54 research outputs found

    Molecular and biochemical diagnosis of Salmonella in wastewater

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    This study aimed to employ biochemical and molecular assays to detect and diagnose Salmonella in wastewater. For this reason, two water samples were collected from Alexandria wastewater treatment plant (S1) and septic tank of a hospital at Alexandria governorate (S2). Selective culture media specific for Salmonella were used to grow and purify a number of isolates from water samples. Direct plate count revealed a high frequency of Salmonella cells in sample S2 than S1. As a confirmatory, species-specific PCR assay was performed for 17 randomly selected bacterial isolates from both water samples. Positive-PCR Salmonella isolates (5 from S1 and 4 from S2) were subjected for identification using API 20E biochemical identification kit. Among various examined antibiotics, rifamycine was the most effective antimicrobial agent on Salmonella isolates. Subsequently, PCR-RFLP of 16S and 23S rDNA genes, Rep-PCR fingerprinting and plasmid profile were employed to recognize among isolates. Out of nine examined restriction endonucleases, HinfI, HincII and HaeIII were the most discriminative enzymes which allowed clear differentiation among isolates, while PCR-RFLP of 23S rDNA was most discriminative than 16S rDNA. Higher levels of polymorphism and specificity were achieved by reproducible genomic fingerprints of Rep-PCR. However, poor discrimination results were achieved by employing plasmid profile assay. @ JASE

    DIVERSITY OF BACILLUS GENOTYPES IN SOIL SAMPLES FROM EL-OMAYED BIOSPHERE RESERVE IN EGYPT

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    Sequencing of the 16S rDNA hypervariant region was applied to determine the presence and composition of Bacillus species in 40 soil samples randomly collected from different habitats in El-Omayed biosphere reserve, Egypt. Although purified cultures showed 18 different phenotypes that were morphologically distinct on a sporulation medium plate, only 4 different nucleotide sequences designated Seq A, B, C and D were revealed. Computational analysis of DNA sequence data suggested that 17 of these isolates are closely related members of the Bacillus cereus/thuringiensis group (Seq B, C and D) and one isolate is belonging to the Bacillus subtilis group (Seq A). Further phenotypic investigations confirmed the diversity of the 17 novel Bacillus cereus/thuringiensis isolates and indicated that the new Bacillus subtilis group isolate is a Bacillus amyloliquefaciens strain. A simple phenotypic discrimination key that can be applied for distinguishing between such closely related Bacillus cereus/thuringiensis members is presented

    Experimental analysis and mathematical prediction of Cd(II) removal by biosorption using support vector machines and genetic algorithms

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    We investigated the bioremoval of Cd(II) in batch mode, using dead and living biomass of Trichoderma viride. Kinetic studies revealed three distinct stages of the biosorption process. The pseudo-second order model and the Langmuir model described well the kinetics and equilibrium of the biosorption process, with a determination coefficient, R2 > 0.99. The value of the mean free energy of adsorption, E, is less than 16 kJ/mol at 25°C, suggesting that, at low temperature, the dominant process involved in Cd(II) biosorption by dead T. viride is the chemical ion-exchange. With the temperature increasing to 4050°C, E values are above 16 kJ/mol, showing that the particle diffusion mechanism could play an important role in Cd(II) biosorption. The studies on T. viride growth in Cd(II) solutions and its bioaccumulation performance showed that the living biomass was able to bioaccumulate 100% Cd(II) from a 50 mg/L solution at pH 6.0. The influence of pH, biomass dosage, metal concentration, contact time and temperature on the bioremoval efficiency was evaluated to further assess the biosorption capability of the dead biosorbent. These complex influences were correlated by means of a modeling procedure consisting in data driven approach in which the principles of artificial intelligence were applied with the help of support vector machines (SVM), combined with genetic algorithms (GA). According to our data, the optimal working conditions for the removal of 98.91% Cd(II) by T. viride were found for an aqueous solution containing 26.11 mg/L Cd(II) as follows: pH 6.0, contact time of 3833 min, 8 g/L biosorbent, temperature 46.5°C. The complete characterization of bioremoval parameters indicates that T. viride is an excellent material to treat wastewater containing low concentrations of metal

