Vol. 50, October, 2015

avis cialis 10 ou 20 1/50  MUTAGENESIS AND FERMENTATION-OPTIMIZATION OF ARTHROBACTER SP. FOR IMPROVED GLUCOSE ISOMERASE SYNTHESIS

Sobhy M. Mohsen, Wael A. Bazaraa, Abd El-Naser A. Khattab*, Nagwa M. El-Shimiand Heba S. Mostafa

Food Science Department, Faculty of Agriculture, Cairo University, Giza, Egypt.

*Genetic and Cytology Department, National Research Center, Cairo, Egypt.

Induced mutants having antibiotic resistance markers generated from Arthrobacter sp.  NRRL B-3728 (wild type), after Ultra Violet (UV) and Ethyl Methane Sulfonate (EMS) treatments, were screened for their glucose isomerase (GI) production and compared to the wild type. Seventy eight mutants from each treatment were examined and the mutant EMS 60-25 D exhibited the highest (49.7 U/ml) GI production with 319.9% improvement than the wild type. Fermentation optimization resulted in an additional 10% improvement in enzyme synthesis in medium (pH 8) contained 3% glucose, 2.3% peptone and 0.1% yeast extract at 30°C for 3 days of fermentation. A total of 330.3% improvement in enzyme production was achieved comparing to the wild type. Enhanced glucose conversion ratio (48%) was also noted compared to 35.3% for the wild type.

acheter cialis discrètement 2/50  PROMISCUITY OF SOME NATIVE TREE-LEGUME RHIZOBIA FROM EGYPT

Rabab A.A. Amer, Diaa M. Swelim, Mohamed A. Ali* and Mohamed Fayez*

Agric. Microbiol. Res. Dept., Soils, Water and Environ. Res. Inst., Agric. Res. Center (ARC) Giza, Egypt

*Agric. Microbiol. Dept., Faculty of Agriculture, Cairo University. Giza, Egypt

Two greenhouse experiments were conducted to examine the host range of some rhizobia isolated from cialis en ligne belgique Leucaena leucocephala root nodules. The tree legumes effet du viagra chez la femme Prosopis juliflora, P. alba, Albizzia lebbek, Leucaena leucocephala, Acacia saligna, A. nilotica and effet du viagra sur la femme Cassia surrantensis and the herb legumes ist viagra jetzt billiger Phaseolus vulgaris, Vigna sinensis and durée de viagra Glycine max were inoculated with culture suspension of five nombre generico de la viagra Leuceana rhizobial isolates. The obtained results emphasized the wide spectrum host range of the examined viagra a paris sans ordonnance Leuceana isolates. In another pot experiment the promiscuity of peut on prendre du viagra à 30 ans L. leucocephala was observed for both tree and herb rhizobia, where all the examined tree and herb legumes can form effective nodules except for A. nilotica and Cassia surrantensis. Ineffective nodulation was observed in Phaseolus vulgaris and P. alba. Cross infection of agriculturally important legumes with isolates from wild legumes may improve rhizobial inoculation for increasing nitrogen uptake by these tree legumes.

3/50  PROTOPLAST FUSION FOR ENHANCED GLUCOSE ISOMERASE SYNTHESIS BY ARTHROBACTER SP. HYPER-PRODUCING MUTANTS

Wael A. Bazaraa, Sobhy M. Mohsen, Abd El-Naser A. Khattab*, Nagwa M. El-Shimi and Heba S. Mostafa

Food Science Department, Faculty of Agriculture, Cairo University, Giza, Egypt.

*Genetic and Cytology Department, National Research Center, Cairo, Egypt.

In attempts to construct superior glucose isomerase-producing strain, protoplast fusion technology was successfully applied using hyper-producing glucose isomerase (GI) mutants. According to their antibiotic responses, 4 mutants were selected to perform 6 crosses. Eight fusants were obtained from each cross and their GI activities were determined. The fusant (C 3-2) exhibited the highest GI synthesis (2.75 folds the wild type). For optimal GI synthesis by the fusant C 3-2, medium contained 3% glucose, 1.2% peptone and 0.1% beef extract at 30°C and pH 8 for 3 days was preferred to increase the activity from 42.4 to 60.1 U/ml with 3.85 times the activity of the wild type. The fusant C 3-2 showed very high conversion ratio of glucose to fructose (48.8%) when compared to 35.3% only of the wild type.

