Omneya Helmy

Dr. Omneya Helmy

Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University
orcid

Research Focus & Metrics

Academic Career Length

10Years (2017-Present)

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

Representative Publications

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12 September 2020 in Pathogens
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Journal Article
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KIKareem Ibrahim
Kareem Ibrahim
OHOmneya Helmy
Omneya Helmy
MKMona Kashef
Mona Kashef
TETharwat R. Elkhamissy
Tharwat R. Elkhamissy
MRMohammed A. Ramadan
Mohammed A. Ramadan
The class 1 carcinogen, Helicobacter pylori, is one of the World Health Organization’s high priority pathogens for antimicrobial development. We used three subtractive proteomics approaches using protein pools retrieved from: chokepoint reactions in the BIOCYC database, the Kyoto Encyclopedia of Genes and Genomes, and the database of essential genes (DEG), to find putative drug targets and their inhibition by drug repurposing. The subtractive channels included non-homology to human proteome, essentiality analysis, sub-cellular localization prediction, conservation, lack of similarity to gut flora, druggability, and broad-spectrum activity. The minimum inhibitory concentration (MIC) of three selected ligands was determined to confirm anti-helicobacter activity. Seventeen protein targets were retrieved. They are involved in motility, cell wall biosynthesis, processing of environmental and genetic information, and synthesis and metabolism of secondary metabolites, amino acids, vitamins, and cofactors. The DEG protein pool approach was superior, as it retrieved all drug targets identified by the other two approaches. Binding ligands (n = 42) were mostly small non-antibiotic compounds. Citric, dipicolinic, and pyrophosphoric acid inhibited H. pylori at an MIC of 1.5–2.5 mg/mL. In conclusion, we identified potential drug targets in H. pylori, and repurposed their binding ligands as possible anti-helicobacter agents, saving time and effort required for the development of new antimicrobial compounds.

22 May 2022 in Fermentation
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MHMerehan Hallol
Merehan Hallol
OHOmneya Helmy
Omneya Helmy
ASAlla-Eldien Shawky
Alla-Eldien Shawky
Ahmed Ibrahim El-BatalAhmed Ibrahim El-Batal
Ahmed Ibrahim El-Batal
MRMohamed Ramadan
Mohamed Ramadan
We set out to isolate alpha-amylase producers from soil samples, optimize the production, and immobilize the enzyme on chitosan-loaded barium ferrite nanoparticles (CLBFNPs). Alpha-amylase producers were isolated on starch agar plates and confirmed by dinitrosalicylic acid assay. The potent isolate was identified by phenotypic methods, 16S-rRNA sequencing, and phylogenetic mapping. Sequential optimization of α-amylase production involved the use of Plackett–Burman (P–BD) and central composite designs (CCD), in addition to exposing the culture to different doses of gamma irradiation. Alpha-amylase was immobilized on CLBFNPs, and the nanocomposite was characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, and scanning electron microscopy, with energy-dispersive analysis of X-ray analysis. Forty-five α-amylase producers were isolated from 100 soil samples. The highest activity (177.12 ± 6.12 U/mg) was detected in the MS009 isolate, which was identified as Bacillus paramycoides. The activity increased to 222.3 ± 5.07 U/mg when using the optimal culture conditions identified by P–BD and CCD, and to 319.45 ± 4.91 U/mg after exposing the culture to 6 kGy. Immobilization of α-amylase on CLBFNPs resulted in higher activity (246.85 ± 6.76 U/mg) compared to free α-amylase (222.254 ± 4.89 U/mg), in addition to retaining activity for up to five cycles of usage. Gamma irradiation improved α-amylase production, while immobilization on CLBFNPs enhanced activity, facilitated enzyme recovery, and enabled its repetitive use.