    Performance of Green Roof Integrated Solar Photovoltaics in Toronto

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    Green (vegetated) roofs and solar photovoltaics are among a range of solutions intended to meet environmental sustainability targets and transition to low-carbon communities. In urban environments, they are means to integrate onsite stormwater management and renewable energy. Research shows that the evaporative cooling from green roofs helps to keep photovoltaics near best operational temperature, while proving that vegetation can survive under variable shade and precipitation conditions. This study evaluated photovoltaic surface temperature and power output at two heights (2 and 4 ft.) from two high-performance roof surface types, green and high-albedo (white) roof membrane, at the University of Toronto’s GRIT Lab. Photovoltaic surface temperature and power output showed dependence on height and surface type. Higher separation (4 ft.) allowed for increased biomass, improved cooling effects, and an increase in power output. This short-term study showed a successful integration of both technologies, and hence a viable option for green building practices. الأسطح الخضراء (النباتية) والضوئية الشمسية هي من بين مجموعة من الحلول التي تهدف إلى تحقيق أهداف الاستدامة البيئية والانتقال إلى المجتمعات منخفضة الكربون. في البيئات الحضرية، هي وسيلة لدمج إدارة مياه الأمطار وتوليد الطاقة المتجددة في الموقع. تبين البحوث أن التبريد التبخيري من الأسطح الخضراء يساعد على إبقاء الخلايا الكهروضوئية بالقرب من أفضل درجة حرارة تشغيلية، مع إثبات أن الغطاء النباتي يمكن أن يبقى على قيد الحياة تحت ظلال وأمطار متغيرة. قيمت هذه الدراسة درجة حرارة الاسطح الكهروضوئية وإنتاج الطاقة على ارتفاعين (2 و 4 قدم) من نوعين من الاسطح، السطح الأخضر و السطح الغشائى عالي الإنعكاس (الأبيض) في مختبر جريت بجامعة تورونتو. أظهرت درجة حرارة الاسطح وإنتاج الطاقة الاعتماد على الارتفاع ونوع السطح. يسمح الفصل ألاعلى (4 قدم) بين الوحدات الضوئية والسطح النباتي بزيادة الكتلة الحيوية، وتحسين آثار التبريد، وزيادة في انتاج الطاقة. وأظهرت هذه الدراسة قصيرة الأجل اندماجا ناجحا بين الخلايا الكهروضوئية الشمسية وأنظمة الأسطح الخضراء، وبالتالي خيارا صالحا لممارسات البناء الأخضر.M.A.S

    Molecular and biochemical diagnosis of Salmonella in wastewater

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    This study aimed to employ biochemical and molecular assays to detect and diagnose Salmonella in wastewater. For this reason, two water samples were collected from Alexandria wastewater treatment plant (S1) and septic tank of a hospital at Alexandria governorate (S2). Selective culture media specific for Salmonella were used to grow and purify a number of isolates from water samples. Direct plate count revealed a high frequency of Salmonella cells in sample S2 than S1. As a confirmatory, species-specific PCR assay was performed for 17 randomly selected bacterial isolates from both water samples. Positive-PCR Salmonella isolates (5 from S1 and 4 from S2) were subjected for identification using API 20E biochemical identification kit. Among various examined antibiotics, rifamycine was the most effective antimicrobial agent on Salmonella isolates. Subsequently, PCR-RFLP of 16S and 23S rDNA genes, Rep-PCR fingerprinting and plasmid profile were employed to recognize among isolates. Out of nine examined restriction endonucleases, HinfI, HincII and HaeIII were the most discriminative enzymes which allowed clear differentiation among isolates, while PCR-RFLP of 23S rDNA was most discriminative than 16S rDNA. Higher levels of polymorphism and specificity were achieved by reproducible genomic fingerprints of Rep-PCR. However, poor discrimination results were achieved by employing plasmid profile assay. @ JASE

    A De Novo Optimized Cell-Free System for the Expression of Soluble and Active Human Tumor Necrosis Factor-Alpha

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    Cell-free (in vitro) expression is a robust alternative platform to the cell-based (in vivo) system for recombinant protein production. Tumor necrosis factor-alpha (TNF-α) is an effective pro-inflammatory cytokine with pleiotropic effects. The aim of the current study was de novo optimized expression of soluble and active human TNF-α by an in vitro method in an E. coli-based cell-free protein synthesis (CFPS) system and its biological activity evaluation. The codon-optimized synthetic human TNF-α gene was constructed by a two-step PCR, cloned into pET101/D-TOPO vector and then expressed by the E. coli CFPS system. Cell-free expression of the soluble protein was optimized using a response surface methodology (RSM). The anticancer activity of purified human TNF-α was assessed against three human cancer cell lines: Caco-2, HepG-2 and MCF-7. Data from RSM revealed that the lowest value (7.2 µg/mL) of cell-free production of recombinant human TNF-α (rhTNF-α) was obtained at a certain incubation time (6 h) and incubation temperature (20 °C), while the highest value (350 µg/mL) was recorded at 4 h and 35 °C. This rhTNF-α showed a significant anticancer potency. Our findings suggest a cell-free expression system as an alternative platform for producing soluble and functionally active recombinant TNF-α for further research and clinical trials

