AMAL EMADELDINE ALI MOHAMED

Reham Samir Mohamed

21/09/2023

https://fjps.springeropen.com/articles/10.1186/s43094-023-00525-w

AMAL EMADELDINE ALI MOHAMED

08/10/2021

https://gutpathogens.biomedcentral.com/articles/10.1186/s13099-021-00454-0

AMAL EMADELDINE ALI MOHAMED

Asmaa A. Abd-Elghaffar , Mohamed E. Rashed 2, , Magdy A. Amin

01/10/2020

After years of global collaboration; we are steps away from a polio-free world. However, the currently conventional inactivated polio vaccine (cIPV) is suboptimal for the post eradication era. cIPV production cost and biosafety hazards hinder its availability and coverage of the global demands. Production of IPV from the attenuated Sabin strains (sIPV) was an ideal solution and scientists work extensively to perfect a safe, effective and affordable sIPV. This study investigated the ability of hydrogen peroxide (H2O2), ascorbic acid (AA) and epigallocatechin-3-gallate (EGCG) asalternativesforFormaldehyde(HCHO)toinactivateSabin-poliovirusesstrainsforsIPVproduction. Sabin-polioviruses vaccine strains were individually treated with AA, EGCG or H2O2 and were compared to HCHO. This was investigated by determination of the inactivation kinetics on HEP2C cells, testing of D-antigen preservation by ELISA and the immune response in Wistar rats of the four vaccine preparations. H2O2, AA and EGCG were able to inactivate polioviruses within 24 h while HCHO required 96 h. Significant high D-antigen levels were observed using AA, EGCG and H2O2 compared to HCHO. Rat sera tested for neutralizing antibodies showed comparable results. Thesefindingssupporttheideaofusingtheseinactivatingagentsassafeandtime-savingalternatives for HCHO to produce sIPV.

AMAL EMADELDINE ALI MOHAMED

01/07/2020

AMAL EMADELDINE ALI MOHAMED

Sahar Y. Al-Okbi, Magdy A. Amin, Amr E. Edris, Osama M. Sharaf, Hoda B Mabrok, and Asmaa A. Ramadan

01/07/2020

AMAL EMADELDINE ALI MOHAMED

Sahar Y Al-Okbi , Magdy A Amin , Amal E A Mohamed , Amr E Edris , Osama M Sharaf , Hoda B Mabrok , Asmaa A Ramadan

01/04/2020

The present research evaluated the protective effect of basil essential oil nanoemulsion (BNO) and its parent basil essential oil (BO) towards steatohepatitis. Chemical composition of BO was assessed followed by formulation into different BNOs using the low energy spontaneous emulsification technique. An ideal formula of BNO was selected among the others based on its ultra-fine particle size (15.42 nm) and physical stability at 25-37℃, which was then tested in steatohepatitis rat model along with BO. Rats were divided into four groups, the first was fed on balanced diet (C), and the other groups were maintained on high fructose saturated fat diet deficient in choline to induce steatohepatitis, one of such groups served as control steatohepatitis (SC), the other groups received daily oral dose of BO and BNO, respectively. Microbiota (Firmicutes and Bacteroidetes) were counted in colon content and their ratio (F/B) was calculated. Liver fat, plasma lipid profile, plama interlukin-6, plasma lipopolysaccharides and plasma and colon content of lipocaline were assessed with histopathological examination of liver and colon. Results showed that the major volatile components of BO were linalool (60.9 %), eugenol (5.1 %) and eucalyptol (9.5%). SC group exhibited significant increase in liver lipids, plasma triglycerides, total cholesterol (TC), low density lipoprotein cholesterol and significant reduction in high density lipoprotein-cholesterol (HDL-C) compared to C group. Significant increase in plasma TC/HDL-C, interlukin-6, and lipocaline and F/B ratio and lipocaline in colon content were demonstrated in SC group without changes in plasma lipopolysaccharides compared to C. Histopathology of SC group showed liver fatty degeneration and fibroblasts activation while the colon demonstrated erosion and mucosal epithelium detachment. Treatment with either BNO or BO showed improvement compared to SC group. BNO was superior in reducing F/B ratio, liver lipids and histopathological changes. BO was more efficient in reducing TC, triglycerides and low density lipoprotein cholesterol. It is concluded that BO and BNO reduced the progression of nonalcoholic steatohepatitis in rat model. Gut microbiota in relation to steatohepatitis and related new therapies needs further investigations.

