451
|
Nikaein D, Sharifzadeh A, Khosravi A. Fungicidal versus Fungistatic activity of five Iranian essences against fluconazole resistant Candida species. JOURNAL OF HERBMED PHARMACOLOGY 2018. [DOI: 10.15171/jhp.2018.43] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
452
|
Abstract
Fungal diseases became a major medical problem in the second half of the 20th century when advances in modern medicine together with the HIV epidemic resulted in large numbers of individuals with impaired immunity. Fungal diseases are difficult to manage because they tend to be chronic, hard to diagnose, and difficult to eradicate with antifungal drugs. This essay considers the future of medical mycology in the 21st century, extrapolating from current trends. In the near horizon, the prevalence of fungal diseases is likely to increase, as there will be more hosts with impaired immunity and drug resistance will inevitably increase after selection by antifungal drug use. We can expect progress in the development of new drugs, diagnostics, vaccines, and immunotherapies. In the far horizon, humanity may face new fungal diseases in association with climate change. Some current associations between chronic diseases and fungal infections could lead to the establishment of fungi as causative agents, which will greatly enhance their medical importance. All trends suggest that the importance of fungal diseases will increase in the 21st century, and enhanced human preparedness for this scourge will require more research investment in this group of infectious diseases.
Collapse
Affiliation(s)
- Arturo Casadevall
- Department of Molecular Microbiology and Immunology, The Johns Hopkins School of Public Health, Baltimore, Maryland
| |
Collapse
|
453
|
Ksiezopolska E, Gabaldón T. Evolutionary Emergence of Drug Resistance in Candida Opportunistic Pathogens. Genes (Basel) 2018; 9:genes9090461. [PMID: 30235884 PMCID: PMC6162425 DOI: 10.3390/genes9090461] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 09/14/2018] [Accepted: 09/17/2018] [Indexed: 01/08/2023] Open
Abstract
Fungal infections, such as candidiasis caused by Candida, pose a problem of growing medical concern. In developed countries, the incidence of Candida infections is increasing due to the higher survival of susceptible populations, such as immunocompromised patients or the elderly. Existing treatment options are limited to few antifungal drug families with efficacies that vary depending on the infecting species. In this context, the emergence and spread of resistant Candida isolates are being increasingly reported. Understanding how resistance can evolve within naturally susceptible species is key to developing novel, more effective treatment strategies. However, in contrast to the situation of antibiotic resistance in bacteria, few studies have focused on the evolutionary mechanisms leading to drug resistance in fungal species. In this review, we will survey and discuss current knowledge on the genetic bases of resistance to antifungal drugs in Candida opportunistic pathogens. We will do so from an evolutionary genomics perspective, focusing on the possible evolutionary paths that may lead to the emergence and selection of the resistant phenotype. Finally, we will discuss the potential of future studies enabled by current developments in sequencing technologies, in vitro evolution approaches, and the analysis of serial clinical isolates.
Collapse
Affiliation(s)
- Ewa Ksiezopolska
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology (BIST), 08003 Barcelona, Spain.
- Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain.
- Institució Catalana de Recerca i Estudis Avançats (ICREA), 08010 Barcelona, Spain.
| |
Collapse
|
454
|
Kim HJ, Han CY, Park JS, Oh SH, Kang SH, Choi SS, Kim JM, Kwak JH, Kim ES. Nystatin-like Pseudonocardia polyene B1, a novel disaccharide-containing antifungal heptaene antibiotic. Sci Rep 2018; 8:13584. [PMID: 30206268 PMCID: PMC6134108 DOI: 10.1038/s41598-018-31801-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 08/20/2018] [Indexed: 11/29/2022] Open
Abstract
Polyene macrolides such as nystatin A1 and amphotericin B belong to a large family of very valuable antifungal polyketide compounds typically produced by soil actinomycetes. Recently, nystatin-like Pseudonocardia polyene (NPP) A1 has been identified as a unique disaccharide-containing tetraene antifungal macrolide produced by Pseudonocardia autotrophica. Despite its significantly increased water solubility and decreased hemolytic activity, its antifungal activity remains limited compared with that of nystatin A1. In this study, we developed NPP B1, a novel NPP A1 derivative harboring a heptaene core structure, by introducing two amino acid substitutions in the putative NADPH-binding motif of the enoyl reductase domain in module 5 of the NPP A1 polyketide synthase NppC. The low level NPP B1 production yield was successfully improved by eliminating the native plasmid encoding a polyketide biosynthetic gene cluster present in P. autotrophica. In vitro and in vivo antifungal activity and toxicity studies indicated that NPP B1 exhibited comparable antifungal activity against Candida albicans and was less toxic than the most potent heptaene antifungal, amphotericin B. Moreover, NPP B1 showed improved pharmacokinetic parameters compared to those of amphotericin B, suggesting that NPP B1 could be a promising candidate for development into a pharmacokinetically improved and less-toxic polyene antifungal antibiotic.
Collapse
Affiliation(s)
- Hye-Jin Kim
- Department of Biological Engineering, Inha University, Incheon, 22212, Korea
| | - Chi-Young Han
- Department of Biological Engineering, Inha University, Incheon, 22212, Korea
| | - Ji-Seon Park
- Jeil Pharmaceutical Co., Ltd., Yongin-si, Gyeonggi-do, 17172, Korea
| | - Sang-Hun Oh
- School of Life Science, Handong Global University, Pohang, 37554, Korea
| | - Seung-Hoon Kang
- Department of Biological Engineering, Inha University, Incheon, 22212, Korea
| | - Si-Sun Choi
- Department of Biological Engineering, Inha University, Incheon, 22212, Korea
| | - Jung-Min Kim
- Jeil Pharmaceutical Co., Ltd., Yongin-si, Gyeonggi-do, 17172, Korea
| | - Jin-Hwan Kwak
- School of Life Science, Handong Global University, Pohang, 37554, Korea
| | - Eung-Soo Kim
- Department of Biological Engineering, Inha University, Incheon, 22212, Korea.
| |
Collapse
|
455
|
Kummari LK, Butler MS, Furlong E, Blundell R, Nouwens A, Silva AB, Kappler U, Fraser JA, Kobe B, Cooper MA, Robertson AAB. Antifungal benzo[b]thiophene 1,1-dioxide IMPDH inhibitors exhibit pan-assay interference (PAINS) profiles. Bioorg Med Chem 2018; 26:5408-5419. [PMID: 30322754 DOI: 10.1016/j.bmc.2018.09.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/21/2018] [Accepted: 09/03/2018] [Indexed: 12/14/2022]
Abstract
Fungi cause serious life-threatening infections in immunocompromised individuals and current treatments are now complicated by toxicity issues and the emergence of drug resistant strains. Consequently, there is a need for development of new antifungal drugs. Inosine monophosphate dehydrogenase (IMPDH), a key component of the de novo purine biosynthetic pathway, is essential for growth and virulence of fungi and is a potential drug target. In this study, a high-throughput screen of 114,000 drug-like compounds against Cryptococcus neoformans IMPDH was performed. We identified three 3-((5-substituted)-1,3,4-oxadiazol-2-yl)thio benzo[b]thiophene 1,1-dioxides that inhibited Cryptococcus IMPDH and also possessed whole cell antifungal activity. Analogs were synthesized to explore the SAR of these hits. Modification of the fifth substituent on the 1,3,4-oxadiazole ring yielded compounds with nanomolar in vitro activity, but with associated cytotoxicity. In contrast, two analogs generated by substituting the 1,3,4-oxadiazole ring with imidazole and 1,2,4-triazole gave reduced IMPDH inhibition in vitro, but were not cytotoxic. During enzyme kinetic studies in the presence of DTT, nucleophilic attack of a free thiol occurred with the benzo[b]thiophene 1,1-dioxide. Two representative compounds with substitution at the 5 position of the 1,3,4-oxadiazole ring, showed mixed inhibition in the absence of DTT. Incubation of these compounds with Cryptococcus IMPDH followed by mass spectrometry analysis showed non-specific and covalent binding with IMPDH at multiple cysteine residues. These results support recent reports that the benzo[b]thiophene 1,1-dioxides moiety as PAINS (pan-assay interference compounds) contributor.
Collapse
Affiliation(s)
- Lalith K Kummari
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Mark S Butler
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Emily Furlong
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Ross Blundell
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Amanda Nouwens
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Alberto B Silva
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia; AC Immune SA, EPFL Innovation Park, CH-1015 Lausanne, Switzerland
| | - Ulrike Kappler
- Centre for Metals in Biology, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - James A Fraser
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Bostjan Kobe
- Australian Infectious Diseases Research Centre, School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Matthew A Cooper
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Avril A B Robertson
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, Queensland 4072, Australia; Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland 4072, Australia.
| |
Collapse
|
456
|
Roque L, Duarte N, Bronze MR, Garcia C, Alopaeus J, Molpeceres J, Hagesaether E, Tho I, Rijo P, Reis C. Development of a bioadhesive nanoformulation with Glycyrrhiza glabra L. extract against Candida albicans. BIOFOULING 2018; 34:880-892. [PMID: 30362371 DOI: 10.1080/08927014.2018.1514391] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Revised: 07/31/2018] [Accepted: 08/14/2018] [Indexed: 06/08/2023]
Abstract
Glycyrrhiza glabra L. is considered an important source of bioactive compounds. This study aimed at the development of an efficient solution for the treatment of oral candidiasis. Several extracts of Glycyrrhiza glabra L. were prepared using different solvents and their potential in vitro antifungal activity was assessed. Ethanolic extracts showed the most promising results against C. albicans. This extract was incorporated into mucoadhesive nanoparticles (PLA, PLGA and alginate), which were further included in an oral gel, an oral film and a toothpaste, respectively. The results showed that nanoparticles were successfully produced, presenting a mean size among 100-900 nm with high encapsulation efficiency. In vitro studies showed that the most bioadhesive formulation was the oral film with extract-loaded PLGA nanoparticles, followed by the toothpaste with extract-loaded alginate nanoparticles and the oral gel with extract-loaded PLA nanoparticles.
