliation(s)
- V Yadav
- Institute of Genomics and Integrative Biology, Mall Road, University Campus, Delhi, India
| | - R Mandhan
- Department of Biotechnology, Kurukshetra University, Kurukshetra, India
| | - Q Pasha
- Institute of Genomics and Integrative Biology, Mall Road, University Campus, Delhi, India
| | - S Pasha
- Institute of Genomics and Integrative Biology, Mall Road, University Campus, Delhi, India
| | - A Katyal
- Dr. B.R. Ambedkar Centre for Biomedical Research, Delhi, India
| | - A K Chhillar
- Shriram Institute for Industrial Research, Delhi, India
| | - J Gupta
- Institute of Genomics and Integrative Biology, Mall Road, University Campus, Delhi, India
| | - R Dabur
- Regional Research Institute (Ay), Kothrud, Pune, India
| | - G L Sharma
- Institute of Genomics and Integrative Biology, Mall Road, University Campus, Delhi, India
| |
Collapse
|
27
|
Pfaller MA, Diekema DJ. Epidemiology of invasive candidiasis: a persistent public health problem. Clin Microbiol Rev 2007; 20:133-63. [PMID: 17223626 PMCID: PMC1797637 DOI: 10.1128/cmr.00029-06] [Citation(s) in RCA: 2793] [Impact Index Per Article: 164.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Invasive candidiasis (IC) is a leading cause of mycosis-associated mortality in the United States. We examined data from the National Center for Health Statistics and reviewed recent literature in order to update the epidemiology of IC. IC-associated mortality has remained stable, at approximately 0.4 deaths per 100,000 population, since 1997, while mortality associated with invasive aspergillosis has continued to decline. Candida albicans remains the predominant cause of IC, accounting for over half of all cases, but Candida glabrata has emerged as the second most common cause of IC in the United States, and several less common Candida species may be emerging, some of which can exhibit resistance to triazoles and/or amphotericin B. Crude and attributable rates of mortality due to IC remain unacceptably high and unchanged for the past 2 decades. Nonpharmacologic preventive strategies should be emphasized, including hand hygiene; appropriate use, placement, and care of central venous catheters; and prudent use of antimicrobial therapy. Given that delays in appropriate antifungal therapy are associated with increased mortality, improved use of early empirical, preemptive, and prophylactic therapies should also help reduce IC-associated mortality. Several studies have now identified important variables that can be used to predict risk of IC and to help guide preventive strategies such as antifungal prophylaxis and early empirical therapy. However, improved non-culture-based diagnostics are needed to expand the potential for preemptive (or early directed) therapy. Further research to improve diagnostic, preventive, and therapeutic strategies is necessary to reduce the considerable morbidity and mortality associated with IC.
Collapse
Affiliation(s)
- M A Pfaller
- Medical Microbiology Division, C606 GH, Department of Pathology, University of Iowa College of Medicine, Iowa City, IA 52242, USA.
| | | |
Collapse
|
28
|
Isham N, Ghannoum MA. Determination of MICs of aminocandin for Candida spp. and filamentous fungi. J Clin Microbiol 2006; 44:4342-4. [PMID: 17021057 PMCID: PMC1698398 DOI: 10.1128/jcm.01550-06] [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: 11/20/2022] Open
Abstract
Candida and Aspergillus spp., as well as other filamentous molds, have increasingly been reported as the causes of severe invasive fungal infections. We evaluated the new echinocandin aminocandin (AMN) for its antifungal activities against a range of fungal pathogens by determination of the MICs for the organisms. The MICs of the comparator drugs amphotericin B, caspofungin, micafungin, and voriconazole were also determined. The MICs of AMN for 25 strains each of non-Candida albicans Candida spp. (including Candida parapsilosis, Candida krusei, Candida guilliermondii, and Candida tropicalis), Aspergillus fumigatus, Scedosporium spp., Fusarium spp., and zygomycetes (including Absidia, Mucor, and Rhizopus spp.) were determined by using the Clinical and Laboratory Standards Institute M27-A2 and M38-A methodologies for yeasts and filamentous molds, respectively. The MIC ranges of AMN for all yeasts were similar (0.03 to 4.0 microg/ml), while the MIC ranges of AMN for filamentous fungi were species specific. AMN demonstrated potent antifungal activity against A. fumigatus, limited activity against Scedosporium spp., and no activity against zygomycetes or Fusarium spp. Our data showed that AMN demonstrated potent antifungal activities against all of the yeasts and Aspergillus isolates tested, suggesting that AMN could be an important addition to our arsenal of antifungals for the treatment of invasive fungal disease.
Collapse
Affiliation(s)
- N Isham
- Center for Medical Mycology, University Hospitals of Cleveland/Case Western Reserve University, 11100 Euclid Avenue, Cleveland, OH 44106, USA
| | | |
Collapse
|
29
|
Morris MI, Villmann M. Echinocandins in the management of invasive fungal infections, part 1. Am J Health Syst Pharm 2006; 63:1693-703. [PMID: 16960253 DOI: 10.2146/ajhp050464.p1] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE The chemistry, pharmacology, spectrum of activity, resistance, pharmacokinetics, pharmacodynamics, clinical efficacy, adverse effiects, drug interactions, dosage and administration, cost, and place in therapy of echinocandins are reviewed. SUMMARY Three echinocandins are currently available: caspofungin, micafungin, and anidulafungin. The principal mechanism of action of the echinocandins is the noncompetitive inhibition of beta-(1,3)-dglucan synthase, an essential component of the cell wall of many fungi that is not present in mammalian cells. Echinocandins exhibit fungicidal activity against Candida species, including triazole-resistant isolates, and fungistatic activity against Aspergillus species. While fungistatic against mold, echinocandins may hold promise for the treatment of these pathogens when given in combination with amphotericin B or broad-spectrum triazoles, such as voriconazole. To date, resistance to echinocandins has been reported in only two patients. Echinocandins exhibit concentration- dependent activity against Candida species. In clinical trials, caspofungin has demonstrated efficacy in treating candidemia, esophageal candidiasis, and febrile neutropenia. Micafungin has demonstrated efficacy as antifungal prophylaxis in hematopoietic stem cell transplant recipients and in the treatment of esophageal candidiasis. Anidulafungin received approved labeling from the Food and Drug Administration in February 2006. Clinical efficacy data will be forthcoming. CONCLUSION Echinocandins are fungicidal against yeast and fungistatic against mold. Their limited toxicity profile and minimal drug-drug interactions make them an attractive new option for the treatment of invasive fungal infections. Their cost may limit their use as initial therapy for patients with fungemia in medical centers or intensive care units with a high rate of triazoleresistant Candida infections.