4/50  PHYSICOCHEMICAL AND MICROBIOLOGICAL STUDY OF THE RIVER NILE WATER QUALITY AT EL-SHARQAWYA CANAL, EGYPT

Shawky Z. Sabae, Mohamed M.S. Farag*, Amal A. Othman, Adel A. Mousa* and Ehab E. Shahin

National Institute of Oceanography and Fisheries (NIOF), Inland Waters and Aquaculture Branch, El-Qanater Research Station, Egypt.

*Botany and Microbiology Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt

     The aim of the present study was to evaluate the Physicochemical and microbial quality of the River Nile water at El-Sharqawya canal, Egypt. The present study was conducted between spring 2013 and winter 2014. Different environmental and chemical parameters such as temperature, transparency, Hydrogen ion concentration (pH), Biological oxygen demand (BOD), Dissolved oxygen (DO), Electric conductivity (EC), and Total dissolved solids (TDS) were examined. In addition, various bacteriological analyses such as total viable bacterial counts (TVBCs), total coliforms (TC), faecal coliforms (FC), faecal streptococci (FS), E.coli, and estimation of different pathogenic bacteria were also studied. Results showed that the physicochemical parameters values varied from 14.5°C to 31.1°C, 50 cm to 150 cm, 7.69 to 8.17, 1.1 mg/l to 7.4 mg/l, 1.6 mg/l to 9.22 mg/l, 331 μs/cm to 531 μs/cm, and 212 mg/l to 409 mg/l for temperature, transparency, pH, BOD, DO, EC, and TDS, respectively. The bacteriological analysis showed that TVBCs was ranged from 1 x104 to 270 x104 cfu/ml, and from 2.5 x104 to 700 x104 cfu/ml for different temperature at 22°C and 37°C, respectively. However, maximum counts were recorded during autumn and/or summer but the minimal counts were detected in summer at 22°C and 37°C, respectively. The present study showed that the count of indicators were ranged from 2.3x102 to 110 x102/100 ml, 2.1x102 to 46x102/100 ml, 1.5x102 to 46x102/100 ml, and 1.1x102 to 28x102/100 ml for total coliforms, fecal coliforms, fecal streptococci, and E. coli, respectively. Pathogenic microbial isolates recovered from the respective water samples were Staphyllococci sp. (100%), Pseudomonas aureginosa (97.5%), Salmonella sp. (72.5%), Shigella sp. (62.5%), and Candida sp. (100%). Antibiogram analysis of the recovered bacterial isolates showed that most effective antibiotics were imipenem followed by ciprofloxacin, doxycycline, and amikacin. All pathogenic strains were resistant to ampicillin, metronidazole, and  methecillin. In conclusion, our results revealed that the River Nile at El-Sharqawya canal was subjected to sewage pollution during the study period.


5/50  BIOREMEDIATION OF PETROLEUM OIL BY PSEUDOMONAS AERUGINOSA AND PSEUDOMONAS FLUORESCENS (BIOTYPE A)ISOLATED FROM PETROLEUM OIL CONTAMINATED SOIL

Maie A. El-Khawaga, Rawheya A. Salah El-Din, Rahal A. Ghonem*, Lobna A. Moussa* and Elshaymaa E. Mussa*

Botany and Microbiology Dept, Fac. Sci., AL-Azhar Univ., Girls Branch, Cairo, Egypt.

