Vol. 12, September, 2005

vertus du viagra 1/12 EXPLORING OF BIOLOGICAL CONTROL OF FUSARIUM WILT DISEASE

A.A. El-Fallal*, F.A. Mansour**, M.M. Namet Alla* and M.M. Mousa*

*Botany Department, Faculty of Science, Mansoura University NewDamietta.

** Botany Department, Faculty of Science, Mansoura University

The present study is planned to evaluate the efficiency of potential antagonistic rhizospheric microorganisms as biocontrol agents of cialis comparatif prix Fusarium wilt disease of tomato. The study began by isolating and purifying the pathogenic kamagra sur marseille Fusarium from infected tomato of different areas of Damietta province.   The pathogenicity test confirmed the responsibility of cialis echec F. oxysporum f. sp. lycopersici for wilt of tomato and the isolate F2 was the most aggressive one. The selected   three most activeisolates against augmenter leffet du cialis F. oxysporum f. sp. levitra foie lycopersici were T23 ( le nouveau viagra Trichoderma harzainum), B3 ( viagra et htap Bacillus subtilis) and A7( cialis aus litauen Streptomyces griseoviridis). Increasing the concentration of the three antagonisticfiltrates of either decreased the percentage of spores germination and average germ tube length of the pathogen.Possibility of employing the antagonistic isolates T23, B3 and A7 for control sucedaneo natural de la viagra Fusarium wilt of tomato were evaluated by using seed bed and seedling and soil treatment. Tomato seed-bed and seedlings or soil treated with the three microorganisms reduced the disease incidence and increased plant growth parameters. In addition, T23 grown on corn/sand   mixture was more effective in reducing disease incidence than using spore suspension and also, using cell culture of A7 and B3 were more effective than cell suspension. The changes in some physiological and metabolic activities in tomato plants were also evaluated. Infection of tomato plants with F. oxysporum f. sp. lycopersici significantly decreased chlorophyll a, b, carotenoids and potassium and increase total phenolic contents, total free amino acids content, protein content,sodium, calcium and phosphorusand some oxidative and hydrolytic enzymes. However, treatment with the bio agents T23, A7 and B3 to the infected plants mostly counter balanced   these decreases and increases of tomato plants.

 

 

2/12 CHEMICAL CONTROL OF SOME EDIBLE MUSHROOM PATHOGENIC BACTERIA

M.E.A. Dawoud, M.M. Eweis and M.A. Rizk

Department of Botany, Faculty of Science, Cairo University

Different concentrations (0.0 – 104 mM) of Li+, Cr6+, Mn2+, Cu2+, Co2+, Zn2+, Sr2+, Mo2+, La2+ and Ba2+ were used to study their effects on the growth of edible mushroom (Agaricus bisporus X25) and it’s pathogenic bacteria (Pseudomonas flourescens and Pseudomonas talaasii). The results showed that, different concentrations decreased the growth of microorganisms (represented in dry weight and linear growth). The tolerance of the organisms to different heavy metals was in the following order: Agaricus bisporus, Zn2+>Cr6+>Mo2+>Li+>Mn2+>Ba2+> Co2+=Sr2+>La2+>Cu2+, Pseudomonas flourescens, Ba2+>Zn2+>La2+>Co2+> Mn2+>Mo2+>Li+>Sr2+>Cr6+>Cu2+, Pseudomonas tolaasii, Mn2+>Zn2+> Mo2+>Li+>Sr2+>La2+>Ba2+>Co2+>Cr6+>Cu2+. The different concentrations of the chosen Cr6+ (that inhibited the pathogens and favoured the growth of mushroom) decreased the mycoproteins, carbohydrates and increased lipid, mineral Cr6+ and consequently energy contents in the mushroom mycelium, Cr6+ accumulation in mushroom tissue was insignificantly different under different Cr6+ concentrations, in the medium, indicating that the tolerance of mushroom to Cr6+ depends upon an exclusion mechanism rather than reduction of chromium Cr6+ to Cr4+. It was concluded that Cr6+ could be added to the mushroom substrate to suppress the growth of pathogenic bacteria especially when its content does not exceed the maximum permiscible dose.

 

3/12 TRANSFORMATIOM OF BURKHOLDERIA CEPACIA PLASMIDS ENCODING DEGRADATION OF POLYHYDROXYALKANOATE

N.E. Yousef

Department of Microbiology, Faculty of Pharmacy, Zagazig University

Out of fourteen strains of Burkholderia cepacia isolated from the environment and characterized phenotypically by biochemical reactions and genotypically by DNA fingerprinting using gel electrophoresis, ten Burkholderia cepacia strains were capable of degrading the Polyhydroxyalkanoate polymer (PHA) and hence clearing the opacity of the polymer containing solid medium. PHA degrading strains produced extra-cellular depolymerase and lipase enzymes and had plasmid of 20 Kb encoded PHA degradation. PHA depolymerases were purified by DEAE anion exchange chromatography after precipitation from the crude enzymes preparations by ammonium sulfate. The molecular weights of the depolymerase enzymes were determined by gel permeation SDS polyacrylamide gel electrophoresis to be about 55-66 K Da.   Burkholderia cepacia plasmids were transferred to plasmid negative E. coli strains that showed neither polyhydroxyalkanoate degradation nor depolymerase and lipase activities. The transconjugant E. coli strains showed plasmids of 20 Kb, depolymerase, lipase activities and degradation of Polyhydroxyalkanoate.