AMAL EMADELDINE ALI MOHAMED

01/06/2019

Background: Quorum quenching, the interference of a Quorum sensing (QS) system that contributes to the pathogenesis through triggering the production of various virulence determinants, is among the newly suggested antivirulence strategies. Purpose: This study aimed at screening of N-Acyl homoserine lactonase activity from local bacterial isolate, and investigating its effect on Pseudomonas aeruginosa (P. aeruginosa) virulence and biofilm formation. Materials and methods: Soil bacteria were screened for aiiA gene coding for lactonase enzyme by Polymerase Chain reaction and sequencing of aiiA gene homologs. Lactonase activity and spectrum were assessed in the cell-free lysate by well diffusion assay using Agrobacterium tumafaciens KYC55. A bacterial isolate showing the highest N-acyl-homoserine lactones degradation percentage was identified by gene amplification and sequencing of the 16S rRNA gene and its aiiA gene homolog. High performance liquid chromatography was used to confirm N-acyl-homoserine lactone degradation. The effect of cell-free lysate on the biofilm formation ability and cytotoxicity of P. aeruginosa PAO1 and P. aeruginosa clinical isolates from different clinical sources were assessed by static microtiter plate and viability assay, respectively Results: Lactonase gene and activity were identified in three Bacillus spp. isolates. They showed broad catalytic activities against tested N-acyl-homoserine lactones. However, The lactonase activity in the cell- free lysate of isolate 30b showed the highest significant degradation percentage on all tested signals; N-butanoyl-L-homoserine lactone (71%), N-hexanoyl-l-homoserine lactone (100%), N-decanoyl-homoserine lactone (100%), N-(3-oxohexanoyl)-L-homoserine lactone (37.5%), N-(oxodecanoyl)-L-homoserine lactone (100%), and N-(3-oxododecanoyl)-L-homoserine lactone (100%). Alignment of the amino acid sequences of AiiA protein of isolate 30b showed 96% identity with Bacillus cereus (B. cereus) homologous lactonases in the GenBank database, and the isolate was designated as B. cereus isolate 30b. Cell-free lysate of B. cereus isolate 30b reduced biofilm formation significantly in 93% of P. aeruginosa isolates. The highest mean percentage of reduction in the biofilm was 86%. Moreover, the viability percentage of human lung carcinoma A549 cells infected by P. aeruginosa and treated with cell-free lysate of B. cereus isolate 30b increased up to 15%. Conclusion: The results of this study highlight the potential of lactonases as a promising strategy to combat Pseudomonas aeruginosa virulence.

AMAL EMADELDINE ALI MOHAMED

Abdelgawad M. Hashem , Ramy K. Aziz

01/04/2019

The gut microbiota enriches the human gene pool and contributes to xenobiotic metabolism. Microbial azoreductases modulate the reduction of azo-bonds, activating produgs and azo polymer-coated dosage forms, or degrading food additives. Here, we aimed to screen the healthy human gut microbiota for food colorant-reducing activity and to characterize factors modulating it. Four representative isolates from screened fecal samples were identified as E. coli (AZO-Ec), E. faecalis (AZO-Ef), E. avium (AZO-Ev) and B. cereus (AZO-Bc). Both AZO-Ef and AZO-Ev decolorized amaranth aerobically and microaerophilically while AZO-Ec and AZO-Bc had higher aerobic reduction rates. The isolates varied in their activities against different dyes, and the azo-reduction activity mostly followed zero-order reaction kinetics, with a few exceptions. Additionally, the isolates had different pH dependence, e.g., AZO-Ec was not affected by pH variation while AZO-Bc exhibited variable degradation kinetics at different pH levels. Cell-free extracts showed NADH-dependent enzymatic activities 14–19 times higher than extracellular fractions. FMN did not affect the reducing activity of AZO-Ef cell-free extract, whereas AZO-Ec, AZO-Ev and AZO-Bc had significantly higher reduction rates in its presence (P values = 0.02, 0.0001 and 0.02, respectively). Using Degenerate primers allowed the amplification of azoreductase genes, whose sequences were 98–99% similar to genes encoding FMN-dependent-NADH azoreductases.

