Person: Elkhatib, Walid F.
Elkhatib, Walid F.
Email Address
Birth Date
ORCID
0000-0001-5815-3200
SCOPUS
56593725900
Research Projects
Organizational Units
Name
Walid F. Elkhatib
Last Name
Elkhatib
First Name
Walid F.
Main Affiliation
Galala University
Job Title
Professor Head of Microbiology Departmen
Search Results
Now showing 1 - 10 of 17
- PublicationOpen AccessAnti-SARS-CoV-2 activities of tanshinone IIA, carnosic acid, rosmarinic acid, salvianolic acid, baicalein, and glycyrrhetinic acid between computational and insights.(Royal society of chemistry, 2021-09-01T00:00:00Z) Elebeedy, Dalia; Kandeil, Ahmed; Ghanem, Aml; Kutkat, Omnia; Alnajjar, Radwan; Saleh, Marwa A.; Abd El Maksoud, Ahmed I.; Badawy, Ingy; Al-Karmalawy, Ahmed A.; Elkhatib, Walid F.Six compounds namely, tanshinone IIA (1), carnosic acid (2), rosmarinic acid (3), salvianolic acid B (4), baicalein (5), and glycyrrhetinic acid (6) were screened for their anti-SARS-CoV-2 activities against both the spike (S) and main protease (Mpro) receptors using molecular docking studies. Molecular docking recommended the superior affinities of both salvianolic acid B (4) and glycyrrhetinic acid (6) as the common results from the previously published computational articles. On the other hand, their actual anti-SARS-CoV-2 activities were tested using plaque reduction assay to calculate their IC values after measuring their CC values using MTT assay on Vero E6 cells. Surprisingly, tanshinone IIA (1) was the most promising member with IC equals 4.08 ng μl. Also, both carnosic acid (2) and rosmarinic acid (3) showed promising IC values of 15.37 and 25.47 ng μl, respectively. However, salvianolic acid (4) showed a weak anti-SARS-CoV-2 activity with an IC value equals 58.29 ng μl. Furthermore, molecular dynamics simulations for 100 ns were performed for the most active compound from the computational point of view (salvianolic acid 4), besides, the most active one biologically (tanshinone IIA 1) on both the S and Mpro complexes of them (four different molecular dynamics processes) to confirm the docking results and give more insights regarding the stability of both compounds inside the SARS-CoV-2 mentioned receptors, respectively. Also, to understand the mechanism of action for the tested compounds towards SARS-CoV-2 inhibition it was necessary to examine the mode of action for the most two promising compounds, tanshinone IIA (1) and carnosic acid (2). Both compounds (1 and 2) showed very promising virucidal activity with a most prominent inhibitory effect on viral adsorption rather than its replication. This recommended the predicted activity of the two compounds against the S protein of SARS-CoV-2 rather than its Mpro protein. Our results could be very promising to rearrange the previously mentioned compounds based on their actual inhibitory activities towards SARS-CoV-2 and to search for the reasons behind the great differences between their and results against SARS-CoV-2. Finally, we recommend further advanced preclinical and clinical studies especially for tanshinone IIA (1) to be rapidly applied in COVID-19 management either alone or in combination with carnosic acid (2), rosmarinic acid (3), and/or salvianolic acid (4).
- PublicationOpen AccessThe antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial(Springer Nature, 2022-02-01) Fahim, Mahmoud M.; Saber, Shehab Eldin Mohamed; Nagy , Mohamed Mokhtar; Schafer, Edgar; Elkhatib, Walid F.Objective: This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups. Materials and methods: Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined. Results: Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05). Conclusions: The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control.
- PublicationOpen AccessGlobal dynamics of SARS-CoV-2 clades and their relation to COVID-19 epidemiology(Springer Nature, 2021-04-19) Hamed, Samira M.; Khairalla, Ahmed S.; Noreddin , Ayman M.; Elkhatib, Walid F.Expansion of COVID-19 worldwide increases interest in unraveling genomic variations of novel SARS-CoV-2 virus. Metadata of 408,493 SARS-CoV-2 genomes submitted to GISAID database were analyzed with respect to genomic clades and their geographic, age, and gender distributions. Of the currently known SARS-CoV-2 clades, clade GR was the most prevalent worldwide followed by GV then GH. Chronological analysis revealed expansion in SARS-CoV-2 clades carrying D614G mutations with the predominance of the newest clade, GV, in the last three months. D614G clades prevail in countries with more COVID-19 cases. Of them, the clades GH and GR were more frequently recovered from severe or deceased COVID-19 cases. In contrast, G and GV clades showed a significantly higher prevalence among asymptomatic patients or those with mild disease. Metadata analysis showed higher (p < 0.05) prevalence of severe/deceased cases among males than females and predominance of GR clade in female patients. Furthermore, severe disease/death was more prevalent (p < 0.05) in elderly than in adults/children. Higher prevalence of the GV clade in children compared to other age groups was also evident. These findings uniquely provide a statistical evidence on the adaptation-driven evolution of SARS-CoV-2 leading to altered infectivity, virulence, and mortality.
