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Salimi M, Javidnia J, Faeli L, Moslemi A, Hedayati M, Haghani I, Aghili S, Moazeni M, Badiee P, Roudbari M, Zarrinfar H, Mohammadi R, Lotfali E, Nouripour‐Sisakht S, Seyedmousavi S, Shokohi T, Abastabar M. Molecular Epidemiology and Antifungal Susceptibility Profile in Nakaseomyces glabrata Species Complex: A 5-Year Countrywide Study. J Clin Lab Anal 2024; 38:e25042. [PMID: 38775102 PMCID: PMC11137845 DOI: 10.1002/jcla.25042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2023] [Revised: 04/05/2024] [Accepted: 04/21/2024] [Indexed: 05/31/2024] Open
Abstract
BACKGROUND The current study aimed to identify Iranian Nakaseomyces (Candida) glabrata complex species in the clinical isolates and determine their antifungal susceptibility profile. METHODS In total, 320 N. glabrata clinical isolates were collected from patients hospitalized in different geographical regions of Iran. The initial screening was performed by morphological characteristics on CHROMagar Candida. Each isolate was identified by targeting the D1/D2 rDNA using a multiplex-PCR method. To validate the mPCR method and determine genetic diversity, the ITS-rDNA region was randomly sequenced in 40 isolates. Additionally, antifungal susceptibility was evaluated against nine antifungal agents following the CLSI M27-A4 guidelines. RESULTS All clinical isolates from Iran were identified as N. glabrata. The analysis of ITS-rDNA sequence data revealed the presence of eight distinct ITS clades and 10 haplotypes among the 40 isolates of N. glabrata. The predominant clades identified were Clades VII, V, and IV, which respectively accounted for 22.5%, 17.5%, and 17.5% isolates. The widest MIC ranges were observed for voriconazole (0.016-8 μg/mL) and isavuconazole (0.016-2 μg/mL), whereas the narrowest ranges were seen with itraconazole and amphotericin B (0.25-2 μg/mL). CONCLUSION Haplotype diversity can be a valuable approach for studying the genetic diversity, transmission patterns, and epidemiology of the N. glabrata complex.
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Affiliation(s)
- Maryam Salimi
- Student Research Committee, School of MedicineMazandaran University of Medical SciencesSariIran
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
| | - Javad Javidnia
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Leila Faeli
- Student Research Committee, School of MedicineMazandaran University of Medical SciencesSariIran
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
| | - Azam Moslemi
- Student Research Committee, School of MedicineMazandaran University of Medical SciencesSariIran
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
| | - Mohammad Taghi Hedayati
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Iman Haghani
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Seyed Reza Aghili
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Maryam Moazeni
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Parisa Badiee
- Clinical Microbiology Research CenterShiraz University of Medical SciencesShirazIran
| | - Maryam Roudbari
- Department of Parasitology and Mycology, School of MedicineIran University of Medical SciencesTehranIran
| | - Hossein Zarrinfar
- Allergy Research CenterMashhad University of Medical SciencesMashhadIran
| | - Rasoul Mohammadi
- Department of Medical Parasitology and Mycology, School of MedicineIsfahan University of Medical SciencesIsfahanIran
| | - Ensieh Lotfali
- Department of Medical Parasitology and Mycology, School of MedicineShahid Beheshti University of Medical SciencesTehranIran
| | | | - Seyedmojtaba Seyedmousavi
- Microbiology Service, Department of Laboratory Medicine, Clinical CenterNational Institutes of HealthBethesdaMarylandUSA
| | - Tahereh Shokohi
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
| | - Mahdi Abastabar
- Invasive Fungi Research Center, Communicable Diseases InstituteMazandaran University of Medical SciencesSariIran
- Department of Medical Mycology, School of MedicineMazandaran University of Medical SciencesSariIran
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Jospe-Kaufman M, Ben-Zeev E, Mottola A, Dukhovny A, Berman J, Carmeli S, Fridman M. Reshaping Echinocandin Antifungal Drugs To Circumvent Glucan Synthase Point-Mutation-Mediated Resistance. Angew Chem Int Ed Engl 2024; 63:e202314728. [PMID: 38161189 DOI: 10.1002/anie.202314728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 12/26/2023] [Accepted: 12/28/2023] [Indexed: 01/03/2024]
Abstract
Echinocandins are a class of antifungal drugs that inhibit the activity of the β-(1,3)-glucan synthase complex, which synthesizes fungal cell wall β-(1,3)-glucan. Echinocandin resistance is linked to mutations in the FKS gene, which encodes the catalytic subunit of the glucan synthase complex. We present a molecular-docking-based model that provides insight into how echinocandins interact with the target Fks protein: echinocandins form a ternary complex with both Fks and membrane lipids. We used reductive dehydration of alcohols to generate dehydroxylated echinocandin derivatives and evaluated their potency against a panel of Candida pathogens constructed by introducing resistance-conferring mutations in the FKS gene. We found that removing the hemiaminal alcohol, which drives significant conformational alterations in the modified echinocandins, reduced their efficacy. Conversely, eliminating the benzylic alcohol of echinocandins enhanced potency by up to two orders of magnitude, in a manner dependent upon the resistance-conferring mutation. Strains that have developed resistance to either rezafungin, the most recently clinically approved echinocandin, or its dehydroxylated derivative RZF-1, exhibit high resistance to rezafungin while demonstrating moderate resistance to RZF-1. These findings provide valuable insight for combating echinocandin resistance through chemical modifications.
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Affiliation(s)
- Moriah Jospe-Kaufman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Efrat Ben-Zeev
- The Whol Drug Discovery institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, 7610001, Rehovot, Israel
| | - Austin Mottola
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Anna Dukhovny
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Judith Berman
- Shmunis School of Biomedical and Cancer Research, George S. Wise Faculty of Life Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Shmuel Carmeli
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
| | - Micha Fridman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, 6997801, Tel Aviv, Israel
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3
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Gómez-Gaviria M, García-Carnero LC, Baruch-Martínez DA, Mora-Montes HM. The Emerging Pathogen Candida metapsilosis: Biological Aspects, Virulence Factors, Diagnosis, and Treatment. Infect Drug Resist 2024; 17:171-185. [PMID: 38268929 PMCID: PMC10807450 DOI: 10.2147/idr.s448213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 01/16/2024] [Indexed: 01/26/2024] Open
Abstract
Fungal infections represent a constant and growing menace to public health. This concern is due to the emergence of new fungal species and the increase in antifungal drug resistance. Mycoses caused by Candida species are among the most common nosocomial infections and are associated with high mortality rates when the infection affects deep-seated organs. Candida metapsilosis is part of the Candida parapsilosis complex and has been described as part of the oral microbiota of healthy individuals. Within the complex, this species is considered the least virulent; however, the prevalence has been increasing in recent years, as well as an increment in the resistance to some antifungal drugs. One of the main concerns of candidiasis caused by this species is the wide range of clinical manifestations, ranging from tissue colonization to superficial infections, and in more severe cases it can spread, which makes diagnosis and treatment difficult. The study of virulence factors of this species is limited, however, proteomic comparisons between species indicate that virulence factors in this species could be similar to those already described for C. albicans. However, differences may exist, taking into account changes in the lifestyle of the species. Here, we provide a detailed review of the current literature about this organism, the caused disease, and some sharing aspects with other members of the complex, focusing on its biology, virulence factors, the host-fungus interaction, the identification, diagnosis, and treatment of infection.
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Affiliation(s)
- Manuela Gómez-Gaviria
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Gto., México
| | - Laura C García-Carnero
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Gto., México
| | - Dario A Baruch-Martínez
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Gto., México
| | - Héctor M Mora-Montes
- Departamento de Biología, División de Ciencias Naturales y Exactas, Universidad de Guanajuato, Guanajuato, Gto., México
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Zheng L, Xu Y, Wang C, Yang F, Dong Y, Guo L. Susceptibility to caspofungin is regulated by temperature and is dependent on calcineurin in Candida albicans. Microbiol Spectr 2023; 11:e0179023. [PMID: 37966204 PMCID: PMC10715083 DOI: 10.1128/spectrum.01790-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 10/06/2023] [Indexed: 11/16/2023] Open
Abstract
IMPORTANCE Echinocandins are the newest antifungal drugs and are first-line treatment option for life-threatening systemic infections. Due to lack of consensus regarding what temperature should be used when evaluating susceptibility of yeasts to echinocandins, typically either 30°C, 35°C, or 37°C is used. However, the impact of temperature on antifungal efficacy of echinocandins is unexplored. In the current study, we demonstrated that Candida albicans laboratory strain SC5314 was more susceptible to caspofungin at 37°C than at 30°C. We also found that calcineurin was required for temperature-modulated caspofungin susceptibility. Surprisingly, the altered caspofungin susceptibility was not due to differential expression of some canonical genes such as FKS, CHS, or CHT genes. The molecular mechanism of temperature-modulated caspofungin susceptibility is undetermined and deserves further investigations.
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Affiliation(s)
- Lijun Zheng
- Department of Ultrasound Medicine, The Second Affiliated Hospital of Soochow University, Suzhou, China
| | - Yi Xu
- Department of Pharmacy, The 960 Hospital of PLA, Jinan, China
| | - Chen Wang
- Department of Pharmacy, The 960 Hospital of PLA, Jinan, China
| | - Feng Yang
- Department of Pharmacology, Shanghai Tenth People’s Hospital, Tongji University School of Medicine, Shanghai, China
| | - Yubo Dong
- Department of Pharmacy, The 960 Hospital of PLA, Jinan, China
| | - Liangsheng Guo
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Soochow University, Suzhou, China
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Czajka KM, Venkataraman K, Brabant-Kirwan D, Santi SA, Verschoor C, Appanna VD, Singh R, Saunders DP, Tharmalingam S. Molecular Mechanisms Associated with Antifungal Resistance in Pathogenic Candida Species. Cells 2023; 12:2655. [PMID: 37998390 PMCID: PMC10670235 DOI: 10.3390/cells12222655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/14/2023] [Accepted: 11/17/2023] [Indexed: 11/25/2023] Open
Abstract
Candidiasis is a highly pervasive infection posing major health risks, especially for immunocompromised populations. Pathogenic Candida species have evolved intrinsic and acquired resistance to a variety of antifungal medications. The primary goal of this literature review is to summarize the molecular mechanisms associated with antifungal resistance in Candida species. Resistance can be conferred via gain-of-function mutations in target pathway genes or their transcriptional regulators. Therefore, an overview of the known gene mutations is presented for the following antifungals: azoles (fluconazole, voriconazole, posaconazole and itraconazole), echinocandins (caspofungin, anidulafungin and micafungin), polyenes (amphotericin B and nystatin) and 5-fluorocytosine (5-FC). The following mutation hot spots were identified: (1) ergosterol biosynthesis pathway mutations (ERG11 and UPC2), resulting in azole resistance; (2) overexpression of the efflux pumps, promoting azole resistance (transcription factor genes: tac1 and mrr1; transporter genes: CDR1, CDR2, MDR1, PDR16 and SNQ2); (3) cell wall biosynthesis mutations (FKS1, FKS2 and PDR1), conferring resistance to echinocandins; (4) mutations of nucleic acid synthesis/repair genes (FCY1, FCY2 and FUR1), resulting in 5-FC resistance; and (5) biofilm production, promoting general antifungal resistance. This review also provides a summary of standardized inhibitory breakpoints obtained from international guidelines for prominent Candida species. Notably, N. glabrata, P. kudriavzevii and C. auris demonstrate fluconazole resistance.
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Affiliation(s)
- Karolina M. Czajka
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
| | - Krishnan Venkataraman
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | | | - Stacey A. Santi
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Chris Verschoor
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Vasu D. Appanna
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
| | - Ravi Singh
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Deborah P. Saunders
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
| | - Sujeenthar Tharmalingam
- Medical Sciences Division, NOSM University, 935 Ramsey Lake Rd., Sudbury, ON P3E 2C6, Canada; (K.M.C.); (K.V.); (C.V.); (R.S.); (D.P.S.)