Collapse
Affiliation(s)
- Luís Roque
- a CBiOS , Universidade Lusófona de Humanidades e Tecnologias , Lisboa , Portugal
- b Department of Biomedical Sciences, Faculty of Pharmacy , University of Alcalá , Alcalá de Henares , Spain
| | - Noélia Duarte
- c iMed.ULisboa-Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
| | - Maria Rosário Bronze
- d Instituto de Biologia Experimental Tecnológica , Universidade de Lisboa , Oeiras , Portugal
| | - Catarina Garcia
- a CBiOS , Universidade Lusófona de Humanidades e Tecnologias , Lisboa , Portugal
- b Department of Biomedical Sciences, Faculty of Pharmacy , University of Alcalá , Alcalá de Henares , Spain
| | - Julia Alopaeus
- e School of Pharmacy , University of Oslo , Oslo , Norway
| | - Jesus Molpeceres
- b Department of Biomedical Sciences, Faculty of Pharmacy , University of Alcalá , Alcalá de Henares , Spain
| | - Ellen Hagesaether
- f Faculty of Health Sciences , OsloMet-Oslo Metropolitan University , Oslo , Norway
| | - Ingunn Tho
- e School of Pharmacy , University of Oslo , Oslo , Norway
| | - Patrícia Rijo
- a CBiOS , Universidade Lusófona de Humanidades e Tecnologias , Lisboa , Portugal
- c iMed.ULisboa-Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
| | - Catarina Reis
- c iMed.ULisboa-Faculdade de Farmácia , Universidade de Lisboa , Lisboa , Portugal
- g IBEB-Faculdade de Ciências , Universidade de Lisboa , Lisboa , Portugal
| |
Collapse
|
457
|
Synthesis of a novel bicyclic scaffold inspired by the antifungal natural product sordarin. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.07.064] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
458
|
Sharma A, Singh S, Tewari R, Bhatt V, Sharma J, Maurya I. Phytochemical analysis and mode of action against Candida glabrata of Paeonia emodi extracts. J Mycol Med 2018; 28:443-451. [DOI: 10.1016/j.mycmed.2018.04.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2018] [Revised: 04/22/2018] [Accepted: 04/27/2018] [Indexed: 01/26/2023]
|
459
|
Structural insights into inhibitor binding to a fungal ortholog of aspartate semialdehyde dehydrogenase. Biochem Biophys Res Commun 2018; 503:2848-2854. [PMID: 30107909 DOI: 10.1016/j.bbrc.2018.08.053] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/19/2018] [Accepted: 08/06/2018] [Indexed: 11/20/2022]
Abstract
The aspartate pathway, uniquely found in plants and microorganisms, offers novel potential targets for the development of new antimicrobial drugs. Aspartate semialdehyde dehydrogenase (ASADH) catalyzes production of a key intermediate at the first branch point in this pathway. Several fungal ASADH structures have been determined, but the prior crystallization conditions had precluded complex formation with enzyme inhibitors. The first inhibitor-bound and cofactor-bound structures of ASADH from the pathogenic fungi Blastomyces dermatitidis have now been determined, along with a structural and functional comparison to other ASADH family members. The structure of this new ASADH is similar to the other fungal orthologs, but with some critical differences in the orientation of some active site functional groups and in the subunit interface region. The presence of this bound inhibitor reveals the first details about inhibitor binding interactions, and the flexible orientation of its aromatic ring provides helpful insights into the design of potentially more potent and selective antifungal compounds.
Collapse
|
460
|
Santos-Gandelman J, Rodrigues ML, Machado Silva A. Future perspectives for cryptococcosis treatment. Expert Opin Ther Pat 2018; 28:625-634. [PMID: 30084284 DOI: 10.1080/13543776.2018.1503252] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
INTRODUCTION Cryptococcosis is one of the most devastating human fungal infections. Despite its impact, none of the standard antifungals were developed after 1990. New, improved, less toxic, affordable and widely available treatment is, therefore, imperative. AREAS COVERED This review offers an insight into technological developments for cryptococcosis disclosed in patent literature. From a broad search of patent documents claiming cryptococcosis treatment and having earliest priority between 1995 and 2015, we selected and summarized compounds/molecules (i) revealed in documents disclosing in vivo activity against Cryptococcus spp. or (ii) found in the pipeline of companies that appeared as assignees in our patent search. This information was complemented with data on compounds under development for this indication from the database Integrity (Clarivate Analytics). EXPERT OPINION This review demonstrates that drug development against cryptococcosis is discrete. However, it also shows that the existing development is not focused on a single class of molecules, but on different types of molecules with distinct fungal targets, reflecting the complexity of generating novel anti-cryptococcal tools. Given the intrinsic difficulties and high costs of drug development and the evident market failure in this field, we consider drug repurposing the most promising avenue for cryptococcosis treatment.
Collapse
Affiliation(s)
- Juliana Santos-Gandelman
- a Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças Negligenciadas (INCT-IDN), Centro de Desenvolvimento Tecnológico em Saúde (CDTS) , Fundação Oswaldo Cruz (Fiocruz) , Rio de Janeiro/RJ , Brazil
| | - Márcio Lourenço Rodrigues
- b Instituto Carlos Chagas (ICC) , Fundação Oswaldo Cruz - Fiocruz. Rua Prof , Algacyr Munhoz Mader, Curitiba/PR , Brazil.,c Instituto de Microbiologia Paulo de Góes , Universidade Federal do Rio de Janeiro - UFRJ , Av. Carlos Chagas Filho, Rio de Janeiro/RJ , Brazil
| | - Alice Machado Silva
- a Instituto Nacional de Ciência e Tecnologia de Inovação em Doenças Negligenciadas (INCT-IDN), Centro de Desenvolvimento Tecnológico em Saúde (CDTS) , Fundação Oswaldo Cruz (Fiocruz) , Rio de Janeiro/RJ , Brazil.,d Instituto René Rachou , Fundação Oswaldo Cruz - Fiocruz Minas , Av. Augusto de Lima, Belo Horizonte , MG , Brazil
| |
Collapse
|
461
|
Denning DW, Kneale M, Sobel JD, Rautemaa-Richardson R. Global burden of recurrent vulvovaginal candidiasis: a systematic review. THE LANCET. INFECTIOUS DISEASES 2018; 18:e339-e347. [PMID: 30078662 DOI: 10.1016/s1473-3099(18)30103-8] [Citation(s) in RCA: 279] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 11/28/2017] [Accepted: 12/19/2017] [Indexed: 01/10/2023]
Abstract
Recurrent vulvovaginal candidiasis is a debilitating, long-term condition that can severely affect the quality of life of affected women. No estimates of the global prevalence or lifetime incidence of this disease have been reported. For this systematic review, we searched PubMed, Embase, and Web of Science databases for population-based studies published between 1985 and 2016 that reported on the prevalence of recurrent vulvovaginal candidiasis, defined as four or more episodes of the infection every year. We identified 489 unique articles, of which eight were included, consisting of 17 365 patients from 11 countries. We generated estimates of annual global prevalence, estimated lifetime incidence and economic loss due to recurrent vulvovaginal candidiasis, and predicted the number of women at risk to 2030. Worldwide, recurrent vulvovaginal candidiasis affects about 138 million women annually (range 103-172 million), with a global annual prevalence of 3871 per 100 000 women; 372 million women are affected by recurrent vulvovaginal candidiasis over their lifetime. The 25-34 year age group has the highest prevalence (9%). By 2030, the population of women with recurrent vulvovaginal candidiasis each year is estimated to increase to almost 158 million, resulting in 20 240 664 extra cases with current trends using base case estimates in parallel with an estimated growth in females from 3·34 billion to 4·181 billion. In high-income countries, the economic burden from lost productivity could be up to US$14·39 billion annually. The high prevalence, substantial morbidity, and economic losses of recurrent vulvovaginal candidiasis require better solutions and improved quality of care for affected women.
Collapse
Affiliation(s)
- David W Denning
- Global Action Fund for Fungal Infections, Geneva, Switzerland; University of Manchester and National Aspergillosis Centre, Wythenshawe Hospital, Manchester University Hospital Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK.
| | - Matthew Kneale
- University of Manchester and National Aspergillosis Centre, Wythenshawe Hospital, Manchester University Hospital Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK
| | - Jack D Sobel
- School of Medicine, Wayne State University, Detroit, MI, USA
| | - Riina Rautemaa-Richardson
- University of Manchester and National Aspergillosis Centre, Wythenshawe Hospital, Manchester University Hospital Foundation Trust, Manchester Academic Health Science Centre, Manchester, UK; Mycology Reference Centre Manchester, Wythenshawe Hospital, Manchester, UK
| |
Collapse
|
462
|
Garcia C, Burgain A, Chaillot J, Pic É, Khemiri I, Sellam A. A phenotypic small-molecule screen identifies halogenated salicylanilides as inhibitors of fungal morphogenesis, biofilm formation and host cell invasion. Sci Rep 2018; 8:11559. [PMID: 30068935 PMCID: PMC6070544 DOI: 10.1038/s41598-018-29973-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Accepted: 07/23/2018] [Indexed: 12/15/2022] Open
Abstract
A poorly exploited paradigm in the antimicrobial therapy field is to target virulence traits for drug development. In contrast to target-focused approaches, antivirulence phenotypic screens enable identification of bioactive molecules that induce a desirable biological readout without making a priori assumption about the cellular target. Here, we screened a chemical library of 678 small molecules against the invasive hyphal growth of the human opportunistic yeast Candida albicans. We found that a halogenated salicylanilide (N1-(3,5-dichlorophenyl)-5-chloro-2-hydroxybenzamide) and one of its analogs, Niclosamide, an FDA-approved anthelmintic in humans, exhibited both antifilamentation and antibiofilm activities against C. albicans and the multi-resistant yeast C. auris. The antivirulence activity of halogenated salicylanilides were also expanded to C. albicans resistant strains with different resistance mechanisms. We also found that Niclosamide protected the intestinal epithelial cells against invasion by C. albicans. Transcriptional profiling of C. albicans challenged with Niclosamide exhibited a signature that is characteristic of the mitochondria-to-nucleus retrograde response. Our chemogenomic analysis showed that halogenated salicylanilides compromise the potential-dependant mitochondrial protein translocon machinery. Given the fact that the safety of Niclosamide is well established in humans, this molecule could represent the first clinically approved antivirulence agent against a pathogenic fungus.
