Ahmed Dewedar

The efficiency of random versus ethno-directed research in the evaluation of Sinai medicinal plants for bioactive compounds

Hexane, ethyl acetate and ethanol extracts of sixty plant species (growing wild in Sinai, Egypt) were screened for antibacterial and antifungal activities against a range of Gram-positive and Gram-negative bacteria, a yeast and dermatophytic fungi. Plants were collected either by random or ethno-directed methods. Plants collected at random (36 species) were gathered from different districts of Sinai, while the ethnobotanical collection (24 species) comprised species used in the folk medicine of the Bedouins in Sinai. Results indicate that plant sampling based on ethnobotanical approach produced greater number of plants showing antimicrobial activity. The results are discussed with respect to the ethnobotanical correlation of active species.

Fate of faecal coliform bacteria in a waste water retention reservoir containing Lemna gibba L.

The comparative survival of total and faecal coliform bacteria was studied in a stable waste-water retention reservoir. The surface of the water reservoir was covered with a macrophyte, Lemna gibba L. Sets of dialysis sacs were suspended in an exposed site to the sun light, while other sets of sacs were suspended beneath the thick green film of L. gibba; where sunlight is almost absent. Total coliform bacteria regrow in sun and in sacs unexposed to sun, while faecal coliform cells exposed to sunlight disappeared with a decay rate 0.1768 h−1. Interestingly, faecal coliform in sacs suspended under the L. gibba green film did not decline during the period of the experiment.

Lack of adverse effect of anti-tumor necrosis factor-α biologics in treatment of rheumatoid arthritis: 5 years follow-up

Rheumatoid arthritis (RA) is a chronic, systemic inflammatory disorder affecting synovial joints and many other organs. Most patients seen in clinical settings have a progressive chronic disease, with radiographic damage, frequent work disability, incremental functional declines and increased mortality rates. The introduction of the biological drugs in treatment of RA has played an important role in prevention of destructive effects of the disease but may have serious adverse effects due to their powerful inhibition of the immune system.

Generic and functional diversity in endophytic actinomycetes from wild Compositae plant species at South Sinai - Egypt.

The diversity of culturable endophytic actinomycetes associated with wild Compositae plants is scantily explored. In this study, one hundred and thirty one endophytic actinobacteria were isolated from ten Compositae plant species collected from South Sinai in Egypt. Microscopic and chemotaxonomic investigation of the isolates indicated fourteen genera. Rare genera, such as Microtetraspora, and Intrasporangium, which have never been previously reported to be endophytic, were identified. Each plant species accommodated between three to eight genera of actinobacteria and unidentified strains were recovered from seven plant species. The generic diversity analysis of endophytic assemblages grouped the plant species into three main clusters, representing high, moderate and low endophytic diversity. The endophytes showed high functional diversity, based on forty four catabolic and plant growth promotion traits; providing some evidence that such traits could represent key criteria for successful residence of endophytes in the endosphere. Stress-tolerance traits were more predictive measure of functional diversity differences between the endophyte assemblages (Shannons index, p = 0.01). The results indicate a potential prominent role of endophytes for their hosts and emphasize the potency of plant endosphere as a habitat for actinobacteria with promising future applications.

COMPARATIVE STUDIES OF MICROBIAL COMMUNITIES ON STONE MONUMENTS IN TEMPERATE AND SEMI-ARID CLIMATES

Climate is recognised to play an important part in influencing the activity of microorganisms on stone in monuments and other objects of cultural value. In the UK and Greece, the numbers and distribution of heterotrophic bacteria were not strongly related to seasonal changes in temperature and rainfall. At Portchester Castle, qualitative changes in bacterial populations have been observed; actinomycetes were found only on decayed stone and dominant on stone from Tell Basta, in semi-arid Egypt. In the Minoan Palace at Petras and the fortifications of Khania, higher counts of halotolerant heterotrophic bacteria were found in sheltered areas on stone showing other biological growths and salt efflorescence. For all monuments, stones of lower mechanical strength supported higher bacterial counts and electron microscopy showed extensive sheets of biofilm. Estimations of carbohydrate in stone could also be related to whether the sites were exposed or protected. There is evidence to suggest that variations in the nature of bacterial populations may be dependent on season in temperate regions and in the Mediterranean climate related to the location within the monument. Biofilm production and perhaps halotolerance provide means by which bacteria resist adverse changes in moisture levels. Extreme fluctuations in moisture may induce major shifts in bacterial populations selecting filamentous, spore-forming types that penetrate deeper into the stone.