 
4/12 HISTOPATHOLOGICAL AND ULTASTRUCTURAL CHANGES INDUCED BY HOLMES’ RIBGRASS (HRG) STRAIN OF TOBACCO MOSAIC VIRUS (TMV) IN TOMATO AND TOBACCO LEAF TISSUES
M.M. El-Shamy
Botany Department, Faculty of Science, Menoufia University, Egypt
Tomato and tobacco leaves infected with HRG strain (as a temperature sensitive strain of TMV) showed mosaic mottling, blistering, severe distortion and abnormalities. Light and electron microscopic examination of infected leaves revealed the undulation and wrinkling of the upper and lower epidermis of tomato leaves. The upper epidermis contained multicellular glandular hairs with multicellular head. Reduction in the number of stomata specially in the lower epidermis were observed. Generally, the mesophyll is not clearly differentiated into palisade and spongy tissues. In some parts of the blade, the mesophyll composed of loosely palisade and spongy tissues with wide intercellular spaces. In other parts, palisade cells were compact, short and appear rich in chloroplasts. There was an increase in the number and size of chloroplasts. Parenchyma cells in the upper midrib protrusion showed more crystals. Phloem and xylem elements were reduced in number and were arranged irregularly. The lignification of xylem vessels was increased. Xylem parenchyma, phloem parenchyma and the surrounding cells appear deformed. Xylem vessels and sometimes the surrounding cells degenerated. Tobacco infected leaves showed the accumulation of different shapes and types of inclusions in the cytoplasm of both palisade and spongy cells in the form of short rod-shaped virus particles, prismatic and massive aggregate of long rods, X-bodies or X-material and P-protein in the form of bands or groups. The virus particles were usually surrounded by endoplasmic reticulum. Chloroplast alterations in the form of membrane disappearance, fewer grana, abnormal starch grains and the increase in the number of osmiophilic globules. Most of the chloroplasts show strange haphazard scattering of thylakoid system and maceration of grana and intergrana lamellae. Cell wall thickening were frequently observed. Mitochondrial alterations in the form of mitochondrial disruption, lacking or absence of cristae, swelling and malformed mitochondria. The number of microbodies was increased due to virus infection.

5/12 BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS BY INDIGENOUS MICROBIAL COMMUNITIES OF SOIL AND WATER

M. Swelam(1), M.A. Abo-State(2), N.H. Aziz(2), N.M. Aly(1) and O.A.A. Khalil(2).

(1) Faculty of Science, Zagazig University (Banha). (2) National Center Radiation Research and Technology, Nasr City, Cairo.

Eight soil and water samples from Saft El Laban, El-Giza governorate, Egypt were used to investigate the ability of their indigenous microbial communities to degrade chlorobenzene, 1,2-dichlorobenzene, 1,4-dichlorobenzene, 2-chloroaniline, 4-chloroaniline, 4-chlorophenol and 2,6-dichlorophenol indolphenol sodium salt. Indigenous microbial communities of soil samples were superior in growing on chloroaromatic compounds than that of water samples communities. Indigenous microbial communities were capable of growing on 1,3 and 5mM of 1,4-dichlorobenzene or 4-chloroaniline as a best sole carbon and energy source. They also capable of growing on the other chloroaromatic compounds but at a less rate.

 

6/12 MecA GENE CARRIAGE AMONG OXACILLIN-RESISTANT COAGULASE-NEGATIVE STAPHYLOCOCCI ISOLATED FROM CANCER PATIENTS- ALTERNATIVES TO VANCOMYCIN THERAPY

S.A. Zaki, S.M. El-Maghraby*, M.E. Omran and M.A.I. Nasr*

Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University and Department of Clinical Pathology-National Cancer Institute,

Cairo University*.

Coagulase-negative staphylococci (CoNS) is responsible for an increasing number of serious nosocomial and community-acquired infections. The aim of the present study is to compare the MicroScan WalkAway system (Dade MicroScan Inc., West Sacramento, California) and the disk diffusion method with PCR detection for the mecA gene used as the "gold standard" assay and to determine alternatives for treatment by vancomycin in infections caused by oxacillin-resistant coagulase-negative staphylococci. Forty-five CoNS isolates were included in this study. Among them, 40 isolates were mecA-positive by PCR. All of them were oxacillin-resistant by both MicroScan WalkAway and disk diffusion method. The two phenotypic methods used showed 88.89% agreement with the PCR detection of mecA. As for antibiotic sensitivity among oxacillin-resistant CoNS, amoxycillin/sulbactam and, amoxycillin/ clavulanic acid showed the highest percentage of resistance (84.44% and 80% respectively). Vancomycin showed 11.11% resistance while linezolid, gatifloxacin and moxifloxacin showed 100% sensitivity. Our results demonstrated that both the MicroScan WalkAway system and the disk diffusion method are technically simple and can be cheaper and easier to perform in routine laboratories than PCR. The use of linezolid, gatifloxacin or moxifloxacin is highly desirable to reduce the overuse of vancomycin for treatment of oxacillin-resistant CoNS infections.  

 

 

7/15 SURFACE EXPOSURE OF GEOBACTER SULFURREDUCENS OUTER MEMBRANE PROTEINS, OmpB, OmpJ AND THEIR RELATIVE IMPACT TO THE ELECTRON TRANSFER TO THE EXTRACELLULAR INSOLUBLE Fe (III)-OXIDES

E. Afkar

Department of Botany, Faculty of Science, Cairo University, Beni-Suef Campus,

OmpB (Outer membrane protein B) and OmpJ (Outer membrane protein J) are two outer membrane proteins that have been identified in the genome of Geobacter sulfurreducens with an open reading frames (ORF02382/GSU1394 and ORF05510/GSU33040) respectively, and have significant role in the electron transfer mechanism to the extracellular Fe (III) and Mn (V) oxides. Site-directed mutagenesis for OmpB and OmpJ resulted in phenotypes, which were unable to grow on the insoluble Fe (III) and Mn (V) oxides. Consequently, the cell surface exposure of OmpB and OmpJ was of interest to study the topology of these two outer membrane proteins. Three different proteolytic agents were used; Pronase, and Trypsin and Proteinase K (pK).   Neither Pronase nor Trypsin was able to degrade OmpB or OmpJ in the intact cells of G. sulfurreducens. Whereas, proteinase K was able to digest the OmpB in intact cells, disrupted cells as well as in the outer membrane fractions at concentrations of 40 U/ml and 10 U/ml respectively. However, Proteinase K was able to partially digest OmpJ in the sonic disrupted cells and completely digest OmpJ in the outer membrane fraction at high concentration 40 U/ml. Therefore, it is concluded that although OmpB and OmpJ are localized into the outer membrane of Geobacter sulfurreducens; OmpB seems to be more exposed to the cell surface than the OmpJ, which is likely to be anchored into the outer membrane.

