Tarek Elsayed

Dr. Tarek Elsayed

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

View All Publications
11 March 2023 in Molecules
Verified
Journal Article
Open access
PDF file
Ahmed Adel HamedAhmed Adel Hamed
Ahmed Adel Hamed
RERiham A. El-Shiekh
Riham A. El-Shiekh
Osama MohamedOsama Mohamed
Osama Mohamed
EAElsayed A. Aboutabl
Elsayed A. Aboutabl
FFFify I. Fathy
Fify I. Fathy
Ahmed A. Al-KarmalawyAhmed A. Al-Karmalawy
Ahmed A. Al-Karmalawy
Alzheimer’s disease poses a global health concern with unmet demand requiring creative approaches to discover new medications. In this study, we investigated the chemical composition and the anticholinesterase activity of Aspergillus niveus Fv-er401 isolated from Foeniculum vulgare (Apiaceae) roots. Fifty-eight metabolites were identified using UHPLC-MS/MS analysis of the crude extract. The fungal extract showed acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory effects with IC50 53.44 ± 1.57 and 48.46 ± 0.41 µg/mL, respectively. Two known metabolites were isolated, terrequinone A and citrinin, showing moderate AChE and BuChE inhibitory activity using the Ellman’s method (IC50 = 11.10 ± 0.38 µg/mL and 5.06 ± 0.15 µg/mL, respectively for AChE, and IC50 15.63 ± 1.27 µg/mL and 8.02 ± 0.08 µg/mL, respectively for BuChE). As evidenced by molecular docking, the isolated compounds and other structurally related metabolites identified by molecular networking had the required structural features for AChE and BuChE inhibition. Where varioxiranol G (−9.76 and −10.36 kcal/mol), penicitrinol B (−9.50 and −8.02 kcal/mol), dicitrinol A (−8.53 and −7.98 kcal/mol) and asterriquinone CT5 (−8.02 and −8.25 kcal/mol) showed better binding scores as AChE and BuChE inhibitors than the co-crystallized inhibitor (between −7.89 and 7.82 kcal/mol) making them promising candidates for the development of new drugs to treat Alzheimer’s.

21 February 2023 in Biology
Verified
Journal Article
Open access
PDF file
Abdelrahman M. SedeekAbdelrahman M. Sedeek
Abdelrahman M. Sedeek
ISIsraa Salah
Israa Salah
HKHasnaa Lotfy Kamel
Hasnaa Lotfy Kamel
MSMohamed Soltan
Mohamed Soltan
ENEman Nour
Eman Nour
TETarek Elsayed
Tarek Elsayed
Streptomyces are factories of antimicrobial secondary metabolites. We isolated a Streptomyces species associated with the Pelargonium graveolens rhizosphere. Its total metabolic extract exhibited potent antibacterial and antifungal properties against all the tested pathogenic microbes. Whole genome sequencing and genome analyses were performed to take a look at its main characteristics and to reconstruct the metabolic pathways that can be associated with biotechnologically useful traits. AntiSMASH was used to identify the secondary metabolite gene clusters. In addition, we searched for known genes associated with plant growth-promoting characteristics. Finally, a comparative and pan-genome analysis with three closely related genomes was conducted. It was identified as Streptomyces vinaceusdrappus strain AC-40. Genome mining indicated the presence of several secondary metabolite gene clusters. Some of them are identical or homologs to gene clusters of known metabolites with antimicrobial, antioxidant, and other bioactivities. It also showed the presence of several genes related to plant growth promotion traits. The comparative genome analysis indicated that at least five of these gene clusters are highly conserved through rochei group genomes. The genotypic and phenotypic characteristics of S. vinaceusdrappus strain AC-40 indicate that it is a promising source of beneficial secondary metabolites with pharmaceutical and biotechnological applications.

23 September 2022 in Australasian Journal of Ultrasound in Medicine
Verified
Journal Article
Open access
TETarek Elsayed
Tarek Elsayed
PSPeter Snelling
Peter Snelling
ESErin J. Stirling
Erin J. Stirling
SWStuart Watkins
Stuart Watkins
Introduction: Point‐of‐care ultrasound (POCUS) is an important tool in emergency medicine (EM), with the Australasian College for Emergency Medicine (ACEM) recommending core modalities as part of fellowship training. In Australia, acquisition of these skills is certified via credentialing but is currently poorly undertaken by EM trainees.Methods: We performed a cross‐sectional survey of EM trainees across two academic teaching hospitals in Gold Coast, Queensland, between December 2018 and January 2019, to determine the current state of training and perceived barriers to credentialing in POCUS.Results: Fifty‐two (59%) eligible EM trainees participated. Although credentialing rates (15%) were low amongst respondents, the majority agreed that it was necessary (69%) and should form part of ACEM training (88%). Amongst these trainees, we identified the desire for increased POCUS training and several barriers including time constraints and the credentialing process itself.Conclusion: Although there is general agreement amongst EM trainees for POCUS credentialing, barriers such as time limitations and technical difficulties were prohibitive for many. We propose the development of an internal structured POCUS training programme within mandatory training time to address these issues.