AMAL EMADELDINE ALI MOHAMED

Rasha A. Hashem, Reham Samir, Tamer M. Essam, Magdy A. Amin

01/05/2018

Azo dyes are complex derivatives of diazene used in food and textile manufacture. They are highly recalcitrant compounds, and account for severe environmental and health problems. Different strains of Pseudomonas species were isolated from textile wastewater effluents. The bioconversion of Remazol black B (a commonly used water soluble dye) by Pseudomonas aeruginosa was observed in static conditions. The bio-decolorization process was optimized by a multi factorial Plackett–Burman experimental design. Decolorization of 200 mg L−1 reached 100% in 32 h. Interestingly, the presence of yeast extract, magnesium and iron in the culture media, highly accelerated the rate of decolorization. Moreover, one of our isolates, P. aeruginosa KY284155, was kept high degradation rates at high pH (pH = 9), which represents the pH of most textile wastewater effluents, and was able to tolerate high concentration of dye up to 500 mg L−1. In bacteria, azo-dye degradation is often initiated by reductive azo compound cleavage catalyzed by azo-reductases. Three genes encoding azo-reductases, paazoR1, paazoR2 and paazoR3, could be identified in the genome of the isolated P. aeruginosa stain (B1). Bioinformatics analyses of the paazoR1, paazoR2 and paazoR3 genes reveal their prevalence and conservation in other P. aeruginosa strains. Chemical oxygen demand dramatically decreased and phyto-detoxification of the azo dye was accomplished by photocatalytic post treatment of the biodegradation products. We suggest applying combined biological photocatalytic post treatment for azo dyes on large scale, for effective, cheap decolorization and detoxification of azo-dyes, rendering them safe enough to be discharged in the environment.

AMAL EMADELDINE ALI MOHAMED

Ahmed H. Korany, Tamer M. Essam, Salwa A. Megahed

01/09/2017

A halophilic cellulase-producing bacterium was isolated from a sediment sample collected from Lake Qarun (Fayoum Province, Egypt). Molecular identification based on 16S rDNA amplification and sequencing revealed 99% homology with Halobacillus sp. and hence was designated as Halobacillus sp. QLS 31. Medium composition and culture conditions were optimized for enhancing the production of cellulase enzyme using the Plackett-Burman statistical design. Ten variables were evaluated for their influence on cellulase production. Carboxymethyl cellulose (CMC), zinc sulfate (ZnSO4), and inoculum size were found to exert a significant effect on cellulase productivity by Halobacillus sp. QLS 31. The maximum specific activity of cellulase enzyme was 48.08 U/mg. Following the predicted conditions, a 7.5-fold increase in cellulase specific activity (175.47 U/mg) was achieved compared to the basal medium (23.19 U/mg) under the following optimized conditions: temperature (30 °C), fermentation time (2 days ), pH value (9), CMC concentration (1%), inoculum size (1%), yeast extract concentration (0.1%), ammonium sulfate ((NH3)2SO4) concentration (0.1%), sodium chloride (NaCl) concentration (20%), and metal inducers: ZnSO4 (0.1%) and Ca/Mg ratio (0.01%). Thus, the results of this study provide an important basis for more efficient, cheap industrial cellulase production from halophilic Halobacillus sp. QLS 31.

AMAL EMADELDINE ALI MOHAMED

Essam TM, Amin MA

01/01/2016

Burkholderia cepaciahas recently received a considerable attention as one of the major risks in susceptible pharmaceutical products. This microorganism can easily propagate and cause vast and severe contamination, especially to the water supplies for pharmaceutical companies. Moreover, it proliferates within the products and can cause severe infections for humans. Therefore, fast and sensitive detection of these bacteria is of a great demand. The present study introduces improved application of a polymerase chain reaction assay with relatively high sensitivity and specificity for the direct detection ofB. cepaciafrom the aqueous pharmaceutical products. A semi-nested polymerase chain reaction approach using the primer set BCR1/BCR2 followed by BCR1/Mr yielding a 465 bp fragment of the recA gene was applied and tested using both crude lysate from isolated colonies and DNA directly extracted from artificially prepared and spiked reference syrup. The polymerase chain reaction assay showed no interference with other bacterial reference and environmental strains tested, includingStaphylococcus aureusATCC® 6538,Pseudomonas aeruginosaATCC® 9027,Escherichia coliATCC® 8739,Salmonella abonyNCTC® 6017,Bacillus subtilisATCC® 6633,Micrococcus luteus, Staphylococcus warneri, Pseudomonas fluorescens, Pseudomonas putida, andRalstonia pickettii Moreover, this semi-nested assay showed a detection limit of around 10 colony-forming units per sample and could detectB. cepaciastrains isolated from a municipal pre-treated potable water tank. Comparing the results for detection ofB. cepaciain 100 randomly collected commercial syrup preparations using both conventional standard method and polymerase chain reaction assay revealed thatB. cepaciawas detected in two samples using polymerase chain reaction assay while all samples showed negative results by conventional culturing and biochemical methods. These results highlight the advantage of using this polymerase chain reaction assay to detectB. cepaciain contaminated pharmaceutical products and even water for pharmaceutical purposes, without the need of culturing or pre-enrichment, where it may give false-negative results and may be misidentified when biochemically tested.

AMAL EMADELDINE ALI MOHAMED

Walaa A. Eraqi, Aymen S. Yassin, Amal E. Ali, and Magdy A. Amin

01/01/2016

AMAL EMADELDINE ALI MOHAMED

Shebl RI, Mohamed AF, Ali AE, Amin MA

01/04/2012