Collapse
Affiliation(s)
- Carlos Garcia
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada
| | - Anaïs Burgain
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada
| | - Julien Chaillot
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada
| | - Émilie Pic
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada
| | - Inès Khemiri
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada
| | - Adnane Sellam
- CHU de Québec Research Center (CHUQ), Université Laval, Quebec City, QC, Canada.
- Department of Microbiology-Infectious Disease and Immunology, Faculty of Medicine, Université Laval, Quebec City, QC, Canada.
- Big Data Research Centre (BDRC-UL), Université Laval, Faculty of Sciences and engineering, Quebec City, QC, Canada.
| |
Collapse
|
463
|
Challenges and recent progress in drug discovery for tropical diseases. Nature 2018; 559:498-506. [PMID: 30046073 PMCID: PMC6129172 DOI: 10.1038/s41586-018-0327-4] [Citation(s) in RCA: 130] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023]
Abstract
Infectious tropical diseases have a huge effect in terms of mortality and morbidity, and impose a heavy economic burden on affected countries. These diseases predominantly affect the world's poorest people. Currently available drugs are inadequate for the majority of these diseases, and there is an urgent need for new treatments. This Review discusses some of the challenges involved in developing new drugs to treat these diseases and highlights recent progress. While there have been notable successes, there is still a long way to go.
Collapse
|
464
|
Kean R, Delaney C, Sherry L, Borman A, Johnson EM, Richardson MD, Rautemaa-Richardson R, Williams C, Ramage G. Transcriptome Assembly and Profiling of Candida auris Reveals Novel Insights into Biofilm-Mediated Resistance. mSphere 2018; 3:e00334-18. [PMID: 29997121 PMCID: PMC6041501 DOI: 10.1128/msphere.00334-18] [Citation(s) in RCA: 125] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 06/21/2018] [Indexed: 12/13/2022] Open
Abstract
Candida auris has emerged as a significant global nosocomial pathogen. This is primarily due to its antifungal resistance profile but also its capacity to form adherent biofilm communities on a range of clinically important substrates. While we have a comprehensive understanding of how other Candida species resist and respond to antifungal challenge within the sessile phenotype, our current understanding of C. auris biofilm-mediated resistance is lacking. In this study, we are the first to perform transcriptomic analysis of temporally developing C. auris biofilms, which were shown to exhibit phase- and antifungal class-dependent resistance profiles. A de novo transcriptome assembly was performed, where sequenced sample reads were assembled into an ~11.5-Mb transcriptome consisting of 5,848 genes. Differential expression (DE) analysis demonstrated that 791 and 464 genes were upregulated in biofilm formation and planktonic cells, respectively, with a minimum 2-fold change. Adhesin-related glycosylphosphatidylinositol (GPI)-anchored cell wall genes were upregulated at all time points of biofilm formation. As the biofilm developed into intermediate and mature stages, a number of genes encoding efflux pumps were upregulated, including ATP-binding cassette (ABC) and major facilitator superfamily (MFS) transporters. When we assessed efflux pump activity biochemically, biofilm efflux was greater than that of planktonic cells at 12 and 24 h. When these were inhibited, fluconazole sensitivity was enhanced 4- to 16-fold. This study demonstrates the importance of efflux-mediated resistance within complex C. auris communities and may explain the resistance of C. auris to a range of antimicrobial agents within the hospital environment.IMPORTANCE Fungal infections represent an important cause of human morbidity and mortality, particularly if the fungi adhere to and grow on both biological and inanimate surfaces as communities of cells (biofilms). Recently, a previously unrecognized yeast, Candida auris, has emerged globally that has led to widespread concern due to the difficulty in treating it with existing antifungal agents. Alarmingly, it is also able to grow as a biofilm that is highly resistant to antifungal agents, yet we are unclear about how it does this. Here, we used a molecular approach to investigate the genes that are important in causing the cells to be resistant within the biofilm. The work provides significant insights into the importance of efflux pumps, which actively pump out toxic antifungal drugs and therefore enhance fungal survival within a variety of harsh environments.
Collapse
Affiliation(s)
- Ryan Kean
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- Institute of Healthcare, Policy and Practise, University of the West of Scotland, Paisley, United Kingdom
| | - Christopher Delaney
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Leighann Sherry
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Andrew Borman
- National Mycology Reference Laboratory, Public Health England South-West, Bristol, United Kingdom
| | - Elizabeth M Johnson
- National Mycology Reference Laboratory, Public Health England South-West, Bristol, United Kingdom
| | - Malcolm D Richardson
- Mycology Reference Centre Manchester, University Hospital of South Manchester & University of Manchester, Manchester Academic Health Sciences Centre, Faculty of Biology, Medicine and Health, Division of Infection, Immunity and Respiratory Medicine, Manchester, United Kingdom
| | - Riina Rautemaa-Richardson
- Mycology Reference Centre Manchester, University Hospital of South Manchester & University of Manchester, Manchester Academic Health Sciences Centre, Faculty of Biology, Medicine and Health, Division of Infection, Immunity and Respiratory Medicine, Manchester, United Kingdom
| | - Craig Williams
- Institute of Healthcare, Policy and Practise, University of the West of Scotland, Paisley, United Kingdom
- ESCMID Study Group for Biofilms (ESGB)‡
| | - Gordon Ramage
- Oral Sciences Research Group, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
- ESCMID Study Group for Biofilms (ESGB)‡
| |
Collapse
|
465
|
Romo JA, Pierce CG, Esqueda M, Hung CY, Saville SP, Lopez-Ribot JL. In Vitro Characterization of a Biaryl Amide Anti-virulence Compound Targeting Candida albicans Filamentation and Biofilm Formation. Front Cell Infect Microbiol 2018; 8:227. [PMID: 30042929 PMCID: PMC6048184 DOI: 10.3389/fcimb.2018.00227] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/18/2018] [Indexed: 12/26/2022] Open
Abstract
We have previously identified a small molecule compound, N-[3-(allyloxy)-phenyl]-4-methoxybenzamide (9029936), that exerts potent inhibitory activity against filamentation and biofilm formation by the Candida albicans SC5314 strain and represents a lead candidate for the development of anti-virulence approaches against C. albicans infections. Here we present data from a series of experiments to further characterize its in vitro activity and drug-like characteristics. We demonstrate the activity of this compound against a panel of C. albicans clinical isolates, including several displaying resistance to current antifungals; as well as against a set of C. albicans gain of function strains in key transcriptional regulators of antifungal drug resistance. The compound also inhibits filamentation and biofilm formation in the closely related species C. dubliniensis, but not C. glabrata or C. tropicalis. Combinatorial studies reveal the potential of compound 9029936 to be used together with currently available conventional antifungals. Results of serial passage experiments indicate that repeated exposure to this compound does not elicit resistance. Viability staining of C. albicans in the presence of high concentrations of compound 9029936 confirms that the compound is not toxic to fungal cells, and cytological staining using image flow cytometry analysis reveals that treatment with the lead compound affects hyphal length, with additional effects on cell wall and integrity of the membrane system. In vitro pharmacological profiling provides further evidence that the lead compound displays a safe profile, underscoring its excellent “drug-like” characteristics. Altogether these results confirm the potential of this compound to be further developed as a true anti-virulence agent for the treatment of C. albicans infections, including those refractory to treatment with conventional antifungal agents.
Collapse
Affiliation(s)
- Jesus A Romo
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Christopher G Pierce
- Department of Biology, University of the Incarnate Word, San Antonio, TX, United States
| | - Marisol Esqueda
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Chiung-Yu Hung
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Stephen P Saville
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Jose L Lopez-Ribot
- Department of Biology, South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, TX, United States
| |
Collapse
|
466
|
Novel carbazole-triazole conjugates as DNA-targeting membrane active potentiators against clinical isolated fungi. Eur J Med Chem 2018; 155:579-589. [DOI: 10.1016/j.ejmech.2018.06.022] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/09/2018] [Accepted: 06/08/2018] [Indexed: 11/20/2022]
|
467
|
Benzofuro[3,2-d]pyrimidines inspired from cercosporamide CaPkc1 inhibitor: Synthesis and evaluation of fluconazole susceptibility restoration. Bioorg Med Chem Lett 2018; 28:2250-2255. [DOI: 10.1016/j.bmcl.2018.05.044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Revised: 05/20/2018] [Accepted: 05/23/2018] [Indexed: 01/05/2023]
|
468
|
Meir Z, Osherov N. Vitamin Biosynthesis as an Antifungal Target. J Fungi (Basel) 2018; 4:E72. [PMID: 29914189 PMCID: PMC6023522 DOI: 10.3390/jof4020072] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 06/12/2018] [Accepted: 06/13/2018] [Indexed: 12/18/2022] Open
Abstract
The large increase in the population of immunosuppressed patients, coupled with the limited efficacy of existing antifungals and rising resistance toward them, have dramatically highlighted the need to develop novel drugs for the treatment of invasive fungal infections. An attractive possibility is the identification of possible drug targets within essential fungal metabolic pathways not shared with humans. Here, we review the vitamin biosynthetic pathways (vitamins A⁻E, K) as candidates for the development of antifungals. We present a set of ranking criteria that identify the vitamin B2 (riboflavin), B5 (pantothenic acid), and B9 (folate) biosynthesis pathways as being particularly rich in new antifungal targets. We propose that recent scientific advances in the fields of drug design and fungal genomics have developed sufficiently to merit a renewed look at these pathways as promising sources for the development of novel classes of antifungals.
