Mohamed El-Mokhtar

Dr. Mohamed El-Mokhtar

Assiut University
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

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

Representative Publications

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1 January 2017 in International Journal of Nanomedicine
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Journal Article
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AMAml Mekkawy
Aml Mekkawy
MEMohamed El-Mokhtar
Mohamed El-Mokhtar
NNNivien Nafady
Nivien Nafady
NYNaeima Yousef
Naeima Yousef
MHMostafa Hamad
Mostafa Hamad
MEMahmoud Elsabahy
Mahmoud Elsabahy
In the present study, silver nanoparticles (AgNPs) were synthesized via biological reduction of silver nitrate using extract of the fungus Fusarium verticillioides (green chemistry principle). The synthesized nanoparticles were spherical and homogenous in size. AgNPs were coated with polyethylene glycol (PEG) 6000, sodium dodecyl sulfate (SDS), and β-cyclodextrin (β-CD). The averaged diameters of AgNPs were 19.2±3.6, 13±4, 14±4.4, and 15.7±4.8 nm, for PEG-, SDS-, and ß-CD-coated and uncoated AgNPs, respectively. PEG-coated AgNPs showed greater stability as indicated by a decreased sedimentation rate of particles in their water dispersions. The antibacterial activities of different AgNPs dispersions were investigated against Gram-positive bacteria (methicillin-sensitive and methicillin-resistant Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli) by determination of the minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs). MIC and MBC values were in the range of 0.93–7.5 and 3.75–15 µg/mL, respectively, which were superior to the reported values in literature. AgNPs-loaded hydrogels were prepared from the coated-AgNPs dispersions using several gelling agents (sodium carboxymethyl cellulose [Na CMC], sodium alginate, hydroxypropylmethyl cellulose, Pluronic F-127, and chitosan). The prepared formulations were evaluated for their viscosity, spreadability, in vitro drug release, and antibacterial activity, and the combined effect of the type of surface coating and the polymers utilized to form the gel was studied. The in vivo wound-healing activity and antibacterial efficacy of Na CMC hydrogel loaded with PEG-coated AgNPs in comparison to the commercially available silver sulfadiazine cream (Dermazin®) were evaluated. Superior antibacterial activity and wound-healing capability, with normal skin appearance and hair growth, were demonstrated for the hydrogel formulations, as compared to the silver sulfadiazine cream. Histological examination of the treated skin was performed using light microscopy, whereas the location of AgNPs in the skin epidermal layers was visualized using transmission electron microscopy.

5 January 2022 in Pharmaceutics
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Journal Article
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MSMohammed sherif Saddik
Mohammed sherif Saddik
Mahmoud M. A. Elsayed ElsayedMahmoud M. A. Elsayed Elsayed
Mahmoud M. A. Elsayed Elsayed
MEMohamed El-Mokhtar
Mohamed El-Mokhtar
HSHaitham Sedky
Haitham Sedky
JAJelan A. Abdel-Aleem
Jelan A. Abdel-Aleem
AAAssociate Prof Heba Ahmed AbouTaleb
Associate Prof Heba Ahmed AbouTaleb
Skin is the largest mechanical barrier against invading pathogens. Following skin injury, the healing process immediately starts to regenerate the damaged tissues and to avoid complications that usually include colonization by pathogenic bacteria, leading to fever and sepsis, which further impairs and complicates the healing process. So, there is an urgent need to develop a novel pharmaceutical material that promotes the healing of infected wounds. The present work aimed to prepare and evaluate the efficacy of novel azithromycin-loaded zinc oxide nanoparticles (AZM-ZnONPs) in the treatment of infected wounds. The Box–Behnken design and response surface methodology were used to evaluate loading efficiency and release characteristics of the prepared NPs. The minimum inhibitory concentration (MIC) of the formulations was determined against Staphylococcus aureus and Escherichia coli. Moreover, the anti-bacterial and wound-healing activities of the AZM-loaded ZnONPs impregnated into hydroxyl propyl methylcellulose (HPMC) gel were evaluated in an excisional wound model in rats. The prepared ZnONPs were loaded with AZM by adsorption. The prepared ZnONPs were fully characterized by XRD, EDAX, SEM, TEM, and FT-IR analysis. Particle size distribution for the prepared ZnO and AZM-ZnONPs were determined and found to be 34 and 39 nm, respectively. The mechanism by which AZM adsorbed on the surface of ZnONPs was the best fit by the Freundlich model with a maximum load capacity of 160.4 mg/g. Anti-microbial studies showed that AZM-ZnONPs were more effective than other controls. Using an experimental infection model in rats, AZM-ZnONPs impregnated into HPMC gel enhanced bacterial clearance and epidermal regeneration, and stimulated tissue formation. In conclusion, AZM -loaded ZnONPs are a promising platform for effective and rapid healing of infected wounds.