24 May 2022 in Journal of Genetic Engineering and Biotechnology
Verified
Journal Article
Open access
PDF file
DHDonia S. Helal
Donia S. Helal
HEHussein El-Khawas
Hussein El-Khawas
TETarek Elsayed
Tarek Elsayed
Successful rhizosphere colonization by plant growth promoting rhizobacteria (PGPR) is of crucial importance to perform the desired plant growth promoting activities. Since rhizocompetence is a dynamic process influenced by surrounding environmental conditions. In the present study, we hypothesized that bacterial isolates obtained from different tomato plant microhabitats (balk soil, rhizosphere, endorhiza, phyllosphere, and endoshoot) grown in different soils (sand, clay, and peat moss) will show different rhizocompetence abilities. To evaluate this hypothesis, bacterial isolates were obtained from different plant microhabitats and screened for their phosphate solubilizing and nitrogen fixing activates. BOX-PCR fingerprint profiles showed high genotypic diversity among the tested isolates and that same genotypes were shared between different soils and/or plant microhabitats. 16S rRNA gene sequences of 25 PGP isolates, representing different plant spheres and soil types, were affiliated to eight genera: Enterobacter, Paraburkholderia, Klebsiella, Bacillus, Paenibacillus, Stenotrophomonas, Pseudomonas, and Kosakonia. The rhizocompetence of each isolate was evaluated in the rhizosphere of tomato plants grown on a mixture of the three soils. Different genotypes of the same bacterial species displayed different rhizocompetence potentials. However, isolates obtained from the above-ground parts of the plant showed high rhizocompetence. In addition, biological control-related genes, ituD and srfC, were detected in the obtained spore forming bacterial isolates. This study evaluates, for the first time, the relationship between plant microhabitat and the rhizocompetence ability in tomato rhizosphere. The results indicated that soil type and plant sphere can influence both the genotypic diversity and rhizocompetence ability of the same bacterial species. Bacterial isolates obtained in this study are promising to be used as an environmentally friendly substitution of chemical fertilizers.

5 August 2022 in Biology
Verified
Journal Article
Open access
PDF file
DEDina Gamal Elsayed
Dina Gamal Elsayed
TETarek Elsayed
Tarek Elsayed
NANadia Amin
Nadia Amin
AAAhmad Al-Shahaby
Ahmad Al-Shahaby
HGHanan Goda
Hanan Goda
Shiga toxin-producing E. coli (STEC) is considered a worldwide public health and food safety problem. Despite the implementation of various different approaches to control food safety, outbreaks persist. The aim of study is to evaluate the applicability of phages, isolated against STEC O157:H7, as prospective food bio-preservatives. Considering the relatively wide host range and greatest protein diversity, two phages (STEC P2 and P4) from four were furtherly characterized. Complete genome analysis confirmed the absence of toxins and virulence factors—encoding genes. The results confirmed the close relation of STEC P2 to phages of Myoviridae, and STEC P4 to the Podoviridae family. The phages retained higher lytic competence of 90.4 and 92.68% for STEC P2 and P4, respectively with the HTST pasteurization. The strong acidic (pH 1) and alkaline (pH 13) conditions had influential effect on the surviving counts of the two phages. The lowest survivability of 63.37 and 86.36% in STEC P2 and P4 lysate, respectively appeared in 2% bile salt solution after 3 h. The results confirmed the strong effect of simulated gastric fluid (SGF) on the survivability of the two phages comparing with simulated intestinal fluid (SIF). Therefore, the two phages could be applied as a natural alternative for food preservation.

1 March 2021 in FEMS Microbiology Ecology
Verified
Journal Article
Closed access
PDF file
TETarek Elsayed
Tarek Elsayed
RGRita Grosch
Rita Grosch
KSKornelia Smalla
Kornelia Smalla
Ralstonia solanacearum biovar2-race3 (Rs r3b2) is an epidemic soil-borne bacterial phytopathogen causing brown rot disease in potato. In this study, we assessed how three soil types stored at the same field site influenced the proportion and diversity of bacterial isolates with in vitro antagonistic activity towards Rs in bulk soil and different potato plant spheres (rhizosphere, endorhiza, endocaulosphere; ecto- and endosphere of seed and yield tubers). In general, the plate counts observed for each sample type were not significantly different. A total of 96 colonies per sample type was picked and screened for in vitro antagonistic activity against Rs. Antagonists were obtained from all bulk soils and plant spheres with the highest proportion obtained from the endorhiza and endocaulosphere of potato plants. BOX-PCR fingerprints of antagonists showed that some were specific for particular plant spheres independent of the soil type, while others originated from different plant spheres of a particular soil type. The majority of antagonists belonged to Pseudomonas. A high proportion of antagonists produced siderophores, and interestingly antagonists from potato tubers frequently carried multiple antibiotic production genes. Our data showed an enrichment of bacteria with genes or traits potentially involved in biocontrol in the rhizosphere and in endophytic compartments.