Collapse
Affiliation(s)
- Zohar Meir
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel.
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel-Aviv University, Ramat-Aviv, Tel-Aviv 69978, Israel.
| |
Collapse
|
469
|
|
470
|
Mokhtari M, Jackson MD, Brown AS, Ackerley DF, Ritson NJ, Keyzers RA, Munkacsi AB. Bioactivity-Guided Metabolite Profiling of Feijoa ( Acca sellowiana) Cultivars Identifies 4-Cyclopentene-1,3-dione as a Potent Antifungal Inhibitor of Chitin Synthesis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2018; 66:5531-5539. [PMID: 29546758 DOI: 10.1021/acs.jafc.7b06154] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Pathogenic fungi continue to develop resistance against current antifungal drugs. To explore the potential of agricultural waste products as a source of novel antifungal compounds, we obtained an unbiased GC-MS profile of 151 compounds from 16 commercial and experimental cultivars of feijoa peels. Multivariate analysis correlated 93% of the compound profiles with antifungal bioactivities. Of the 18 compounds that significantly correlated with antifungal activity, 5 had not previously been described from feijoa. Two novel cultivars were the most bioactive, and the compound 4-cyclopentene-1,3-dione, detected in these cultivars, was potently antifungal (IC50 = 1-2 μM) against human-pathogenic Candida species. Haploinsufficiency and fluorescence microscopy analyses determined that the synthesis of chitin, a fungal-cell-wall polysaccharide, was the target of 4-cyclopentene-1,3-dione. This fungal-specific mechanism was consistent with a 22-70-fold reduction in antibacterial activity. Overall, we identified the agricultural waste product of specific cultivars of feijoa peels as a source of potential high-value antifungal compounds.
Collapse
Affiliation(s)
- Mona Mokhtari
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Michael D Jackson
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Alistair S Brown
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - David F Ackerley
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
- Centre for Biodiscovery , Victoria University of Wellington , Wellington 6012 , New Zealand
| | | | - Robert A Keyzers
- Centre for Biodiscovery , Victoria University of Wellington , Wellington 6012 , New Zealand
- School of Chemical and Physical Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
| | - Andrew B Munkacsi
- School of Biological Sciences , Victoria University of Wellington , Wellington 6012 , New Zealand
- Centre for Biodiscovery , Victoria University of Wellington , Wellington 6012 , New Zealand
| |
Collapse
|
471
|
Ramachandran R, Ramesh S, Ramkumar S, Chakrabarti A, Roy U. Calcium Alginate Bead-mediated Enhancement of the Selective Recovery of a Lead Novel Antifungal Bacillomycin Variant. Appl Biochem Biotechnol 2018; 186:917-936. [PMID: 29797296 DOI: 10.1007/s12010-018-2778-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Accepted: 05/04/2018] [Indexed: 12/20/2022]
Abstract
In the pursuit of new antifungal compounds, five coproduced lipopeptide variants (AF1 to AF5) from wild-type Bacillus subtilis RLID 12.1 were identified in our previous study. Out of five, AF4 was identified as a novel lead molecule belonging to the bacillomycin family showing less cytotoxicity at its respective minimum inhibitory concentrations (MIC) evaluated against 81 strains of Candida and Cryptococcus species (including clinical isolates); besides this, AF4 purified in the present study exhibited encouraging MIC values against 10 clinical mycelial fungi. Aiming for a selective production augmentation of AF4 lipopeptide variant, a new fermentation media comprising malt extract (1.01%), dextrose (0.55%), peptone (1.79%), MnSO4 (2 mM), and NaCl (0.5%) was formulated. Maximum production of 954.8 ± 10.8 mg/L was achieved with 44% selectivity at 30 °C compared to unoptimized conditions (186.4 ± 6.1 mg/L). Use of calcium alginate beads in the formulated media during the onset of lipopeptide production resulted in an augmentation in the selectivity of the most efficacious AF4 variant to about 72% presumably due to attenuation of other coproduced lipopeptide variants AF1 and AF2. Difference in yield of lipopeptides varied with bead size, bead preparation ratios, and sodium alginate concentrations. Use of Ca-alginate beads in the upstream production process of the lead AF4 variant may be considered as a novel strategy to address the potential challenge that may arise during the scale-up and downstream processing steps. Another significant finding derived from the study is that the proportion of bacillomycin variants of B. subtilis RLID 12.1 could be controlled by temperature and metal ions under static and shaking conditions.
Collapse
Affiliation(s)
- Ramya Ramachandran
- Department of Biological Sciences, Birla Institute of Technology And Science Pilani KK Birla Goa Campus, Goa, 403726, India
| | - Swetha Ramesh
- Department of Biological Sciences, Birla Institute of Technology And Science Pilani KK Birla Goa Campus, Goa, 403726, India
| | - Srinath Ramkumar
- Department of Biological Sciences, Birla Institute of Technology And Science Pilani KK Birla Goa Campus, Goa, 403726, India
| | - Arunaloke Chakrabarti
- Department of Medical Microbiology, Post Graduate Institute of Medical Education & Research, Chandigarh, India
| | - Utpal Roy
- Department of Biological Sciences, Birla Institute of Technology And Science Pilani KK Birla Goa Campus, Goa, 403726, India.
| |
Collapse
|
472
|
Geddes-McAlister J, Shapiro RS. New pathogens, new tricks: emerging, drug-resistant fungal pathogens and future prospects for antifungal therapeutics. Ann N Y Acad Sci 2018; 1435:57-78. [DOI: 10.1111/nyas.13739] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 03/19/2018] [Accepted: 03/28/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Jennifer Geddes-McAlister
- Department of Molecular and Cellular Biology; University of Guelph; Guelph Ontario Canada
- Department of Proteomics and Signal Transduction; Max Planck Institute of Biochemistry; Munich Germany
| | - Rebecca S. Shapiro
- Department of Molecular and Cellular Biology; University of Guelph; Guelph Ontario Canada
| |
Collapse
|
473
|
Amino Acid Metabolism and Transport Mechanisms as Potential Antifungal Targets. Int J Mol Sci 2018; 19:ijms19030909. [PMID: 29562716 PMCID: PMC5877770 DOI: 10.3390/ijms19030909] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 03/13/2018] [Accepted: 03/15/2018] [Indexed: 01/15/2023] Open
Abstract
Discovering new drugs for treatment of invasive fungal infections is an enduring challenge. There are only three major classes of antifungal agents, and no new class has been introduced into clinical practice in more than a decade. However, recent advances in our understanding of the fungal life cycle, functional genomics, proteomics, and gene mapping have enabled the identification of new drug targets to treat these potentially deadly infections. In this paper, we examine amino acid transport mechanisms and metabolism as potential drug targets to treat invasive fungal infections, including pathogenic yeasts, such as species of Candida and Cryptococcus, as well as molds, such as Aspergillus fumigatus. We also explore the mechanisms by which amino acids may be exploited to identify novel drug targets and review potential hurdles to bringing this approach into clinical practice.
Collapse
|
474
|
Revie NM, Iyer KR, Robbins N, Cowen LE. Antifungal drug resistance: evolution, mechanisms and impact. Curr Opin Microbiol 2018; 45:70-76. [PMID: 29547801 DOI: 10.1016/j.mib.2018.02.005] [Citation(s) in RCA: 271] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 02/12/2018] [Indexed: 12/17/2022]
Abstract
Microorganisms have a remarkable capacity to evolve resistance to antimicrobial agents, threatening the efficacy of the limited arsenal of antimicrobials and becoming a dire public health crisis. This is of particular concern for fungal pathogens, which cause devastating invasive infections with treatment options limited to only three major classes of antifungal drugs. The paucity of antifungals with clinical utility is in part due to close evolutionary relationships between these eukaryotic pathogens and their human hosts, which limits the unique targets to be exploited therapeutically. This review highlights the mechanisms by which fungal pathogens of humans evolve resistance to antifungal drugs, which provide crucial insights to enable development of novel therapeutic strategies to thwart drug resistance and combat fungal infectious disease.
