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Salazar SB, Pinheiro MJF, Sotti-Novais D, Soares AR, Lopes MM, Ferreira T, Rodrigues V, Fernandes F, Mira NP. Disclosing azole resistance mechanisms in resistant Candida glabrata strains encoding wild-type or gain-of-function CgPDR1 alleles through comparative genomics and transcriptomics. G3 (BETHESDA, MD.) 2022; 12:jkac110. [PMID: 35532173 PMCID: PMC9258547 DOI: 10.1093/g3journal/jkac110] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 04/25/2022] [Indexed: 12/03/2022]
Abstract
The pathogenic yeast Candida glabrata is intrinsically resilient to azoles and rapidly acquires resistance to these antifungals, in vitro and in vivo. In most cases azole-resistant C. glabrata clinical strains encode hyperactive CgPdr1 variants, however, resistant strains encoding wild-type CgPDR1 alleles have also been isolated, although remaining to be disclosed the underlying resistance mechanism. In this study, we scrutinized the mechanisms underlying resistance to azoles of 8 resistant clinical C. glabrata strains, identified along the course of epidemiological surveys undertaken in Portugal. Seven of the strains were found to encode CgPdr1 gain-of-function variants (I392M, E555K, G558C, and I803T) with the substitutions I392M and I803T being herein characterized as hyper-activating mutations for the first time. While cells expressing the wild-type CgPDR1 allele required the mediator subunit Gal11A to enhance tolerance to fluconazole, this was dispensable for cells expressing the I803T variant indicating that the CgPdr1 interactome is shaped by different gain-of-function substitutions. Genomic and transcriptomic profiling of the sole azole-resistant C. glabrata isolate encoding a wild-type CgPDR1 allele (ISTB218) revealed that under fluconazole stress this strain over-expresses various genes described to provide protection against this antifungal, while also showing reduced expression of genes described to increase sensitivity to these drugs. The overall role in driving the azole-resistance phenotype of the ISTB218 C. glabrata isolate played by these changes in the transcriptome and genome of the ISTB218 isolate are discussed shedding light into mechanisms of resistance that go beyond the CgPdr1-signalling pathway and that may alone, or in combination, pave the way for the acquisition of resistance to azoles in vivo.
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Affiliation(s)
- Sara B Salazar
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Maria Joana F Pinheiro
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Danielle Sotti-Novais
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Ana R Soares
- Department of Medical Sciences, Institute of Biomedicine (iBiMED), University of Aveiro, Aveiro 3810, Portugal
| | - Maria M Lopes
- Departamento de Microbiologia e Imunologia, Faculdade de Farmácia da Universidade de Lisboa, Lisboa 1649-003, Portugal
| | - Teresa Ferreira
- Laboratório de Microbiologia, Hospital Dona Estefânia (Centro Hospitalar Universitário Lisboa Central), Lisboa 1169-045, Portugal
| | - Vitória Rodrigues
- Seção de Microbiologia, Laboratório SYNLAB—Lisboa, Grupo SYNLAB Portugal, Lisboa 1070-061, Portugal
| | - Fábio Fernandes
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
| | - Nuno P Mira
- iBB, Institute for Bioengineering and Biosciences, Instituto Superior Técnico—Department of Bioengineering, Universidade de Lisboa, Lisboa 1049-001, Portugal
- Associate Laboratory i4HB—Institute for Health and Bioeconomy at Instituto Superior Técnico, Universidade de Lisboa, Lisboa 1049-001, Portugal
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Shantal CJN, Juan CC, Lizbeth BUS, Carlos HGJ, Estela GPB. Candida glabrata is a successful pathogen: an artist manipulating the immune response. Microbiol Res 2022; 260:127038. [DOI: 10.1016/j.micres.2022.127038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2021] [Revised: 04/02/2022] [Accepted: 04/07/2022] [Indexed: 02/07/2023]
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Kaypetch R, Rudrakanjana P, Churnjitapirom P, Tua-Ngam P, Tonput P, Tantivitayakul P. Geraniol and thymoquinone inhibit Candida spp. biofilm formation on acrylic denture resin without affecting surface roughness or color. J Oral Sci 2022; 64:161-166. [PMID: 35321964 DOI: 10.2334/josnusd.21-0435] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
PURPOSE This study was designed to investigate the in vitro effects of geraniol (GE) and thymoquinone (TQ) on Candida biofilms on denture acrylic and any accompanying changes in acrylic surface roughness or color. METHODS The susceptibility of Candida species to GE and TQ was determined using the broth microdilution method and time-kill assay. A minimum biofilm eradication concentration (MBEC) assay was performed using 7-day Candida biofilms grown on denture acrylic. RESULTS The minimum inhibitory concentration (MIC) of GE and TQ for Candida spp. was 256 and 32 µg/mL, respectively. The Candida strain complete kill rates for GE and TQ at 5-fold MIC were determined after 1 h of incubation. At 5-fold MIC, GE and TQ inhibited the preformed biofilm activity (MBEC80) of all Candida strains on denture acrylic by more than 80% after treatment for 3 h. At sub-MIC levels, GE and TQ prevented the development of C. albicans and C. tropicalis hyphae. SEM images demonstrated that GE and TQ damaged the fungal cell membrane and induced cell lysis. On the other hand, GE and TQ at 10-fold MIC did not alter the surface roughness or color of the denture acrylic. CONCLUSION GE and TQ are interesting natural substances that could be developed as promising disinfectants for removable dentures.
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Affiliation(s)
| | | | | | | | - Pairin Tonput
- Research Office, Faculty of Dentistry, Mahidol University
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