Biology subjects

Fahal, A. H.

Publications and source records attributed to Fahal, A. H..

4 recordsLinked to original sources

bioRxiv2022

Iron regulatory pathways differentially expressed during Madurella mycetomatis grain development in Galleria mellonella

BackgroundMycetoma is a neglected, chronic granulomatous infection of the subcutaneous tissue, most often caused by the fungal pathogen Madurella mycetomatis. Characteristic of the infection is the formation of grains. However, knowledge of the function and formation of the grain is limited. To map the processes leading to M. mycetomatis grain formation, we used a Galleria mellonella larvae infection model and time-course transcriptomic profiling. MethodsGalleria mellonella larvae were infected with M. mycetomatis genome strain mm55. At 4h, 24h, 72h and 168h post-inoculation, RNA was extracted from larval content. Two types of sequencing libraries were prepared for time-course transcriptomic profiling and analysis. FindingsIn the infected G. mellonella, 88.0% of the RNA sequence reads mapped to G. mellonella, while only 0.01% mapped to M. mycetomatis. Differential Gene Expression analysis revealed that 3,498 G. mellonella and 136 M. mycetomatis genes were differentially expressed during infection. Most of the enriched GO terms of both host and pathogen are linked to energy pathways, nucleobase metabolic process as well as cation and iron transport. Genes related to iron transport were highly expressed by both G. mellonella (transferrin and ferritin) and M. mycetomatis (SidA, SidD and SidI). A protein-protein interaction network analysis of D. melanogaster homologous genes in M. mycetomatis revealed the expression of the entire siderophore biosynthesis pathway throughout infection. InterpretationThe identification of the importance of iron acquisition during grain formation can be exploited as a potential novel diagnostic and therapeutic strategy for mycetoma. Research in contextO_ST_ABSEvidence before this studyC_ST_ABSMycetoma is a chronic, neglected tropical infectious disease, characterised by a large subcutaneous mass and the formation of black grains in the affected tissue. Treatment for mycetoma is disappointing as in 25-50% of the patients recurrences are noted and up to 15% of patients will have to undergo amputation. The main reason behind this poor treatment response is the formation of protective structures by the pathogen upon entering the human body. These structures are called grains and provide a strong barrier for antifungal agents. Although grains are the hallmark of mycetoma, it is currently not known how these grains are formed. To improve the current therapy, it is important to gain insights in grain formation. Added value of this studyWe unravel the processes leading to grain formation and development in an invertebrate model of Madurella mycetomatis grain. We were able to build a model of grain formation and demonstrated that iron sequestering plays an important role in this process. Our findings were an important milestone in understanding the pathogenesis of mycetoma which has been a mystery for decades. Implications of all the available evidenceThe findings, will provide leads for future drug development of mycetoma treatment and therefore, improve patients live and end the need for amputations.

microbiology↗

bioRxiv2022

Systematic whole-genome sequencing reveals an unexpected diversity among actinomycetoma pathogens and provides insights into their antibacterial susceptibilities