    The petroleum oil biodegradation potential of Pseudomonas aeruginosa and Pseudomonas fluorescens biotype A, which were isolated from petroleum oil contaminated soil was investigated in this study.  Thirty two bacterial isolates were isolated and purified from the oil contaminated soil. The growth of 32 bacterial isolates recorded from 0 to 9.29Log CFU/ml.Two isolates showed highest growth which recorded 9.29 and 9.26 Log CFU/ml respectively and discolored completely a redox indicator dye 2, 6, Dichlorophenol indophenol (2, 6, DCPIP) within 15 hours of incubation were identified by the Biolog technique as Pseudomonas aeruginosa and Pseudomonas fluorescens (biotype  A), respectively. The optimum temperature, pH, agitation speed value and petroleum oil concentration for the two species were 30 ºC, 7, 150 rpm and 1 % respectively. The  two bacteria  species  were  inoculated  into Mineral  Salt Medium (MSM)  supplemented  with 1% crude  oil  and incubated at pH7 and 30 ºC  for 30 days to test the petroleum oil degradation, bacterial counts (Log CFU ml-1), fluorescein diacetate hydrolysis assay (FDA) and pH were determined at different time intervals (0, 5, 10, 20 and 30 days) as an indication for petroleum oil degradation.Generally the degradation rate of petroleum oil was gradually increased with the time of incubation with the two species, hence P. aeruginosaand P. fluorescens degrade 62.46 and 55.53 % of added petroleum oil, respectively, at the end of the experiment period. This study showed that Pseudomonas aeruginosa and Pseudomonas fluorescens biotype Acan be used as the good petroleum hydrocarbons degraders.

6/50  PROMINENCE OF PLANT GROWTH PROMOTERS AND SOME ORGANIC SUBSTANCES TO (CALENDULA OFFICINALIS L.)  PLANT UNDER SALINITY CONDITIONS

Maie M.A. Mohsen, Hassan Ismail*and Heba Sh.  Shehata*

Medicinal & Aromatic Plants, Res. Dept., Hort. Res. Inst., A. R. C., Dokky, Giza, Egypt.

*Agric. Microbiol. Res. Dept., Soil, Warter and Environ. Res. Inst.  A.R.C.,

Giza, Egypt. 

     Two factorial experiments in split plot design were carried out during the successive growing seasons of 2011/ 12 and 2012/13 to investigate effects of  some salt tolerant microorganisms, (Azotobacter chroococcum, Azopirillum lipoferum, Bacillus polymyxa, Bacillus subtilis, Pseudomonas fluorescens and white rot fungus Pleurotus columbines) as well as plant growth promoting  (PGP) alone or with different organic treatments cattle manure (CM)  at 20 m3/fed.,ascorbic acid (ASC)  at 100 ppm and humic acid (HA) at 100ppm as foliar spray and  their interactions under saline  soil conditions on marigold (Calendula officinalis L.), flowering and chemical properties of soil. Significant increases in plant height (cm), number of branches, leaves and inflorescences /plant, leaf area of median leaf of main stem and fresh and dry weights of shoots, roots and inflorescences per plant (g), diameter of inflorescences (cm), chlorophyll (A&B), total carotenoids in leaves and ray flowers,total carbohydrates and N,P,K percentage in leaves were recorded with the treatments CM+ ASC+HA with (PGP) followed by that the treatment CM+HA with (PGPR)  and CM+ASC with (PGP). Nitrogenase and dehydrogenase in soil were enhanced by all tested treatments specially in case of organic matter treatments with PGP which reflected on the quality and quantity of Marigold plats.

7/50  MOLECULAR  DETECTION OF A NOVEL  QUORUM  SENSING  SYSTEM  REGULATING  SOME VIRULENCE  FACTORS  IN  STENOTROPHOMONAS  MALTOPHILIA  CLINICAL  ISOLATES  IN EGYPT.

Hamida  M.  Aboushleib,  Hoda  M.G. Omar,  Rania  Abozahra* and

 Kholoud Baraka*

Pharmaceutical Microbiology Department, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt.

* Microbiology and immunology Department, Faculty of Pharmacy, Damanhour University, Damanhour, Egypt.

