Ahmed Abdel-Azeem

Dr. Ahmed Abdel-Azeem


Research Focus & Metrics

Academic Career Length

21Years (2006-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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17 August 2021 in Studies in Mycology
Verified
Journal Article
Open access
PCP.W. Crous
P.W. Crous
LLL. Lombard
L. Lombard
MSMarcelo Sandoval-Denis
Marcelo Sandoval-Denis
KSK.A. Seifert
K.A. Seifert
HSH.-J. Schroers
H.-J. Schroers
MTM. Thines
M. Thines
Recent publications have argued that there are potentially serious consequences for researchers in recognising distinct genera in the terminal fusarioid clade of the family Nectriaceae. Thus, an alternate hypothesis, namely a very broad concept of the genus Fusarium was proposed. In doing so, however, a significant body of data that supports distinct genera in Nectriaceae based on morphology, biology, and phylogeny is disregarded. A DNA phylogeny based on 19 orthologous protein-coding genes was presented to support a very broad concept of Fusarium at the F1 node in Nectriaceae. Here, we demonstrate that re-analyses of this dataset show that all 19 genes support the F3 node that represents Fusarium sensu stricto as defined by F. sambucinum (sexual morph synonym Gibberella pulicaris). The backbone of the phylogeny is resolved by the concatenated alignment, but only six of the 19 genes fully support the F1 node, representing the broad circumscription of Fusarium. Furthermore, a re-analysis of the concatenated dataset revealed alternate topologies in different phylogenetic algorithms, highlighting the deep divergence and unresolved placement of various Nectriaceae lineages proposed as members of Fusarium. Species of Fusarium s. str. are characterised by Gibberella sexual morphs, asexual morphs with thin- or thick-walled macroconidia that have variously shaped apical and basal cells, and trichothecene mycotoxin production, which separates them from other fusarioid genera. Here we show that the Wollenweber concept of Fusarium presently accounts for 20 segregate genera with clear-cut synapomorphic traits, and that fusarioid macroconidia represent a character that has been gained or lost multiple times throughout Nectriaceae. Thus, the very broad circumscription of Fusarium is blurry and without apparent synapomorphies, and does not include all genera with fusarium-like macroconidia, which are spread throughout Nectriaceae (e.g., Cosmosporella, Macroconia, Microcera). In this study four new genera are introduced, along with 18 new species and 16 new combinations. These names convey information about relationships, morphology, and ecological preference that would otherwise be lost in a broader definition of Fusarium. To assist users to correctly identify fusarioid genera and species, we introduce a new online identification database, Fusarioid-ID, accessible at www.fusarium.org. The database comprises partial sequences from multiple genes commonly used to identify fusarioid taxa (act1, CaM, his3, rpb1, rpb2, tef1, tub2, ITS, and LSU). In this paper, we also present a nomenclator of names that have been introduced in Fusarium up to January 2021 as well as their current status, types, and diagnostic DNA barcode data. In this study, researchers from 46 countries, representing taxonomists, plant pathologists, medical mycologists, quarantine officials, regulatory agencies, and students, strongly support the application and use of a more precisely delimited Fusarium (= Gibberella) concept to accommodate taxa from the robust monophyletic node F3 on the basis of a well-defined and unique combination of morphological and biochemical features. This F3 node includes, among others, species of the F. fujikuroi, F. incarnatum-equiseti, F. oxysporum, and F. sambucinum species complexes, but not species of Bisifusarium [F. dimerum species complex (SC)], Cyanonectria (F. buxicola SC), Geejayessia (F. staphyleae SC), Neocosmospora (F. solani SC) or Rectifusarium (F. ventricosum SC). The present study represents the first step to generating a new online monograph of Fusarium and allied fusarioid genera (www.fusarium.org).

1 May 2021 in Biocatalysis and Agricultural Biotechnology
Verified
Journal Article
Closed access
Ajar Nath YadavAjar Nath Yadav
Ajar Nath Yadav
DKDivjot Kour
Divjot Kour
TKTanvir Kaur
Tanvir Kaur
RDRubee Devi
Rubee Devi
AYAshok Yadav
Ashok Yadav
ASAnil Kumar Saxena
Anil Kumar Saxena

18 February 2019 in Biomolecules
Verified
Journal Article
Open access
PDF file
PRPrateeksha
Prateeksha
MYMohammad Yusuf
Mohammad Yusuf
BSBrahma N. Singh
Brahma N. Singh
SSSurya Sudheer
Surya Sudheer
RKRavindra N. Kharwar
Ravindra N. Kharwar
VGVijai Kumar Gupta
Vijai Kumar Gupta
Chrysophanol is a unique anthraquinone having broad-spectrum therapeutic potential along with ecological importance. It is the first polyketide that has been reported to be biosynthesized in an organism-specific manner. The traditional Chinese and Korean medicinal systems provide evidence of the beneficial effects of chrysophanol on human health. The global distribution of chrysophanol encountered in two domains of life (bacteria and eukaryota) has motivated researchers to critically evaluate the properties of this compound. A plethora of literature is available on the pharmacological properties of chrysophanol, which include anticancer, hepatoprotective, neuroprotective, anti-inflammatory, antiulcer, and antimicrobial activities. However, the pharmacokinetics and toxicity studies on chrysophanol demand further investigations for it to be used as a drug. This is the first comprehensive review on the natural sources, biosynthetic pathways, and pharmacology of chrysophanol. Here we reviewed recent advancements made on the pharmacokinetics of the chrysophanol. Additionally, we have highlighted the knowledge gaps of its mechanism of action against diseases and toxicity aspects.