- School of Natural Sciences, Laurentian University, Sudbury, ON P3E 2C6, Canada;
- Health Sciences North Research Institute, Sudbury, ON P3E 2H2, Canada; (D.B.-K.); (S.A.S.)
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Szekely J, Rakchang W, Rattanaphan P, Kositpantawong N. Fluconazole and echinocandin resistance of Candida species in invasive candidiasis at a university hospital during pre-COVID-19 and the COVID-19 outbreak. Epidemiol Infect 2023; 151:e146. [PMID: 37622338 PMCID: PMC10540169 DOI: 10.1017/s0950268823001346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 08/09/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023] Open
Abstract
Antifungal susceptibility of Candida species is decreasing. Successful treatment for antifungal-resistant candida infection is challenging and associated with significant mortality. We performed a prospective observational study to identify the species and antifungal susceptibilities of invasive isolates of Candida species over a 5-year period at a university hospital in southern Thailand. Between 2017 and 2021, the species distribution was 39.1% Candida tropicalis, 24.8% Candida albicans, 20.3% Candida parapsilosis complex, 10.5% Candida glabrata, and 5.2% miscellaneous Candida spp. Notable observations include elevated minimal inhibitory concentration (MIC) and decrease susceptibility of C. tropicalis and C. glabrata to echinocandin and all tested triazoles. A shift of MIC90 value in the COVID-19 era was seen in C. albicans and C. tropicalis with azoles and echinocandins. Azole resistance increased among C. tropicalis isolates, and echinocandin resistance also increased among C. parapsilosis and C. glabrata isolates. Novel alterations in FKS1 HS1 and HS2 were detected in both isolates of anidulafungin-resistant C. parapsilosis. As Candida species have become more resistant to azoles and less susceptible to echinocandin development, the need arose to observe the emergence of resistance to both antifungal classes in candida clinical isolates, for a more effective infection control in the hospital.
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Affiliation(s)
- Jidapa Szekely
- Faculty of Medical Technology, Prince of Songkla University, Hat Yai, Thailand
| | - Wiraphan Rakchang
- Department of Pathology, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
| | - Paramaporn Rattanaphan
- Clinical Microbiology Unit, Department of Pathology, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
| | - Narongdet Kositpantawong
- Department of Internal Medicine, Faculty of Medicine, Prince of Songkla University, Hat Yai, Thailand
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Branco J, Miranda IM, Rodrigues AG. Candida parapsilosis Virulence and Antifungal Resistance Mechanisms: A Comprehensive Review of Key Determinants. J Fungi (Basel) 2023; 9:jof9010080. [PMID: 36675901 PMCID: PMC9862255 DOI: 10.3390/jof9010080] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 12/29/2022] [Accepted: 01/03/2023] [Indexed: 01/07/2023] Open
Abstract
Candida parapsilosis is the second most common Candida species isolated in Asia, Southern Europe, and Latin America and is often involved in invasive infections that seriously impact human health. This pathogen is part of the psilosis complex, which also includes Candida orthopsilosis and Candida metapsilosis. C. parapsilosis infections are particularly prevalent among neonates with low birth weights, individuals who are immunocompromised, and patients who require prolonged use of a central venous catheter or other indwelling devices, whose surfaces C. parapsilosis exhibits an enhanced capacity to adhere to and form biofilms. Despite this well-acknowledged prevalence, the biology of C. parapsilosis has not been as extensively explored as that of Candida albicans. In this paper, we describe the molecular mechanistic pathways of virulence in C. parapsilosis and show how they differ from those of C. albicans. We also describe the mode of action of antifungal drugs used for the treatment of Candida infections, namely, polyenes, echinocandins, and azoles, as well as the resistance mechanisms developed by C. parapsilosis to overcome them. Finally, we stress the importance of the ongoing search for species-specific features that may aid the development of effective control strategies and thus reduce the burden on patients and healthcare costs.
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Affiliation(s)
- Joana Branco
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- Center for Health Technology and Services Research—CINTESIS@RISE, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal
- Correspondence: ; Tel./Fax: +351-225513662
| | - Isabel M. Miranda
- Cardiovascular Research & Development Centre—UnIC@RISE, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal
| | - Acácio G. Rodrigues
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal
- Center for Health Technology and Services Research—CINTESIS@RISE, Faculty of Medicine, University of Porto, 4200-450 Porto, Portugal
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Bezerra LP, Freitas CDT, Silva AFB, Amaral JL, Neto NAS, Silva RGG, Parra ALC, Goldman GH, Oliveira JTA, Mesquita FP, Souza PFN. Synergistic Antifungal Activity of Synthetic Peptides and Antifungal Drugs against Candida albicans and C. parapsilosis Biofilms. Antibiotics (Basel) 2022; 11:antibiotics11050553. [PMID: 35625197 PMCID: PMC9138075 DOI: 10.3390/antibiotics11050553] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 04/17/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
C. albicans and C. parapsilosis are biofilm-forming yeasts responsible for bloodstream infections that can cause death. Synthetic antimicrobial peptides (SAMPs) are considered to be new weapons to combat these infections, alone or combined with drugs. Here, two SAMPs, called Mo-CBP3-PepI and Mo-CBP3-PepIII, were tested alone or combined with nystatin (NYS) and itraconazole (ITR) against C. albicans and C. parapsilosis biofilms. Furthermore, the mechanism of antibiofilm activity was evaluated by fluorescence and scanning electron microscopies. When combined with SAMPs, the results revealed a 2- to 4-fold improvement of NYS and ITR antibiofilm activity. Microscopic analyses showed cell membrane and wall damage and ROS overproduction, which caused leakage of internal content and cell death. Taken together, these results suggest the potential of Mo-CBP3-PepI and Mo-CBP3-PepIII as new drugs and adjuvants to increase the activity of conventional drugs for the treatment of clinical infections caused by C. albicans and C. parapsilosis.
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Affiliation(s)
- Leandro P. Bezerra
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Cleverson D. T. Freitas
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
- Correspondence: (C.D.T.F.); (P.F.N.S.)
| | - Ayrles F. B. Silva
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Jackson L. Amaral
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Nilton A. S. Neto
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Rafael G. G. Silva
- Department of Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil;
| | - Aura L. C. Parra
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Gustavo H. Goldman
- Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, São Paulo P.O. Box 05508-000, SP, Brazil;
| | - Jose T. A. Oliveira
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
| | - Felipe P. Mesquita
- Drug Research and Development Center, Department of Physiology and Pharmacology, Federal University of Ceará, Rua Coronel, Nunes de Melo 100, Caixa, Fortaleza 60430-275, CE, Brazil;
| | - Pedro F. N. Souza
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, Fortaleza 60451, CE, Brazil; (L.P.B.); (A.F.B.S.); (J.L.A.); (N.A.S.N.); (A.L.C.P.); (J.T.A.O.)
- Drug Research and Development Center, Department of Physiology and Pharmacology, Federal University of Ceará, Rua Coronel, Nunes de Melo 100, Caixa, Fortaleza 60430-275, CE, Brazil;
- Correspondence: (C.D.T.F.); (P.F.N.S.)
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Echinocandins Susceptibility Patterns of 2,787 Yeast Isolates: Importance of the Thresholds for the Detection of FKS Mutations. Antimicrob Agents Chemother 2022; 66:e0172521. [PMID: 35412354 DOI: 10.1128/aac.01725-21] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Since echinocandins are recommended as first line therapy for invasive candidiasis, detection of resistance, mainly due to alteration in FKS protein, is of main interest. EUCAST AFST recommends testing both MIC of anidulafungin and micafungin, and breakpoints (BPs) have been proposed to detect echinocandin-resistant isolates. We analyzed MIC distribution for all three available echinocandins of 2,787 clinical yeast isolates corresponding to 5 common and 16 rare yeast species, using the standardized EUCAST method for anidulafungin and modified for caspofungin and micafungin (AM3-MIC). In our database, 64 isolates of common pathogenic species were resistant to anidulafungin, according to the EUCAST BP, and/or to caspofungin, using our previously published threshold (AM3-MIC ≥ 0.5 mg/L). Among these 64 isolates, 50 exhibited 21 different FKS mutations. We analyzed the capacity of caspofungin AM3-MIC and anidulafungin MIC determination in detecting isolates with FKS mutation. They were always identified using caspofungin AM3-MIC and the local threshold while some isolates were misclassified using anidulafungin MIC and EUCAST threshold. However, both methods misclassified four wild-type C. glabrata as resistant. Based on a large data set from a single center, the use of AM3-MIC testing for caspofungin looks promising in identifying non-wild-type C. albicans, C. tropicalis and P. kudiravzevii isolates, but additional multicenter comparison is mandatory to conclude on the possible superiority of AM3-MIC testing compared to the EUCAST method.
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10
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Logviniuk D, Jaber QZ, Dobrovetsky R, Kozer N, Ksiezopolska E, Gabaldón T, Carmeli S, Fridman M. Benzylic Dehydroxylation of Echinocandin Antifungal Drugs Restores Efficacy against Resistance Conferred by Mutated Glucan Synthase. J Am Chem Soc 2022; 144:5965-5975. [PMID: 35347986 PMCID: PMC8991007 DOI: 10.1021/jacs.2c00269] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Each year, infections caused by fungal pathogens claim the lives of about 1.6 million people and affect the health of over a billion people worldwide. Among the most recently developed antifungal drugs are the echinocandins, which noncompetitively inhibit β-glucan synthase, a membrane-bound protein complex that catalyzes the formation of the main polysaccharide component of the fungal cell wall. Resistance to echinocandins is conferred by mutations in FKS genes, which encode the catalytic subunit of the β-glucan synthase complex. Here, we report that selective removal of the benzylic alcohol of the nonproteinogenic amino acid 3S,4S-dihydroxy-l-homotyrosine of the echinocandins anidulafungin and rezafungin, restored their efficacy against a large panel of echinocandin-resistant Candida strains. The dehydroxylated compounds did not significantly affect the viability of human-derived cell culture lines. An analysis of the efficacy of the dehydroxylated echinocandins against resistant Candida strains, which contain mutations in the FKS1 and/or FKS2 genes of the parental strains, identified amino acids of the Fks proteins that are likely to reside in proximity to the l-homotyrosine residue of the bound drug. This study describes the first example of a chemical modification strategy to restore the efficacy of echinocandin drugs, which have a critical place in the arsenal of antifungal drugs, against resistant fungal pathogens.
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Affiliation(s)
- Dana Logviniuk
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Qais Z Jaber
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Roman Dobrovetsky
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Noga Kozer
- The Wohl Drug Discovery institute of the Nancy and Stephen Grand Israel National Center for Personalized Medicine, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Ewa Ksiezopolska
- Barcelona Supercomputing Centre (BSC-CNS), Jordi Girona, 29, Barcelona 08034, Spain.,Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain
| | - Toni Gabaldón
- Barcelona Supercomputing Centre (BSC-CNS), Jordi Girona, 29, Barcelona 08034, Spain.,Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology, Baldiri Reixac, 10, Barcelona 08028, Spain.,Catalan Institution for Research and Advanced Studies (ICREA), Passeig de Lluís Companys, 23, Barcelona 08010, Spain.,Centro Investigación Biomédica En Red de Enfermedades Infecciosas, Madrid 28029, Spain
| | - Shmuel Carmeli
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Micha Fridman
- School of Chemistry, Raymond & Beverly Sackler Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 6997801, Israel
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11
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Perrine-Walker F. Caspofungin resistance in Candida albicans: genetic factors and synergistic compounds for combination therapies. Braz J Microbiol 2022; 53:1101-1113. [PMID: 35352319 PMCID: PMC9433586 DOI: 10.1007/s42770-022-00739-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 03/25/2022] [Indexed: 11/25/2022] Open
Abstract
Caspofungin and other echinocandins have been used for the treatment of human infections by the opportunistic yeast pathogen, Candida albicans. There has been an increase in infections by non-albicans Candida species such as Candida glabrata, Candida parapsilosis, Candida tropicalis, Candida krusei, and Candida auris in clinical or hospital settings. This is problematic to public health due to the increasing prevalence of echinocandin resistant species/strains. This review will present a summary on various studies that investigated the inhibitory action of caspofungin on 1,3-β-D-glucan synthesis, on cell wall structure, and biofilm formation of C. albicans. It will highlight some of the issues linked to caspofungin resistance or reduced caspofungin sensitivity in various Candida species and the potential benefits of antimicrobial peptides and other compounds in synergy with caspofungin.
