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Wu C, Fan J, Hu D, Sun H, Lu G, Wang Y, Yang Y. The Three-Dimensional Structure of the Genome of the Dark Septate Endophyte Exophiala tremulae and Its Symbiosis Effect on Alpine Meadow Plant Growth. J Fungi (Basel) 2025; 11:246. [PMID: 40278067 PMCID: PMC12028334 DOI: 10.3390/jof11040246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2024] [Revised: 02/16/2025] [Accepted: 02/27/2025] [Indexed: 04/26/2025] Open
Abstract
The establishment of artificial grassland is a good pathway for resolving serious social and economic problems in the Qinghai-Tibet Plateau. Some beneficial indigenous microbes may be used to improve productivity in artificial grassland. The genome of the indigenous dark septate fungus, Exophiala tremulae CICC2537, was sequenced and assembled at the chromosome level using the PacBio sequencing platform, with the assistance of the Hi-C technique for scaffolding, and its 3D genome structures were investigated. The genome size of E. tremulae is 51.903848 Mb, and it contains eight chromosomes. A total of 12,277 protein-coding genes were predicted, and 11,932 genes (97.19%) were annotated. As for the distribution of exon and intron number and the distribution of gene GC and CDS GC, E. tremulae showed similar distribution patterns to the other investigated members of the genus Exophiala. The analysis of carbohydrate-active enzymes showed that E. tremulae possesses the greatest number of enzymes with auxiliary activities and the lowest number of enzymes with carbohydrate-binding modules among the investigated fungi. The total number of candidate effector proteins was 3337, out of which cytoplasmic and apoplastic effector proteins made up 3100 and 163, respectively. The whole genome of E. tremulae contained 40 compartment As and 76 compartment Bs, and there was no significant difference in GC content in its compartment As and Bs. The whole genome of E. tremulae was predicted to contain 155 topologically associating domains (TADs), and their average length was 250,000 bp, but there were no significant differences in the numbers of genes and the GC content per bin localized within the boundaries and interiors of TADs. Comparative genome analysis showed that E. tremulae diverged from Exophiala mesophila about 34.1 (30.0-39.1) Myr ago, and from Exophiala calicioides about 85.6 (76.1-90.6) Myr ago. Compared with all the investigated fungi, the numbers of contraction and expansion gene families in the E. tremulae genome were 13 and 89, respectively, and the numbers of contraction and expansion genes were 14 and 670, respectively. Our work provides a basis for the use of the dark septate fungus in alpine artificial grassland and further research into its symbiosis mechanisms, which may improve the growth of plant species used in the Qinghai-Tibet Plateau.
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Affiliation(s)
- Chu Wu
- College of Horticulture & Gardening, Yangtze University, Jingzhou 434025, China; (C.W.); (Y.Y.)
| | - Junjie Fan
- College of Life Science, Yangtze University, Jingzhou 434025, China; (J.F.); (Y.W.)
| | - Die Hu
- College of Horticulture & Gardening, Yangtze University, Jingzhou 434025, China; (C.W.); (Y.Y.)
| | - Honggang Sun
- Research Institute of Subtropical Forestry, Chinese Academy of Forestry, Hangzhou 311400, China;
| | - Guangxin Lu
- College of Agriculture & Animal Husbandry, Qinghai University, Xining 810016, China;
| | - Yun Wang
- College of Life Science, Yangtze University, Jingzhou 434025, China; (J.F.); (Y.W.)
| | - Yujie Yang
- College of Horticulture & Gardening, Yangtze University, Jingzhou 434025, China; (C.W.); (Y.Y.)