9 February 2021 in Mini-Reviews in Medicinal Chemistry
Verified
Journal Article
Closed access
PDF file
SSShilpi Srivastava
Shilpi Srivastava
Zeba UsmaniZeba Usmani
Zeba Usmani
Atanas G. AtanasovAtanas G. Atanasov
Atanas G. Atanasov
VSVinod Kumar Singh
Vinod Kumar Singh
NSNagendra Pratap Singh
Nagendra Pratap Singh
ABAtul Bhargava
Atul Bhargava
Metal nanoparticles are nanosized entities with dimensions of 1-100 nm that are increasingly in demand due to applications in diverse fields like electronics, sensing, environmental remediation, oil recovery and drug delivery. Metal nanoparticles possess large surface energy and properties different from bulk materials due to their small size, large surface area with free dangling bonds and higher reactivity. High cost and pernicious effects associated with the chemical and physical methods of nanoparticle synthesis are gradually paving the way for biological methods due to their eco-friendly nature. Considering the vast potentiality of microbes and plants as sources, biological synthesis can serve as a green technique for the synthesis of nanoparticles as an alternative to conventional methods. A number of reviews are available on green synthesis of nanoparticles but few have focused on covering the entire biological agents in this process. Therefore present paper describes the use of various living organisms like bacteria, fungi, algae, bryophytes and tracheophytes in the biological synthesis of metal nanoparticles, the mechanisms involved and the advantages associated therein.

3 July 2019 in PLOS ONE
Verified
Journal Article
Open access
PDF file
Ajit Kumar PassariAjit Kumar Passari
Ajit Kumar Passari
KUKalidas Upadhyaya
Kalidas Upadhyaya
GSGarima Singh
Garima Singh
AAAhmed Abdel-Azeem
Ahmed Abdel-Azeem
STSugitha Thankappan
Sugitha Thankappan
BSBhim Pratap Singh
Bhim Pratap Singh
Biotic stresses in plants have a significant impact on agricultural productivity. In the present study, in vivo experiments were conducted to determine the physiological responses of tomato (Solanum lycopersicum L.) seedlings by inoculation with an endophytic actinobacterium, Streptomyces thermocarboxydus isolate BPSAC147 under greenhouse conditions. Further, photochemical quantum yield of photosystem II (PSII) (Fv/Fm), photochemical quenching (qP) and non-photochemical (NPQ) were calculated in seedlings inoculated with S. thermocarboxydus (T1) and were compared with control (T0) plants. Furthermore, the electron transport rate (ETR) of PSII exhibited a significant increase in T1 plants, relative to T0 plants. These results indicate that inoculation of tomato seedlings with S. thermocarboxydus had a positive effect on the process of photosynthesis, resulting in enhanced chlorophyll fluorescence parameters due to increased ETR in the thylakoid membrane. GC-MS analysis showed significant differences in the volatile compounds in the different treatments performed under greenhouse conditions. The present study suggests that S. thermocarboxydus can be used as new biocontrol agent to control Fusarium wilt in tomato crops and enhance productivity by enhancing photosynthesis.

1 January 2020 in Journal of Renewable Materials
Verified
Journal Article
Open access
PDF file
AAAhmed Abdel-Azeem
Ahmed Abdel-Azeem
ANAmr NADA
Amr NADA
AOAnthonia O’dOnovan
Anthonia O’dOnovan
Vijay Kumar ThakurVijay Kumar Thakur
Vijay Kumar Thakur
Amr ElkelishAmr Elkelish
Amr Elkelish
There is an increasing interest in developing nanoparticles with diverse biologic activities. To this end, we prepared 10 to 15 nm silver nanoparticles (AgNP) from native isolates of Trichoderma atroviride. Within this study, endophytic fungi hosted four medicinal plants in Saint Katherine Protectorate, South Sinai, Egypt have been isolated by surface sterilization technique on four isolation media. Ten species, based on their frequency of occurrence, out of twenty recovered taxa were tested for their capability to synthesize extracellular AgNPs. Trichoderma atroviride hosted Chiliadenus montanus was found to be the best candidate for the production of mycogenic AgNPs among all examined species. The mycosynthesized AgNPs were compared with chemically synthesized and characterized using Ultraviolet-visible (UV-vis) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) techniques. The HRTEM result showed the distribution of spherical AgNPs ranging from 10 to 15 nm. Trichoderma atroviride isolate was subjected to sequencing for confirmation of phenotypic identification. The internal transcribed spacer (ITS) 1–5.8 s – ITS2 rDNA sequences obtained were compared with those deposited in the GenBank Database and registered with accession number MH283876 in the NCBI Database. Antibacterial, anticandidal and antifungal effects of chemically and mycosynthesized AgNPs were examined at various concentrations in vitro against six pathogenic bacteria and 4 pathogenic fungi by agar well diffusion technique. Standard antibiotics; Gentamicin, Amoxicillin, Clotrimazole, and Nystatin at 5 μg/disk were taken as positive controls, while 5% DMSO was used as the negative control. Our data revealed that the application of mycogenic AgNPs at a concentration of 100 ppm resulted in maximum inhibition of pathogenic bacteria and fungi. These data suggest that AgNPs from native isolates of Trichoderma atroviride (MH283876) offer a source of rapid synthesis of eco-friendly, economical biomaterials that show antimicrobial activities.