Biochemical, molecular and anti-tumor characterization of L-methionine gamma lyase produced by local Pseudomonas sp. in Egypt.

A soil inhabiting Pseudomonas sp. has been examined for producing L- methionine gamma-lyase enzyme. The identity of the tested bacteria was verified by VITEK2, and MALDI-TOF analysis in addition to molecular confirmation by 16S rDNA sequence and submitted in Genbank under accession number ON993898.1. Production of the targeted enzyme was done using a commercial medium including L-methionine, as the main substrate. This obtained enzyme was precipitated using acetone (1:1v/v) followed by purification with Sephadex G100 and sepharose columns. The specific activity of the purified enzyme (105.8 µmol/ mg/min) increased by 1.89 folds after the purification steps. The peptide fingerprint of the native MGL was verified from the proteomics analysis, with identical conserved active site domains with database-deposited MGLs. The molecular mass of the pure MGL denatured subunit was (>40 kDa) and that of the native enzyme was (>150 kDa) ensuring their homotetrameric identity. The purified enzyme showed absorption spectra at 280 nm and 420 nm for the apo-MGL and PLP coenzyme, respectively. Amino acids suicide analogues analysis by DTNB, hydroxylamine, iodoacetate, MBTH, mercaptoethanol and guanidine thiocyanate reduced the relative activity of purified MGL. From the kinetic properties, the catalytic effectiveness (Kcat/km) of Pseudomonas sp. MGL was 10.8 mM -1 S-1 for methionine and 5.51 mM -1 S-1 for cysteine, respectively. The purified MGL showed highly significant antiproliferative activity towards the liver carcinoma cell line (HEPG-2) and breast carcinoma cell line (MCF-7) with half inhibitory concentration values (IC50) 7.23 U/ml and 21.14 U/ml, respectively. No obvious signs of toxicity on liver and kidney functions in the examined animal models were observed.

Sensitive and selective colorimetric detection of Staphylococcus aureus-SPA gene by engineered gold nanosensor.

Staphylococcal protein A (SPA) is an important virulence factor that enables Staphylococcus aureus to evade host immune responses. The current work aims to detect the S. aureus SPA gene by a colorimetric method based on gold nanoparticles (AuNPs). For this purpose, the chromosomal DNA of S. aureus was extracted. Thereafter, primers and thiolated oligonucleotide probe were designed based on protein A sequence data in the gene bank. PCR analysis was performed, and the PCR product was electrophoresed on 2 % agarose gel. Gold nanosensor (Au-Ns) was synthesized by the reaction between AuNPs and the thiolated oligonucleotide probe. The physicochemical properties of AuNPs and Au-Ns were characterized. The detection of the SPA gene was performed based on color change detected by the naked eye and UV-vis spectrophotometry. Finally, the described method was optimized and validated for standard, clinical, and food samples. The PCR analysis showed a characteristic fragment of the SPA gene with a molecular size of 545 base pairs (bp) and a detection limit of 60 pg/ µL. The physicochemical analyses illustrated Au-Ns' correct preparation with a zeta potential of -13.42 mV and particle size range 6-11 nm. Moreover, Au-Ns showed 100 % specificity with a detection limit (DL) of 6 fg/ µL. The proposed method was well described to be applied in clinical and research laboratories.

Chemical Constitution and Antimicrobial Activity of Kombucha Fermented Beverage.

Kombucha is a traditional beverage of sweetened black tea fermented with a symbiotic association of acetic acid bacteria and yeasts. In this study, kombucha fermented beverage (KFB) appeared to include nine chemical groups (alcohols, acids, lactones, condensed heterocyclic compounds, antibiotics, esters, aldehydes, fatty acids, and alkaloids) of many bioactive metabolites, as elucidated by gas chromatography-mass spectrometry (GC-MS) and IR spectra. The fermented metabolic components of KFB seem collectively to act in a synergistic action giving rise to the antimicrobial activity. Four types of kombucha preparations (fermented, neutralized, heat-treated and unfermented) were demonstrated with respect to their antimicrobial activity against some pathogenic bacterial and fungal strains using agar well diffusion assay. KFB exerted the strongest antimicrobial activities when compared with neutralized and heat-treated kombucha beverages (NKB and HKB). Staphylococcus aureus ATCC6538 (S. aureus) and Escherichia coli ATCC11229 (E. coli) were the organisms most susceptible to the antimicrobial activity of kombucha beverage preparations. Finally, the KFB preparation showed remarkable inhibitory activity against S. aureus and E. coli bacteria in a brain heart infusion broth and in some Egyptian fruit juices (apple, guava, strawberry, and tomato). These data reveal that kombucha is not only a prophylactic agent, but also appears to be promising as a safe alternative biopreservative, offering protection against pathogenic bacteria and fungi.

Chemical Constitution and Antimicrobial Activity of Kefir Fermented Beverage.

Kefir beverage (KB) is a fermented milk initiated by kefir grains rich with starter probiotics. The KB produced in this study seemed to contain many chemical compounds elucidated by gas chromatography-mass spectrometry (GC-MS) and IR spectra. These compounds could be classified into different chemical groups such as alcohols, phenols, esters, fatty esters, unsaturated fatty esters, steroids, polyalkenes, heterocyclic compounds and aromatic aldehydes. Both KB and neutralized kefir beverage (NKB) inhibited some pathogenic bacteria including Escherichia coli ATCC11229 (E. coli), Listeria monocytogenes ATCC 4957 (L. monocytogenes), Bacillus cereus ATCC 14579 (B. cereus), Salmonella typhimurium ATCC 14028 (Sal. typhimurium) as well as some tested fungal strains such as Aspergillus flavus ATCC 16872 (A. flavus) and Aspergillus niger ATCC 20611 (A. niger), but the inhibitory activity of KB was more powerful than that obtained by NKB. It also appeared to contain four lactic acid bacteria species, one acetic acid bacterium and two yeast species. Finally, the KB inhibited distinctively both S. aureus and Sal. typhimurium bacteria in a brain heart infusion broth and in some Egyptian fruit juices, including those made with apples, guava, strawberries and tomatoes.

Consumer-oriented evaluation of the service provided by the department of health education and information in Alexandria, Egypt.

BACKGROUND: Assessing consumers' satisfaction with health education services can help in monitoring the quality of provided service and understanding consumers' perceptions and utilization patterns of the service. MATERIALS AND METHODS: A cross-sectional descriptive study targeting consumers attending the health education sessions provided by Alexandria Department of Health Education and Information (DHEI) at different governmental health facilities and nongovernmental organizations was performed. A simple random sample of 400 participants was interviewed using an interview questionnaire assessing respondents' socioeconomic characteristics, health literacy, attitude toward health education services, and satisfaction with the health education service provided by the DHEI. RESULTS: Approximately 70% of the consumers' sample showed fair health literacy level. Most of the sample mentioned physicians a credible source of health knowledge followed by 58.8% who selected health education sessions as another trusted health information source. Overall, 90% of the sample was highly satisfied by the service overall. Behavior and skills of the service providers were the most satisfying aspects, whereas health education materials obtained the least satisfaction. Consumers' educational level and healthcare affordability proved to have a significant positive influence on their satisfaction (ß=0.307 and 0.191, respectively) whereas occupation and family income showed a significant negative influence (P<0.001). CONCLUSION: The service provided by Alexandria DHEI is highly satisfying to its target audience mainly in terms of providers and accessibility. Enhancing the technical skills of the department staff through training is highly recommended. The department is also recommended to advocate for the credibility of social workers and health visitors as health educators among the community.