16 July 2018 in Infectious Agents and Cancer
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DADoaa AlEraky
Doaa AlEraky
OHOmneya Helmy
Omneya Helmy
YRYasser M. Ragab
Yasser M. Ragab
ZAZeinab Abdul-Khalek
Zeinab Abdul-Khalek
EEEman A. El-Seidi
Eman A. El-Seidi
MRMohammed A. Ramadan
Mohammed A. Ramadan
Helicobacter pylori (H. pylori) infection has been recognized as a significant threat for gastric cancer. However, studies that investigated the oncogenic factors and antimicrobial resistance of H. pylori in Egyptian isolates with gastric cancer are rare. The current study aimed to examine: (1) The pattern of antimicrobial resistance of H. pylori isolates of Egyptian gastric cancer patients, and (2) the prevalence of Cytotoxin-associated gene A (CagA). Samples were collected from patients with gastric cancer. Isolation of H. pylori was performed using Columbia blood agar supplemented with 10% horse blood, and selective supplement of H. pylori for 3 to 5 days at 37 °C under microaerophilic condition. Isolates were identified by biochemical traits of H. pylori: oxidase, urease and catalase tests. Antimicrobial susceptibility of H. pylori isolates was examined against five antimicrobial agents using disc diffusion method. After that, extraction of DNA and Polymerase Chain Reaction (PCR) were performed to amplify the target genes. Twelve samples were collected from six males and six females Egyptian patients with cancer with an age range from 22 to 65 years. These cases are scarce and samples were collected over a period of almost eleven months. All isolates were confirmed as positive H. pylori through colony morphology and biochemical tests. The most effective antibiotic found was ciprofloxacin whereas all isolates showed resistance to metronidazole and erythromycin. The target CagA oncogene gene with expected product size was reported and seven (out of twelve) isolates (58%) were identified as CagA positive. The current study is unique in two main aspects. First, it reported the pattern of antimicrobial susceptibility and prevalence of CagA gene in H. pylori from Egyptian patients. Second, it exclusively recruited isolates from gastric cancer patients which were confirmed by clinical and laparoscopic examination. The moderately high prevalence of CagA gene in Egyptian cancer patients calls for more vigilance against that oncogene.

13 January 2018 in Jundishapur Journal of Microbiology
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WGWesam Elsayed Gawad
Wesam Elsayed Gawad
OHOmneya Helmy
Omneya Helmy
WTWael Mostafa Tawakkol
Wael Mostafa Tawakkol
AHAbdelgawad Mohamed Hashem
Abdelgawad Mohamed Hashem
Background: Urinary tract infections are the most commonly encountered infections in clinics and outpatient settings and are mainly caused by Uropathogenic Escherichia coli (UPEC). Multidrug-resistant bacteria (MDR) have become a major public health threat, worldwide. Objectives: This study aimed at investigating the prevalence of the MDR phenotype, efflux pump-mediated resistance, and the ability for in vitro biofilm formation among UPEC clinical isolates from Egypt. Methods: Uropathogenic E. coli isolates were collected from 2 Egyptian governorates, identified, and classified in their corresponding phylogenetic group by the polymerase chain reaction (PCR). Antimicrobial susceptibility testing was done using the Kirby-Bauer disk diffusion method. AcrAB-TolC efflux pump major genes were detected by PCR; efflux pump-mediated resistance was determined by the efflux pump inhibitor microplate-based assay. The ability for in-vitro biofilm formation was also tested. Results: The phylogenetic analysis of the UPEC isolates revealed that most of the isolates belonged to groups B2 and D. The MDR phenotype was detected in 90.8% of UPEC isolates; efflux pump-mediated resistance was detected in all MDR isolates. The acrA, acrB, and tolC were detected in 74.84% of MDR isolates. The ability for in-vitro biofilm formation was recorded in 76.5% of the UPEC isolates. Conclusions: The MDR phenotype and the ability for in-vitro biofilm formation were predominant among UPEC in Egypt. The high prevalence of MDR efflux pumps necessitates the application of new treatment strategies to inhibit this phenomenon. Keywords: Biofilms; Drug Resistance; Uropathogenic Escherichia coli