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Nakatani R, Ashiarai M, Yoshihara H, Yada K, Nozaki T, Ushigusa T, Mori N, Hasegawa D. Multidisciplinary management of disseminated Exophiala dermatitidis mycosis in an infant with mixed phenotype acute leukemia: a case report. BMC Infect Dis 2022; 22:797. [PMID: 36274136 PMCID: PMC9590134 DOI: 10.1186/s12879-022-07773-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/09/2022] [Indexed: 11/10/2022] Open
Abstract
Background Exophiala dermatitidis is a dematiaceous fungus isolated from various environmental sources. Systemic E. dermatitidis infections can lead to fatal outcomes, and treatment has not yet been standardized. Although E. dermatitidis is also known to cause cutaneous infection, it has not been previously reported to appear as ecthyma gangrenosum (EG), an uncommon cutaneous lesion in neutropenic patients that is mainly caused by Pseudomonas aeruginosa. Case presentation A 2-month-old male infant with mixed-phenotype acute leukemia presented with prolonged fever unresponsive to antibacterial and antifungal agents during myelosuppression due to remission induction therapy. He also presented with skin lesions on the left wrist and left lower quadrant of the abdomen. The abdominal lesion gradually turned black and necrotic, which was consistent with the findings of the EG. E. dermatitidis was isolated from the blood, stool, wrist skin, and endotracheal aspirate. During hematopoietic recovery, consolidation in both lungs was evident. Multiagent antifungal treatment failed to eliminate E. dermatitidis from blood. In order to salvage the central venous catheter, ethanol lock therapy (ELT) was adopted, following which the blood culture became negative. The abdominal lesion that evolved as a necrotic mass connecting the small intestine and subcutaneous tissue adjacent to the skin was surgically resected. After these interventions, the general condition improved. Conclusion Disseminated E. dermatitidis mycosis in the neutropenic infant was successfully managed with a multidisciplinary treatment consisting of multiagent antifungal treatment, ELT, and surgery.
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Maraki S, Katzilakis N, Neonakis I, Stafylaki D, Meletiadis J, Hamilos G, Stiakaki E. Exophiala dermatitidis Central Line-Associated Bloodstream Infection in a Child with Ewing's Sarcoma: Case Report and Literature Review on Paediatric Infections. Mycopathologia 2022; 187:595-602. [PMID: 35994217 DOI: 10.1007/s11046-022-00658-1] [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: 05/18/2022] [Accepted: 08/04/2022] [Indexed: 10/15/2022]
Abstract
Exophiala dermatitidis is a dematiaceous, ubiquitous, dimorphic fungus, which can cause a wide range of invasive diseases in both immunocompromised and immunocompetent hosts. Bloodstream infections due to E. dermatitidis are rarely encountered in clinical practice, especially in pediatric patients. We describe a case of central line-associated bloodstream infection due to E. dermatitidis in a 4.5-year-old boy with Ewing's sarcoma. The fungus was isolated from blood specimens taken from the Hickman line. The isolate was identified by its phenotypic characteristics, by MALDI-TOF and by using molecular methods. The infection was successfully treated with voriconazole and catheter removal. The literature was also reviewed on pediatric infections caused by E. dermatitidis, focusing on clinical manifestations and challenges associated with diagnosis and management.
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Affiliation(s)
- Sofia Maraki
- Department of Clinical Microbiology and Microbial Pathogenesis, University Hospital of Heraklion, Crete, Greece.