Collapse
Affiliation(s)
- Nicole M Revie
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Kali R Iyer
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5G 1M1, Canada.
| |
Collapse
|
475
|
Mohammad H, Elghazawy NH, Eldesouky HE, Hegazy YA, Younis W, Avrimova L, Hazbun T, Arafa RK, Seleem MN. Discovery of a Novel Dibromoquinoline Compound Exhibiting Potent Antifungal and Antivirulence Activity That Targets Metal Ion Homeostasis. ACS Infect Dis 2018; 4:403-414. [PMID: 29370698 DOI: 10.1021/acsinfecdis.7b00215] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Globally, invasive fungal infections pose a significant challenge to modern human medicine due to the limited number of antifungal drugs and the rise in resistance to current antifungal agents. A vast majority of invasive fungal infections are caused by species of Candida, Cryptococcus, and Aspergillus. Novel antifungal molecules consisting of unexploited chemical scaffolds with a unique mechanism are a pressing need. The present study identifies a dibromoquinoline compound (4b) with broad-spectrum antifungal activity that inhibits the growth of pertinent species of Candida (chiefly C. albicans), Cryptococcus, and Aspergillus at a concentration of as low as 0.5 μg/mL. Furthermore, 4b, at a subinhibitory concentration, interfered with the expression of two key virulence factors (hyphae and biofilm formation) involved in C. albicans pathogenesis. Three yeast deletion strains ( cox17Δ, ssa1Δ, and aft2Δ) related to metal ion homeostasis were found to be highly sensitive to 4b in growth assays, indicating that the compound exerts its antifungal effect through a unique, previously unexploited mechanism. Supplementing the media with either copper or iron ions reversed the strain sensitivity to 4b, further corroborating that the compound targets metal ion homeostasis. 4b's potent antifungal activity was validated in vivo, as the compound enhanced the survival of Caenorhabditis elegans infected with fluconazole-resistant C. albicans. The present study indicates that 4b warrants further investigation as a novel antifungal agent.
Collapse
Affiliation(s)
- Haroon Mohammad
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, Indiana 47907, United States
| | - Nehal H. Elghazawy
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Sheikh Zayed District, Sixth of October City, Cairo, Egypt 12588
| | - Hassan E. Eldesouky
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, Indiana 47907, United States
| | - Youssef A. Hegazy
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, Indiana 47907, United States
| | - Waleed Younis
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, Indiana 47907, United States
| | - Larisa Avrimova
- Bindley Bioscience Center, Purdue University, 1201 W State Street, West Lafayette, Indiana 47907, United States
| | - Tony Hazbun
- Bindley Bioscience Center, Purdue University, 1201 W State Street, West Lafayette, Indiana 47907, United States
- Department of Medicinal Chemistry and Molecular Pharmacology, College of Pharmacy, Purdue University, 575 Stadium Mall Drive, West Lafayette, Indiana 47907, United States
| | - Reem K. Arafa
- Biomedical Sciences Program, University of Science and Technology, Zewail City of Science and Technology, Sheikh Zayed District, Sixth of October City, Cairo, Egypt 12588
| | - Mohamed N. Seleem
- Department of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, 625 Harrison Street, West Lafayette, Indiana 47907, United States
- Purdue Institute of Inflammation, Immunology, and Infectious Disease, 610 Purdue Mall, West Lafayette, Indiana 47907, United States
| |
Collapse
|
476
|
Gupta S, Chandna N, Singh AK, Jain N. Regioselective Synthesis of N 2-Alkylated-1,2,3 Triazoles and N 1-Alkylated Benzotriazoles: Cu 2S as a Recyclable Nanocatalyst for Oxidative Amination of N, N-Dimethylbenzylamines. J Org Chem 2018; 83:3226-3235. [PMID: 29463081 DOI: 10.1021/acs.joc.8b00107] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Copper chalcogenide nanoparticles (Cu2S) synthesized for the first time from a single-source precursor, CuSPh, act as highly efficient and reusable heterogeneous catalyst for regioselective amination of N, N-dimethylbenzylamines with various azoles. The reaction involves N-H/C-H cross-dehydrogenative coupling (CDC) and demonstrates wide functional group tolerance. It provides highly selective access to N1-alkylated benzotriazoles, N2-alkylated 1,2,3-triazoles and 4-phenyl-1,2,3-triazoles, and N-alkylated carbazoles in 70-89% yields under solvent-free conditions. The Cu2S nanocatalyst has been characterized by PXRD, XPS, SEM-EDX, and HR-TEM analysis. Mechanistic studies suggest that the reaction follows a radical pathway and involves an iminium ion intermediate.
Collapse
Affiliation(s)
- Sonu Gupta
- Department of Chemistry , Indian Institute of Technology , New Delhi , India 110016
| | - Nisha Chandna
- Department of Chemistry , Indian Institute of Technology , New Delhi , India 110016
| | - Ajai K Singh
- Department of Chemistry , Indian Institute of Technology , New Delhi , India 110016
| | - Nidhi Jain
- Department of Chemistry , Indian Institute of Technology , New Delhi , India 110016
| |
Collapse
|
477
|
Abstract
Cryptococcal meningitis is the most common central nervous system infection in the world today. It occurs primarily, but not exclusively, in immunocompromised individuals and despite substantial improvement in management of clinical events like AIDS, the numbers of cases of cryptococcosis remain very high. Unfortunately, despite several antifungal agents available for treatment, morbidity and mortality rates remain high with this fungal infection. In this Review, we will describe the treatments and strategies for success, identify the failures, and provide insights into the future developments / improvements for management. This sugar-coated yeast can play havoc within the human brain. Our goals must be to either prevent or diagnose disease early and treat aggressively with all our clinical tools when disease is detected.
Collapse
Affiliation(s)
- Ahmad Mourad
- Department of Medicine, Medical Center, Duke University, Durham, NC, USA
| | - John R Perfect
- Department of Medicine, Medical Center, Duke University, Durham, NC, USA
| |
Collapse
|
478
|
Mionić Ebersold M, Petrović M, Fong WK, Bonvin D, Hofmann H, Milošević I. Hexosomes with Undecylenic Acid Efficient against Candida albicans. NANOMATERIALS (BASEL, SWITZERLAND) 2018; 8:E91. [PMID: 29414873 PMCID: PMC5853723 DOI: 10.3390/nano8020091] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 01/28/2018] [Accepted: 02/01/2018] [Indexed: 11/22/2022]
Abstract
Due to the growing issues with fungal infections, especially with Candida, there is still a need to develop novel anti-Candida materials. One of the known antifungal agents is undecylenic acid (UA), which still cannot be efficiently used due to its oily nature, and thus limited solubility. By taking advantage of the properties of UA, we developed an emulsion with hexagonal phase, i.e., hexosomes, whose structure and morphology was studied by small-angle X-ray scattering and cryo-electron microscopy, respectively. The presence of UA in the hexosome was confirmed by spectroscopy. Moreover, we studied the anti-Candida effect of hexosomes and their cytotoxicity toward human cells. The minimal inhibitory concentration for the 50% and 90% Candida-growth reduction was found at 0.01 and 0.16 wt % hexosomes, respectively (i.e., 2 and 32 pghex/C.a.cell, respectively). The percentage of metabolically active Candida was reduced by 72-96% at hexosome concentrations of 1.0-8.2 pghex/C.a.cell as compared to untreated Candida. Furthermore, at the same concentration range the embedded filamentation test after 24 and 48 h showed the inhibition of both the filamentation and growth of Candida, while the preliminary toxicity test showed that hexosomes were nontoxic for human cells. All these render the here-developed hexosomes with UA efficient and promising anti-Candida agents.
Collapse
Affiliation(s)
- Marijana Mionić Ebersold
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Milica Petrović
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
- Faculty of Medicine, University of Niš, 18000 Niš, Serbia.
| | - Wye-Khay Fong
- Adolphe Merkle Institute, University of Fribourg, 1700 Fribourg, Switzerland.
| | - Debora Bonvin
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Heinrich Hofmann
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Irena Milošević
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| |
Collapse
|
479
|
Xu L, Li Y, Biggins JB, Bowman BR, Verdine GL, Gloer JB, Alspaugh JA, Bills GF. Identification of cyclosporin C from Amphichorda felina using a Cryptococcus neoformans differential temperature sensitivity assay. Appl Microbiol Biotechnol 2018; 102:2337-2350. [PMID: 29396588 DOI: 10.1007/s00253-018-8792-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/02/2018] [Accepted: 01/16/2018] [Indexed: 12/25/2022]
Abstract
We used a temperature differential assay with the opportunistic fungal pathogen Cryptococcus neoformans as a simple screening platform to detect small molecules with antifungal activity in natural product extracts. By screening of a collection extracts from two different strains of the coprophilous fungus, Amphichorda felina, we detected strong, temperature-dependent antifungal activity using a two-plate agar zone of inhibition assay at 25 and 37 °C. Bioassay-guided fractionation of the crude extract followed by liquid chromatography-mass spectrometry (LC-MS) and nuclear magnetic resonance spectroscopy (NMR) identified cyclosporin C (CsC) as the main component of the crude extract responsible for growth inhibition of C. neoformans at 37 °C. The presence of CsC was confirmed by comparison with a commercial standard. We sequenced the genome of A. felina to identify and annotate the CsC biosynthetic gene cluster. The only previously characterized gene cluster for the biosynthesis of similar compounds is that of the related immunosuppressant drug cyclosporine A (CsA). The CsA and CsC gene clusters share a high degree of synteny and sequence similarity. Amino acid changes in the adenylation domain of the CsC nonribosomal peptide synthase's sixth module may be responsible for the substitution of L-threonine compared to L-α-aminobutyric acid in the CsA peptide core. This screening strategy promises to yield additional antifungal natural products with a focused spectrum of antimicrobial activity.