1 February 2021 in Infection and Drug Resistance
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Journal Article
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SKSawsan Mohammed Kareem
Sawsan Mohammed Kareem
Israa M.S. Al-KadmyIsraa M.S. Al-Kadmy
Israa M.S. Al-Kadmy
SKSaba S Kazaal
Saba S Kazaal
AAAlaa N Mohammed Ali
Alaa N Mohammed Ali
SASarah Naji Aziz
Sarah Naji Aziz
Helal HettaHelal Hetta
Helal Hetta
Background and Aim: Recently, the extensive use of quinolones led to increased resistance to these antimicrobial agents, with different rates according to the organism and the geographical region. The aim of this study was to detect the resistance rate of Klebsiella pneumoniae Iraqi isolates toward quinolone antimicrobial agents, to determine genetic mutations in gyrA and parC, to screen for efflux-pump activity, and to screen the presence of plasmid-mediated quinolone resistance (PMQR) genes. Methods: Forty-three K. pneumoniae isolates were confirmed phenotypically and genotypically by Vitek 2 system and species specific primers by PCR using the targeting rpo gene followed by sequencing. Antibiotic susceptibility test was carried out using disc diffusion method. Quinolone resistant isolates were subjected to ciprofloxacin MIC testing, and cartwheel method to screen for efflux pump activity. The presence of the plasmid mediated quinolone resistance genes qepA, qnrB, qnrS, and aac(6)Ib was tested by PCR. Sequencing of gyrA and parC was performed. Results: We observed a high rate of resistance to ceftriaxone, gentamicin ciprofloxacin, and levofloxacin. Low rate of resistance was detected against amikacin and azithromycin. Ciprofloxacin MIC results revealed that 96.1% of the isolates had MICs > 256 μg/mL, 83.4% had MICs > 512 μg/mL while 34.6% had MIC > 1024 μg/mL. Testing of isolates against ciprofloxacin mixed with EtBr at various concentrations resulted in decreased resistant. Sequencing results showed that Ser83Leu was the most common mutation in gyrA that was observed in all quinolone resistant isolates, followed by Asp87Asn. Ser80Ile mutation in parC was observed in 77.7% of the tested isolates. The prevalence of PMQR genes was 92.5% aac (6)-Ib, 51.8% qnrB, 40.7% qepA, and 37% qnrS. Conclusion: Quinolone resistance is common in K. pneumoniae isolates in Baghdad. The frequent mutation in gyrA and parC, and the presence of PMQR genes is alarming.

1 October 2020 in Infection and Drug Resistance
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HRHaidi Karam-Allah Ramadan
Haidi Karam-Allah Ramadan
MMManal A Mahmoud
Manal A Mahmoud
MAMohamed Zakaria Aburahma
Mohamed Zakaria Aburahma
AEAmal A Elkhawaga
Amal A Elkhawaga
MEMohamed El-Mokhtar
Mohamed El-Mokhtar
MMMohammed A Medhat
Mohammed A Medhat
Background: The emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) resulted in a worldwide devastating effect with a diagnostic challenge. Identifying risk factors of severity aids in assessment for the need of early hospitalization. We aimed to demonstrate, for the first time, the clinical, laboratory and radiological characteristics of coronavirus disease 2019 (COVID-19) patients, to identify the predictors of severity and to describe the antimicrobial resistance profile in patients from Upper Egypt. Materials and Methods: Demographic characters, clinical presentations, laboratory, and radiological data were recorded and analyzed. Presence of other respiratory microorganisms and their sensitivity patterns were identified using the VITEK2 system. Resistance-associated genes were tested by PCR. Results: The study included 260 COVID-19 patients. The majority were males (55.4%) aged between 51 and 70 years. Hypertension, diabetes, and ischemic heart disease were common comorbidities. Main clinical manifestations were fever (63.8%), cough (57.7%), dyspnea (40%) and fatigue (30%). According to severity, 51.5% were moderate, 25.4% mild and 23% severe/critical. Lymphopenia, elevated CRP, ferritin, and D-dimer occurred in all patients with significantly higher value in the severe group. Age > 53 years and elevated ferritin ≥ 484 ng/mL were significant risk factors for severity. About 10.7% of the COVID-19 patients showed bacterial and/or fungal infections. Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were the predominant isolated bacteria while Candida albicans and Candida glabrata were the predominant isolated fungi. All Staphylococci were methicillin-resistant and carried the mecA gene. Gram-negative isolates were multidrug-resistant and carried different resistance-associated genes, including NDM-1, KPC, TEM, CTX-M, and SHV. Conclusion: Older age and elevated serum ferritin were significant risk factors for severe COVID-19. Bacterial co-infection and multidrug resistance among patients with COVID-19 in Upper Egypt is common. Testing for presence of other co-infecting agents should be considered, and prompt treatment should be carried out according to the antimicrobial sensitivity reports.