 

 

8/12 MRSA (METHICILLIN-RESISTANT S. AUREUS) AMONG ADDICTS

A.A. El Sharif

Department of Microbiology & Immunology, Faculty of Pharmacy,

Al-Azhar University, Cairo, Egypt.

Over the last 3 decades, methicillin-resistant Staphylococcus aureus (MRSA) have emerged as significant pathogens in community acquired and nosocomial infections. However Staphylococcus aureus is an organism that is frequently found on human carriage sites, it's capable of producing many potential virulence factors. There is a considerable spectrum of diseases caused by this bacterium. In Staphylococcus aureus, mec A and fem A are the genetic determinants of methicillin resistance. This study was carried out on sixty addicts to detect the rate of MRSA carriage among them and the consequences of it. MRSA isolates were identified from sixty addicts. Identification was carried out by using a multiplex PCR strategy for mec A and fem A genes. The rate of MRSA carriage and factors increasing the infection were studied. The results of PCR study demonstrated that mec A and femA genes were found in 100% of identified MRSA. It was noticed that nasopharyngeal carriage rate of MRSA among addicts are higher than that among non addicts population.

 

9/12 Purification and Characterization of an Extracellular b-Mannosidase from

Sclerotium rolfsii Sacc.

M. Eweis1 and M.E.A. Dawoud2

Botany Department, Faculty of Science, Cairo University, Giza, Egypt

An extracellular -mannosidase (EC.3.2.1.25) was purified 123.22 fold from the culture filtrate of Sclerotium rolfsii Sacc. by dialysis, precipitation with 0.7 saturation ammonium sulfate, gel filtration through Sephadex G-75 and ion-exchange chromatography on diethylaminoethyl cellulose with a yield of 57.79% and specific activity of 32.903 units. mg-1 protein. The purified enzyme exhibited maximal activity at pH 4.5 and 30oC, and was stable in the pH range of 3.5 to 5.0 and at temperature up to 30oC. Km of the enzyme was calculated to be 3.8 mg.ml-1. The molecular weight was determined by SDS-polyacrylamide gel electrophoresis to be 51 kDa. Participation of SH-groups in the catalytic sites of the enzyme is confirmed. Quantitative estimation of amino acids in the purified proteins obtained from the culture of S.rolfsii revealed that, contained 17 amino acids and the proteins were rich with the aromatic amino acids; phenylalanine and tyrosine (41.6% of the total amino acids), acidic amino acids, aspartic and glutamic (31.02% of the total amino acids). However, glycine comprised an abstemious proportion (2.2% of the total amino acids).

 

 

10/12 PRODUCTION, OPTIMIZATION, PURIFICATION, CHARACTERIZATION, COMPATIBILITY AND STABILITY OF EXTRACELLULAR LIPASE OF ASPERGILLUS FLAVUS

S.A. El-Aasar

Botany Department, Faculty of Science, Zagazig University, Egypt.

Aspergillus flavus isolate was selected from a screening program for extracellular lipase production out of seven species of genus Aspergillus isolated from milled olive seeds. The optimization of lipase production revealed a maximum production of 86.40 u/ml in an optimized medium containing 0.5%(w/v) corn oil as a lipidic carbon source, 0.4% (w/v) ammonium phosphate as a nitrogen source and in the presence of 0.1% (w/v) potassium phosphate, 0.5%(w/v) magnesium sulphate, 0.5% (w/v) calcium chloride and 30 ppm salicylic acid in the production broth medium adjusted at pH 6.5 and incubated at 32.5oC for 120 h. The lipases of A. flavus were extracted and partially purified by 70% ammonium sulphate, so increased the specific enzyme activity by 1.81 fold. Further purification by gel filtration using Sephadex G50 increased the specific enzyme activity by 4.85 fold. Maximum lipase activity was obtained by one ml purified enzyme using 0.8% (w/v) corn oil adjusted at pH of 7.5 and incubated for 120 min at 35oC. The concentrated crude enzyme showed a high level of stability where it retained about 88% of its activity in the presence of chlorine at 50oC. Moreover, compatibility and stability of the enzyme subjected to various commercial detergents and chlorine as an oxidizing agent were studied.

 


11/12 ISOLATION AND IDENTIFICATION OF YERSINIA SPECIES FROM WATER AND FISHES OF MANZALA LAKE, EGYPT

A. Ismail1, M. Abu doubara2 , F.A. Mansour2 and M. Zaki1

1Biology Department, faculty of Education,   Suez Canal University, Egypt.

2Botany Department, faculty of Science, Monsoura University, Egypt.

Water samples were collected from 4 sites while fish samples were collected from 2 sites of Manzala Lake. The sities represented high impact of human and animals activity of the lake. Yersinia spp were counted on the Yersinia selective agar plates which reached the highest counts in water samples from El Mataryia area (3.4x 103 c.f.u / ml) and (9x 103 c.f.u / g) in the intestine of fishes. 50 isolates were identified using the recommended API 20 E system. Results revealed that 46% of total isolates were recorded to belong to the species: Y. Enterocolitica (20%), Y. Pseudotuberculosis (12%), Y. entermedia (12%) and Y. Kristensenii (2%).