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Affiliation(s)
- Francine Perrine-Walker
- Department of Biochemistry and Genetics, La Trobe Institute For Molecular Science, La Trobe University, Bundoora, VIC, 3086, Australia.
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12
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da Silva Dantas A, Nogueira F, Lee KK, Walker LA, Edmondson M, Brand AC, Lenardon MD, Gow NAR. Crosstalk between the calcineurin and cell wall integrity pathways prevents chitin overexpression in Candida albicans. J Cell Sci 2021; 134:jcs258889. [PMID: 34792152 PMCID: PMC8729787 DOI: 10.1242/jcs.258889] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 11/09/2021] [Indexed: 10/26/2022] Open
Abstract
Echinocandins such as caspofungin are frontline antifungal drugs that compromise β-1,3 glucan synthesis in the cell wall. Recent reports have shown that fungal cells can resist killing by caspofungin by upregulation of chitin synthesis, thereby sustaining cell wall integrity (CWI). When echinocandins are removed, the chitin content of cells quickly returns to basal levels, suggesting that there is a fitness cost associated with having elevated levels of chitin in the cell wall. We show here that simultaneous activation of the calcineurin and CWI pathways generates a subpopulation of Candida albicans yeast cells that have supra-normal chitin levels interspersed throughout the inner and outer cell wall, and that these cells are non-viable, perhaps due to loss of wall elasticity required for cell expansion and growth. Mutations in the Ca2+-calcineurin pathway prevented the formation of these non-viable supra-high chitin cells by negatively regulating chitin synthesis driven by the CWI pathway. The Ca2+-calcineurin pathway may therefore act as an attenuator that prevents the overproduction of chitin by coordinating both chitin upregulation and negative regulation of the CWI signaling pathway. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Alessandra da Silva Dantas
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter EX4 4QD, UK
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Filomena Nogueira
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
- Children's Cancer Research Institute, Labdia and Max F. Perutz Laboratories, Vienna 1090, Austria
| | - Keunsook K. Lee
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
- NGeneBio Company, 288 Digital-ro, Guro-gu, Seoul 08390, South Korea
| | - Louise A. Walker
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Matt Edmondson
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter EX4 4QD, UK
| | - Alexandra C. Brand
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter EX4 4QD, UK
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
| | - Megan D. Lenardon
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Neil A. R. Gow
- School of Biosciences, University of Exeter, Geoffrey Pope Building, Exeter EX4 4QD, UK
- School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Aberdeen AB25 2ZD, UK
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13
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Impact of FKS1 genotype on echinocandin in-vitro susceptibility in Candida auris and in -vivo response in a murine model of infection. Antimicrob Agents Chemother 2021; 66:e0165221. [PMID: 34780273 DOI: 10.1128/aac.01652-21] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Objectives: Echinocandins are frontline antifungal agents in the management of invasive infections due to multi-drug resistant Candida auris. The study aimed to evaluate echinocandin resistance in C. auris isolates of multicentric origin, identify the resistance mechanism, and analyze the pharmacodynamic response to caspofungin in a neutropenic mouse model of infection. Methods: A total of 199 C. auris isolates originating from thirty centres across India were tested for susceptibility to echinocandins. Isolates with reduced susceptibility were evaluated for FKS1 mutations and in-vivo response to caspofungin in a murine model of disseminated candidiasis. In addition, the response to echinocandins was assessed in light of in-vitro growth kinetics, chitin content; and transcript levels of chitin synthase and FKS1 genes. Results: We report 10 resistant C. auris isolates with four FKS1 mutations: F635Y (n=2), F635L (n=4), S639F (n=3), and R1354S (n=1). Of these, F635Y and R1354S exhibited the most profound resistance in mouse model of disseminated infection. S639F and F635L mutations conferred a moderate in vivo resistance, whereas wild-type isolates exhibiting borderline MIC were susceptible in vivo. FKS1 genotype was more accurate predictor of in-vivo response than the MIC of the isolates. Isolates with high basal or inducible chitin content exhibited higher in vitro MIC in FKS1 mutant compared to wild-type. Conclusions FKS1 mutations play a major role in clinically relevant echinocandin resistance in C. auris with differential in vivo outcomes. This study could have implications for clinical practice and, therefore, warrants further studies.
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Szarvas J, Rebelo AR, Bortolaia V, Leekitcharoenphon P, Schrøder Hansen D, Nielsen HL, Nørskov-Lauritsen N, Kemp M, Røder BL, Frimodt-Møller N, Søndergaard TS, Coia JE, Østergaard C, Westh H, Aarestrup FM. Danish Whole-Genome-Sequenced Candida albicans and Candida glabrata Samples Fit into Globally Prevalent Clades. J Fungi (Basel) 2021; 7:jof7110962. [PMID: 34829249 PMCID: PMC8622182 DOI: 10.3390/jof7110962] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Revised: 11/05/2021] [Accepted: 11/09/2021] [Indexed: 11/16/2022] Open
Abstract
Candida albicans and Candida glabrata are opportunistic fungal pathogens with increasing incidence worldwide and higher-than-expected prevalence in Denmark. We whole-genome sequenced yeast isolates collected from Danish Clinical Microbiology Laboratories to obtain an overview of the Candida population in the country. The majority of the 30 C. albicans isolates were found to belong to three globally prevalent clades, and, with one exception, the remaining isolates were also predicted to cluster with samples from other geographical locations. Similarly, most of the eight C. glabrata isolates were predicted to be prevalent subtypes. Antifungal susceptibility testing proved all C. albicans isolates to be susceptible to both azoles and echinocandins. Two C. glabrata isolates presented azole-resistant phenotypes, yet all were susceptible to echinocandins. There is no indication of causality between population structure and resistance phenotypes for either species.
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Affiliation(s)
- Judit Szarvas
- Division for Global Surveillance, National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.R.R.); (V.B.); (P.L.); (F.M.A.)
- Correspondence:
| | - Ana Rita Rebelo
- Division for Global Surveillance, National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.R.R.); (V.B.); (P.L.); (F.M.A.)
| | - Valeria Bortolaia
- Division for Global Surveillance, National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.R.R.); (V.B.); (P.L.); (F.M.A.)
| | - Pimlapas Leekitcharoenphon
- Division for Global Surveillance, National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.R.R.); (V.B.); (P.L.); (F.M.A.)
| | | | - Hans Linde Nielsen
- Department of Clinical Microbiology, Aalborg University Hospital, 9100 Aalborg, Denmark;
| | | | - Michael Kemp
- Department of Clinical Microbiology, Odense University Hospital, 5000 Odense, Denmark;
| | - Bent Løwe Røder
- Department of Clinical Microbiology, Slagelse Hospital, 4200 Slagelse, Denmark;
| | | | | | - John Eugenio Coia
- Department of Clinical Microbiology, Sydvestjysk Hospital, 6700 Esbjerg, Denmark;
| | - Claus Østergaard
- Department of Clinical Microbiology, Vejle Hospital, 7100 Vejle, Denmark;
| | - Henrik Westh
- Department of Clinical Microbiology, Hvidovre Hospital, 2650 Hvidovre, Denmark;
- Department of Clinical Medicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Frank Møller Aarestrup
- Division for Global Surveillance, National Food Institute, Technical University of Denmark, 2800 Kongens Lyngby, Denmark; (A.R.R.); (V.B.); (P.L.); (F.M.A.)
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15
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Durand C, Maubon D, Cornet M, Wang Y, Aldebert D, Garnaud C. Can We Improve Antifungal Susceptibility Testing? Front Cell Infect Microbiol 2021; 11:720609. [PMID: 34568095 PMCID: PMC8461061 DOI: 10.3389/fcimb.2021.720609] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 08/23/2021] [Indexed: 11/24/2022] Open
Abstract
Systemic antifungal agents are increasingly used for prevention or treatment of invasive fungal infections, whose prognosis remains poor. At the same time, emergence of resistant or even multi-resistant strains is of concern as the antifungal arsenal is limited. Antifungal susceptibility testing (AFST) is therefore of key importance for patient management and antifungal stewardship. Current AFST methods, including reference and commercial types, are based on growth inhibition in the presence of an antifungal, in liquid or solid media. They usually enable Minimal Inhibitory Concentrations (MIC) to be determined with direct clinical application. However, they are limited by a high turnaround time (TAT). Several innovative methods are currently under development to improve AFST. Techniques based on MALDI-TOF are promising with short TAT, but still need extensive clinical validation. Flow cytometry and computed imaging techniques detecting cellular responses to antifungal stress other than growth inhibition are also of interest. Finally, molecular detection of mutations associated with antifungal resistance is an intriguing alternative to standard AFST, already used in routine microbiology labs for detection of azole resistance in Aspergillus and even directly from samples. It is still restricted to known mutations. The development of Next Generation Sequencing (NGS) and whole-genome approaches may overcome this limitation in the near future. While promising approaches are under development, they are not perfect and the ideal AFST technique (user-friendly, reproducible, low-cost, fast and accurate) still needs to be set up routinely in clinical laboratories.
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Affiliation(s)
| | - Danièle Maubon
- TIMC, Univ Grenoble Alpes, CNRS, Grenoble INP, Grenoble, France.,Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France
| | - Muriel Cornet
- TIMC, Univ Grenoble Alpes, CNRS, Grenoble INP, Grenoble, France.,Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France
| | | | | | - Cécile Garnaud
- TIMC, Univ Grenoble Alpes, CNRS, Grenoble INP, Grenoble, France.,Parasitology-Mycology, CHU Grenoble Alpes, Grenoble, France
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16
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Aldejohann AM, Herz M, Martin R, Walther G, Kurzai O. Emergence of resistant Candida glabrata in Germany. JAC Antimicrob Resist 2021; 3:dlab122. [PMID: 34377983 PMCID: PMC8346698 DOI: 10.1093/jacamr/dlab122] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 07/08/2021] [Accepted: 07/12/2021] [Indexed: 12/22/2022] Open
Abstract
Background Candida glabrata is the second leading fungal pathogen causing candidaemia and invasive candidiasis in Europe. This yeast is recognized for its rapid ability to acquire antifungal drug resistance. Objectives We systematically evaluated 176 C. glabrata isolates submitted to the German National Reference Center for Invasive Fungal Infections (NRZMyk) between 2015 and 2019 with regard to echinocandin and fluconazole susceptibility. Methods Susceptibility testing was performed using a reference protocol (EUCAST) and a range of commercial assays. Hot spot regions of the echinocandin target FKS genes were sequenced using Sanger sequencing. Results In total, 84 of 176 isolates were initially classified as anidulafungin-resistant based on EUCAST testing. Of those, 71 harboured mutations in the glucan synthase encoding FKS genes (13% in FKS1, 87% in FKS2). Significant differences in anidulafungin MICs were found between distinct mutation sites. 11 FKS wild-type (WT) isolates initially classified as resistant exhibited anidulafungin MICs fluctuating around the interpretation breakpoint upon re-testing with multiple assays. Two FKS WT isolates consistently showed high anidulafungin MICs and thus must be considered resistant despite the absence of target gene mutations. Over one-third of echinocandin-resistant strains displayed concomitant fluconazole resistance. Of those, isolates linked to bloodstream infection carrying a change at Ser-663 were associated with adverse clinical outcome. Conclusions Resistant C. glabrata strains are emerging in Germany. Phenotypic echinocandin testing can result in misclassification of susceptible strains. FKS genotyping aids in detecting these strains, however, echinocandin resistance may occur despite a wild-type FKS genotype.