Collapse
Affiliation(s)
- Lijian Xu
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, 1881 East Road, 3SCR6.4676, Houston, TX, 77054, USA
- College of Agricultural Resources and Environment, Heilongjiang University, Harbin, 150080, China
| | - Yan Li
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, 1881 East Road, 3SCR6.4676, Houston, TX, 77054, USA
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China
| | - John B Biggins
- LifeMine Therapeutics, 430 E. 29th Street, Suite 830, New York, NY, 10016, USA
| | - Brian R Bowman
- LifeMine Therapeutics, 430 E. 29th Street, Suite 830, New York, NY, 10016, USA
| | - Gregory L Verdine
- LifeMine Therapeutics, 430 E. 29th Street, Suite 830, New York, NY, 10016, USA
| | - James B Gloer
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242, USA
| | - J Andrew Alspaugh
- Departments of Biochemistry and Medicine, Duke University Medical Center, Durham, NC, 27710, USA
| | - Gerald F Bills
- Texas Therapeutics Institute, The Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, 1881 East Road, 3SCR6.4676, Houston, TX, 77054, USA.
| |
Collapse
|
480
|
Targeting Candida spp. to develop antifungal agents. Drug Discov Today 2018; 23:802-814. [PMID: 29353694 DOI: 10.1016/j.drudis.2018.01.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 12/09/2017] [Accepted: 01/04/2018] [Indexed: 01/15/2023]
Abstract
Invasive fungal infections are a complex challenge throughout the world because of their high incidence, mainly in critically ill patients, and high mortality rates. The antifungal agents currently available are limited; thus, there is a need for the rapid development of new drugs. In silico methods are a modern strategy to explore interactions between new compounds and specific fungal targets, but they depend on precise genetic information. Here, we discuss the main Candida spp. target genes, including information about null mutants, virulence, cytolocalization, co-regulatory genes, and compounds that are related to protein expression. These data will provide a basis for the future in silico development of antifungal drugs.
Collapse
|
481
|
Lazić J, Ajdačić V, Vojnovic S, Zlatović M, Pekmezovic M, Mogavero S, Opsenica I, Nikodinovic-Runic J. Bis-guanylhydrazones as efficient anti-Candida compounds through DNA interaction. Appl Microbiol Biotechnol 2018; 102:1889-1901. [PMID: 29330691 DOI: 10.1007/s00253-018-8749-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/25/2017] [Accepted: 12/27/2017] [Indexed: 10/18/2022]
Abstract
Candida spp. are leading causes of opportunistic mycoses, including life-threatening hospital-borne infections, and novel antifungals, preferably aiming targets that have not been used before, are constantly needed. Hydrazone- and guanidine-containing molecules have shown a wide range of biological activities, including recently described excellent antifungal properties. In this study, four bis-guanylhydrazone derivatives (BG1-4) were generated following a previously developed synthetic route. Anti-Candida (two C. albicans, C. glabrata, and C. parapsilosis) minimal inhibitory concentrations (MICs) of bis-guanylhydrazones were between 2 and 15.6 μg/mL. They were also effective against preformed 48-h-old C. albicans biofilms. In vitro DNA interaction, circular dichroism, and molecular docking analysis showed the great ability of these compounds to bind fungal DNA. Competition with DNA-binding stain, exposure of phosphatidylserine at the outer layer of the cytoplasmic membrane, and activation of metacaspases were shown for BG3. This pro-apoptotic effect of BG3 was only partially due to the accumulation of reactive oxygen species in C. albicans, as only twofold MIC and higher concentrations of BG3 caused depolarization of mitochondrial membrane which was accompanied by the decrease of the activity of fungal mitochondrial dehydrogenases, while the activity of oxidative stress response enzymes glutathione reductase and catalase was not significantly affected. BG3 showed synergistic activity with amphotericin B with a fractional inhibitory concentration index of 0.5. It also exerted low cytotoxicity and the ability to inhibit epithelial cell (TR146) invasion and damage by virulent C. albicans SC5314. With further developments, BG3 may further progress in the antifungal pipeline as a DNA-targeting agent.
Collapse
Affiliation(s)
- Jelena Lazić
- Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, Belgrade, 11158, Serbia.,Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, 11000, Serbia
| | - Vladimir Ajdačić
- Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, Belgrade, 11158, Serbia
| | - Sandra Vojnovic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, 11000, Serbia
| | - Mario Zlatović
- Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, Belgrade, 11158, Serbia
| | - Marina Pekmezovic
- Department of Microbial Pathogenicity Mechanisms, Hans Knöll Institute, Jena, Germany
| | - Selene Mogavero
- Department of Microbial Pathogenicity Mechanisms, Hans Knöll Institute, Jena, Germany
| | - Igor Opsenica
- Faculty of Chemistry, University of Belgrade, Studentski trg 16, P.O. Box 51, Belgrade, 11158, Serbia.
| | - Jasmina Nikodinovic-Runic
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Vojvode Stepe 444a, Belgrade, 11000, Serbia.
| |
Collapse
|
482
|
Petrović M, Bonvin D, Hofmann H, Mionić Ebersold M. Fungicidal PMMA-Undecylenic Acid Composites. Int J Mol Sci 2018; 19:E184. [PMID: 29316713 PMCID: PMC5796133 DOI: 10.3390/ijms19010184] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 12/24/2017] [Accepted: 01/01/2018] [Indexed: 12/12/2022] Open
Abstract
Undecylenic acid (UA), known as antifungal agent, still cannot be used to efficiently modify commercial dental materials in such a way that this affects Candida. Actually, issues with Candida infections and fungal resistance compromise the use of Poly(methyl-methacrylate) (PMMA) as dental material. The challenge remains to turn PMMA into an antifugal material, which can ideally affect both sessile (attached) and planktonic (free-floating) Candida cells. We aimed to tackle this challenge by designing PMMA-UA composites with different UA concentrations (3-12%). We studied their physico-chemical properties, the antifungal effect on Candida and the cytotoxicity toward human cells. We found that UA changes the PMMA surface into a more hydrophilic one. Mainly, as-preparation composites with ≥6% UA reduced sessile Candida for >90%. After six days, the composites were still efficiently reducing the sessile Candida cells (for ~70% for composites with ≥6% UA). Similar results were recorded for planktonic Candida. Moreover, the inhibition zone increased along with the UA concentration. The antifungal effect of UA was also examined at the surface of an UA-loaded agar and the minimal inhibitory concentration (MIC90) was below the lowest-studied 0.0125% UA. Furthermore, the embedded filamentation test after 24 h and 48 h showed complete inhibition of the Candida growth at 0.4% UA.
Collapse
Affiliation(s)
- Milica Petrović
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
- Faculty of Medicine, University of Nis, 18006 Niš, Serbia.
| | - Debora Bonvin
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Heinrich Hofmann
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| | - Marijana Mionić Ebersold
- Powder Technology Laboratory, Institute of Materials, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland.
| |
Collapse
|
483
|
Dietl AM, Meir Z, Shadkchan Y, Osherov N, Haas H. Riboflavin and pantothenic acid biosynthesis are crucial for iron homeostasis and virulence in the pathogenic mold Aspergillus fumigatus. Virulence 2018; 9:1036-1049. [PMID: 30052132 PMCID: PMC6068542 DOI: 10.1080/21505594.2018.1482181] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Accepted: 05/22/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND Aspergillus fumigatus is the most prevalent airborne fungal pathogen, causing invasive fungal infections mainly in immunosuppressed individuals. Death rates from invasive aspergillosis remain high because of limited treatment options and increasing antifungal resistance. The aim of this study was to identify key fungal-specific genes participating in vitamin B biosynthesis in A. fumigatus. Because these genes are absent in humans they can serve as possible novel targets for antifungal drug development. METHODS By sequence homology we identified, deleted and analysed four key A. fumigatus genes (riboB, panA, pyroA, thiB) involved respectively in the biosynthesis of riboflavin (vitamin B2), pantothenic acid (vitamin B5), pyridoxine (vitamin B6) and thiamine (vitamin B1). RESULTS Deletion of riboB, panA, pyroA or thiB resulted in respective vitamin auxotrophy. Lack of riboflavin and pantothenic acid biosynthesis perturbed many cellular processes including iron homeostasis. Virulence in murine pulmonary and systemic models of infection was severely attenuated following deletion of riboB and panA, strongly reduced after pyroA deletion and weakly attenuated after thiB deletion. CONCLUSIONS This study reveals the biosynthetic pathways of the vitamins riboflavin and pantothenic acid as attractive targets for novel antifungal therapy. Moreover, the virulence studies with auxotrophic mutants serve to identify the availability of nutrients to pathogens in host niches. ABBREVIATIONS BPS: bathophenanthrolinedisulfonate; BSA: bovine serum albumin; CFU: colony forming unit; -Fe: iron starvation; +Fe: iron sufficiency; hFe: high iron; NRPSs: nonribosomal peptide synthetases; PKSs: polyketide synthaseses; wt: wild type.
Collapse
Affiliation(s)
- Anna-Maria Dietl
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| | - Zohar Meir
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Yona Shadkchan
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine Ramat-Aviv, Tel-Aviv, Israel
| | - Hubertus Haas
- Division of Molecular Biology, Biocenter, Medical University of Innsbruck, Innsbruck, Austria
| |
Collapse
|
484
|
Integrated transcriptomic analysis of Trichosporon Asahii uncovers the core genes and pathways of fluconazole resistance. Sci Rep 2017; 7:17847. [PMID: 29259317 PMCID: PMC5736589 DOI: 10.1038/s41598-017-18072-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/05/2017] [Indexed: 12/15/2022] Open
Abstract
Trichosporon asahii (T. asahii) has emerged as a dangerous pathogen that causes rare but life-threatening infections. Its resistance to certain antifungal agents makes it difficult to treat, especially for patients undergoing long-term antibiotic therapy. In this study, we performed a series of fluconazole (FLC) perturbation experiments for two T. asahii strains, a clinical isolate stain CBS 2479 (T2) and an environmental isolate strain CBS 8904 (T8), to uncover potential genes and pathways involved in FLC resistance. We achieved 10 transcriptomes of T2 and T8 that were based on dose and time series of FLC perturbations. Systematic comparisons of the transcriptomes revealed 32 T2 genes and 25 T8 genes that are highly sensitive to different FLC perturbations. In both T2 and T8 strains with the phenotype of FLC resistance, the processes of oxidation-reduction and transmembrane transport were detected to be significantly changed. The antifungal susceptibility testing of FLC and penicillin revealed their resistance pathways are merged. Accumulated mutations were found in 564 T2 and 225 T8 genes, including four highly mutated genes that are functionally related to the target of rapamycin complex (TOR). Our study provides abundant data towards genome-wide understanding of the molecular basis of FLC resistance in T. asahii.