 

 

12/12 POLYPHASIC TAXONOMY OF SOME STREPTOMYCETES ISOLATED FROM SAND DUNE SAMPLES IN BORG EL-ARAB

W.N. Hozzein

Botany Department, Faculty of Science, Beni-Suef, Egypt

In a screening program to discover new soil microorganisms for the production of novel bioactive compounds, three actinomycete strains were isolated from sand dunes’ samples collected from Borg El-Arab, Egypt. The taxonomic position of those isolates was established using a polyphasic approach. The strains, designated S134T, S155T and S181T were found to have morphological and chemical properties typical of genus Streptomyces. At maturity, the aerial mycelia differentiated into long spore chains with smooth surface. They contain LL-diaminopimelic acid, no diagnostic sugars, type PII phospholipids, and MK-9(H6), MK-9(H2) and MK-9(H8) as the predominant menaquinones. Characters consistent with their assignment to the genus Streptomyces. The 16S rDNA sequence analysis not only supported the classification of the three isolates in the genus Streptomyces but also showed that S155T and S181T formed a separate clade in the Streptomyces 16S rDNA tree. It is evident from both the phylogenetic and phenotypic data that the three isolates should be formally recognized as novel species of the genus Streptomyces.

 

 

13/12 UTILIZATION OF SIMPLESSE – TYPE ®100 AS A FAT REPLACER IN THE MANUFACTURE OF LOW FAT FETA CHEESE

M.M. Ashour, H.H. Arafat*, M.M. Nasr* and A.H. Gerguis

Food Science Dept., Faculty of Agric., Zagazig Univ.

*Animal Production Institute Agricultural Research Center, Dokki, Cairo

Low fat Feta cheese was manufactured from buffaloe's milk retentate and using replacer simplesse ®100 at level af 0.2%. The addition of simplesse ®100 enhanced the quality of cheese when compared with control. The chemical composition of cheese was not affected by the addition of simplesse ®100. The Microbiological quality was affected in a better way. With respect to the rheological quality as elasticity and apparent viscosity was better in compare with control. In connection to microstructure the cheese showed a close compact protein matrix, all of the above mentioned results were observed while the cheese was fresh but after storing the cheese for 25 days, the chemical and microbiological composition were changed, and the rheological and microstructure of cheese became better. The obtained results revealed that using of 0.2% simplesse ®100 produced a better low fat Feta cheese with good properties.

 

14/12 BIODEGRADATION OF CERTAIN HERBICIDES BY ARTHROBACTER AND THE USE OF THIS ISOLATE IN BIOREMEDIATION OF CONTAMINATED SOIL

E.H. Ashour, S.M.M. Bayoumy, M.A. El-Sawah and S.A. Shady

Microbiol. Dept., Faculty of Agriculture, Mansoura University, Mansoura, Egypt.

Twenty five bacterial isolates were obtained from soil heavily polluted with pesticides. Capability of these isolates to grow on nutrient medium containing selected herbicides, i.e., pendimethalin, thiobencarb and bromoxynil, were tested. The most efficient isolate was identified as Arthrobacter. Following bacterial growth of Arthrobacter in nutrient broth supplemented with different concentrations of tested herbicides, bromoxynil herbicide showed dramatic effect and more toxicity towards the growth of Arthrobacter cells, while, it was tolerant to pendimethalinherbicide. Moreover, the response of Arthrobacter towards the three herbicides in free-carbon mineral salts medium was highly significantly varied, where pendimethalin was the most degradable one. The effects of pendimethalin herbicide on both forms of Arthrobacter inocula (free form and encapsulated alginate beads) in broth medium and soil were investigated. Results indicated that immobilized-cells were more effective and highly significant than free-cells. In addition, microcosms were applied to follow the potential application of Arthrobacter in soil as microbial cleansing for the environment. It was found that immobilized-cell numbers were significantly greater in soil were comparing with free-cells inoculum. The residues of pendimethalin in soil were extracted and determined by GLC. Releasing Arthrobacter into the soil resulted in pronounced reduction of pendimethalin amount in soil, where remaining amounts were 18.39% only and mostly disappeared after 3 and 6 weeks, respectively. It can be concluded that the introduction of bio-preparations were capable to actively colonize in soil and remove the herbicides contamination from the environment in situ. Moreover, alginate encapsulation may provide an effective method of microbial inoculation to allow extent survival of introduced bacteria in soil.

 

 

15/12 Decolourization of textile dye wastewater by actinomycetes

S.A. El-Shatoury, H.M. Abdulla and A. Dewedar

Botany Department, Faculty of Science, Suez Canal University, Ismailia, Egypt

Seventy-seven actinomycete isolates, recovered from industrial sludge, were able to grow on textile effluent as a sole carbon source in minimal medium and to decolourize 5 triphenylmethane and 6 azo dyes with different extents on agar plates. These belonged to seven genera: Nocardioides, Streptomyces, Micromonospora, Nocardiopsis, Pseudonocardia, Actinomadura and Planobispora. In batch culture experiment, a Nocardioides fulvus strain removed 90% of colour from raw textile effluent and reduced its chemical oxygen demand by 17.5% in 5 days. Investigation of decolourization abilities, high tolerance to inhibitors and wide enzymatic activities of selected strains suggests that they are promising actinomycetes for the biotreatment of textile dye wastewater.

 

 

16/12 METHOD FOR IMMOBILIZING LIVING BACTERIAL CELLS UNDER LIQUID CULTURE MEDIUM USING MUSSEL ADHESIVE PROTEIN FOR DYNAMIC ATOMIC FORCE MICROSCOPY STUDIES

M. Gad

Microbiology Dept., Faculty of Science, Ain-Shams University, Abbaseya, Cairo, 11566 Egypt.