Mycetoma is a neglected tropical chronic granulomatous inflammatory disease of the skin and subcutaneous tissues. More than 70 species with a broad taxonomic diversity have been implicated as agents of mycetoma. Understanding the full range of causative organisms and their antibiotic sensitivity profiles are essential for the appropriate treatment of infections. The present study focuses on the analysis of full genome sequences and antibiotic resistance profiles of actinomycetoma strains from patients seen at the Mycetoma Research Centre in Sudan with a view to developing rapid diagnostic tests. Seventeen pathogenic isolates obtained by surgical biopsies were sequenced using MinION and Illumina methods, and their antibiotic resistance profiles determined. The results highlight an unexpected diversity of actinomycetoma causing pathogens, including three Streptomyces isolates assigned to species not previously associated with human actinomycetoma and one new Streptomyces species. Thus, current approaches for clinical and histopathological classification of mycetoma may need to be updated. The standard treatment for actinomycetoma is a combination of sulfamethoxazole/trimethoprim and amoxicillin/clavulanic acid. Most tested isolates were not susceptible to sulfamethoxazole/trimethoprim or to amoxicillin alone. However, the addition of the {beta}-lactamase inhibitor clavulanic acid to amoxicillin increased susceptibility, particularly for Streptomyces somaliensis and Streptomyces sudanensis. Actinomadura madurae isolates appear to be particularly resistant under laboratory conditions, suggesting that alternative agents, such as amikacin, should be considered for more effective treatment. The results obtained will inform future diagnostic methods for the identification of actinomycetoma and treatment. Author SummaryMycetoma is a common health and medical problem that is endemic in many tropical and subtropical countries and has devastating effects on patients. The destructive nature of late-stage infection means that treatment often requires long term use of antibiotic therapy, massive surgical excisions and amputation. Several different bacterial species have been described as causing this disease but our understanding of the true diversity of mycetoma causing bacteria has been limited by a lack of molecular sequence data. We have now sequenced the genomes of 17 samples isolated from patients at the Mycetoma Research Centre in Sudan, revealing a diverse range of species associated with infection including one new Streptomyces species, and three species with no previous association with human mycetoma. Crucially, all isolates had a high level of resistance against the current first-line antibiotics used to treat actinomycetoma under laboratory conditions. This resistance was strongest in Actinomadura madurae, which was also the most frequently observed species isolated from patients in our study. We hope that these results will aid in the development of future rapid diagnostic tools and the improvement of treatment outcomes.

genomics↗

bioRxiv2018

The Role of Interleukin-1 cytokine family (IL-1β, IL-37) and interleukin-12 cytokine family (IL-12, IL-35) in eumycetoma infection pathogenesis

Mycetoma is a neglected tropical disease, endemic in many tropical and subtropical regions, characterised by massive deformity and disability and can be fatal if untreated early and appropriately. Interleukins (IL)-35 and IL-37 are newly discovered cytokines that play an important role in suppressing the immune system. However, the expression of these interleukins in patients with Madurella mycetomatis (M. mycetomatis) induced eumycetoma has not yet been explored. This study aims to determine the levels of the IL-1 family (IL-1{beta}, IL-37) and IL-12 family (IL-12, IL-35) in a group of these patients and the association between these cytokines levels and the patients demographic characteristics. The present, a case-control study was conducted at the Mycetoma Research Centre, Soba University Hospital, University of Khartoum, Sudan and it included 140 individuals. They were divided into two groups; group I: healthy controls [n = 70; median age 25 years (range 12 to 70 years)]. Group II: mycetoma patients [n = 70 patients; median age 25 (range 13 to 70 years)]. Cytokines levels were measured in sera using enzyme-linked immunosorbent assay (ELISA).\n\nThere was no significant correlation between the IL-1{beta} and IL-12 levels and the lesions size and disease duration, whereas levels of IL-37 and IL-35 were significantly correlated with that. The analysis of the risk factors of higher circulatory levels of IL-37 in patients of mycetoma showed a significant negative association with IL-1{beta} cytokine, where a unit increment in IL-1{beta} will decrease the levels of IL-37 by 35.28 pg/ml. The levels of IL-37 among the patients with a duration of mycetoma infection [≤] one year had significantly decreased by an average of 18.45 compared to patients with a mycetoma infections duration of [≥] 5years (reference group). Furthermore, the risk factors of higher levels of IL-35 in mycetoma patients revealed a significant negative association with IL-12, as a unit increment in IL-12 decreases the levels of IL-35by 8.99 pg/ml (p < 0.001). Levels of IL-35 among the patients with duration of mycetoma infection [≤] one year had significantly decreased (p-value = 0.002) on average by 41.82 compared to patients with a duration of mycetoma infection [≥] five years (reference group). In conclusion, this study indicates that both IL-35 and IL-37 are negatively associated with the levels of IL-1{beta} and IL-12 in eumycetoma mycetoma infection; and high levels of IL-37 and IL-35 may have a negative impact on disease progression.\n\nAuthors SummaryMycetoma is a progressive chronic granulomatous fungal or bacterial infection that may result in massive destruction of subcutaneous tissues, muscles and bones. Mycetoma is a neglected disease which is endemic in many tropical and subtropical areas. If the disease is not treated properly, eventually it ends up with amputation and adverse medical, health and socioeconomic effects on patients and the community.\n\nPrevious data suggested a crucial role of adaptive immunity in host resistance to causative agents and the disease progression. The recently identified IL-35 and IL-37 cytokines revealed an important role in immune suppression. Nevertheless, the expression of these interleukins in patients with mycetoma has not yet been investigated. Therefore, the present case-control study aimed to determine the levels of IL-1 family (IL-1{beta}, IL-37) and IL-12 family (IL-12, IL-35) in these patients and the association between these cytokines levels and the patients demographic characteristics.\n\nThe results of this study showed that the levels of IL-37 and IL-35 were consistently positively correlated with different diameters of mycetoma lesions as well as its duration. However, the levels of IL-1{beta} and IL-12 were consistently negatively correlated with different diameters of lesions and the duration of mycetoma infection. The analysis of the risk factors of higher circulatory levels of IL-37 in patients of mycetoma showed a significant negative association with IL-1{beta} cytokine. Furthermore, the risk factors of higher levels of IL-35 in patients of mycetoma revealed a significant negative association with IL-12. These findings uncover a possible the role of IL-35 and IL-37 in the pathogenesis of mycetoma and may declare their potential value in the treatment of mycetoma.