Collapse
|
485
|
Romo JA, Pierce CG, Chaturvedi AK, Lazzell AL, McHardy SF, Saville SP, Lopez-Ribot JL. Development of Anti-Virulence Approaches for Candidiasis via a Novel Series of Small-Molecule Inhibitors of Candida albicans Filamentation. mBio 2017; 8:e01991-17. [PMID: 29208749 PMCID: PMC5717394 DOI: 10.1128/mbio.01991-17] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Accepted: 11/02/2017] [Indexed: 12/14/2022] Open
Abstract
Candida albicans remains the main etiologic agent of candidiasis, the most common fungal infection and now the third most frequent infection in U.S. hospitals. The scarcity of antifungal agents and their limited efficacy contribute to the unacceptably high morbidity and mortality rates associated with these infections. The yeast-to-hypha transition represents the main virulence factor associated with the pathogenesis of C. albicans infections. In addition, filamentation is pivotal for robust biofilm development, which represents another major virulence factor for candidiasis and further complicates treatment. Targeting pathogenic mechanisms rather than growth represents an attractive yet clinically unexploited approach in the development of novel antifungal agents. Here, we performed large-scale phenotypic screening assays with 30,000 drug-like small-molecule compounds within ChemBridge's DIVERSet chemical library in order to identify small-molecule inhibitors of C. albicans filamentation, and our efforts led to the identification of a novel series of bioactive compounds with a common biaryl amide core structure. The leading compound of this series, N-[3-(allyloxy)-phenyl]-4-methoxybenzamide, was able to prevent filamentation under all liquid and solid medium conditions tested, suggesting that it impacts a common core component of the cellular machinery that mediates hypha formation under different environmental conditions. In addition to filamentation, this compound also inhibited C. albicans biofilm formation. This leading compound also demonstrated in vivo activity in clinically relevant murine models of invasive and oral candidiasis. Overall, our results indicate that compounds within this series represent promising candidates for the development of novel anti-virulence approaches to combat C. albicans infections.IMPORTANCE Since fungi are eukaryotes, there is a limited number of fungus-specific targets and, as a result, the antifungal arsenal is exceedingly small. Furthermore, the efficacy of antifungal treatment is compromised by toxicity and development of resistance. As a consequence, fungal infections carry high morbidity and mortality rates, and there is an urgent but unmet need for novel antifungal agents. One appealing strategy for antifungal drug development is to target pathogenetic mechanisms associated with infection. In Candida albicans, one of the most common pathogenic fungi, morphogenetic transitions between yeast cells and filamentous hyphae represent a key virulence factor associated with the ability of fungal cells to invade tissues, cause damage, and form biofilms. Here, we describe and characterize a novel small-molecule compound capable of inhibiting C. albicans filamentation both in vitro and in vivo; as such, this compound represents a leading candidate for the development of anti-virulence therapies against candidiasis.
Collapse
Affiliation(s)
- Jesus A Romo
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Christopher G Pierce
- Department of Biology, University of the Incarnate Word, San Antonio, Texas, USA
| | - Ashok K Chaturvedi
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Anna L Lazzell
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Stanton F McHardy
- Department of Chemistry and Center for Innovation in Drug Discovery, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Stephen P Saville
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| | - Jose L Lopez-Ribot
- Department of Biology and South Texas Center for Emerging Infectious Diseases, The University of Texas at San Antonio, San Antonio, Texas, USA
| |
Collapse
|
486
|
The Genomic Landscape of the Fungus-Specific SWI/SNF Complex Subunit, Snf6, in Candida albicans. mSphere 2017; 2:mSphere00497-17. [PMID: 29152582 PMCID: PMC5687922 DOI: 10.1128/msphere.00497-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/14/2022] Open
Abstract
SWI/SNF is an ATP-dependent chromatin-remodeling complex that is required for the regulation of gene expression in eukaryotes. While most of the fungal SWI/SNF components are evolutionarily conserved with those of the metazoan SWI/SNF, subunits such as Snf6 are specific to certain fungi and thus represent potential antifungal targets. We have characterized the role of the Snf6 protein in Candida albicans. Our data showed that although there was low conservation of its protein sequence with other fungal orthologs, Snf6 was copurified with bona fide SWI/SNF complex subunits. The role of Snf6 in C. albicans was investigated by determining its genome-wide occupancy using chromatin immunoprecipitation coupled to tiling arrays in addition to transcriptional profiling of the snf6 conditional mutant. Snf6 directs targets that were enriched in functions related to carbohydrate and amino acid metabolic circuits, to cellular transport, and to heat stress responses. Under hypha-promoting conditions, Snf6 expanded its set of targets to include promoters of genes related to respiration, ribosome biogenesis, mating, and vesicle transport. In accordance with the genomic occupancy data, an snf6 doxycycline-repressible mutant exhibited growth defects in response to heat stress and also when grown in the presence of different fermentable and nonfermentable carbon sources. Snf6 was also required to differentiate invasive hyphae in response to different cues. This study represents the first comprehensive characterization, at the genomic level, of the role of SWI/SNF in the pathogenic yeast C. albicans and uncovers functions that are essential for fungal morphogenesis and metabolic flexibility. IMPORTANCECandida albicans is a natural component of the human microbiota but also an opportunistic pathogen that causes life-threatening infections in immunosuppressed patients. Current therapeutics include a limited number of molecules that suffer from limitations, including growing clinical resistance and toxicity. New molecules are being clinically investigated; however, the majority of these potential antifungals target the same processes as do the standard antifungals and might confront the same problems of toxicity and loss of efficiency due to the common resistance mechanisms. Here, we characterized the role of Snf6, a fungus-specific subunit of the chromatin-remodeling complex SWI/SNF. Our genomic and phenotypic data demonstrated a central role of Snf6 in biological processes that are critical for a fungal pathogen to colonize its host and cause disease, suggesting Snf6 as a possible antifungal target.
Collapse
|
487
|
McCarthy MW, Walsh TJ. Containment strategies to address the expanding threat of multidrug-resistant Candida auris. Expert Rev Anti Infect Ther 2017; 15:1095-1099. [PMID: 29110544 DOI: 10.1080/14787210.2017.1402678] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
INTRODUCTION Candida auris is an emerging multidrug resistant human yeast pathogen associated with nosocomial transmission and high mortality. The organism can be a challenge to diagnose, may be even more difficult to treat, and continues to pose an expanding threat to patients. Areas covered: Our medical center and others in the surrounding area have seen a concerning rise in confirmed cases of C. auris infection and substantial resources have been dedicated to containment measures. We draw on our in vitro and in vivo work with this organism to examine the most effective ways to curb the current outbreak. Expert commentary: We explore novel strategies to halt the spread C. auris, including enhanced molecular diagnostics, novel therapeutics, and epidemiologic studies to determine risk factors for infection and transmission.
Collapse
Affiliation(s)
- Matthew William McCarthy
- a Weill Cornell Medical College, Assistant Attending Physician, Division of General Internal Medicine , New York-Presbyterian Hospital , New York , NY , USA.,b Transplantation-Oncology Infectious Diseases Program, Chief, Medical Mycology Research Laboratory, Pediatrics, and Microbiology & Immunology , Weill Cornell Medical Center, Henry Schueler Foundation Scholar, Sharpe Family Foundation Scholar in Pediatric Infectious Diseases , New York , NY , USA
| | - Thomas J Walsh
- a Weill Cornell Medical College, Assistant Attending Physician, Division of General Internal Medicine , New York-Presbyterian Hospital , New York , NY , USA.,b Transplantation-Oncology Infectious Diseases Program, Chief, Medical Mycology Research Laboratory, Pediatrics, and Microbiology & Immunology , Weill Cornell Medical Center, Henry Schueler Foundation Scholar, Sharpe Family Foundation Scholar in Pediatric Infectious Diseases , New York , NY , USA
| |
Collapse
|
488
|
Inborn errors of immunity underlying fungal diseases in otherwise healthy individuals. Curr Opin Microbiol 2017; 40:46-57. [PMID: 29128761 DOI: 10.1016/j.mib.2017.10.016] [Citation(s) in RCA: 77] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 10/20/2017] [Indexed: 01/02/2023]
Abstract
It has been estimated that there are at least 1.5 million fungal species, mostly present in the environment, but only a few of these fungi cause human disease. Most fungal diseases are self-healing and benign, but some are chronic or life-threatening. Acquired and inherited defects of immunity, including breaches of mucocutaneous barriers and circulating leukocyte deficiencies, account for most severe modern-day mycoses. Other types of infection typically accompany these fungal infections. More rarely, severe fungal diseases can strike otherwise healthy individuals. Historical reports of fungi causing chronic peripheral infections (e.g. affecting the nails, skin, hair), and invasive diseases (e.g. brain, lungs, liver), in otherwise healthy patients, can be traced back to the mid-20th century. These fungi typically cause endemic, but not epidemic diseases, are more likely to underlie sporadic than familial cases, and only threaten a small proportion of infected individuals. The basis of this 'idiosyncratic' susceptibility has long remained unexplained, but it has recently become apparent that 'idiopathic' fungal diseases, in children, teenagers, and even adults, may be caused by single-gene inborn errors of immunity. The study of these unusual primary immunodeficiencies (PIDs) has led to the identification of molecules and cells playing a crucial role in human host defenses against certain fungi at particular anatomic sites. A picture is emerging of inborn errors of IL-17 immunity selectively underlying chronic mucocutaneous candidiasis, with little inter-individual variability, and of inborn errors of CARD9 immunity underlying various life-threatening invasive fungal diseases, differing between patients.