A method for immobilizing living bacterial cells on flat surfaces like glass and atomically flat ones like mica was developed. The cells were immobilized using a marine protein that is secreted by the foot of the common mussel Mytilus edulis. Mytilus edulis foot protein-1 (Mefp-1) is a highly repetitive proline rich protein that adheres to a variety of substrates, including wet and biofilm-coated surfaces. Its unusually strong adhesive and cohesive properties are at least partly attributable to dihydroxyphenylalanine (DOPA) residues, which can form crosslinks and bond to different surfaces non-specifically. The dynamics of the polymerization process of the protein was imaged by Atomic Force Microscopy (AFM). The magnitude of the adhesive forces of the protein during polymerization was measured by the force mode of AFM. High resolution images of the immobilized bacteria under liquid culture medium could be obtained successfully for several hours using contact mode AFM. This method is useful for studying the morphological changes of living microbial cells exposed to biologically active ma­terials. Such studies will reveal far more information about the mode of action of drugs or other physiological changes or environmental conditions that alter cellular phenotype.

 

 

17/12 KOMBUCHA MUSHROOM AND OUR LIFE

S.S. Abd El-Salam

Botany Department, Faculty of Science, Benha University, Benha,

Early reports on Kombucha, a traditional fermented tea beverage, suggested that it has anti-microbial activity against a spectrum of organisms and itself through the production of organic acids, low amount of alcohol and decrease the pH to reach less than 3.0 , this is benefit to the people suffering from cancer usually have pH higher than 7.56. Kombucha will cause the a blood pH to fall by increasing its acidity which is usually about 2.5. Then after the gastric secretions got obsorbed the blood reaches to 1.7. Therefore, the focus of this study was to increase the total acidity of kombucha tea by testing some factors as various natural nutritional medium and carbon sources where the tea has been well kombucha mushroom growth, highly total acidity and pH 2.5 at 10 g sucrose and 6.5 g tea per 100ml culture medium compared to different carbon sources and concentrations of sucrose. Chemical analysis of total acids was carried by high performance liquid chromatography, acetic acid and gluconic acid were detected. Finally, investigate the effect of ionizing radiation as gamma radiation and x rays on total acidity production by kombucha mushroom tea, it is noticed that highly acids amounts (98 % per 100 ml culture medium) at 1 KGy of X-rays for 10 min. compared to Gamma where it decreased total acidity (90 % ml at the same dose) nearly.

 

18/12 STUDIES ON KERATINASE ENZYMES ISOLATED FROM DIFFERENT STRAINS OF TRICHOPHYTON MENTAGROPHYTES

H.M. Mubarak

Microbiology Department, Faculty of Science, Tanta University

Ten Trichophyton mentagrophytes strains were differentiated according to their microscopic examination, colour, type of tinea they caused, pathogenecity test. In this study it was found that T. mentagrophytes var. quinckeanum was the most pathogenic strain. Over a period of 28 days the 10 Trichophyton mentagrophytes strains were examined for their ability to secrete keratinolytic enzymes. Production of enzymes was stimulated by various keratins used as substrates. Duration and intensity of keratinase secretion were strongly influenced by the keratinous substrate. Duration and intensity of the enzyme production also differed among the 10 dermatophyte strains. Ten similar enzymes were isolated with molecular weights 48 K Da.. The isolated enzyme was used to show its role in pathogenecity on Ginea pig.

 

 

19/12 BIOCONVERSION OF FOOD PROCESSING WASTES BY PLEUROTUS OSTREATUS INTO PROTEIN ENRICHED PRODUCT

A.S. Hamza, G.A.M.A. Darwish and K.A. Abdel-Kawi*

Central Laboratory for Food and Feed, Agricultural Research Center, Giza, Egypt

*Soil, Water and Environment Research Institute, Agricultural Research Center, Giza, Egypt

Agro-industrial wastes containing lignocellulose can be upgraded by solid state fermentation using white rot fungi. Thus, soaked and pasteurized food processing waste (artichoke petals) mixed with cucurbit husk and mandarin peels at different ratios (3:1, 1:1, 1:3) and packed in polyethylene bags was inoculated with white rot fungi (Pleurotus ostreatus) and incubated for 30 days at 28oC, using solid state fermintation technique. Results showed that artichoke petals and cucurbit husk with ratio of 1:3 decreased lignin content from 16.00 to 5.92%, and increased protein value from 16.25 to 25.84% when combined mixture was treated with Pleurotus ostreatus.

 

 

20/12 MICROBIOLOGICAL STUDIES ON THE PRODUCTION OF a-GALACTOSIDASE BY STREPTOMYCES HYGROSCOPICUS NRRL B- 1476

N.H. Ali, L.A. Mohamed, O.M. Abdel-Fatah, M.A. Elsayed and A.M. Elshafei

Department of Microbial Chemistry, National Research Centre, El-Tahrir Street, Dokki, Cairo, Egypt

Ten Streptomyces strains were screened for their abilities to produce a-galactosidase when grown on modified Czapek Dox’s liquid medium containing different leguminous seeds powders as carbon sources. Streptomyces hygroscopicus NRRL B-1476 is the only strain that gave positive results. Endocellular enzyme gave the highest yield as compared with the extracellular one. Modified soybean Czapek Dox’s liquid medium, in which 1% soybean seed powder and 0.2% sodium nitrate were incorporated as carbon and nitrogen sources respectively, was the best medium for enzyme production. Highest amount of enzyme was recorded when Str. hygroscopicus NRRL B-1476 was grown at pH 6.0 and 30°C under static cultural conditions. Paper or thin-layer chromatographic identification of the products resulting from the enzymatic hydrolysis indicated that galactose & glucose could be identified from melibiose, galactose & sucrose from raffinose and finally galactose & raffinose from stachyose.