immunology↗

bioRxiv2018

The Accuracy of Histopathological and Cytopathological Techniques in the Identification of the Mycetoma Causative Agents

Mycetoma is a devastating neglected tropical disease, caused by various fungal and bacterial pathogens. Correct diagnosis to the species level is mandatory for proper treatment. In endemic areas, various diagnostic tests and techniques are in use to achieve that, and that includes grain culture, surgical biopsy histopathological examination, fine needle aspiration cytological (FNAC) examination and in certain centres molecular diagnosis such as PCR.\n\nIn this retrospective study, the sensitivity, specificity and diagnostic accuracy of grain culture, surgical biopsy histopathological examination and FNAC to identify the mycetoma causative organisms were determined. The histopathological examination appeared to have better sensitivity and specificity.\n\nThe histological examination results were correct in 714 (97.5%) out of 750 patients infected with Madurella mycetomatis, in 133 (93.6%) out of 142 patients infected with Streptomyces somaliensis, in 53 (74.6%) out of 71 patients infected with Actinomadura madurae and in 12 (75%) out of 16 patients infected with Actinomadura pelletierii.\n\nFNAC results were correct in 604 (80.5%) out of 750 patients with Madurella mycetomatis eumycetoma, in 50 (37.5%) out of 133 Streptomyces somaliensis patients, 43 (60.5%) out of 71 Actinomadura madurae patients and 11 (68.7%) out of 16 Actinomadura pelletierii. The mean time required to obtain the FNAC result was one day, and for the histopathological examinations results it was 3.5 days, and for grain, it was a mean of 16 days.\n\nIn conclusion, histopathological examination and FNAC are more practical techniques for rapid species identification than grain culture in many endemic regions.\n\nAuthor summaryIn mycetoma endemic regions, the medical and health settings are commonly suboptimal, and only a few diagnostic tests and techniques are available. That had badly affected the patients proper diagnosis and management and thus the late presentation of patients with advanced disease. In this retrospective study, the experience of the MRC on the common in use diagnostic tests in the period between 1991 and 2018 is presented.\n\nIn this study, the sensitivity, specificity rates and diagnostic accuracy of grain culture, surgical biopsy histopathological examination and FNAC to identify the mycetoma causative organisms were determined. The histopathological examination appeared to have better sensitivity and specificity. Furthermore, the grain culture identification needs high experience, it is the tedious procedure, and cross-contamination is common hence misdiagnosis is frequent. It can be concluded that histopathological examination and FNAC are more practical techniques for rapid species identification than grain culture in many endemic regions with poor diagnostic setting.

microbiology↗