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Affiliation(s)
| | - Michaela Herz
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Ronny Martin
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany
| | - Grit Walther
- National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology- Hans Knoell Institute, Jena, Germany
| | - Oliver Kurzai
- Institute for Hygiene and Microbiology, University of Würzburg, Würzburg, Germany.,National Reference Center for Invasive Fungal Infections, Leibniz Institute for Natural Product Research and Infection Biology- Hans Knoell Institute, Jena, Germany
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17
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Caspofungin resistance in clinical Aspergillus Flavus isolates. J Mycol Med 2021; 31:101166. [PMID: 34293598 DOI: 10.1016/j.mycmed.2021.101166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 05/28/2021] [Accepted: 06/11/2021] [Indexed: 11/23/2022]
Abstract
INTRODUCTION AND AIMS The present study was conducted to determine the candidate genes involved in caspofungin (CAS) resistance in clinical isolates of Aspergillus flavus (A. flavus). MATERIALS AND METHODS The antifungal susceptibility assay of the CAS was performed on 14 clinical isolates of A. flavus using the CLSI-M-38-A2 broth micro-dilution protocol. Since CAS had various potencies, the minimum effective concentration (MEC) of anidulafungin (AND) was also evaluated in the present study. The FKS1 gene sequencing was conducted to assess whether mutations occurred in the whole FKS1 gene as well as hot spot regions of the FKS1 gene of the two resistant isolates. A complementary DNA-amplified fragment length polymorphism (CDNA-AFLP) method was performed to investigate differential gene expression between the two resistant and two sensitive clinical isolates in the presence of CAS. Furthermore, quantitative real-time PCR (QRT-PCR) was utilized to determine the relative expression levels of the identified genes. RESULTS No mutations were observed in the whole FKS1 gene hot spot regions of the FKS1 genes in the resistant isolates. A subset of two genes with known biological functions and four genes with unknown biological functions were identified in the CAS-resistant isolates using the CDNA-AFLP. The QRT-PCR revealed the down-regulation of the P-type ATPase and ubiquinone biosynthesis methyltransferase COQ5 in the CAS-resistant isolates, compared to the susceptible isolates. CONCLUSION The findings showed that P-type ATPase and ubiquinone biosynthesis methyltransferase COQ5 might be involved in the CAS-resistance A. flavus clinical isolates. Moreover, a subset of genes was differentially expressed to enhance fungi survival in CAS exposure. Further studies are recommended to highlight the gene overexpression and knock-out experiments in A. flavus or surrogate organisms to confirm that these mentioned genes confer the CAS resistant A. flavus.
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18
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Lee Y, Puumala E, Robbins N, Cowen LE. Antifungal Drug Resistance: Molecular Mechanisms in Candida albicans and Beyond. Chem Rev 2021; 121:3390-3411. [PMID: 32441527 PMCID: PMC8519031 DOI: 10.1021/acs.chemrev.0c00199] [Citation(s) in RCA: 311] [Impact Index Per Article: 103.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Fungal infections are a major contributor to infectious disease-related deaths across the globe. Candida species are among the most common causes of invasive mycotic disease, with Candida albicans reigning as the leading cause of invasive candidiasis. Given that fungi are eukaryotes like their human host, the number of unique molecular targets that can be exploited for antifungal development remains limited. Currently, there are only three major classes of drugs approved for the treatment of invasive mycoses, and the efficacy of these agents is compromised by the development of drug resistance in pathogen populations. Notably, the emergence of additional drug-resistant species, such as Candida auris and Candida glabrata, further threatens the limited armamentarium of antifungals available to treat these serious infections. Here, we describe our current arsenal of antifungals and elaborate on the resistance mechanisms Candida species possess that render them recalcitrant to therapeutic intervention. Finally, we highlight some of the most promising therapeutic strategies that may help combat antifungal resistance, including combination therapy, targeting fungal-virulence traits, and modulating host immunity. Overall, a thorough understanding of the mechanistic principles governing antifungal drug resistance is fundamental for the development of novel therapeutics to combat current and emerging fungal threats.
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Affiliation(s)
- Yunjin Lee
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Emily Puumala
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Nicole Robbins
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
| | - Leah E Cowen
- Department of Molecular Genetics, University of Toronto, 661 University Avenue, Toronto, Ontario M5G 1M1, Canada
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19
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Howard KC, Dennis EK, Watt DS, Garneau-Tsodikova S. A comprehensive overview of the medicinal chemistry of antifungal drugs: perspectives and promise. Chem Soc Rev 2020; 49:2426-2480. [PMID: 32140691 DOI: 10.1039/c9cs00556k] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The emergence of new fungal pathogens makes the development of new antifungal drugs a medical imperative that in recent years motivates the talents of numerous investigators across the world. Understanding not only the structural families of these drugs but also their biological targets provides a rational means for evaluating the merits and selectivity of new agents for fungal pathogens and normal cells. An equally important aspect of modern antifungal drug development takes a balanced look at the problems of drug potency and drug resistance. The future development of new antifungal agents will rest with those who employ synthetic and semisynthetic methodology as well as natural product isolation to tackle these problems and with those who possess a clear understanding of fungal cell architecture and drug resistance mechanisms. This review endeavors to provide an introduction to a growing and increasingly important literature, including coverage of the new developments in medicinal chemistry since 2015, and also endeavors to spark the curiosity of investigators who might enter this fascinatingly complex fungal landscape.
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Affiliation(s)
- Kaitlind C Howard
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536-0596, USA.
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20
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Salazar SB, Simões RS, Pedro NA, Pinheiro MJ, Carvalho MFNN, Mira NP. An Overview on Conventional and Non-Conventional Therapeutic Approaches for the Treatment of Candidiasis and Underlying Resistance Mechanisms in Clinical Strains. J Fungi (Basel) 2020; 6:jof6010023. [PMID: 32050673 PMCID: PMC7151124 DOI: 10.3390/jof6010023] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 02/06/2020] [Accepted: 02/07/2020] [Indexed: 02/06/2023] Open
Abstract
Fungal infections and, in particular, those caused by species of the Candida genus, are growing at an alarming rate and have high associated rates of mortality and morbidity. These infections, generally referred as candidiasis, range from common superficial rushes caused by an overgrowth of the yeasts in mucosal surfaces to life-threatening disseminated mycoses. The success of currently used antifungal drugs to treat candidiasis is being endangered by the continuous emergence of resistant strains, specially among non-albicans Candida species. In this review article, the mechanisms of action of currently used antifungals, with emphasis on the mechanisms of resistance reported in clinical isolates, are reviewed. Novel approaches being taken to successfully inhibit growth of pathogenic Candida species, in particular those based on the exploration of natural or synthetic chemicals or on the activity of live probiotics, are also reviewed. It is expected that these novel approaches, either used alone or in combination with traditional antifungals, may contribute to foster the identification of novel anti-Candida therapies.
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Affiliation(s)
- Sara B. Salazar
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Rita S. Simões
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Nuno A. Pedro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Joana Pinheiro
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
| | - Maria Fernanda N. N. Carvalho
- Centro de Química Estrutural, Complexo I, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal;
| | - Nuno P. Mira
- Department of Bioengineering, Institute of Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal; (S.B.S.); (R.S.S.); (N.A.P.); (M.J.P.)
- Correspondence:
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Costa-de-Oliveira S, Rodrigues AG. Candida albicans Antifungal Resistance and Tolerance in Bloodstream Infections: The Triad Yeast-Host-Antifungal. Microorganisms 2020; 8:microorganisms8020154. [PMID: 31979032 PMCID: PMC7074842 DOI: 10.3390/microorganisms8020154] [Citation(s) in RCA: 87] [Impact Index Per Article: 21.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 01/10/2020] [Accepted: 01/16/2020] [Indexed: 01/08/2023] Open
Abstract
Candida albicans represents the most frequent isolated yeast from bloodstream infections. Despite the remarkable progress in diagnostic and therapeutic approaches, these infections continue to be a critical challenge in intensive care units worldwide. The economic cost of bloodstream fungal infections and its associated mortality, especially in debilitated patients, remains unacceptably high. Candida albicans is a highly adaptable microorganism, being able to develop resistance following prolonged exposure to antifungals. Formation of biofilms, which diminish the accessibility of the antifungal, selection of spontaneous mutations that increase expression or decreased susceptibility of the target, altered chromosome abnormalities, overexpression of multidrug efflux pumps and the ability to escape host immune defenses are some of the factors that can contribute to antifungal tolerance and resistance. The knowledge of the antifungal resistance mechanisms can allow the design of alternative therapeutically options in order to modulate or revert the resistance. We have focused this review on the main factors that are involved in antifungal resistance and tolerance in patients with C. albicans bloodstream infections.
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Affiliation(s)
- Sofia Costa-de-Oliveira
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Al. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Center for Research in Health Technologies and Information Systems (CINTESIS), R. Dr. Plácido da Costa, 4200-450 Porto, Portugal
- Correspondence: ; Tel.: +351-220-426-870
| | - Acácio G. Rodrigues
- Division of Microbiology, Department of Pathology, Faculty of Medicine, University of Porto, Al. Hernâni Monteiro, 4200-319 Porto, Portugal;
- Center for Research in Health Technologies and Information Systems (CINTESIS), R. Dr. Plácido da Costa, 4200-450 Porto, Portugal
- Burn Unit, São João Hospital Center, Al. Hernâni Monteiro, 4200-319 Porto, Portugal
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Blatzer M, Beauvais A, Henrissat B, Latgé JP. Revisiting Old Questions and New Approaches to Investigate the Fungal Cell Wall Construction. Curr Top Microbiol Immunol 2020; 425:331-369. [PMID: 32418033 DOI: 10.1007/82_2020_209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The beginning of our understanding of the cell wall construction came from the work of talented biochemists in the 70-80's. Then came the era of sequencing. Paradoxically, the accumulation of fungal genomes complicated rather than solved the mystery of cell wall construction, by revealing the involvement of a much higher number of proteins than originally thought. The situation has become even more complicated since it is now recognized that the cell wall is an organelle whose composition continuously evolves with the changes in the environment or with the age of the fungal cell. The use of new and sophisticated technologies to observe cell wall construction at an almost atomic scale should improve our knowledge of the cell wall construction. This essay will present some of the major and still unresolved questions to understand the fungal cell wall biosynthesis and some of these exciting futurist approaches.
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Affiliation(s)
- Michael Blatzer
- Experimental Neuropathology Unit, Institut Pasteur, 25 rue du Docteur Roux, 75015, Paris, France
| | - Anne Beauvais
- Mycology Department, Institut Pasteur, 25 rue du Docteur Roux, 75015, Paris, France
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR 7257-CNRS & Aix-Marseille Université, 13288, Marseille cedex 9, France.,Department of Biological Sciences, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Jean-Paul Latgé
- Institute of Molecular Biology and Biotechnology of the Foundation for Research and Technology Hellas (IMBB-FORTH), Heraklion, Greece.