 

 

21/12 GENOTYPIC AND PHENOTYPIC CHARACTERIZATION OF CLINICAL AND ENVIRONMENTAL BURKHOLDERIA CEPACIA ISOLATES

W. Hegazy, N.E. Yousef, H. Abddel Salam and H.K. Abdel Latif

Department of Microbiology, Faculty of Pharmacy, Zagazig University

A total of 31 Burkholderia cepacia isolates were isolated from clinical samples of cystic fibrosis (CF), respiratory tract (16 isolates), urinary tract (1 isolate), septic wounds (8 isolates) and from environmental samples (6 isolates) of soil, macerated onions and water canals. The isolates were characterized by phenotypic and genotyping methods. Phenotypic methods were determined by biochemical reactions, susceptibility to antimicrobial agents and outer membrane profiles (OMPs). The genotyping methods were determined by polymerase chain reaction (PCR) and plasmid profile analysis. Although phenotypic characteristics of the clinical and environmental isolates were variable, genomic typing (PCR) identified the majority of the isolates.

 

 

22/12 QUALITY EVALUATION OF PROBIOTIC RAS CHEESE

M.E. Aly, M.M. El-Abbassy, S.N. Taha and S.A. Khalifa

Food Science Department, Faculty of Agriculture, Zagazig University, Zagazig, Egypt

Ras cheese was manufactured from cows' milk with 1% level of the following starters : Lactococcus lactis subsp. lactis (1%); Lactococcus lactis subsp. lactis + Lactobacillus casei (1:1); Lactococcus lactis subsp. lactis + Lactobacillus delbreuckii subsp. bulgaricus (1:1); Lactococcus lactis subsp. lactis + Lactobacillus helveticus (1:1) and Lactococcus lactis subsp. lactis + Streptococcus salaivarius subsp. thermophilus (1:1), Bifidobacterium bifidum was added to Ras cheese curd before moulding at level of 1%. The control cheese was manufactured from cows' milk with 1% Lactococcus lactis subsp. lactis, without adding Bif. bifidum. The results showed the increase of acidity in all treatments more than control cheese. The addition of bifidobacteria to the cheese manufactured with Lactococcus lactis subsp. lactis and Lb. casei got the highest scores in sensory evaluation in all stages. The scores were higher than the control and the other treatments. The chemical analysis revealed that the use of Lb. casei along with the Bif. bifidum caused the higher values of SN/TN%; NPN/TN%; AAN/TN% and TVFA%. The use of Lb. casei along with the Bif. bifidum gave a higher counts of total bacterial, bifidobacterila; proteolytic and lipolytic bacterial counts.

 

23/12 BIOCHEMICAL STUDIES ON AMYLASE FROM SOME ASPERGILLUS ORYZAE STRAINS

N.H. Ali

Department of Microbial Chemistry, National Research Centre, El-Tahrir Street, Dokki, Cairo, Egypt

Four strains of filamentous fungi were screened for their abilities to produce amylases. Aspergillus oryzae NRRL477 gave the highest level of extracellular α- amylase when grown on modified Czapek-Dox's medium containing 2% soluble starch and 0.2% sodium nitrate as the only carbon and nitrogen sources respectively, at 30°C and 4 days under static cultural conditions. Chromatographic identification of the products resulting from enzymatic hydrolysis of starch in the reaction mixture indicate the presence of maltose and glucose. Optimum pH and temperature for α-amylase activity was found to be 8.0 and 50°C respectively. The enzyme activity was strongly inhibited by FeSO4, CuSO4, CoSO4 and HgCl2 at a concentration of 5mM and 10mM, whileas the addition of EDTA and 2-mercaptoethanol at the same two concentrations, resulted to a slight inhibitory effect. The enzyme activity increased about 28% by dialyzing the extract against 0.03M phosphate buffer (pH8.0). The apparent Km value was calculated for starch as a substrate and found to be 1.66mg/ml.

 

 

24/12 MYCOTOXIN-PRODUCING POTENTIAL OF ASPERGILLI AND PENICILLI OF CEREAL GRAINS AND WHEAT STRAW

M.R. Metwalli

Botany Department, Faculty of Science, Benha University, Benha, Egypt.

One hundred sixty isolates belonging to the genera Aspergillus and Penicillium isolated from 25 samples of each of wheat, barley, maize, sorghum and wheat straw collected from different localities in Egypt, were screened for toxin-producing potential. Seventy one isolates produced one or more of the following mycotoxins: aflatoxins, kojic acid, gliotoxin, fumagillin, sterigmatocystin, citrinin, ochratoxins, rubratoxin, patulin, penicillic acid, rugulosin and verruculogen. Citrinin production by A. egyptiacus is reported for the first time.

