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Zhou S, Ismail MAI, Aimanianda V, de Hoog GS, Kang Y, Ahmed SA. Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis. Med Mycol 2024; 62:myae034. [PMID: 38578660 DOI: 10.1093/mmy/myae034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.
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Affiliation(s)
- Shaoqin Zhou
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
| | - Mawahib A I Ismail
- Mycology Reference Laboratory, University of Khartoum, 11115, Khartoum, Sudan
| | - Vishukumar Aimanianda
- Immunobiology of Aspergillus, Institut Pasteur, Universite ́ Paris Cite ́ 75015, Paris, France
| | - G Sybren de Hoog
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
| | - Yingqian Kang
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
| | - Sarah A Ahmed
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
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Zhou S, Ismail MAI, Buil JB, Gabr A, Verweij PE, Mahgoub ES, de Hoog S, Kang Y, Ahmed SA. Fungi involved in rhinosinusitis in arid regions: insights from molecular identification and antifungal susceptibility. Microbiol Spectr 2023; 11:e0183123. [PMID: 37772821 PMCID: PMC10580872 DOI: 10.1128/spectrum.01831-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 08/07/2023] [Indexed: 09/30/2023] Open
Abstract
Fungal rhinosinusitis (FRS) is a common problem worldwide, with an increasing burden in arid climate regions. Aspergillus species are the most common causative agents involved. In the present study, we investigated the prevalence, molecular characterization, and antifungal susceptibility of opportunists causing FRS in Sudan on the basis of strains collected over a period of 5 years. β-Tubulin and calmodulin sequencing were used for species identification, and antifungal susceptibility profiles were evaluated by the protocol of the European Committee on Antimicrobial Susceptibility Testing (EUCAST). Predominant species belonged to the Aspergillus flavus complex (n = 244), A. terreus complex (n = 16), A. fumigatus complex (n = 7), and other fungi (n = 17). Molecular identification of 94 strains of Aspergillus revealed the following species: A. flavus (n = 88), A. terreus (n = 1), A. citrinoterreus (n = 2), A. fumigatus (n = 1), A. caespitosus (n = 1), and A. sydowii (n = 1). Several A. flavus and an A. fumigatus isolates showed reduced susceptibility to azoles (minimum inhibitory concentrations above the clinical breakpoints or epidemiological cutoff values). Despite several mutations revealed in cyp51A of these isolates, none could be directly linked to azole resistance. Molecular identification of fungi causing FRS is useful to identify cryptic species and for epidemiologic studies. IMPORTANCE Fungal rhinosinusitis (FRS) is a significant clinical problem in arid regions. This study provides new insights into the prevalence, etiology, and antifungal susceptibility of FRS pathogens in Sudan, where the disease burden is high. Aspergillus species, particularly the A. flavus complex, were identified as the primary FRS pathogens in the region, with some evidence of antifungal resistance. The molecular identification of fungal species causing FRS is useful for detecting antifungal resistance, identifying cryptic species, and characterizing the epidemiology of the disease. The emergence of Azole resistance Aspergilli in Sudan highlights the need for continued surveillance and appropriate use of antifungal agents. These findings have important implications for clinical management, public health policy, and future research on FRS. Publishing this study in Microbiology Spectrum would enable other researchers and clinicians to build on these findings, ultimately improving the diagnosis, treatment, and prevention of FRS.
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Affiliation(s)
- Shaoqin Zhou
- School of Public Health, the key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Basic Medical Science, Guizhou Medical University, Guiyang, China
- Radboudumc-CWZ Centre of Expertise for Mycology, Nijmegen, the Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | | | - Jochem B. Buil
- Radboudumc-CWZ Centre of Expertise for Mycology, Nijmegen, the Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | - Aida Gabr
- Mycology Reference Laboratory, University of Khartoum, Khartoum, Sudan
| | - Paul E. Verweij
- Radboudumc-CWZ Centre of Expertise for Mycology, Nijmegen, the Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
| | - El-Sheikh Mahgoub
- Mycology Reference Laboratory, University of Khartoum, Khartoum, Sudan
| | - Sybren de Hoog
- Radboudumc-CWZ Centre of Expertise for Mycology, Nijmegen, the Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
- Foundation Atlas of Clinical Fungi, Hilversum, the Netherlands
| | - Yingqian Kang
- School of Public Health, the key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Basic Medical Science, Guizhou Medical University, Guiyang, China
| | - Sarah A. Ahmed
- Radboudumc-CWZ Centre of Expertise for Mycology, Nijmegen, the Netherlands
- Department of Medical Microbiology, Radboudumc, Nijmegen, the Netherlands
- Foundation Atlas of Clinical Fungi, Hilversum, the Netherlands
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