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Truong T, Zeng G, Lim TK, Cao T, Pang LM, Lee YM, Lin Q, Wang Y, Seneviratne CJ. Proteomics Analysis ofCandida albicans dnm1Haploid Mutant Unraveled the Association between Mitochondrial Fission and Antifungal Susceptibility. Proteomics 2019; 20:e1900240. [DOI: 10.1002/pmic.201900240] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 11/05/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Thuyen Truong
- Oral Sciences, Faculty of DentistryNational University of Singapore 9 Lower Kent Ridge Road Singapore 119085
| | - Guisheng Zeng
- Institute of Molecular and Cell BiologyAgency for Science, Technology and Research 61 Biopolis Drive, Proteos Singapore 138673
| | - Teck Kwang Lim
- Department of Biological SciencesFaculty of Science, National University of Singapore 16 Science Drive 4, S2 Singapore 117558
| | - Tong Cao
- Oral Sciences, Faculty of DentistryNational University of Singapore 9 Lower Kent Ridge Road Singapore 119085
| | - Li Mei Pang
- National Dental Research Institute SingaporeSinghealth Duke NUS, Singapore 5 Second Hospital Ave Singapore 168938
| | - Yew Mun Lee
- Department of Biological SciencesFaculty of Science, National University of Singapore 16 Science Drive 4, S2 Singapore 117558
| | - Qingsong Lin
- Department of Biological SciencesFaculty of Science, National University of Singapore 16 Science Drive 4, S2 Singapore 117558
| | - Yue Wang
- Institute of Molecular and Cell BiologyAgency for Science, Technology and Research 61 Biopolis Drive, Proteos Singapore 138673
- Department of Biochemistry, Yong Loo Lin School of MedicineNational University of Singapore 10 Medical Dr Singapore 117597
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Asadzadeh M, Alanazi AF, Ahmad S, Al-Sweih N, Khan Z. Lack of detection of Candida nivariensis and Candida bracarensis among 440 clinical Candida glabrata sensu lato isolates in Kuwait. PLoS One 2019; 14:e0223920. [PMID: 31618264 PMCID: PMC6795469 DOI: 10.1371/journal.pone.0223920] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 10/01/2019] [Indexed: 12/12/2022] Open
Abstract
Occurrence of Candida nivariensis and Candida bracarensis, two species phenotypically similar to Candida glabrata sensu stricto, in human clinical samples from different geographical settings remains unknown. This study developed a low-cost multiplex PCR (mPCR) and three species-specific singleplex PCR assays. Reference strains of common Candida species were used during development and the performance of mPCR and singleplex PCR assays was evaluated with 440 clinical C. glabrata sensu lato isolates. The internal transcribed spacer (ITS) region of rDNA was also sequenced from 85 selected isolates and rDNA sequence variations were used for determining genetic relatedness among the isolates by using MEGA X software. Species-specific amplicons for C. glabrata (~360 bp), C. nivariensis (~250 bp) and C. bracarensis (~180 bp) were obtained in mPCR while no amplicon was obtained from other Candida species. The three singleplex PCR assays also yielded expected results with reference strains of Candida species. The mPCR amplified ~360 bp amplicon from all 440 C. glabrata sensu lato isolates thus identifying all clinical isolates in Kuwait as C. glabrata sensu stricto. The results of mPCR were confirmed for all 440 isolates as they yielded an amplicon only in C. glabrata sensu stricto-specific singleplex PCR assay. The rDNA sequence data identified 28 ITS haplotypes among 85 isolates with 18 isolates belonging to unique haplotypes and 67 isolates belonging to 10 cluster haplotypes. In conclusion, we have developed a simple, low-cost mPCR assay for rapid differentiation of C. glabrata sensu stricto from C. nivariensis and C. bracarensis. Our data obtained from a large collection of clinical C. glabrata sensu lato isolates show that C. nivariensis and C. bracarensis are rare pathogens in Kuwait. Considerable genetic diversity among C. glabrata sensu stricto isolates was also indicated by rDNA sequence analyses.
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Affiliation(s)
- Mohammad Asadzadeh
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Ahlam F. Alanazi
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
- * E-mail: ,
| | - Noura Al-Sweih
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
| | - Ziauddin Khan
- Department of Microbiology, Faculty of Medicine, Kuwait University, Jabriya, Kuwait
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25
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Sikora M, Kuthan R, Piskorska-Malolepsza K, Golas-Pradzynska M, Domański D, Augustynowicz-Kopeć E, Swoboda-Kopec E. Prevalence and Antifungal Susceptibility of the Emerging Fungal Species, Candida nivariensis, Isolated in a Teaching Hospital in Poland. Pol J Microbiol 2019; 68:303-308. [PMID: 31880875 PMCID: PMC7256724 DOI: 10.33073/pjm-2019-032] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Revised: 04/29/2019] [Accepted: 05/01/2019] [Indexed: 01/12/2023] Open
Abstract
The data on susceptibility to antifungals of new species within Candida glabrata complex are limited. Our study was to enrich a global knowledge of yeast epidemiology and drug resistance. The study was focused on the identification of species within clinical isolates of the C. glabrata complex and on the determination of their resistance to antifungals. Four hundred forty-five clinical C. glabrata sensu lato strains were isolated from different clinical samples at routine mycological exams at the Infant Jesus Teaching Hospital in Warsaw. The identification of the most of tested isolates to species complex level was performed using the ID 32 C system. The identification of C. nivariensis and C. bracarensis species within the C. glabrata complex was performed by DNA sequencing. The MICs of amphotericin B, fluconazole, itraconazole, posaconazole, voriconazole, caspofungin, anidulafungin, and micafungin were determined by E-test. Twenty-four isolates did not have an ITS-1 region, characteristic of C. glabrata sensu stricto and their D1/D2 regions of the 26S rRNA were 99% homologous to C. nivariensis 26S rRNA. No strains of C. bracarensis were recovered. C. nivariensis strains were very susceptible to amphotericin B, anidulafungin, micafungin, and caspofungin. Ninety-two percent of C. nivariensis were resistant to itraconazole. The halves of the strains was resistant to posaconazole. Eighty-three percent of C. nivariensis were susceptible to voriconazole. None of the tested strains were susceptible to fluconazole. In the present study, none of the C. nivariensis strains were simultaneously resistant to azoles and echinocandins. C. nivariensis should be recognized as an emerging pathogen, resistant to azoles.
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Affiliation(s)
- Magdalena Sikora
- Department of Dental Microbiology, Medical University of Warsaw , Warsaw , Poland ; Department of Microbiology, Infant Jesus Teaching Hospital , Warsaw , Poland
| | - Robert Kuthan
- Department of Microbiology, Infant Jesus Teaching Hospital , Warsaw , Poland ; Chair and Department of Medical Microbiology, Medical University of Warsaw , Warsaw , Poland
| | - Katarzyna Piskorska-Malolepsza
- Department of Microbiology, Infant Jesus Teaching Hospital , Warsaw , Poland ; Chair and Department of Medical Microbiology, Medical University of Warsaw , Warsaw , Poland
| | | | | | - Ewa Augustynowicz-Kopeć
- Department of Microbiology, National Tuberculosis and Lung Diseases Research Institute , Warsaw , Poland
| | - Ewa Swoboda-Kopec
- Department of Microbiology, Infant Jesus Teaching Hospital , Warsaw , Poland ; Chair and Department of Medical Microbiology, Medical University of Warsaw , Warsaw , Poland
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Shivarathri R, Tscherner M, Zwolanek F, Singh NK, Chauhan N, Kuchler K. The Fungal Histone Acetyl Transferase Gcn5 Controls Virulence of the Human Pathogen Candida albicans through Multiple Pathways. Sci Rep 2019; 9:9445. [PMID: 31263212 PMCID: PMC6603162 DOI: 10.1038/s41598-019-45817-5] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/14/2019] [Indexed: 12/28/2022] Open
Abstract
Fungal virulence is regulated by a tight interplay of transcriptional control and chromatin remodelling. Despite compelling evidence that lysine acetylation modulates virulence of pathogenic fungi such as Candida albicans, the underlying mechanisms have remained largely unexplored. We report here that Gcn5, a paradigm lysyl-acetyl transferase (KAT) modifying both histone and non-histone targets, controls fungal morphogenesis - a key virulence factor of C. albicans. Our data show that genetic removal of GCN5 abrogates fungal virulence in mice, suggesting strongly diminished fungal fitness in vivo. This may at least in part arise from increased susceptibility to killing by macrophages, as well as by other phagocytes such as neutrophils or monocytes. Loss of GCN5 also causes hypersensitivity to the fungicidal drug caspofungin. Caspofungin hypersusceptibility requires the master regulator Efg1, working in concert with Gcn5. Moreover, Gcn5 regulates multiple independent pathways, including adhesion, cell wall-mediated MAP kinase signaling, hypersensitivity to host-derived oxidative stress, and regulation of the Fks1 glucan synthase, all of which play critical roles in virulence and antifungal susceptibility. Hence, Gcn5 regulates fungal virulence through multiple mechanisms, suggesting that specific inhibition of Gcn5 could offer new therapeutic strategies to combat invasive fungal infections.
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Affiliation(s)
- Raju Shivarathri
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Michael Tscherner
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | - Florian Zwolanek
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria
| | | | - Neeraj Chauhan
- Public Health Research Institute, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
- Department of Microbiology, Biochemistry and Molecular Genetics, New Jersey Medical School, Rutgers The State University of New Jersey, Newark, NJ, 07103, USA.
| | - Karl Kuchler
- Medical University of Vienna, Max Perutz Labs Vienna, Campus Vienna Biocenter, A-1030, Vienna, Austria.
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Antifungal Susceptibility Profile of Candida Albicans Isolated from Vulvovaginal Candidiasis in Xinjiang Province of China. Mycopathologia 2019; 184:413-422. [PMID: 30968320 DOI: 10.1007/s11046-018-0305-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022]
Abstract
We investigated the antifungal susceptibility profiles of 207 independent Candida albicans strains isolated from patients with vulvovaginal candidiasis (VVC) in Xinjiang Province of China. Using CLSI M27-A3 and M27-S4 guidelines, anidulafungin and micafungin were the most active drugs against C. albicans showing an MIC50/MIC90 corresponding to 0.016/0.0313 µg/mL, followed by caspofungin (0.25/0.25 µg/mL), posaconazole (0.125/0.5 µg/mL), ravuconazole (0.063/1 µg/mL), itraconazole (0.125/1 µg/mL), amphotericine B (0.5/1 µg/mL), isavuconazole (0.063/2 µg/mL), 5-flucytosine (1/2 µg/mL), voriconazole (0.125/4 µg/mL), and fluconazole (0.5/4 µg/mL). 96.1% (199)-100.0% (207) isolates were sensitive to the three echinocandins tested, amphotericine B and 5-flucytosine. The in vitro activity of triazoles against all isolates tested was variable; itraconazole and voriconazole had reduced the activity to almost half of the isolates (55.1% (114) and 51.2% (106) susceptible, respectively). Fluconazole was active against 76.3% (158) isolates tested. The new triazoles ravuconazole, isavuconazole and posaconazole showed good in vitro potency against 89.9% (186)-95.2% (197) of isolates with the geometric mean MIC (µg/mL) of 0.10, 0.12 and 0.14 µg/mL, respectively. In conclusion, our study indicates that for effective management of systemic candidiasis in Xinjiang Province of China, it is important to determine the susceptibility profiles of isolated C. albicans from patients with VVC.
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28
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Cortés JCG, Curto MÁ, Carvalho VSD, Pérez P, Ribas JC. The fungal cell wall as a target for the development of new antifungal therapies. Biotechnol Adv 2019; 37:107352. [PMID: 30797093 DOI: 10.1016/j.biotechadv.2019.02.008] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 01/23/2019] [Accepted: 02/16/2019] [Indexed: 12/17/2022]
Abstract
In the past three decades invasive mycoses have globally emerged as a persistent source of healthcare-associated infections. The cell wall surrounding the fungal cell opposes the turgor pressure that otherwise could produce cell lysis. Thus, the cell wall is essential for maintaining fungal cell shape and integrity. Given that this structure is absent in host mammalian cells, it stands as an important target when developing selective compounds for the treatment of fungal infections. Consequently, treatment with echinocandins, a family of antifungal agents that specifically inhibits the biosynthesis of cell wall (1-3)β-D-glucan, has been established as an alternative and effective antifungal therapy. However, the existence of many pathogenic fungi resistant to single or multiple antifungal families, together with the limited arsenal of available antifungal compounds, critically affects the effectiveness of treatments against these life-threatening infections. Thus, new antifungal therapies are required. Here we review the fungal cell wall and its relevance in biotechnology as a target for the development of new antifungal compounds, disclosing the most promising cell wall inhibitors that are currently in experimental or clinical development for the treatment of some invasive mycoses.