Collapse
|
489
|
McCarthy MW, Walsh TJ. The fungal meningitis outbreak five years later: what have we learned about Exserohilum rostratum? EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2017. [DOI: 10.1080/23808993.2017.1392827] [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]
Affiliation(s)
- Matthew W. McCarthy
- Medicine, Weill Cornell Medical College, Assistant Attending Physician, Division of General Internal Medicine, New York-Presbyterian Hospital, New York, NY, USA
| | - Thomas J. Walsh
- Transplantation-Oncology Infectious Diseases Program, Chief, Medical Mycology Research Laboratory, Medicine, Pediatrics, and Microbiology & Immunology, Weill Cornell Medical Center, Henry Schueler Foundation Scholar, Sharpe Family Foundation Scholar in Pediatric Infectious Diseases, New York, NY, USA
| |
Collapse
|
490
|
Fang XF, Li D, Tangadanchu VKR, Gopala L, Gao WW, Zhou CH. Novel potentially antifungal hybrids of 5-flucytosine and fluconazole: Design, synthesis and bioactive evaluation. Bioorg Med Chem Lett 2017; 27:4964-4969. [PMID: 29050784 DOI: 10.1016/j.bmcl.2017.10.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/06/2017] [Accepted: 10/08/2017] [Indexed: 10/18/2022]
Abstract
A series of novel potentially antifungal hybrids of 5-flucytosine and fluconazole were designed, synthesized and characterized by 1H NMR, 13C NMR, IR and HRMS spectra. Bioactive assay manifested that some prepared compounds showed moderate to good antifungal activities in comparison with fluconazole and 5-flucytosine. Remarkably, the 3,4-dichlorobenzyl hybrid 7h could inhibit the growth of C. albicans ATCC 90023 and clinical resistant strain C. albicans with MIC values of 0.008 and 0.02 mM, respectively. The active molecule 7h could not only rapidly kill C. albicans but also efficiently permeate membrane of C. albicans. Molecular docking study revealed that compound 7h could interact with the active site of CACYP51 through hydrogen bond. Quantum chemical studies were also performed to explain the high antifungal activity. Further preliminary mechanism research suggested that molecule 7h could intercalate into calf thymus DNA to form a steady supramolecular complex, which might block DNA replication to exert the powerful bioactivities.
Collapse
Affiliation(s)
- Xian-Fu Fang
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
| | - Di Li
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
| | - Vijai Kumar Reddy Tangadanchu
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
| | - Lavanya Gopala
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
| | - Wei-Wei Gao
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China
| | - Cheng-He Zhou
- Institute of Bioorganic & Medicinal Chemistry, Key Laboratory of Applied Chemistry of Chongqing Municipality, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
| |
Collapse
|
491
|
McCarthy MW, Walsh TJ. Harnessing the potential of CRISPR-Cas9 to advance the study of human fungal pathogens. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2017. [DOI: 10.1080/23808993.2017.1375851] [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]
Affiliation(s)
- Matthew William McCarthy
- Hospital Medicine, Joan and Sanford I Weill Medical College of Cornell University, New York, NY, USA
| | - Thomas J. Walsh
- Transplantation-Oncology Infectious Diseases Program, Weill Cornell Medical Center, New York, NY, USA
| |
Collapse
|
492
|
Immune Recognition of Fungal Polysaccharides. J Fungi (Basel) 2017; 3:jof3030047. [PMID: 29371564 PMCID: PMC5715945 DOI: 10.3390/jof3030047] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 08/21/2017] [Accepted: 08/23/2017] [Indexed: 02/06/2023] Open
Abstract
The incidence of fungal infections has dramatically increased in recent years, in large part due to increased use of immunosuppressive medications, as well as aggressive medical and surgical interventions that compromise natural skin and mucosal barriers. There are relatively few currently licensed antifungal drugs, and rising resistance to these agents has led to interest in the development of novel preventative and therapeutic strategies targeting these devastating infections. One approach to combat fungal infections is to augment the host immune response towards these organisms. The polysaccharide-rich cell wall is the initial point of contact between fungi and the host immune system, and therefore, represents an important target for immunotherapeutic approaches. This review highlights the advances made in our understanding of the mechanisms by which the immune system recognizes and interacts with exopolysaccharides produced by four of the most common fungal pathogens: Aspergillus fumigatus, Candida albicans, Cryptococcus neoformans, and Histoplasma capsulatum. Work to date suggests that inner cell wall polysaccharides that play an important structural role are the most conserved across diverse members of the fungal kingdom, and elicit the strongest innate immune responses. The immune system senses these carbohydrates through receptors, such as lectins and complement proteins. In contrast, a greater diversity of polysaccharides is found within the outer cell walls of pathogenic fungi. These glycans play an important role in immune evasion, and can even induce anti-inflammatory host responses. Further study of the complex interactions between the host immune system and the fungal polysaccharides will be necessary to develop more effective therapeutic strategies, as well as to explore the use of immunosuppressive polysaccharides as therapeutic agents to modulate inflammation.
Collapse
|
493
|
McCarthy MW, Walsh TJ. Drugs currently under investigation for the treatment of invasive candidiasis. Expert Opin Investig Drugs 2017; 26:825-831. [PMID: 28617137 DOI: 10.1080/13543784.2017.1341488] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION The widespread implementation of immunosuppressants, immunomodulators, hematopoietic stem cell transplantation and solid organ transplantation in clinical practice has led to an expanding population of patients who are at risk for invasive candidiasis, which is the most common form of fungal disease among hospitalized patients in the developed world. The emergence of drug-resistant Candida spp. has added to the morbidity associated with invasive candidiasis and novel therapeutic strategies are urgently needed. Areas covered: In this paper, we explore investigational agents for the treatment of invasive candidiasis, with particular attention paid to compounds that have recently entered phase I or phase II clinical trials. Expert opinion: The antifungal drug development pipeline has been severely limited due to regulatory hurdles and a systemic lack of investment in novel compounds. However, several promising drug development strategies have recently emerged, including chemical screens involving Pathogen Box compounds, combination antifungal therapy, and repurposing of existing agents that were initially developed to treat other conditions, all of which have the potential to redefine the treatment of invasive candidiasis.
Collapse
Affiliation(s)
- Matthew W McCarthy
- a Medicine, Weill Cornell Medical Center , Division of General Internal Medicine , New York , NY , USA
| | - Thomas J Walsh
- b Transplantation-Oncology Infectious Diseases Program, Medical Mycology Research Laboratory, Medicine, Pediatrics, and Microbiology & Immunology Weill Cornell Medical Center , Henry Schueler Foundation Scholar, Sharpe Family Foundation Scholar in Pediatric Infectious Diseases , New York , NY , USA
| |
Collapse
|
494
|
Efficacy and safety of micafungin versus extensive azoles in the prevention and treatment of invasive fungal infections for neutropenia patients with hematological malignancies: A meta-analysis of randomized controlled trials. PLoS One 2017; 12:e0180050. [PMID: 28700646 PMCID: PMC5507498 DOI: 10.1371/journal.pone.0180050] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2017] [Accepted: 06/08/2017] [Indexed: 12/24/2022] Open
Abstract
Background Current studies that compare the efficacy and safety of micafungin (MCFG) with that of triazoles for the prophylaxis and treatment of invasive fungal infections (IFIs) demonstrate a lack of sufficient evidence and yield conflicting results. To compare the efficacy and safety of MCFG and triazoles in the prevention and treatment of IFIs, we conducted a meta-analysis and trial sequential analysis (TSA). Methods For the meta-analysis, we systematically searched the databases of PubMed, Embase and Cochrane Central Register of Controlled Trials and relevant database articles for randomized controlled studies published through November 2016. Comparative studies of the efficacy and safety of MCFG versus triazoles in the prevention and treatment of IFIs were selected. Meta-analysis was performed by R software with the “metafor” package. Pooled results were expressed as risk ratios (RRs) with corresponding 95% confidence intervals (CI). TSA was adopted to assess the studies’ power with TSA version 0.9 beta. Results Nine current studies were included in the meta-analysis (1049 cases and 959 controls). Pooled trial comparisons indicated that MCFG does have significantly higher treatment success rates (RR = 1.13; 95% CI, 1.02–1.25; p = 0.0205) and reduces the number of overall IFIs (RR = 0.75; 95% CI, 0.61–0.92; p = 0.0056). However, MCFG demonstrates no difference in all-cause mortality (RR = 0.76; 95% CI, 0.52–1.12, p = 0.1624). For the safety evaluation, MCFG had a significantly lower incidence of severe adverse events (AEs) (RR = 0.45; 95% CI, 0.25–0.83; p = 0.0105), hepatic impairment (RR = 0.70; 95% CI, 0.50–0.97; p = 0.0363) and premature discontinuation (RR = 0.51; 95% CI, 0.34–0.76, p = 0.0010). Meta-regression analysis disclosed the correction of mean age and treatment success rates (P < 0.0001). Meanwhile, TSA demonstrated sufficient power to show efficacy. Conclusions The treatment success rate of MCFG is superior to that of triazoles for the prophylaxis and treatment of IFIs, and correction of the mean patient age demonstrates that efficacy increases as patient age decreases. MCFG appears to be well-tolerated with manageable side effects and lower withdrawal rates. However, additional clinical trials should be conducted on specific drug-related mortality and AEs to gather sufficient evidence on these matters.
Collapse
|