1 February 2020 in Infection and Drug Resistance
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Journal Article
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MEMohamed El-Mokhtar
Mohamed El-Mokhtar
KHKhaled M Hassanein
Khaled M Hassanein
AAAhmed S Ahmed
Ahmed S Ahmed
GGGamal Fm Gad
Gamal Fm Gad
MAMohamed M Amin
Mohamed M Amin
OHOsama Fe Hassanein
Osama Fe Hassanein
Aim: This study aimed to describe the inhibitory activity of cell-free supernatants (CFS) of lactobacilli against extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae (K pneumoniae) and Pseudomonas aeruginosa (P aeruginosa). Material and Methods: Pathogenic clinical strains of K pneumoniae and P aeruginosa were isolated from urine samples and selected for investigation. Anti-bacterial activities of the CFS of lactobacilli were assessed by agar well diffusion, MTT assay, as well as time-kill tests. In addition, the antibiofilm characteristics were analyzed by the microplate method against fresh and 24 h-old biofilms. The ability of CFS to interfere with bacterial invasion was analyzed by flow cytometry. Results: Although all tested strains were ESBL producers and showed a multidrug-resistant phenotype, the CFS displayed a high anti-ESBL activity with inhibition zone diameters greater than 13 mm in the agar well diffusion assays against both pathogens. The growth kinetics of K pneumoniae and P aeruginosa were dramatically decreased in the presence of the CFS. The CFS not only inhibited the biofilm formation by these pathogens but also was able to remove the 24-h formed biofilms. The invasion abilities of FITC-labelled K pneumoniae decreased from 30.3%± 7 to 15.4%± 5 and invasion of FITC-labelled P aeruginosa was reduced from 36.9%± 7 to 25.2%± 5. Conclusion: CFS of lactobacilli exhibit anti-ESBL activities, which suggests its potential application for controlling or preventing colonization of infections caused by ESBL-producing bacteria.

6 February 2021 in Pharmaceutics
Verified
Journal Article
Open access
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MSMohammed sherif Saddik
Mohammed sherif Saddik
Mahmoud M. A. Elsayed ElsayedMahmoud M. A. Elsayed Elsayed
Mahmoud M. A. Elsayed Elsayed
Mohamed Salaheldin . A Abd-ElkaderMohamed Salaheldin . A Abd-Elkader
Mohamed Salaheldin . A Abd-Elkader
MEMohamed El-Mokhtar
Mohamed El-Mokhtar
JAJelan A. Abdel-Aleem
Jelan A. Abdel-Aleem
AAAssociate Prof Heba Ahmed AbouTaleb
Associate Prof Heba Ahmed AbouTaleb
Colorectal cancer (CRC) is the third highest major cause of morbidity and mortality worldwide. Hence, many strategies and approaches have been widely developed for cancer treatment. This work prepared and evaluated the antitumor activity of 5-Fluorouracil (5-Fu) loaded chromium nanoparticles (5-FuCrNPs). The green biosynthesis approach using Harpullia (H) pendula aqueous extract was used for CrNPs preparation, which was further loaded with 5-Fu. The prepared NPs were characterized for morphology using scanning and transmission electron microscopes (SEM and TEM). The results revealed the formation of uniform, mono-dispersive, and highly stable CrNPs with a mean size of 23 nm. Encapsulation of 5-Fu over CrNPs, with a higher drug loading efficiency, was successful with a mean size of 29 nm being produced. In addition, Fourier transform infrared (FTIR) and X-ray diffraction pattern (XRD) were also used for the investigation. The drug 5-Fu was adsorbed on the surface of biosynthesized CrNPs in order to overcome its clinical resistance and increase its activity against CRC cells. Box–Behnken Design (BBD) and response surface methodology (RSM) were used to characterize and optimize the formulation factors (5-Fu concentration, CrNP weight, and temperature). Furthermore, the antitumor activity of the prepared 5-FuCrNPs was tested against CRC cells (CACO-2). This in vitro antitumor study demonstrated that 5-Fu-loaded CrNPs markedly decreased the IC50 of 5-Fu and exerted more cytotoxicity at nearly all concentrations than 5-Fu alone. In conclusion, 5-FuCrNPs is a promising drug delivery system for the effective treatment of CRC.