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Affiliation(s)
- Juan Carlos G Cortés
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
| | - M-Ángeles Curto
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Vanessa S D Carvalho
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Pilar Pérez
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain
| | - Juan Carlos Ribas
- Instituto de Biología Funcional y Genómica and Departamento de Microbiología y Genética, Consejo Superior de Investigaciones Científicas (CSIC)/Universidad de Salamanca, Salamanca, Spain.
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Pais P, Galocha M, Viana R, Cavalheiro M, Pereira D, Teixeira MC. Microevolution of the pathogenic yeasts Candida albicans and Candida glabrata during antifungal therapy and host infection. MICROBIAL CELL 2019; 6:142-159. [PMID: 30854392 PMCID: PMC6402363 DOI: 10.15698/mic2019.03.670] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Infections by the pathogenic yeasts Candida albicans and Candida glabrata are among the most common fungal diseases. The success of these species as human pathogens is contingent on their ability to resist antifungal therapy and thrive within the human host. C. glabrata is especially resilient to azole antifungal treatment, while C. albicans is best known for its wide array of virulence features. The core mechanisms that underlie antifungal resistance and virulence in these pathogens has been continuously addressed, but the investigation on how such mechanisms evolve according to each environment is scarcer. This review aims to explore current knowledge on micro-evolution experiments to several treatment and host-associated conditions in C. albicans and C. glabrata. The analysis of adaptation strategies that evolve over time will allow to better understand the mechanisms by which Candida species are able to achieve stable phenotypes in real-life scenarios, which are the ones that should constitute the most interesting drug targets.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Romeu Viana
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Mafalda Cavalheiro
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Diana Pereira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
| | - Miguel Cacho Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal.,iBB - Institute for Bioengineering and Biosciences, Biological Sciences Research Group, Instituto Superior Técnico, Lisboa, Portugal
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30
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Spettel K, Barousch W, Makristathis A, Zeller I, Nehr M, Selitsch B, Lackner M, Rath PM, Steinmann J, Willinger B. Analysis of antifungal resistance genes in Candida albicans and Candida glabrata using next generation sequencing. PLoS One 2019; 14:e0210397. [PMID: 30629653 PMCID: PMC6328131 DOI: 10.1371/journal.pone.0210397] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 12/21/2018] [Indexed: 12/13/2022] Open
Abstract
Introduction/Objectives An increase in antifungal resistant Candida strains has been reported in recent years. The aim of this study was to detect mutations in resistance genes of azole-resistant, echinocandin-resistant or multi-resistant strains using next generation sequencing technology, which allows the analysis of multiple resistance mechanisms in a high throughput setting. Methods Forty clinical Candida isolates (16 C. albicans and 24 C. glabrata strains) with MICs for azoles and echinocandins above the clinical EUCAST breakpoint were examined. The genes ERG11, ERG3, TAC1 and GSC1 (FKS1) in C. albicans, as well as ERG11, CgPDR1, FKS1 and FKS2 in C. glabrata were sequenced. Results Fifty-four different missense mutations were identified, 13 of which have not been reported before. All nine echinocandin-resistant Candida isolates showed mutations in the hot spot (HS) regions of FKS1, FKS2 or GSC1. In ERG3 two homozygous premature stop codons were identified in two highly azole-resistant and moderately echinocandin-resistant C. albicans strains. Seven point mutations in ERG11 were determined in azole-resistant C. albicans whereas in azole-resistant C. glabrata, no ERG11 mutations were detected. In 10 out of 13 azole-resistant C. glabrata, 12 different potential gain-of-function mutations in the transcription factor CgPDR1 were verified, which are associated with an overexpression of the efflux pumps CDR1/2. Conclusion This study showed that next generation sequencing allows the thorough investigation of a large number of isolates more cost efficient and faster than conventional Sanger sequencing. Targeting different resistance genes and a large sample size of highly resistant strains allows a better determination of the relevance of the different mutations, and to differentiate between causal mutations and polymorphisms.
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Affiliation(s)
- Kathrin Spettel
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Barousch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Athanasios Makristathis
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Iris Zeller
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Marion Nehr
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Brigitte Selitsch
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
| | - Michaela Lackner
- Division of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Peter-Michael Rath
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Joerg Steinmann
- Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
- Institute of Clinical Hygiene, Medical Microbiology and Infectiology, Paracelsus Medical University, Nuremberg, Germany
| | - Birgit Willinger
- Department of Laboratory Medicine, Division of Clinical Microbiology, Medical University of Vienna, Vienna, Austria
- * E-mail:
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31
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Pais P, Galocha M, Teixeira MC. Genome-Wide Response to Drugs and Stress in the Pathogenic Yeast Candida glabrata. PROGRESS IN MOLECULAR AND SUBCELLULAR BIOLOGY 2019; 58:155-193. [PMID: 30911893 DOI: 10.1007/978-3-030-13035-0_7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Candida glabrata is the second most common cause of candidemia worldwide and its prevalence has continuously increased over the last decades. C. glabrata infections are especially worrisome in immunocompromised patients, resulting in serious systemic infections, associated to high mortality rates. Intrinsic resistance to azole antifungals, widely used drugs in the clinical setting, and the ability to efficiently colonize the human host and medical devices, withstanding stress imposed by the immune system, are thought to underlie the emergence of C. glabrata. There is a clear clinical need to understand drug and stress resistance in C. glabrata. The increasing prevalence of multidrug resistant isolates needs to be addressed in order to overcome the decrease of viable therapeutic strategies and find new therapeutic targets. Likewise, the understanding of the mechanisms underlying its impressive ability thrive under oxidative, nitrosative, acidic and metabolic stresses, is crucial to design drugs that target these pathogenesis features. The study of the underlying mechanisms that translate C. glabrata plasticity and its competence to evade the immune system, as well as survive host stresses to establish infection, will benefit from extensive scrutiny. This chapter provides a review on the contribution of genome-wide studies to uncover clinically relevant drug resistance and stress response mechanisms in the human pathogenic yeast C. glabrata.
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Affiliation(s)
- Pedro Pais
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Mónica Galocha
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal
| | - Miguel Cacho Teixeira
- Department of Bioengineering, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal. .,Biological Sciences Research Group, Institute for Bioengineering and Biosciences (iBB), Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal.
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Hori Y, Shibuya K. Role of FKS Gene in the Susceptibility of Pathogenic Fungi to Echinocandins. Med Mycol J 2018; 59:E31-E40. [PMID: 29848909 DOI: 10.3314/mmj.18.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Echinocandins are antifungal agents that specifically inhibit the biosynthesis of 1,3-β-D-glucan, a major structural component of fungal cell walls. Echinocandins are recommended as first-line or alternative/salvage therapy for candidiasis and aspergillosis in antifungal guidelines of various countries. Resistance to echinocandins has been reported in recent years. The mechanism of echinocandin resistance involves amino acid substitutions in hot spot regions of the FKS gene product, the catalytic subunit of 1,3-β-D-glucan synthase. This resistance mechanism contributes to not only acquired resistance in Candida spp., but also inherent resistance in some pathogenic fungi. An understanding of the echinocandin resistance mechanism is important to develop both effective diagnosis and treatment options for echinocandin-resistant fungal diseases.
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Affiliation(s)
- Yasuhiro Hori
- Department of Surgical Pathology, Toho University School of Medicine
| | - Kazutoshi Shibuya
- Department of Surgical Pathology, Toho University School of Medicine
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Lallitto F, Prigitano A, Mangione F, Piralla A, Tamarozzi F, Marone P, Cavanna C. Presence of L701 M mutation in the FKS1 gene of echinocandin-susceptible Candida krusei isolates. Diagn Microbiol Infect Dis 2018; 92:311-314. [PMID: 30131237 DOI: 10.1016/j.diagmicrobio.2018.07.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 06/04/2018] [Accepted: 07/05/2018] [Indexed: 11/30/2022]
Abstract
Resistance of Candida krusei isolates to echinocandins, the recommended drugs to treat candidemia, has been associated with mutations in hot spot (HS) regions of the FKS1 gene or L701 M mutation in a region between HS1 and HS3 of FKS1. However, the role of L701 M mutation alone in causing reduced echinocandins susceptibility is still unclear. We analyzed a region between HS1 and HS3 of FKS1 of 25 C. krusei isolates from clinical samples. Susceptibility to echinocandins was determined by a commercial broth microdilution assay and by the microdilution method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST). The L701 M mutation was detected in 22/25 (88%) C. krusei isolates with low MIC values in the absence of other HS mutations. The presence of isolated L701 M mutation in C. krusei clinical isolates susceptible to echinocandins suggests that this mutation may be just associated to polymorphism in the C. krusei population.
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Affiliation(s)
- Fabiola Lallitto
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy
| | - Anna Prigitano
- Department of Biomedical Sciences for Health, Università degli Studi di Milano, Via Pascal 36, 20133, Milan, Italy
| | - Francesca Mangione
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy
| | - Antonio Piralla
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy
| | - Francesca Tamarozzi
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy
| | - Piero Marone
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy
| | - Caterina Cavanna
- Microbiology and Virology Department, Fondazione IRCCS Policlinico San Matteo, Viale C. Golgi 19, 27100, Pavia, Italy.
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de Oliveira Santos GC, Vasconcelos CC, Lopes AJO, de Sousa Cartágenes MDS, Filho AKDB, do Nascimento FRF, Ramos RM, Pires ERRB, de Andrade MS, Rocha FMG, de Andrade Monteiro C. Candida Infections and Therapeutic Strategies: Mechanisms of Action for Traditional and Alternative Agents. Front Microbiol 2018; 9:1351. [PMID: 30018595 PMCID: PMC6038711 DOI: 10.3389/fmicb.2018.01351] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Accepted: 06/05/2018] [Indexed: 12/14/2022] Open
Abstract
The Candida genus comprises opportunistic fungi that can become pathogenic when the immune system of the host fails. Candida albicans is the most important and prevalent species. Polyenes, fluoropyrimidines, echinocandins, and azoles are used as commercial antifungal agents to treat candidiasis. However, the presence of intrinsic and developed resistance against azole antifungals has been extensively documented among several Candida species. The advent of original and re-emergence of classical fungal diseases have occurred as a consequence of the development of the antifungal resistance phenomenon. In this way, the development of new satisfactory therapy for fungal diseases persists as a major challenge of present-day medicine. The design of original drugs from traditional medicines provides new promises in the modern clinic. The urgent need includes the development of alternative drugs that are more efficient and tolerant than those traditional already in use. The identification of new substances with potential antifungal effect at low concentrations or in combination is also a possibility. The present review briefly examines the infections caused by Candida species and focuses on the mechanisms of action associated with the traditional agents used to treat those infections, as well as the current understanding of the molecular basis of resistance development in these fungal species. In addition, this review describes some of the promising alternative molecules and/or substances that could be used as anticandidal agents, their mechanisms of action, and their use in combination with traditional drugs.