    Whole spectrum of Aeromonas hydrophila virulence determinants and the identification of novel SNPs using comparative pathogenomics

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    Abstract Aeromonas hydrophila is a ubiquitous fish pathogen and an opportunistic human pathogen. It is mostly found in aquatic habitats, but it has also been isolated from food and bottled mineral waters. It causes hemorrhagic septicemia, ulcerative disease, and motile Aeromonas septicemia (MAS) in fish and other aquatic animals. Moreover, it might cause gastroenteritis, wound infections, and septicemia in humans. Different variables influence A. hydrophila virulence, including the virulence genes expressed, host susceptibility, and environmental stresses. The identification of virulence factors for a bacterial pathogen will help in the development of preventive and control measures. 95 Aeromonas spp. genomes were examined in the current study, and 53 strains were determined to be valid A. hydrophila. These genomes were examined for pan- and core-genomes using a comparative genomics technique. A. hydrophila has an open pan-genome with 18,306 total genes and 1620 genes in its core-genome. In the pan-genome, 312 virulence genes have been detected. The effector delivery system category had the largest number of virulence genes (87), followed by immunological modulation and motility genes (69 and 46, respectively). This provides new insight into the pathogenicity of A. hydrophila. In the pan-genome, a few distinctive single-nucleotide polymorphisms (SNPs) have been identified in four genes, namely: d-glycero-beta-d-manno-heptose-1,7-bisphosphate 7-phosphatase, chemoreceptor glutamine deamidase, Spermidine N (1)-acetyltransferase, and maleylpyruvate isomerase, which are present in all A. hydrophila genomes, which make them molecular marker candidates for precise identification of A. hydrophila. Therefore, for precise diagnostic and discrimination results, we suggest these genes be considered when designing primers and probes for sequencing, multiplex-PCR, or real-time PCR

    Diversity of Bacillus genotypes in soil samples from El-Omayed Biosphere Reserve in Egypt

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    Sequencing of the 16S rDNA hypervariant region was applied to determine the presence and composition of Bacillus species in 40 soil samples randomly collected from different habitats in El-Omayed biosphere reserve, Egypt. Although purified cultures showed 18 different phenotypes that were morphologically distinct on a sporulation medium plate, only 4 different nucleotide sequences designated Seq A, B, C and D were revealed. Computational analysis of DNA sequence data suggested that 17 of these isolates are closely related members of the Bacillus cereus/thuringiensis group (Seq B, C and D) and one isolate is belonging to the Bacillus subtilis group (Seq A). Further phenotypic investigations confirmed the diversity of the 17 novel Bacillus cereus/thuringiensis isolates and indicated that the new Bacillus subtilis group isolate is a Bacillus amyloliquefaciens strain. A simple phenotypic discrimination key that can be applied for distinguishing between such closely related Bacillus cereus/thuringiensis members is presented

    The role of biofeedback in the rehabilitation of veno-occlusive erectile dysfunction

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    Background Pelviperineal muscles play a role in erection through the enhancement of blood flow to the penis. Hence, the reinforcement of the power of such muscles through noninvasive visual pressure biofeedback rehabilitation may be helpful in erectile function improvement. Aim The aim of this study was to assess the value of pelviperineal muscles′ visual pressure biofeedback rehabilitation in the treatment of organic veno-occlusive erectile dysfunction (ED). Materials and methods This study included 30 patients with veno-occlusive ED. Exclusion criteria were neurological, psychological, endocrinal, and arterial insufficiency ED. Also, patients with malignancies, chronic renal failure, liver cell failure, urological congenital abnormalities, pelvic surgery, pelvic radiation, or trauma and patients on medications known to cause ED were excluded. All patients performed visual pressure biofeedback strengthening of the pelviperineal muscles three times weekly for 3 months. In addition to clinical and laboratory evaluations, patients were assessed by a self-administered questionnaire, a neurophysiological examination, a pharmacopenile duplex ultrasound, and the anal hold pressure. Results According to the self-administered questionnaire, 16/30 patients (53.3%) showed either partial or complete improvement (11 and five patients, respectively). On comparing prerehabilitation and postrehabilitation Results of the pharmacopenile duplex ultrasound, 18/30 patients (60%) showed either partial or complete improvement (13 and five patients, respectively). The anal hold pressure improved from 120.7 to 189.9 after biofeedback rehabilitation. Conclusion Pelviperineal muscles′ visual pressure biofeedback rehabilitation is effective, inexpensive, noninvasive, safe, and easily applicable in the treatment of venogenic ED and does not have as much side effects as medication
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