Collapse
Affiliation(s)
- Michele I Morris
- Division of Infectious Diseases, School of Medicine, University of Miami, Miami, FL 33136, USA.
| | | |
Collapse
|
30
|
Abstract
Invasive candidiasis remains an important nosocomial infection that continues to present major diagnostic and therapeutic challenges to the clinician. Changes in the epidemiology of this disorder have occurred for many reasons, and included especially the extensive use of prophylactic antifungal agents, broad-spectrum antibacterial agents, and medical devices (eg, chronic indwelling intravascular catheters). The diagnosis of IC remains elusive in many patients, and there is a critical need for improved diagnostics that will provide clinicians the opportunity to intervene earlier in the course of disease. Newer antifungal agents offer promise in the treatment of candidemia and other forms of IC, but the optimal use of these agents, particularly in the approach to non-albicans Candida infections, needs to be explored in more detail. Furthermore, despite an overwhelming amount of data concerning risk factors and excess mortality associated with the development of IC, there is no consistent approach to treatment and primary prevention among individuals who are deemed to be at highest risk for this complication. Research that focuses on these important clinical areas could provide valuable insights into the diagnosis and management of this common and evolving infection.
Collapse
Affiliation(s)
- Peter G Pappas
- Division of Infectious Diseases, Department of Medicine, University of Alabama at Birmingham, AL 35294-0006, USA.
| |
Collapse
|
31
|
Abstract
The hyalohyphomycetes (especially Fusarium spp) have emerged as significant pathogens in severely immunocompromised patients. Human infections by Fusarium spp can be superficial or limited to single organs in otherwise healthy patients. Such infections are rare and tend to respond well to therapy. By contrast, disseminated fusarial hyalohyphomycosis affects the immunocompromised host and frequently is fatal. Successful outcome is determined by the degree of immunosuppression and the extent of the infection. These infections may be suspected clinically on the basis of a constellation of clinical and laboratory findings, which should lead to prompt therapy.
Collapse
Affiliation(s)
- Marcio Nucci
- Hematology Service, Department of Internal Medicine, Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro, Brazil
| | | |
Collapse
|
32
|
Abstract
Epidemiologic changes that include immune-compromised patients and drug-resistant fungi have caused an increase in nosocomial infections by Candida albicans and non-albicans Candida species. Other fungi, aspergilla and Cryptococcus (environmental contaminants), are opportunistic invaders of the immune-compromised (transplant, HIV) patients. The environmental fungi Coccidioides immitis (dry arid areas), Histoplasma capsulatum (Avian-infested areas), and Blastomyces dermatitidis (aquatic areas) can cause infections in immune-competent and immune-deficient patients. Each fungus can cause changes in the prostate that mimic bacterial infection, benign prostatic hypertrophy, or neoplasm. Diagnosis can be established by urine cultures or needle biopsy of the prostate. Prostate surgery for carcinoma or benign enlargement may detect latent fungal infection. Different fungal species can have divergent clinical manifestations and require different treatment. In some cases, asymptomatic localized fungal prostatitis can be cured by removal of the infected gland. Symptomatic and disseminated infection may require prostatectomy and systemic antifungal therapy.
Collapse
Affiliation(s)
- Gilbert J Wise
- Division of Urology, Maimonides Medical Center, 48-02 10th Avenue, Brooklyn, NY 11219, USA.
| | | |
Collapse
|
33
|
Abstract
Viral and fungal infections in liver transplant recipients are important to recognize and treat early because of their association with substantial morbidity and mortality. Some viruses, such as cytomegalovirus and human herpesvirus 6, have immunomodulatory properties and can facilitate other infections, including fungal infections. Cytomegalovirus has long been recognized as an important virus in transplantation, but in the past decade other viruses have also received attention in the medical literature because of their association with particular clinical syndromes. Although human herpesvirus 6 has been associated with fever, rash, and encephalitis, a direct cause-and-effect relationship is still lacking. Human herpesvirus 8 has been found to be the cause of Kaposi sarcoma. Molecular techniques (e.g., pp65 antigenemia and polymerase chain reaction) that have been introduced for routine diagnosis of viruses have facilitated the diagnosis of asymptomatic viral infections and the institution of preemptive therapy. Nonetheless, the diagnosis of invasive fungal infections in liver transplant recipients is often delayed and thus associated with high mortality. Despite the use of new antifungal agents in clinical practice and the reduced incidence of fungal infections because of antifungal prophylaxis regimens, mortality has not decreased. Future patient outcomes may improve with early identification of patients who have risk factors for invasive fungal infections and with the development of new molecular diagnostic techniques for early detection.
Collapse
Affiliation(s)
- Shimon Kusne
- Division of Infectious Diseases, Mayo Clinic, Scottsdale, AZ 85054, USA.
| | | |
Collapse
|