       Stenotrophomonas maltophilia  has raised to prominence over the last decade as an important nosocomial pathogen associated with significant case fatality ratios. Quorum sensing (QS) regulates the production of virulence factors such as twitching motility and biofilm formation in S. maltophilia.  The rpf gene was found to regulate this QS system. In this study we aimed to detect this gene and to assess its relation with the presence of the QS- dependent virulence factors.  Twenty two S. maltophilia clinical isolates were collected from different specimens over the years 2012 and 2013. They were identified by biochemical methods then confirmed by vitek 2 system. Their Susceptibility to different antibiotics was tested. Virulence factors including biofilm formation and twitching motility were phenotypically detected. The rpf gene was amplified by PCR using two primer pairs. Twenty (90.9%) out of the 22 tested isolates were found to be rpf positive. Fourteen (70%) of them were positive for both twitching motility and biofilm production and the remaining 6 (30%) rpf  positive isolates were  phenotypically  negative and they didn’t exhibit any of the tested virulence factors. The two rpf negative isolates were found to be positive for both twitching motility and biofilm production. These results emphasize on the role of QS in S. maltophilia virulence. However, QS deficient clinical isolates occur and are still capable of causing clinical infections in humans. Concerning the molecular detection of the QS gene rpf, our second primer pair used gave much more better results than our first primer and the primers used by other researchers. So it is recommended to use it in future studies, as this will reduce time, labour and running cost.


8/50  PHENOTYPIC AND GENOTYPIC EVALUATION OF GATIFLOXACIN RESISTANCE IN STAPHYLOCOCCUS AUREUS AND PSEUDOMONAS AERUGINOSA CLINICAL ISOLATES IN EGYPT

Mervat A. Kassem, Marwa A. Yakout*, Moustafa A. El-Nakeeb and

Nevine L. Seiffein*

Pharmaceutical Microbiology Department, Faculty of Pharmacy, Alexandria University, Alexandria, Egypt

* Department of Microbiology and Immunology, Faculty of Pharmacy and Drug Manufacturing, Pharos Alexandria University, Egypt

    Pseudomonas aeruginosa andStaphylococcus aureus continue to be predominant causes of infection with high resistance to antibiotics. Gatifloxacin (GAT) is a broad-spectrum fluoroquinolones, active against Gram-positive and Gram-negative bacteria. This study aimed to determine the prevalence of GAT resistance among tested isolates and to study the phenotypic and genetic elements related to drug resistance with attempts to reduce it. One hundred and eight clinical isolates were identified biochemically and their antibiotic susceptibility pattern was determined. Mutations in the quinolone resistance determining region (QRDR) genes were investigated as well as the possible involvement of efflux pumps in mediating fluoroquinolones resistance. Moreover, the post antibiotic effect (PAE) and combinations with other compounds were tested to reduce the resistance and dosing regimens of GAT. Resistance to GAT againstP. aeruginosa and S. aureus isolates were found to be 59.2% and 42.5 %, respectively. The PAEofthe P. aeruginosa isolates reached 2 h while that for S. aureus isolates was 1.6 hr. GAT showed synergistic effect when combined with ciprofloxacin and cefoperazone and obvious synergy when combined with benzalkonium chloride. Upon sequencing the QRDR of gyrA, grlA and parC genes some point and silent mutations were detected. GAT has bactericidal activity against S. aureus and P. aeruginosa.Mutations could be rapidly and reliably detected by DNA sequencing. Resistance to GAT in several bacterial species is due to point mutations in the QRDR of the target enzymes rather than other resistance mechanisms. Synergism of GAT with ciprofloxacin and cefoperazone was observed against some strains that were non-susceptible to either antibiotic alone.

 

9/50  BACTERIAL CHITINASE AS A BIOCONTROL AGENT OF PHYTOPATHOGENIC FUNGI

Mohsen A. Sayed and Khaled F.Y. El-Yasergy

Botany and Microbiology Department, Faculty of Science, Cairo University,

Giza, Egypt.

Five bacterial species (Bacillus subtilis, B. megaterium, Enterobacter aerogene, Pseudomonas fluorescens and P. putida) were isolated from the rhizosphere of wilted tomato plants. Bacterial species were assayed for their chitinase activity. Bacillus subtilis recorded the highest chitinolytic activity among isolated bacterial species. The optimum conditions for chitinase activity were 40 °C and pH 7.0. Cations of Mg2+, Ca2+ and Na+ increased the enzyme activity, whereas the activity was markedly inhibited by Pb2+, Hg2+ and Cd2+. The enzyme was partially purified by Dialysis. B. subtilis chitinase could hydrolyze the cell walls of five phytopathogenic fungi (Aspergillus niger, A. flavus, Fusarium oxysporum, Penicillium chrysogenum and P. lanosum) so it can be used as a safe biocontrol agent.