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Affiliation(s)
- Giselle C. de Oliveira Santos
- Programa de Doutorado em Biotecnologia da Rede Nordeste de Biotecnologia (RENORBIO), Universidade Federal do Maranhão, São Luís, Brazil
| | - Cleydlenne C. Vasconcelos
- Programa de Doutorado em Biotecnologia da Rede Nordeste de Biotecnologia (RENORBIO), Universidade Federal do Maranhão, São Luís, Brazil
| | - Alberto J. O. Lopes
- Postgraduate Program in Health Sciences, Universidade Federal do Maranhão, São Luís, Brazil
| | | | - Allan K. D. B. Filho
- Departamento de Engenharia Elétrica, Programa de Doutorado em Biotecnologia da Rede Nordeste de Biotecnologia (RENORBIO), Universidade Federal do Maranhão, São Luís, Brazil
| | | | - Ricardo M. Ramos
- Department of Information, Environment, Health and Food Production, Laboratory of Information Systems, Federal Institute of Piauí, Teresina, Brazil
| | | | - Marcelo S. de Andrade
- Postgraduate Program in Health Sciences, Universidade Federal do Maranhão, São Luís, Brazil
| | - Flaviane M. G. Rocha
- Laboratório de Micologia Médica, Programa de Mestrado em Biologia Parasitária, Universidade Ceuma, São Luís, Brazil
| | - Cristina de Andrade Monteiro
- Laboratório de Micologia Médica, Programa de Mestrado em Biologia Parasitária, Universidade Ceuma, São Luís, Brazil
- Departmento de Biologia, Instituto Federal do Maranhão, São Luís, Brazil
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Belmadani A, Semlali A, Rouabhia M. Dermaseptin-S1 decreasesCandida albicansgrowth, biofilm formation and the expression of hyphal wall protein 1 and aspartic protease genes. J Appl Microbiol 2018; 125:72-83. [DOI: 10.1111/jam.13745] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 02/19/2018] [Accepted: 02/19/2018] [Indexed: 11/29/2022]
Affiliation(s)
- A. Belmadani
- Oral Ecology Research Group; Faculty of Dentistry; Laval University; Quebec QC Canada
| | - A. Semlali
- Department of Biochemistry; College of Science; King Saud University; Riyadh Saudi Arabia
| | - M. Rouabhia
- Oral Ecology Research Group; Faculty of Dentistry; Laval University; Quebec QC Canada
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Sequencing of FKS Hot Spot 1 from Saprochaete capitata To Search for a Relationship to Reduced Echinocandin Susceptibility. Antimicrob Agents Chemother 2018; 62:AAC.01246-17. [PMID: 29229638 DOI: 10.1128/aac.01246-17] [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] [Received: 06/16/2017] [Accepted: 11/22/2017] [Indexed: 11/20/2022] Open
Abstract
Saprochaete capitata, formerly known as Geotrichum capitatum, is an emerging fungal pathogen with low susceptibility to echinocandins. Here, we report the nucleotide sequence of the S. capitata hot spot 1 region of the FKS gene (FKS HS1), which codifies for the catalytic subunit of β-1,3-d-glucan synthase, the target of echinocandins. For that purpose, we first designed degenerated oligonucleotide primers derived from conserved flanking regions of the FKS1 HS1 segment of 12 different fungal species. Interestingly, analysis of the translated FKS HS1 sequences of 12 isolates of S. capitata revealed that all of them exhibited the same F-to-L substitution in a position that is highly related to reduced echinocandin susceptibility.
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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.
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Tanaka Y, Sasaki M, Ito F, Aoyama T, Sato-Okamoto M, Takahashi-Nakaguchi A, Chibana H, Shibata N. Cooperation between ER stress and calcineurin signaling contributes to the maintenance of cell wall integrity in Candida glabrata. Fungal Biol 2017; 122:19-33. [PMID: 29248112 DOI: 10.1016/j.funbio.2017.09.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 09/04/2017] [Accepted: 09/30/2017] [Indexed: 10/18/2022]
Abstract
Candida glabrata is the second most common source of Candida infections in humans. In this pathogen, the maintenance of cell wall integrity (CWI) frequently precludes effective pharmacological treatment by antifungal agents. In numerous fungi, cell wall modulation is reported to be controlled by endoplasmic reticulum (ER) stress, but how the latter affects CWI maintenance in C. glabrata is not clearly understood. Here, we characterized a C. glabrata strain harboring a mutation in the CNE1 gene, which encodes a molecular chaperone associated with nascent glycoprotein maturation in the ER. Disruption of cne1 induced ER stress and caused changes in the normal cell wall structure, specifically a reduction in the β-1,6-glucan content and accumulation of chitin. Conversely, a treatment with the typical ER stress inducer tunicamycin up-regulated the production of cell wall chitin but did not affect β-1,6-glucan content. Our results also indicated that C. glabrata features a uniquely evolved ER stress-mediated CWI pathway, which differs from that in the closely related species Saccharomyces cerevisiae. Furthermore, we demonstrated that ER stress-mediated CWI pathway in C. glabrata is also induced by the disruption of other genes encoding proteins that function in a correlated manner in the quality control of N-linked glycoproteins in the ER. These results suggest that calcineurin and ER quality control system act as a platform for maintaining CWI in C. glabrata.
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Affiliation(s)
- Yutaka Tanaka
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Masato Sasaki
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Fumie Ito
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan
| | - Toshio Aoyama
- Department of Electronic and Information Engineering, Suzuka National College of Technology, Shirako-tyo, Suzuka, Mie 510-0294, Japan
| | - Michiyo Sato-Okamoto
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | | | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8673, Japan
| | - Nobuyuki Shibata
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, 4-4-1 Komatsushima, Aoba-ku, Sendai 981-8558, Japan.
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Bar-Yosef H, Vivanco Gonzalez N, Ben-Aroya S, Kron SJ, Kornitzer D. Chemical inhibitors of Candida albicans hyphal morphogenesis target endocytosis. Sci Rep 2017; 7:5692. [PMID: 28720834 PMCID: PMC5515890 DOI: 10.1038/s41598-017-05741-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 06/01/2017] [Indexed: 01/12/2023] Open
Abstract
Candida albicans is an opportunistic pathogen, typically found as a benign commensal yeast living on skin and mucosa, but poised to invade injured tissue to cause local infections. In debilitated and immunocompromised individuals, C. albicans may spread to cause life-threatening systemic infections. Upon contact with serum and at body temperature, C. albicans performs a regulated switch to filamentous morphology, characterized by emergence of a germ tube from the yeast cell followed by mold-like growth of branching hyphae. The ability to switch between growth morphologies is an important virulence factor of C. albicans. To identify compounds able to inhibit hyphal morphogenesis, we screened libraries of existing drugs for inhibition of the hyphal switch under stringent conditions. Several compounds that specifically inhibited hyphal morphogenesis were identified. Chemogenomic analysis suggested an interaction with the endocytic pathway, which was confirmed by direct measurement of fluid-phase endocytosis in the presence of these compounds. These results suggest that the activity of the endocytic pathway, which is known to be particularly important for hyphal growth, represents an effective target for hyphae-inhibiting drugs.
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Affiliation(s)
- Hagit Bar-Yosef
- Department of Molecular Microbiology, B. Rappaport Faculty of Medicine, Technion - I.I.T. and the Rappaport Institute for Research in the Medical Sciences, Haifa, 31096, Israel
| | - Nora Vivanco Gonzalez
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Shay Ben-Aroya
- Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Stephen J Kron
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, IL, 60637, USA.
| | - Daniel Kornitzer
- Department of Molecular Microbiology, B. Rappaport Faculty of Medicine, Technion - I.I.T. and the Rappaport Institute for Research in the Medical Sciences, Haifa, 31096, Israel.
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Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi. Mediators Inflamm 2017; 2017:9870679. [PMID: 28694566 PMCID: PMC5485324 DOI: 10.1155/2017/9870679] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/28/2017] [Accepted: 05/23/2017] [Indexed: 12/30/2022] Open
Abstract
Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs.
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Activity of Combined Antifungal Agents Against Multidrug-Resistant Candida glabrata Strains. Mycopathologia 2017; 182:819-828. [PMID: 28493006 DOI: 10.1007/s11046-017-0141-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 05/04/2017] [Indexed: 10/19/2022]
Abstract
In this study, we evaluated the in vitro activity of echinocandins, azoles, and amphotericin B alone and in combination against echinocandin/azole-sensitive and echinocandin/azole-resistant Candida glabrata isolates. Susceptibility tests were performed using the broth microdilution method in accordance with the Clinical and Laboratory Standards Institute document M27-A3. The checkerboard method was used to evaluate the fractional inhibitory concentration index of the interactions. Cross-resistance was observed among echinocandins; 15% of the isolates resistant to caspofungin were also resistant to anidulafungin and micafungin. Synergistic activity was observed in 70% of resistant C. glabrata when anidulafungin was combined with voriconazole or posaconazole. Higher (85%) synergism was found in the combination of caspofungin and voriconazole. The combinations of caspofungin with fluconazole, posaconazole and amphotericin B, micafungin with fluconazole, posaconazole and voriconazole, and anidulafungin with amphotericin B showed indifferent activities for the majority of the isolates. Anidulafungin combined with fluconazole showed the same percentage of synergism and indifference (45%). Antagonism was detected in 50% of isolates when micafungin was combined with amphotericin B. Combinations of echinocandins and antifungal azoles have great potential for in vivo assays which are required to evaluate the efficacy of these combinations against multidrug-resistant C. glabrata strains.
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Techaparin A, Thanonkeo P, Klanrit P. High-temperature ethanol production using thermotolerant yeast newly isolated from Greater Mekong Subregion. Braz J Microbiol 2017; 48:461-475. [PMID: 28365094 PMCID: PMC5498443 DOI: 10.1016/j.bjm.2017.01.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 01/04/2017] [Accepted: 01/05/2017] [Indexed: 11/24/2022] Open
Abstract
The application of high-potential thermotolerant yeasts is a key factor for successful ethanol production at high temperatures. Two hundred and thirty-four yeast isolates from Greater Mekong Subregion (GMS) countries, i.e., Thailand, The Lao People's Democratic Republic (Lao PDR) and Vietnam were obtained. Five thermotolerant yeasts, designated Saccharomyces cerevisiae KKU-VN8, KKU-VN20, and KKU-VN27, Pichia kudriavzevii KKU-TH33 and P. kudriavzevii KKU-TH43, demonstrated high temperature and ethanol tolerance levels up to 45 °C and 13% (v/v), respectively. All five strains produced higher ethanol concentrations and exhibited greater productivities and yields than the industrial strain S. cerevisiae TISTR5606 during high-temperature fermentation at 40 °C and 43 °C. S. cerevisiae KKU-VN8 demonstrated the best performance for ethanol production from glucose at 37 °C with an ethanol concentration of 72.69 g/L, a productivity of 1.59 g/L/h and a theoretical ethanol yield of 86.27%. The optimal conditions for ethanol production of S. cerevisiae KKU-VN8 from sweet sorghum juice (SSJ) at 40 °C were achieved using the Box–Behnken experimental design (BBD). The maximal ethanol concentration obtained during fermentation was 89.32 g/L, with a productivity of 2.48 g/L/h and a theoretical ethanol yield of 96.32%. Thus, the newly isolated thermotolerant S. cerevisiae KKU-VN8 exhibits a great potential for commercial-scale ethanol production in the future.
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Affiliation(s)
- Atiya Techaparin
- Graduate School, Khon Kaen University, Khon Kaen 40002, Thailand; Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand
| | - Pornthap Thanonkeo
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand
| | - Preekamol Klanrit
- Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; Fermentation Research Center for Value Added Agricultural Products (FerVAAP), Khon Kaen University, Khon Kaen 40002, Thailand.
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43
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Grosset M, Desnos-Ollivier M, Godet C, Kauffmann-Lacroix C, Cazenave-Roblot F. Recurrent episodes of Candidemia due to Candida glabrata, Candida tropicalis and Candida albicans with acquired echinocandin resistance. Med Mycol Case Rep 2016; 14:20-23. [PMID: 27995055 PMCID: PMC5155041 DOI: 10.1016/j.mmcr.2016.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 12/03/2016] [Accepted: 12/06/2016] [Indexed: 11/17/2022] Open
Abstract
Mixed fungal infection and acquired echinocandin resistance of Candida spp. remain infrequent. In this study we have reported the case of a patient hospitalized for tuberculosis who experienced multiple infections due to three common Candida species (C. albicans, C. glabrata, C. tropicalis). Furthermore, consecutive isolates from blood cultures and heart valve were found resistant to azoles (C. tropicalis) and to echinocandin with either novel (C. tropicalis) or previously described (C. albicans) missense mutations in the Fks gene.