 

 

25/12 MOLECULAR CHARACTERIZATION OF DIARRHEAGENIC ESCHERICHIA COLI ISOLATES

A. AbdEl Aziz; T. El Banna; A. Abo Kamar; M. Abo Skeena* and A. Saafan**

Dept. of Microbiology, Faculty of Pharmacy, *Dept. of Pediatric, Faculty of Medicine, Tanta University, **Beni Suef University, Egypt

Five hundred stool samples were collected from cases (aged from 1 week to 2 years) suffering from diarrhea attended the Unit of Rehydration and Diarrheal Diseases, Tanta University Hospital, during the period form June 2000 to August 2001, were enrolled in this study. Out of the collected samples 174 diarrheagenic Escherichia coli isolates were recovered. These isolates were categorized into 5 groups including: 22 enterohemorrhagic Escherichia coli (EHEC) of serotype O157:H7, 33 entrotoxigenic E. coli (ETEC), 50 enteropathogenic E. coli (EPEC), 44 enteroaggregative E. coli (EAEC) and 25 enteroinvasive E. coli (EIEC) isolates. Characterization of the EHEC O157:H7 isolates was based on their growth characteristics on sorbitol MacConkey agar, Salah-Fung I and Salah-Fung II media and serodiagnosis using O157 and H7 antisera. Eight of these isolates produced enterohemolysin. On the other hand, the multiplex polymerase chain reaction (PCR) assays showed that all isolates exhibited the eae gene, 12 of these isolates (54.5%) possessed gene mediated shiga like toxin 2 (Stx2), 7 isolates (31.8%) possessed gene of shiga like toxin 1 (Stx1) and 3 isolates (13.6%) exhibited both genes. The ETEC isolates were characterized by detection of colonization factor antigens (CFA/I and CFA/II) using mannose resistant heamagglutination test. Of these isolates 29 (87.8%) possessed CFA/I and 4 (12.1%) possessed CFA/II. Bioassay (infant mice test) and genetic an alysis (Multiplex PCR assays) revealed that 7 isolates (21.2%) produced both heat-labile and heat-stable toxins (LT and ST), 11 isolates (33.3%) were only LT producers, while 15 isolates (45.4%) only produced ST. The EPEC isolates showed characteristic localized adherence on HEp-2 cells. Multiplex PCR results revealed that these isolates had the intimin protein, coding gene, eae, while 80% of them possessed the bundle forming pilli, coding gene bfpA, that carried on the enteropathogenic aggregative factor (EAF) mediated plasmid. The EAEC isolates were differentiated from EPEC on the basis of scum formation on the surface of liquid culture media and their aggregative pattern of cells prepared from formed pellicles and also by the microscopic characteristics of aggregative adherence on HEp-2 cells. Twenty five isolates had the characters of EIEC. They were nonmotile, lacked lysine-decarboxylase enzyme and caused keratoconjunctivitis in ginnea pigs as detected by (Sereny) test. The multiplex PCR assays revealed that these isolates had the ial invasin gene. Conjugation and curing experiments revealed that a 60 MDa plasmid was responsible for enterohemolysin production in EHEC. Two non-transferable plasmids in ETEC isolates with molecular sizes of 62 MDa and 87 MDa mediated heat-stable and labile toxin producing respectively. The sixty MDa plasmid was responsible for adhesion to HEP-2 cells in EPEC, a 60 MDa plasmid was responsible for aggregation of EAEC cells. Lastly, a 140 MDa plasmid encoded the invasiveness of EIEC.

 

 

26/12 MECHANISMS OF ANTIMICROBIAL RESISTANCE AMONGEST DIARRHEAGENIC ESCHERICHIA COLI ISOLATES

T. El Banna; A. Abd ElAziz; A. Abo Kamar; M. Abo Skeena* and A. Saafan**

FROM

Dept. of Microbiology Faculty of Pharmacy, *Dept. of Pediatric Faculty of Medicine, Tanta University, **Beni Suef University, Egypt

One hundred and seventy four diarrheagenic Escherichia coli isolates (including: 22 enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7, 33 enterotoxigenic E. coli (ETEC), 50 enteropathogenic E. coli (EPEC), 44 enteroaggregative E. coli (EAEC) and 25 enteroinvasive E. coli (EIEC) isolates were involved in the present study. Susceptibility of the different isolates to 20 different antimicrobial agents, using the agar dilution method, varied dramatically from one drug to another. All E. coli isolates, except 2 were multiple drug resistant and about 95.6 of them were resistant to 4-17 agents. High incidences of resistance more than 90% were to ampicillin, amoxicillin, chloramphenicol, erythromycin, and sulfamethoxazole-trimethoprime. Incidence of resistance to third generation cephalosporins was 38.5%. Forty-eight resistance patterns were recognized and out of these patterns 6 were common among the different categories. Out of the selected 67 third generation cephalosporins resistant isolates 71.6% were β-lactamase producers. The isoelectric focusing points (pI) experiments revealed that these β-lactamases possessed pIof 5.4, 5.7, 7.7 and 8.2. Analysis of the obtained data indicated that these isolates secreated extended spectrum β-lactamases in addition to penicillinase. Plasmid analysis of the selected isolates from each category of diarrheagenic E. coli and obtained transconjugatives and curred strains, in, addition to their susceptibility to the different antimicrobials showed that the diarrheagenic E. coli isolates harboured plasmids with different sizes that ranged from 1.2 MDa and 150 MDa. Many of these plasmids were transferable. Each plasmid mediated more than one resistance markers and the gene coding form each marker was carried on more than one plasmid. Moreover, the plasmids encoded genes of the virulence factors were also coding resistance for more than antimicrobial agents. Regarding the outer membrane protein (OMP) all isolates had an OMP of 50 and 45 kDa. While, the OMP 40 kDa was absent in the quinolone resistant isolates, the weighed 116 kDa OMP was present. Five out of the 18 primarily quinolone resistant isolates exhibited efflux mechanism. These isolates showed accumulation of the fluorescent dye N-phenylnaphthylamine (NPN) inside the cells that remained relatively higher when the cells treated with the efflux inhibitor carbonyl cyanide m-chlorophenylhydrazone (CCCP) with or without the cell permeabilizer polymyxin nonapeptide (PMNB). We therefore reported the responsibility of the plasmids, β-lactamase enzymes production, the impaired permeability through alteration of OMPs expression and the drug efflux were mechanisms of resistance to antimicrobials among the isolated diarrheagenic E. coli. The role of plasmids in development of multiple drug resistance was the predominant mechanisms. The carrying of drug resistanc markers on different plasmids including that coding for virulence factor, complicate the drug therapy by bacterial pathogens.