| | - Nikolaos Katzilakis
- Department of Pediatric Hematology-Oncology, University Hospital of Heraklion and Laboratory of Blood Diseases and Childhood Cancer Biology, Medical School, University of Crete, Heraklion, Greece
| | - Ioannis Neonakis
- Department of Clinical Microbiology and Microbial Pathogenesis, University Hospital of Heraklion, Crete, Greece
| | - Dimitra Stafylaki
- Department of Clinical Microbiology and Microbial Pathogenesis, University Hospital of Heraklion, Crete, Greece
| | - Joseph Meletiadis
- Clinical Microbiology Laboratory, Attikon University Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - George Hamilos
- Department of Clinical Microbiology and Microbial Pathogenesis, University Hospital of Heraklion, Crete, Greece
| | - Eftichia Stiakaki
- Department of Pediatric Hematology-Oncology, University Hospital of Heraklion and Laboratory of Blood Diseases and Childhood Cancer Biology, Medical School, University of Crete, Heraklion, Greece
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A fatal neonatal case of fungemia due to Exophiala dermatitidis-case report and literature review. BMC Pediatr 2022; 22:482. [PMID: 35948953 PMCID: PMC9364490 DOI: 10.1186/s12887-022-03518-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 07/23/2022] [Indexed: 12/03/2022] Open
Abstract
Background Systemic infections caused by the black yeast-like fungus Exophiala dermatitidis are rare, but are associated with high mortality especially in immunocompromised patients. We report the first case of E. dermatitidis fungemia in a premature extremely low birth weight (ELBW) neonate who succumbed despite antifungal therapy with liposomal amphotericin (AMB) and fluconazole. A systematic review of all fungemia cases due to E. dermatitidis was also conducted aiming for a better understanding of the risk factors, treatment strategies and outcomes. Case presentation A male, ELBW premature neonate, soon after his birth, developed bradycardia, apnoea and ultimately necrotizing enterocolitis with intestinal perforation requiring surgical intervention. Meanwhile, he had also multiple risk factors for developing bloodstream infection, such as intubation, mechanical ventilation, central venous catheter (CVC), parenteral nutrition, empirical and prolonged antibiotic use. His blood cultures were positive, firstly for Acinetobacter junii and then for Klebsiella pneumoniae together with E. dermatitidis while on fluconazole prophylaxis and antibiotic empiric therapy. Despite the treatment with broad spectrum antibiotics, liposomal AMB and fluconazole, the newborn succumbed. A literature review identified another 12 E. dermatitidis bloodstream infections, mainly in patients with hematologic malignancies and solid organ transplant recipients (61%), with overall mortality 38% despite CVC removal and antifungal therapy. Conclusions Due to the rarity of E. dermatitidis infections, little is known about the characteristics of this yeast, the identification methods and the optimal therapy. Identification by common biochemical tests was problematic requiring molecular identification. Resolution of neonatal fungemia is difficult despite proper antifungal therapy especially in cases with multiple and severe risk factors like the present one. Therapeutic intervention may include CVC removal and treatment for at least 3 weeks with an azole (itraconazole or fluconazole after susceptibility testing) or AMB monotherapy but not echinocandins or AMB plus azole combination therapy.
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Tzar MN, Meor Jamaludin WHB, Abdul Wahab A, Ding CH. Exophiala dermatitidis, ‘the real black fungus’ fungemia in a patient with COVID-19. IDCases 2022; 27:e01428. [PMID: 35127454 PMCID: PMC8800164 DOI: 10.1016/j.idcr.2022.e01428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 01/27/2022] [Accepted: 01/27/2022] [Indexed: 11/30/2022] Open
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Usuda D, Higashikawa T, Hotchi Y, Usami K, Shimozawa S, Tokunaga S, Osugi I, Katou R, Ito S, Yoshizawa T, Asako S, Mishima K, Kondo A, Mizuno K, Takami H, Komatsu T, Oba J, Nomura T, Sugita M. Exophiala dermatitidis. World J Clin Cases 2021; 9:7963-7972. [PMID: 34621853 PMCID: PMC8462220 DOI: 10.12998/wjcc.v9.i27.7963] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 04/03/2021] [Accepted: 08/24/2021] [Indexed: 02/06/2023] Open
Abstract
Exophiala is a genus comprising several species of opportunistic black yeasts, which belongs to Ascomycotina. It is a rare cause of fungal infections. However, infections are often chronic and recalcitrant, and while the number of cases is steadily increasing in both immunocompromised and immunocompetent people, detailed knowledge remains scarce regarding infection mechanisms, virulence factors, specific predisposing factors, risk factors, and host response. The most common manifestations of Exophiala infection are skin infections, and the most frequent type of deep infection is pulmonary infection due to inhalation. The invasive disease ranges from cutaneous or subcutaneous infection to systemic dissemination to internal organs. The final identification of the causative organism should be achieved through a combination of several methods, including the newly introduced diagnostic analysis, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry, together with sequencing of the ribosomal ribonucleic acid internal transcribed spacer region of the fungi, and histological and culture findings. Regarding treatment, because anti-infective agents and natural compounds exhibited poor antibiofilm activity, few treatments have ultimately been found to be effective for specific antifungal therapy, so the optimal antifungal therapy and duration of therapy for these infections remain unknown. Therefore, most forms of disease caused by Exophiala dermatitidis require aggressive combination therapies: Both surgical intervention and aggressive antifungal therapy with novel compounds and azoles are necessary for effective treatment.