10/50  EMERGENCE OF RESISTANCE TO CARBAPENEMS AMONG ESCHERICHIA COLI CLINICAL ISOLATES: A NEW THREAT TO THE EFFICACY OF LIFE SAVING ANTIBIOTICS IN EGYPT

Nourhan H. Fanaki, Hoda M. Omar and Eva A. Edward

Pharmaceutical Microbiology Department, Faculty of Pharmacy, Alexandria University, Egypt

       The world wide spread of carbapenem-resistant Enterobacteriaceae (CRE) has become a major challenge in health care settings. Infections with CRE result in significant morbidity, mortality, and health-care costs. In this study, ninety-seven Enterobacteriaceae clinical isolates, including 40 E. coli, were collected from different governorates, in Egypt. Of these E. coli isolates, twenty were resistant to meropenem and only two isolates (E38 and E41), were resistant to both carbapenems (imipenem and meropenem). Plasmid mediated carbapenem resistance was investigated by conjugation and curing experiments using menthol as a natural curing agent. Intra and inter-species transfer of plasmids conferring resistance to both carbapenems occured by conjugation between E.coli isolates and also between E. coli and other Enterobacteriaceae isolates. Curing was successful only in case of E38 when triple the published concentration of menthol (0.325 mg/ml) was used. The combinations of carbapenems (imipenem or meropenem) with colistin, rifampicin or amikacin against the two carbapenem resistant E. coli  isolates (E38, E41), were tested separately using the checkerboard assay. The time-kill assay was performed to test the triple combinations of menthol and imipenem or meropenem with one of the three mentioned antibiotics against E38 . It was noticed that such triple combinations were synergistic in case of both amikacin and colistin. The morphological changes of treated bacterial cells by menthol, (512 ug/ml), were studied using transmission electron microscopy (TEM). Polymerase chain reaction (PCR) and phenotypic methods were applied for the differentiation of carbapenemases. PCR was found to be the most reliable technique. The Genes blaNDMand blaVIM, were the most prevalent encoding for carbapenemases among the tested E. coli isolates, E38 and E41.In conclusion, from this study, the triple combination therapy including menthol was the most appropriate for combating carbapenem resistant E. coli, as menthol showed promising antimicrobial and anti-plasmid activity.

11/50  EFFECT OF PLANT DEFENSE ELICITORS ON SOYBEAN (GLYCINE MAX L.) GROWTH, PHOTOSYNTHETIC PIGMENTS, OSMOLYTS AND LIPID COMPONENTS IN RESPONSE TO COTTON WORM (SPODOPTERA LITTORALIS) INFESTATION

Heba I Mohamed, Abdel Haleem M.A. Mohammed and Asmaa M. Mogazy

Faculty of Education, Biological and Geological Sciences Department, Ain Shams University, El Makres St. Roxy, Cairo, Egypt

      The aim of this study was to evaluate the effect of two elicitors' methyl jasmonate (MeJA20µM) and sodium nitroprusside (SNP 500 µM) on six soybean genotypes (Giza21, Giza22, Giza35, Giza82, Giza83 and Giza111) to enhance the ability of susceptible genotypes to resist cotton leaf worm (Spodoptera littoralis).Results showed that Giza82 and Giza22 were susceptible genotypes, Giza 83 and Giza 21 were moderate resistant genotypes and Giza35 and Giza111 were resistant genotypes. Both treatments methyl jasmonate and sodium nitroprusside positively affected the morphological criteria and photosynthetic pigments of all soybean genotypes. Also, Both treatments caused significant increase in the soluble protein, soluble sugars, amino acids, proline, glycolipids and phospholipids content in shoots of all soybean genotypes. On the other hand treatments showed no significant effect on total lipid content in susceptible genotypes. Lipid peroxidation and H2O2 significantly decreased in response to treatments. Generally methyl jasmonate treatment was found to be more effective than sodium nitroprusside and enhanced the resistance of the susceptible genotypes by increased the osmolytes contents. 
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