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Affiliation(s)
- Marine Grosset
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
| | - Marie Desnos-Ollivier
- Institut Pasteur, Unité de Mycologie Moléculaire, Centre National de Référence Mycologie et Antifongiques, 25 rue du Dr Roux, Paris 75015, France
| | - Cendrine Godet
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
| | | | - France Cazenave-Roblot
- Service de Maladies Infectieuses et tropicales, CHU de Poitiers, 2 rue de la Milétrie, Poitiers 86021, France
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Tanaka Y, Sasaki M, Ito F, Aoyama T, Sato-Okamoto M, Takahashi-Nakaguchi A, Chibana H, Shibata N. KRE5 Suppression Induces Cell Wall Stress and Alternative ER Stress Response Required for Maintaining Cell Wall Integrity in Candida glabrata. PLoS One 2016; 11:e0161371. [PMID: 27548283 PMCID: PMC4993462 DOI: 10.1371/journal.pone.0161371] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 08/04/2016] [Indexed: 01/10/2023] Open
Abstract
The maintenance of cell wall integrity in fungi is required for normal cell growth, division, hyphae formation, and antifungal tolerance. We observed that endoplasmic reticulum stress regulated cell wall integrity in Candida glabrata, which possesses uniquely evolved mechanisms for unfolded protein response mechanisms. Tetracycline-mediated suppression of KRE5, which encodes a predicted UDP-glucose:glycoprotein glucosyltransferase localized in the endoplasmic reticulum, significantly increased cell wall chitin content and decreased cell wall β-1,6-glucan content. KRE5 repression induced endoplasmic reticulum stress-related gene expression and MAP kinase pathway activation, including Slt2p and Hog1p phosphorylation, through the cell wall integrity signaling pathway. Moreover, the calcineurin pathway negatively regulated cell wall integrity, but not the reduction of β-1,6-glucan content. These results indicate that KRE5 is required for maintaining both endoplasmic reticulum homeostasis and cell wall integrity, and that the calcineurin pathway acts as a regulator of chitin-glucan balance in the cell wall and as an alternative mediator of endoplasmic reticulum stress in C. glabrata.
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Affiliation(s)
- Yutaka Tanaka
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Masato Sasaki
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Fumie Ito
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Toshio Aoyama
- Department of Electronic and Information Engineering, Suzuka National College of Technology, Suzuka, Japan
| | | | | | - Hiroji Chibana
- Medical Mycology Research Center, Chiba University, Chiba, Japan
| | - Nobuyuki Shibata
- Department of Infection and Host Defense, Tohoku Medical and Pharmaceutical University, Sendai, Japan
- * E-mail:
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45
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The fungal resistome: a risk and an opportunity for the development of novel antifungal therapies. Future Med Chem 2016; 8:1503-20. [PMID: 27485839 DOI: 10.4155/fmc-2016-0051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The risks for toxicity of novel antifungal compounds, together with the emergence of resistance, makes the use of inhibitors of resistance, in combination with antifungal compounds, a suitable strategy for developing novel antifungal formulations. Among them, inhibitors of efflux pumps are suitable candidates. Increasing drug influx or interfering with the stress response may also improve the efficacy of antifungals. Therapies as induction of fungal apoptosis or immunostimulation are also good strategies for reducing the risks for resistance and to improve antifungals' efficacy. Understanding the effect of the acquisition of resistance on the fungal physiology and determining the collateral sensitivity networks are useful for the development of novel strategies based on combination of antifungals for improving the efficacy of the therapy.
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46
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Gonçalves SS, Souza ACR, Chowdhary A, Meis JF, Colombo AL. Epidemiology and molecular mechanisms of antifungal resistance in CandidaandAspergillus. Mycoses 2016; 59:198-219. [DOI: 10.1111/myc.12469] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Revised: 12/14/2015] [Accepted: 12/18/2015] [Indexed: 12/15/2022]
Affiliation(s)
- Sarah Santos Gonçalves
- Laboratório Especial de Micologia, Disciplina de Infectologia, Escola Paulista de Medicina; Universidade Federal de São Paulo; São Paulo SP Brazil
| | - Ana Carolina Remondi Souza
- Laboratório Especial de Micologia, Disciplina de Infectologia, Escola Paulista de Medicina; Universidade Federal de São Paulo; São Paulo SP Brazil
| | - Anuradha Chowdhary
- Department of Medical Mycology; Vallabhbhai Patel Chest Institute; University of Delhi; Delhi India
| | - Jacques F. Meis
- Department of Medical Microbiology and Infectious Diseases; Canisius Wilhelmina Hospital; Nijmegen the Netherlands
- Department of Medical Microbiology; Radboud University Medical Centre; Nijmegen the Netherlands
| | - Arnaldo Lopes Colombo
- Laboratório Especial de Micologia, Disciplina de Infectologia, Escola Paulista de Medicina; Universidade Federal de São Paulo; São Paulo SP Brazil
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47
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Abstract
Fungal infections due to Candida and Aspergillus species cause extensive morbidity and mortality, especially among immunosuppressed patients, and antifungal therapy is critical to patient management. Yet only a few drug classes are available to treat invasive fungal diseases, and this problem is compounded by the emergence of antifungal resistance. Echinocandin drugs are the preferred choice to treat candidiasis. They are the first cell wall-active agents and target the fungal-specific enzyme glucan synthase, which catalyzes the biosynthesis of β-1,3-glucan, a key cell wall polymer. Therapeutic failures occur rarely among common Candida species, with the exception of Candida glabrata, which is frequently multidrug resistant. Echinocandin resistance in susceptible species is always acquired during therapy. The mechanism of resistance involves amino acid changes in hot-spot regions of Fks subunits of glucan synthase, which decrease the sensitivity of the enzyme to drug. Cellular stress response pathways lead to drug adaptation, which promotes the formation of resistant fks strains. Clinical factors promoting echinocandin resistance include empiric therapy, prophylaxis, gastrointestinal reservoirs, and intra-abdominal infections. A better understanding of the echinocandin-resistance mechanism, along with cellular and clinical factors promoting resistance, will facilitate more effective strategies to overcome and prevent echinocandin resistance.
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Affiliation(s)
- David S Perlin
- New Jersey Medical School, Rutgers Biomedical and Health Sciences, Public Health Research Institute, Newark, New Jersey
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48
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Quick Detection of FKS1 Mutations Responsible for Clinical Echinocandin Resistance in Candida albicans. J Clin Microbiol 2015; 53:2037-41. [PMID: 25878347 DOI: 10.1128/jcm.00398-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2015] [Accepted: 04/09/2015] [Indexed: 01/02/2023] Open
Abstract
A rapid molecular-based assay for the detection of the Candida albicans FKS1 gene mutations responsible for resistance to echinocandin drugs was designed and evaluated. The assay consisted of a multiplexed PCR set of 5 tubes able to detect the most commonly described resistance mechanism, including FKS1 hot spot 1 and hot spot 2 mutations. The performance and specificity of the assay was evaluated using a double-blinded panel of 50 C. albicans strains. The assay showed a sensitivity of 96% and was able to detect all homozygous mutants included in the collection of strains, demonstrating that it is a robust, quick, and labor-saving method that is suitable for a routine clinical diagnostic laboratory.
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49
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Cowen LE, Sanglard D, Howard SJ, Rogers PD, Perlin DS. Mechanisms of Antifungal Drug Resistance. Cold Spring Harb Perspect Med 2014; 5:a019752. [PMID: 25384768 DOI: 10.1101/cshperspect.a019752] [Citation(s) in RCA: 336] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Antifungal therapy is a central component of patient management for acute and chronic mycoses. Yet, treatment choices are restricted because of the sparse number of antifungal drug classes. Clinical management of fungal diseases is further compromised by the emergence of antifungal drug resistance, which eliminates available drug classes as treatment options. Once considered a rare occurrence, antifungal drug resistance is on the rise in many high-risk medical centers. Most concerning is the evolution of multidrug- resistant organisms refractory to several different classes of antifungal agents, especially among common Candida species. The mechanisms responsible are mostly shared by both resistant strains displaying inherently reduced susceptibility and those acquiring resistance during therapy. The molecular mechanisms include altered drug affinity and target abundance, reduced intracellular drug levels caused by efflux pumps, and formation of biofilms. New insights into genetic factors regulating these mechanisms, as well as cellular factors important for stress adaptation, provide a foundation to better understand the emergence of antifungal drug resistance.
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Affiliation(s)
- Leah E Cowen
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Dominique Sanglard
- University of Lausanne and University Hospital Center, Institute of Microbiology, 1011 Lausanne, Switzerland
| | - Susan J Howard
- University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, United Kingdom
| | - P David Rogers
- College of Pharmacy, The University of Tennessee Health Science Center, Memphis, Tennessee 38163
| | - David S Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, New Jersey 07103
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50
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Perlin DS. Echinocandin resistance, susceptibility testing and prophylaxis: implications for patient management. Drugs 2014; 74:1573-85. [PMID: 25255923 PMCID: PMC4201113 DOI: 10.1007/s40265-014-0286-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This article addresses the emergence of echinocandin resistance among Candida species, mechanisms of resistance, factors that promote resistance and confounding issues surrounding standard susceptibility testing. Fungal infections remain a significant cause of global morbidity and mortality, especially among patients with underlying immunosupression. Antifungal therapy is a critical component of patient management for acute and chronic diseases. Yet, therapeutic choices are limited due to only a few drug classes available to treat systemic disease. Moreover, the problem is exacerbated by the emergence of antifungal resistance, which has resulted in difficult to manage multidrug resistant strains. Echinocandin drugs are now the preferred choice to treat a range of candidiasis. These drugs target and inhibit the fungal-specific enzyme glucan synthase, which is responsible for the biosynthesis of a key cell wall polymer. Therapeutic failures involving acquisition of resistance among susceptible organisms like Candida albicans is largely a rare event. However, in recent years, there is an alarming trend of increased resistance among strains of Candida glabrata, which in many cases are also resistant to azole drugs. Echinocandin resistance is always acquired during therapy and the mechanism of resistance is well established to involve amino acid changes in "hot-spot" regions of the Fks subunits carrying the catalytic portion of glucan synthase. These changes significantly decrease the sensitivity of the enzyme to drug resulting in higher MIC values. A range of drug responses, from complete to partial refractory response, is observed depending on the nature of the amino acid substitution, and clinical responses are recapitulated in pharmacodynamic models of infection. The cellular processes promoting the formation of resistant Fks strains involve complex stress response pathways, which yield a variety of adaptive compensatory genetic responses. Stress-adapted cells become drug tolerant and can form stable drug resistant FKS mutations with continued drug exposure. A major concern for resistance detection is that classical broth microdilution techniques show significant variability among clinical microbiology laboratories for certain echinocandin drugs and Candida species. The consequence is that susceptible strains are misclassified according to established clinical breakpoints, and this has led to confusion in the field. Clinical factors that appear to promote echinocandin resistance include the expanding use of antifungal agents for empiric therapy and prophylaxis. Furthermore, host reservoirs such as biofilms in the gastrointestinal tract or intra-abdominal infections can seed development of resistant organisms during therapy. A fundamental understanding of the primary molecular resistance mechanism, along with cellular and clinical factors that promote resistance emergence, is critical to develop better diagnostic tools and therapeutic strategies to overcome and prevent echinocandin resistance.
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Affiliation(s)
- David S Perlin
- Public Health Research Institute, New Jersey Medical School, Rutgers, The State University of New Jersey, Newark, NJ, 07103, USA,
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