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Affiliation(s)
- Daisuke Usuda
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Toshihiro Higashikawa
- Department of Geriatric Medicine, Kanazawa Medical University Himi Municipal Hospital, Himi-shi 935-8531, Toyama-ken, Japan
| | - Yuta Hotchi
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Kenki Usami
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Shintaro Shimozawa
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Shungo Tokunaga
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Ippei Osugi
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Risa Katou
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Sakurako Ito
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Toshihiko Yoshizawa
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Suguru Asako
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Kentaro Mishima
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Akihiko Kondo
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Keiko Mizuno
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Hiroki Takami
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Takayuki Komatsu
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Jiro Oba
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Tomohisa Nomura
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
| | - Manabu Sugita
- Department of Emergency and Critical Care Medicine, Juntendo University Nerima Hospital, Nerima-ku 177-8521, Tokyo, Japan
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Itoh N, Murakami H, Ishibana Y, Matsubara Y, Yaguchi T, Kamei K. Challenges in the diagnosis and management of central line-associated blood stream infection due to Exophiala dermatitidis in an adult cancer patient. J Infect Chemother 2021; 27:1360-1364. [PMID: 33888421 DOI: 10.1016/j.jiac.2021.04.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Revised: 04/03/2021] [Accepted: 04/08/2021] [Indexed: 11/15/2022]
Abstract
BACKGROUND Exophiala (Wangiella) dermatitidis is a clinically relevant black yeast. Although E. dermatitidis rarely causes human infection, it can cause superficial and deep-seated infections, and cutaneous and subcutaneous diseases. Cases of fungemia and central line-associated bloodstream infections due to E. dermatitidis are extremely uncommon, and their clinical manifestations and prognosis are still not well-known. Herein, we report a case of central line-associated bloodstream infections in a patient with cancer. These infections were caused by melanized yeast that was finally identified as E. dermatitidis via internal transcribed spacer sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. CASE PRESENTATION A 75-year-old man with thoracic esophageal cancer and early gastric cancer presented with a 1-day history of fever during his hospitalization at our hospital. A central venous port was placed in the patient for total parenteral nutrition. Two E. dermatitidis isolates were recovered from two blood samples drawn at different times from a peripheral vein and this central venous port. The isolate was identified as E. dermatitidis by internal transcribed spacer sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The central venous port was removed, and the patient was administered micafungin and voriconazole. Although the minimum inhibitory concentrations of E. dermatitidis for voriconazole and minimum effective concentrations for micafungin were 2 μg/mL and 4 μg/m, respectively, the bacteremia was successfully treated. CONCLUSIONS Although no clear treatment guidelines have been proposed for E. dermatitidis infections, immediate removal of central venous catheters is the key to improving central line-associated bloodstream infections.
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Affiliation(s)
- Naoya Itoh
- Division of Infectious Diseases, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan; Collaborative Chairs Emerging and Reemerging Infectious Diseases, National Center for Global Health and Medicine, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan.
| | - Hiromi Murakami
- Division of Infectious Diseases, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Yuichi Ishibana
- Division of Infectious Diseases, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Yuki Matsubara
- Department of Clinical Oncology, Aichi Cancer Center Hospital, 1-1 Kanokoden, Chikusa-ku, Nagoya, Aichi, 464-8681, Japan
| | - Takashi Yaguchi
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan
| | - Katsuhiko Kamei
- Medical Mycology Research Center, Chiba University, 1-8-1 Inohana, Chiba, 260-8673, Japan
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