- PublicationOpen AccessAntibiofilm activity of green synthesized silver nanoparticles against biofilm associated enterococcal urinary pathogens(Springer Nature, 2022-03-09) Swidan, Nada S.; Hashem, Yomna A.; Yassien, Mahmoud A.; Elkhatib, Walid F.Abstract: Biofilm-formed enterococcal urinary tract clinical isolates (n = 92) were used for studying the antibiofilm activity of cinnamon, ginger, and chemical AgNPs. The average particle sizes of cinnamon, ginger, and chemical AgNPs were 8.7, 41.98, and 55.7 nm, respectively. The results of Fourier transform infrared analysis revealed that phytocompounds, such as cinnamaldehyde and gingerol, were the main compounds incorporated in the synthesis of cinnamon and ginger AgNPs, respectively. The purity and crystalline nature of the AgNPs have been confirmed by energy dispersive X-ray and X-ray Diffraction analysis. The results of antimicrobial activity showed that MIC of ginger, cinnamon, and chemical AgNPs were 37.64, 725.7, and 61.08 μg/ml, respectively. On studying the antibiofilm activity of AgNPs at sub-MIC values (1/2, 1/4, and 1/8 MIC), the results revealed that it was concentration dependent. Therefore, further studies were carried out to evaluate the antibiofilm activity of AgNPs at a concentration of 18 μg/ml. The results showed that ginger and chemical AgNPs reduced the formed biofilm to 39.14% and 65.32% and the number of adherent cells on the urinary catheter surface to 42.73% and 69.84%, respectively, as compared to that of the control, while cinnamon AgNPs showed no significant activity. Accordingly, ginger AgNPs had the most potent antibacterial and antiadherent activity against biofilm-associated enterococcal isolates.
- PublicationMetadata onlyThe antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial(Springer, 2021-10-25) Fahim, Mahmoud M.; Saber, Shehab Eldin Mohamed; Nagy, Mohamed Mokhtar; Schafer, Edgar; Elkhatib, Walid F.Objective This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups. Materials and methods Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined. Results Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05). Conclusions The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control.
- PublicationMetadata onlyImprovement of caffeic acid biotransformation into para‐hydroxybenzoic acid by CI‐24 via gamma irradiation and model‐based optimization.(John Wiley & Sons, 2021-04-19) Singab, Raghda Abdelnasser; Elleboudy, Nooran Sherif; Yassein, Mahmoud Abdulmegead; Hassouna, Nadia Adelhaleem; Elkhatib, Walid F.Para-hydroxybenzoic acid (PHBA) has great potential in biological applications due to its putative antiviral activity against SARS-CoV-2 and its antimicrobial activity in the face of the radically increasing number of multidrug-resistant pathogens. This is in addition to its antimutagenic, anti-inflammatory, antioxidant, hypoglycemic, antiestrogenic, and antiplatelet aggregating activities. In this study, an approximate sixfold increase in the production of PHBA was achieved via biotransformation of caffeic acid by Candida albicans. The improvement was performed in two steps: first, through mutation by gamma irradiation (5 KGy dose), resulting in the recovery of a mutant (CI-24), which produced approximately triple the amount of PHBA produced by the wild-type isolate. Then, biotransformation by this mutant was further optimized via response surface methodology model-based optimization. The maximum PHBA production (7.47 mg/mL) was obtained in a fermentation medium composed of 1% w/v yeast extract as a nitrogen source, with an initial pH of 6.6, incubated at 28 °C at an agitation rate of 250 rpm. To further enhance the performance and economics of the process, cells of the CI-24 mutant were immobilized in calcium alginate beads and could retain an equivalent biotransformation capacity after three successive biotransformation cycles.
- PublicationOpen AccessArchitecturally safe and healthy classrooms: eco-medical concept to achieve sustainability in light of COVID-19 global pandemic(Taylor & Francis Group, 2021-01-01) Saeed, Doha M.; Selim, Ahmed M.; Elkhatib, Walid F.In March 2020, the World Health Organization (WHO) officially announced the COVID-19 outbreak as a global pandemic. With this announcement, the world is facing a major challenge. This research commenced as an initiative to conceptualize internal architectural space design to cope with epidemics, to ensure an architectural anti-virus environment. In fact, architectural spaces with high occupancy loads are considered a fertile environment for the spread of this virus. This study discusses classrooms as one of those patterns with high densities for a significant reason; previous studies have revealed that pupils between the ages of 5 to 18 years may be carriers of the infection, but without symptoms; therefore, this category is considered a major source of transmitting the infection to their families and society. Accordingly, this research will address the most important standards, and design norms for these spaces using an electronic questionnaire and computational fluid dynamics (CFD) model, to achieve two objectives: first, a healthy classroom to reduce the COVID-19 infection among pupils to promote both wellbeing and performance of users, and second, a sustainable classroom from architecture, HVAC, and a medical point of view. In addition, four alternative classroom designs were proposed based on the interpretive results from the questionnaire and simulation.