OHOmneya Helmy
Omneya Helmy
MKMona T Kashef
Mona T Kashef
Objectives: We set out to investigate the prevalence, different mechanisms, and clonal relatedness of multidrug resistance (MDR) among third-generation cephalosporin-resistant Gram-negative clinical isolates from Egypt. Materials and methods: A total of 118 third-generation cephalosporin-resistant Gram-negative clinical isolates were included in this study. Their antimicrobial susceptibility pattern was determined using Kirby–Bauer disk diffusion method. Efflux pump-mediated resistance was tested by the efflux-pump inhibitor-based microplate assay using chlorpromazine. Detection of different aminoglycoside-, β-lactam-, and quinolone-resistance genes was done using polymerase chain reaction. The genetic diversity of MDR isolates was investigated using random amplification of polymorphic DNA. Results: Most of the tested isolates exhibited MDR phenotypes (84.75%). The occurrence of efflux pump-mediated resistance in the different MDR species tested was 40%–66%. Acinetobacter baumannii isolates showed resistance to most of the tested antibiotics, including imipenem. The blaOXA-23-like gene was detected in 69% of the MDR A. baumannii isolates. The MDR phenotype was detected in 65% of Pseudomonas aeruginosa isolates, of which only 23% exhibited efflux pump-mediated resistance. On the contrary, efflux-mediated resistance to piperacillin and gentamicin was recorded in 47.5% of piperacillin-resistant and 25% of gentamicin-resistant MDR Enterobacteriaceae. Moreover, the plasmid-mediated quinolone-resistance genes (aac(6’)-Ib-cr, qnrB, and qnrS) were detected in 57.6% and 83.33% of quinolone-resistant MDR Escherichia coli and Klebsiella pneumoniae isolates, respectively. The β-lactamase-resistance gene blaSHV-31 was detected for the first time in one MDR K. pneumoniae isolate from an endotracheal tube specimen in Egypt, accompanied by blaTEM-1, blaCTX-M-15, blaCTX-M-14, aac(6’)-Ib-cr, qnrS, and multidrug efflux-mediated resistance. Conclusion: MDR phenotypes are predominant among third-generation cephalosporin-resistant Gram-negative bacteria in Egypt and mediated by different mechanisms, with an increased role of efflux pumps in Enterobacteriaceae.

2 October 2020 in BMC Biotechnology
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SESarah Mohamed El-Korany
Sarah Mohamed El-Korany
OHOmneya Helmy
Omneya Helmy
AHAli El Halawany
Ali El Halawany
YRYasser El-Mohammadi Ragab
Yasser El-Mohammadi Ragab
HZHamdallah Hafez Zedan
Hamdallah Hafez Zedan
Background: Obesity and its related diseases are increasing worldwide. One of the best therapeutic strategies for obesity management is through the inhibition of pancreatic lipase (PL) enzyme. So far orlistat is the only FDA approved PL inhibitor, but with unpleasant side effects. New efficacious anti-obesity drugs are needed to achieve a successful reduction in the incidence and prevalence of obesity. Many microbial metabolites have PL inhibitory activity. Screening soil inhabitants for PL inhibitors could help in increasing the available anti-obesity drugs. We aimed to isolate and identify alternative PL inhibitors from soil flora.Results: We screened the crude mycelial methanolic extracts of 39 soil samples for PL inhibitory activity by the quantitative lipase colorimetric assay, using the substratep-nitrophenyl palmitate and orlistat as positive control. AspsarO, a PL inhibitor producer, was isolated from an agricultural field soil in Giza, Egypt. It was identified asAspergillus oryzaeusing colony morphology, microscopical characteristics,18SrDNA sequencing, and molecular phylogeny. Increasing the PL inhibitor activity, in AspsarO cultures, from 25.9 ± 2% to 61.4 ± 1.8% was achieved by optimizing the fermentation process using a Placket–Burman design. The dried 100% methanolic fraction of the AspsarO culture had an IC50of 7.48 μg/ml compared to 3.72 μg/ml for orlistat. It decreased the percent weight gain, significantly reduced the food intake and serum triglycerides levels in high-fat diet-fed Sprague–Dawley rats. Kojic acid, the active metabolite, was identified using several biological guided chromatographic and1H and13C NMR techniques and had an IC50of 6.62 μg/ml. Docking pattern attributed this effect to the interaction of kojic acid with the key amino acids (Lys80, Trp252, and Asn84) in PL enzyme binding site.Conclusion: Combining the results of the induced obesity animal model, in silico molecular docking and the lipase inhibitory assay, suggests that kojic acid can be a new therapeutic option for obesity management. Besides, it can lower serum triglycerides in obese patients.