The efficacy of an oxidation pond in mineralizing some industrial waste products with special reference to fluorene degradation : A case study

The efficacy of the oxidation pond on the outskirts of the 10th of Ramadan, the main industrial city, in Egypt was examined. Samples of wastewater collected from the inlet and the outlet were screened for some priority pollutants. Acenaphthene and fluorene were the most frequently detected polycyclic aromatic hydrocarbons, while dimethyl phthalate was the most frequently detected phthalate ester. The spectrum of pollutants, their concentrations and frequencies were similar in the inlet and the outlet, indicating an inferior mineralization capability of the pond. Several degradative bacterial strains were isolated from the pond and grown on M56 minimal media supplemented with different pollutants as the carbon source. The efficacy of pure and mixed cultures to break down fluorene, the most frequently detected pollutant was examined. Fluorene degradation was fast in the first 10 days, then followed by a slow phase. Mixed culture had a higher rate of fluorene degradation in comparison to pure cultures. High performance liquid chromatography analysis of fluorene degradation showed three degradative metabolites. But GC/MS analysis detected one compound, identified as acetamide. The present work has indicated the poor efficacy of the pond. Lack of primary treatment of industrial effluent at factory level, coupled with shock loads of toxicants that may damage the microorganisms and their degradative capabilities are presumably main factors behind such inferior performance. Moreover, the type of pollutants discharged into the pond tend to fluctuate and change depending on the rate from the factories discharge and work shifts. Such irregular feeding of persistent pollutants may have led to a wash out of specialized strains of bacteria capable to degrade such persistent pollutants.

The efficacy of gravel bed hydroponic system in the removal of DDT residues from sewage effluent

A high performance liquid chromatography method was employed to monitor DDT and some of its metabolites in sewage effluent which had undergone primary treatment. A gravel bed hydroponic (GBH) system was designed to treat the effluent in order to reuse it in agricultural purposes. The system was made of six channels covered with common reeds (Phragmitis australis). High concentrations of DDT-type residues were detected in the effluent. Results indicated the ability of GBH system to remove more than 80% effluent-borne DDT residues.

Variations in the Bioaccumulation Rates of Heavy Metal by Immobilized and Free Gramnegative and Gram - Positive Bacterial Cells Isolated from an Aerated Lagoon

The uptake of heavy metals by all immobilized microbial cell strains (bacterial beads: bacterial cells in alginate) is better than by free cells. The average removal percentage for all six metals by Gram-positive bacterial beads showed that Bacillus megaterium (81%), Bacillus flexus (73%), Bacillus amyloliquefaciens (70%) and Bacillus cereus (66%). While Immobilized Gram-negative cells of Pseudomonas veronii and Rahnella aquatilis were good for the uptake of metals such as copper, nickel and cobalt. Rahnella aquatilis and Pseudomonas veronii accumulated Cu, Ni and Co by respectively (91.5%, 77 %), (90.1%, 85 %) and (75%, 74%), while Pb was only accumulated by Pseudomonas veronii (67 %). On the other hand, Sphingobacterium daejeonense and Roseomona saquatica were relatively weak in accumulating heavy metals. On the other hand, the uptake of heavy metals by all free microbial cell strains possessed no significant difference by varying metals type and bacterial strains, except Co and Pb were poorly accumulated. Immobilization in alginate beads provides a protective environment for these agents for sufficient time of heavy metals removal. Immobilized systems currently offer various advantages over free systems. Rahnella aquatilis was reported for the first time in this research as a potential organism for the bioaccumulation of some toxic heavy metals from domestic wastewaters.

Asymmetric polyarthritis as an initial presentation of Rosai‐Dorfman disease

Rosai‐Dorfman disease (RDD) is a rare benign reactive lymphoproliferative disorder characterised by a histopathological pattern with sinus histiocytosis and hemophagocytosis. It usually presents with fever, elevated erythrocyte sedimentation rate, cervical lymphadenopathy, other lymph node and extra‐nodal site involvement. We present the case of a 25‐year‐old female patient with polyarthritis mimicking rheumatoid arthritis (RA). When the para‐aortic lymph node was biopsied, it showed extensive histiocytic proliferation; some clusters of plasma cells, lymphocytes and rare multinucleated cells were seen, suggesting a diagnosis of RDD. There is nothing in the literature regarding the polyarthritic presentation of the disease. To the best of our knowledge, our patient is the first case of RDD presenting with a clinical picture mimicking atypical seronegative RA.