Publications

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2022
Ibrahim, K. A., M. O. N. A. T. KASHEF, T. R. Elkhamissy, M. A. Ramadan, and undefined, "Aspartate α-decarboxylase a new therapeutic target in the fght against Helicobacter pylori infection", Frontiers in Microbiology, vol. 13, pp. 1019666., 2022.
2021
ElDein, M. T. A., A. S. Yassin, O. El‑Tayeb, and M. O. N. A. T. KASHEF, "Chlorhexidine leads to the evolution of antibiotic‑resistant Pseudomonas aeruginosa", European Journal of Clinical Microbiology & Infectious Diseases, vol. 40, pp. 2349–2361, 2021.
Gamal, A. A., H. Y. Abbas, N. A. M. Abdelwahed, M. O. N. A. T. KASHEF, K. Mahmoud, M. A. Esawy, and M. A. Ramadan, "Optimization strategy of Bacillus subtilis MT453867 levansucrase and evaluation of levan role in pancreatic cancer treatment", International Journal of Biological Macromolecules, vol. 182, issue 2021, pp. 1590–1601, 2021.
2020
Kahef, M. T., and R. K. Aziz, "Drug Factory Microbiome: Top Three Actionable Challenges and Prospects", OMICS A Journal of Integrative Biology, vol. 24, issue 1, pp. 55-56, 2020.
Hosny, A. E. - D. M. S., M. N. Fakhry, W. El-Khayat, and M. O. N. A. T. KASHEF, "Risk factors associated with preterm labor, with special emphasis on preterm premature rupture of membranes and severe preterm labor", Journal of chinese medical association, vol. 83, pp. 280-287, 2020. risk_factors_associated_with_preterm_labor_with.13.pdf
2019
Hosny, A. E. - D. M. S., S. A. Rasmy, D. S. Aboul-Magd, M. O. N. A. T. KASHEF, and Z. E. El-Bazza, "The increasing threat of silver-resistance in clinical isolates from wounds and burns", Infection and drug resistance, vol. 12, pp. 1985-2001, 2019.
2018
Safwat, N. A., M. O. N. A. T. KASHEF, R. K. Aziz, K. F. Amer, and M. A. Ramadan, "Quercetin 3-O-glucoside recovered from the wild Egyptian Sahara plant, Euphorbia paralias L., inhibits glutamine synthetase and has antimycobacterial activity", tuberculosis, vol. 108, pp. 106-113, 2018.
2017
Hosny, A. E. - D. M. S., W. El-Khayat, M. O. N. A. T. KASHEF, and M. N. Fakhry, "Association between preterm labor and genitourinary tract infections caused by Trichomonas vaginalis, Mycoplasma hominis, Gram-negative bacilli, and coryneforms.", Journal of the Chinese Medical Association : JCMA, 2017 Jan 13. Abstract

BACKGROUND: Preterm labor (PTL) is responsible for most cases of neonatal death. In most of these cases, the causes of PTL have not been established although several risk factors have been described. Therefore, the aim of this study was to investigate risk factors for PTL before 37 gestational weeks among Egyptian women.

METHODS: In this case-control study, 117 pregnant women without risk factors for PTL were chosen. The control group (n=45) had term labor (gestational weeks≥37 weeks), and the case group (n=72) had PTL (gestational weeks < 37 weeks). The two groups were screened for urinary and vaginal infections. The role of different demographic characteristics, patient history, and clinical signs were also investigated.

RESULTS: Several risk factors were identified in this study, including age<20 years, nulliparity, previous abortion and previous preterm birth, menses vaginal bleeding, a vaginal pH>5, a positive whiff test, Trichomonas vaginalis infection, Mycoplasma hominis infection, coryneforms heavy vaginal growth, and any vaginal growth of Gram-negative bacilli. Urinary tract infection with any colony count was not associated with PTL.

CONCLUSION: Our study demonstrated that the main risk factors for PTL were vaginal infection with T. vaginalis, M. hominis, coryneforms, and Gram-negative bacilli, and their determinants (vaginal pH>5, positive whiff test, heavy vaginal bleeding). Both young age (< 20 years) and poor obstetric history were also the risk factors. Therefore, screening for genitourinary tract infections is strongly recommended to be included in prenatal care.

Ibrahim, E. S., M. O. N. A. T. KASHEF, T. M. Essam, and M. A. Ramadan, "A Degradome-Based Polymerase Chain Reaction to Resolve the Potential of Environmental Samples for 2,4-Dichlorophenol Biodegradation.", Current microbiology, vol. 74, issue 12, pp. 1365-1372, 2017 Dec. Abstract

A clean way to overcome environmental pollution is biodegradation. In this perspective, at the intersection of biodegradation and metagenomics, the degradome is defined as the totality of genes related to the biodegradation of a certain compound. It includes the genetic elements from both culturable and uncultured microorganisms. The possibility of assessing the biodegradation potential of an environmental samples, using a degradome-based polymerase chain reaction, was explored. 2,4-Dichlorophenol (2,4-DCP) was chosen as a model and the use of tfdB gene as a biodegradation marker was confirmed by bioinformatics study of TfdB protein. Five primer pairs were designed for the detection of different tfdB gene families. A total of 16 environmental samples were collected from Egyptian agricultural soils and wastewaters and tested for the presence of 2,4-DCP. The biodegradation capacity of 2,4-DCP was determined, for all isolated consortia, to reach up to 350 mg/l. Metagenomic DNA was extracted directly from the soil samples while successive 2,4-DCP-degrading microbial communities were enriched, with increasing concentrations of 2,4-DCP, then their DNA was extracted. The extracted DNA was tested for the distribution of the tfdB gene using a degradome-based polymerase chain reaction. tfdB-1 and tfdB-2 were detected in 5 and 9 samples, respectively. However, the co-existence of both genes was detected only in five samples. All tfdB positive samples were capable of 2,4-DCP degradation. The developed approach of assessing the potential of different environments for degrading 2,4-DCP was successfully measured in terms of accuracy (81.25%) and specificity (100%).