- PublicationOpen AccessIn vivo evaluation of a recombinant N-acylhomoserine lactonase formulated in a hydrogel using a murine model infected with MDR Pseudomonas aeruginosa clinical isolate, CCASUP2(Springer, 2021-07-27) Sakr, Masarra M.; Aboshanab, Khaled M.; Mantawy, Eman M.; Yassien, Mahmoud A.; Hassouna, Nadia A.; Elkhatib, Walid F.Failure in the treatment of P. aeruginosa, due to its broad spectrum of resistance, has been associated with increased patient mortality. One alternative approach for infection control is quorum quenching which was found to decrease virulence of such pathogen. In this study, the efficiency of a recombinant Ahl-1 lactonase formulated as a hydrogel was investigated to control the infection of multidrug resistant (MDR) P. aeruginosa infected burn using a murine model. The recombinant N-acylhomoserine lactonase (Ahl-1) was formulated as a hydrogel. To test its ability to control the infection of MDR P. aeruginosa, a thermal injury model was used. Survival rate, and systemic spread of the infection were evaluated. Histopathological examination of the animal dorsal skin was also done for monitoring the healing and cellular changes at the site of infection. Survival rate in the treated group was 100% relative to 40% in the control group. A decrease of up to 3 logs of bacterial count in the blood samples of the treated animals relative to the control group and a decrease of up to 4 logs and 2.3 logs of bacteria in lung and liver samples, respectively were observed. Histopathological examination revealed more enhanced healing process in the treated group. Accordingly, by promoting healing of infected MDR P. aeruginosa burn and by reducing systemic spread of the infection as well as decreasing mortality rate, Ahl-1 hydrogel application is a promising strategy that can be used to combat and control P. aeruginosa burn infections.
- PublicationMetadata onlyBiogenic and biocompatible silver nanoparticles for an apoptotic anti-ovarian activity and as polydopamine-functionalized antibiotic carrier for an augmented antibiofilm activity.(Elsevier, 2021-10-01) Aboelmaati, Mohamed G.; Abdel Gaber, Sara A.; Soliman, Wafaa E.; Abdelhameed, Amr M.; Sahyon, Heba A.; El-Kemary, Maged; Elkhatib, Walid F.Silver nanoparticles (AgNPs) could be employed in the combat against COVID-19, yet are associated with toxicities. In this study, biogenic and biocompatible AgNPs using the agro-waste, non-edible Hibiscus sabdariffa stem were synthesized. Under optimized reaction conditions, synthesized green AgNPs were crystalline, face cubic centered, spherical with a diameter of around 17 nm and a surface charge of -20 mV. Their murine lethal dose 50 (LD50) was 4 folds higher than the chemical AgNPs. Furthermore, they were more murine hepato- and nephro-tolerated than chemical counterparts due to activation of Nrf-2 and HO-1 pathway. They exerted an apoptotic anti-ovarian cancer activity with IC50 value 6 times more than the normal cell line. Being functionalized with polydopamine and conjugated to either moxifloxacin or gatifloxacin, the conjugates exerted an augmented antibiofilm activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii biofilms that was significantly higher than antibiotic alone or functionalized AgNPs suggesting a synergistic activity. In conclusion, this study introduced a facile one-pot synthesis of biogenic and biocompatible AgNPs with preferential anti-cancer activity and could be utilized as antibiotic delivery system for a successful eradication of Gram-negative biofilms.
- PublicationMetadata onlyProtective Role of Copper Oxide-Streptomycin Nano-drug Against Potato Brown Rot Disease Caused by Ralstonia solanacearum(Springer Nature, 2021-04-15) Attia, Mohamed S.; Balabel, Naglaa M.; Ababutain, Ibtisam M.; Osman, Mahmoud S.; Nofel, Mohamed M.; Abd Elkodous, Mohamed; El-Batal, Ahmed I.; Elkhatib, Walid F.; El-Sayyad, Gharieb SaiedPotato plants can be infected by different bacterial diseases, among them, the potato brown rot disease, caused by Ralstonia solanacearum. The novelty of the present research is to assess the potential impact of the synthesized copper oxide NPs (CuO NPs)-streptomycin nano-drug synthesized by gamma irradiation for inducing the systemic resistance against potato brown rot disease. CuO NPs-streptomycin was completely-characterized by UV–Vis., XRD, FTIR, HRTEM, SEM, and EDX elemental analysis. In the greenhouse experiment, the efficiency of CuO NPs was tested after three times of application. Disease index percent, phytochemicals, and metabolic indicators of resistance (as a response to induction of systemic resistance) were investigated. Our results indicated that treatment with CuO NPs during planting was more effective for increasing the protection percent by 55.8% and reducing the disease severity by 37.5% in the infected potato plants. CuO NPs-streptomycin increased not only the photosynthetic pigments but also the osmolytes contents. The highest reduction in malondialdehyde (44.89%) and hydrogen peroxide (32.9%) contents was achieved in the case of potato plants treated one week after planting. Therefore, it suggested applying CuO NPs-streptomycin in controlling plant disease since they are cost-effective and eco-friendly.