HELMY, O. M. N. E. Y. A. M., and M. O. N. A. T. KASHEF, "Different phenotypic and molecular mechanisms associated with multidrug resistance in Gram-negative clinical isolates from Egypt.", Infection and drug resistance, vol. 10, pp. 479-498, 2017. Abstract

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.

Akhter, S., R. K. Aziz, M. O. N. A. T. KASHEF, E. S. Ibrahim, B. Bailey, and R. A. Edwards, "Kullback Leibler divergence in complete bacterial and phage genomes.", PeerJ, vol. 5, pp. e4026, 2017. Abstract

The amino acid content of the proteins encoded by a genome may predict the coding potential of that genome and may reflect lifestyle restrictions of the organism. Here, we calculated the Kullback-Leibler divergence from the mean amino acid content as a metric to compare the amino acid composition for a large set of bacterial and phage genome sequences. Using these data, we demonstrate that (i) there is a significant difference between amino acid utilization in different phylogenetic groups of bacteria and phages; (ii) many of the bacteria with the most skewed amino acid utilization profiles, or the bacteria that host phages with the most skewed profiles, are endosymbionts or parasites; (iii) the skews in the distribution are not restricted to certain metabolic processes but are common across all bacterial genomic subsystems; (iv) amino acid utilization profiles strongly correlate with GC content in bacterial genomes but very weakly correlate with the G+C percent in phage genomes. These findings might be exploited to distinguish coding from non-coding sequences in large data sets, such as metagenomic sequence libraries, to help in prioritizing subsequent analyses.

Hosny, A. E. - D. M. S., M. O. N. A. T. KASHEF, H. A. Taher, and Z. E. El-Bazza, "The use of unirradiated and γ-irradiated zinc oxide nanoparticles as a preservative in cosmetic preparations.", International journal of nanomedicine, vol. 12, pp. 6799-6811, 2017. Abstract

PURPOSE: Microbial contamination of different cosmetic preparations, as a result of preservative failure, presents a major public health threat. Also, most of the known preservatives have serious consumer side effects. The antimicrobial activity of zinc oxide nanoparticles (ZnO NP) is well documented. Therefore, we aimed to determine the possible use of unirradiated and γ-irradiated ZnO NP as a cosmetic preservative.

METHODS: The possible use of ZnO NP as a preservative was tested and compared to commonly used preservatives using a challenge test. Their activity was tested in six different types of preparations. The effect of γ radiation on the antimicrobial activity of ZnO NP was tested through determination of the obtained zone diameters against different microorganisms and the total aerobic microbial count in tested preparations. The antimicrobial activity, of unirradiated and γ-irradiated ZnO NP during storage was also determined.

RESULTS: ZnO NP were superior to other commonly used preservatives in all tested cosmetic preparations. They pass the challenge test in all types of tested preparations. γ irradiation enhanced their antimicrobial activity in all tested preparations. The irradiation causes a reduction in NP sizes that is directly proportional to the applied radiation dose. Upon storage, ZnO NP were effective in maintaining the microbial count of the product within the acceptable range. Their activity in stored products was enhanced by γ irradiation.

CONCLUSION: Unirradiated and γ-irradiated ZnO NP can be used as effective preservatives. They are compatible with the components of all tested products. γ irradiation enhanced the antimicrobial activity of ZnO NP.

Hosny, A. M. S., M. O. N. A. T. KASHEF, S. A. Rasmy, D. S. Aboul-Magd, and Z. E. El-Bazza, "Antimicrobial activity of silver nanoparticles synthesized using honey and gamma radiation against silver-resistant bacteria from wounds and burns", Advances in Natural Sciences: Nanoscience and Nanotechnology, vol. 8, pp. 045009 (7pp), 2017.
KASHEF, M. O. N. A. T., and O. M. N. E. Y. A. M. HELMY, "Genetic Characterization of a Novel Composite Transposon Carrying armA and aac(6)-Ib Genes in an Escherichia coli Isolate from Egypt", Polish Journal of Microbiology, vol. 66, issue 2, pp. 163-169, 2017.
2013
Yassin, A., M. Tawfeek, R. Hashem, Y. Nagy, Y. Hashem, S. AbdelSalam, A. Emad, Y. Ragab, A. Kholiefy, A. Shawky, et al., "Antibiotic resistance patterns among common Gram positive and Gram negative pathogens in clinical isolates from major hospitals in Cairo, Egypt", II international conference on antimicrobial research, Lisbon, portugal, Boca Raton, Florida, USA, BrownWalker Press,, pp. 34-39, 2013.
2012
Kashif, M. T., A. S. Yassin, and A. E. - D. M. S. Hosny, "Detection of AmpC beta-lactamases using sodium salicylate", Journal of Microbiological Methods, vol. 91, issue 3, pp. 354–357, 2012.
Kashif, M. T., and A. E. - D. M. S. Hosny, "A study on occurrence of plasmid mediated AmpC ß-lactamases among gram negative clinical isolates and evaluation of different methods used for their detection.", Journal of Applied Sciences Research, vol. 8, issue 4, pp. 2280-2285, 2012.
2011
kashif, M. T., A. E. - D. M. S. Hosny, M. A. E. - H. Ramadan, and A. K. M. Ahmady, "Parameters Affecting Detectability of Staphylococcus Heteroresistance to Different Antibiotics", Journal of Applied Sciences Research, vol. 7, issue 6, pp. 975-979, 2011.
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