 

 

27/12 EFFECT OF CANE LENGTH ON BUD BEHAVIOUR, YIELD, FRUIT QUALITY, AND WOOD RIPENING OF “SUPERIOR” GRAPEVINE CULTIVAR.

M.I.F. FAWZI

Hort . Res. Dept. National Research Centre, Dokki, Giza, Egypt.

This study was carried out during succesive season, 1999 and 2000 in order to out the optimum cane length and number of canes to be left on the vine of “ Superior “ grape cultivars to get high yield with best fruit quality. Cane were pruned to different number of buds 9,10,12,14,16,20 buds/ cane, total number of buds / vine being fixed to 80-84 buds. The results obtained showed that percentage of bursted buds, cluster index and compactness coefficient were increased by increasing cane length to 20buds/cane, while the fruitfull buds and fertility coefficient increased at cane length 12,14 buds/cane. In addition the yield / vine tended to increase either as average number of clusters/ vines or avenage weight of clusters/ vine. Thus, the high significant values of numbers of berries / cluster, cluster length, rachis weight and berry weight were obtained also by 12,14 buds / cane treatment. Moreover increasing cane length to 16-20 buds/ cane reduced berry firmness, T.S.S %, T.S.S / acid ratio and total sugar % , whereas total acidity was increased. Thus, vines pruned leaving 7 canes with 12 buds / cane showed a higher percent of T.S.S and total sugar % than the other level pruning. An increase in wood ripening accurred at 9,10,12 buds/ cane. While, total carbohydrates % was decreased with increasing cane length. Generally, pruning “ Superior” grape cultivar leaving 6 or 7 canes with 14 or 12 buds / cane , recpectively resulted in a higher yield, better fruits   quality and wood ripening.

 

 


28/12 GREEN MICROALGAE WATER EXTRACT AS POSTHARVEST TREATMENTS ON FLAME SEEDLESS AND ROUMI RED GRAPES

E.A.A. Abd El-Moniem*; M.I.F. Fawzi** and M.A.A. El-Naggar***

* Hort. Cultural crops technology Dept., National Research Center, Dokki,

Giza, Egypt.

** Hort. Rec. Dept., National Research Center, Dokki, Giza, Egypt.

*** Plant Pathology Dept., National Research Center, Dokki, Giza, Egypt.

The main causal organisms of postharvest fruit rots of grabes were Botrytis cinerea, pencillium expensum cladosporium herbarum, and stemphylium herbarum during storage periods in the two seasons (2004, 2005). The most frequent fungi, on grapes of each of Flame seedless or Roumi red cultivars were Botrytis cinerea, Penicillium expensum and Cladosporiun herbarum during storage at 0oc for up to 30 day. The total associated fungi, to grapes increased as the storage periods increased under both natural inoculation canditions and artificial inoculation. Meanwhile, the higest infection percentage of either B.cinerea and P.expensum exhibited on Flame seedless cultivar, however on Roumi red cultivar the highest percentage was of B. cinerea and C.herbarum. Coating grapes (cvs. Flame seedless and Roumi red) with green algae cell extract after 30 days of storage at 0oC, indicated that the most effective concentration was 75% which reduced percentage of total wastage on Flame Seedless and Roumi red cultivars to 5.92%, 7.23% and 5.90%, 8.25% in the two seasons respectively, as compare with 23.55%, 30.50% and 20.60%, 25.15% on uncoated fruits (control) at both seasons. Coating berries of both cultivars with water extracts of green algae at 75%-100% caused greater reduction in weight loss (%), fruit shatter and decay (%) than which obtained at lower concentrations (25-50%) when berries were stored up to 30 days at the two seasons. The coating treatment affect slightly on the total soluble solid content (%) and acidity it cause more or less values than the standared levels. The effect coating on reducing sugars showed an increase in sugar content in both Flame seedless and Roumi red cultivars at both seasons, compared with the content of uncoated berries. The increase in sugar content was at its maximum content after 30 days of storage.  

 

 

29/12 MICROBIOLOGICAL STUDY ON SOME MICROORGANISMS ASSOCIATED WITH IMMUNOSUPPRESSED PATIENTS

G.F.M. Gad*, E.B. Mohamed*, A.A. Abd El-Monem***, R.A. El-Domany*

and M.S.E. Ashour **

Microbiology Departments, Faculty of pharmacy, El-Minia University* and Al-Azhar University**, Faculty of medicine Beni Suef University***

The aim of this work was to study the prevalence of bacterial infections among different types of immunosuppressed patients, evaluation the activity of antibacterial agents against the isolated strains, detection of β–lactamase in antibiotics-resistant strains and studying the plasmid profile of highly resistant and β-lactamase producing strains.       This study was carried out on 400 different immunosuppressed patients suffering from cancer, diabetes, burn or tuberculosis. Six hundreds and eighty nine bacterial isolates were recovered from different clinical samples (urine, sputum, or swab) collected from the patients according to infection sites. Staph. aureus was the most frequent isolated organism (20.89%) followed by E. coli (11.9%), Staph. epidermidis (10.74%), Ps. aeruginosa (8.99%), Klebseilla pneumoniae (7.25%), C. albicans (5.8%), Strep. pyogenes (5.66%). The sensitivity pattern for the isolated bacterial strains revealed that gatifloxacin, levofloxacin, imipenem, ciprofloxacin, ofloxacin and amikacin, were the most active antimicrobial agents against most of the isolated strains (99.28%, 98.94%, 95.2%, 92.65%, 88.57% and 88.23% respectively). Methicillin resistance applied to Staph. aureus and Staph. epidermidis strains revealed that 29.6% were methicillin resistant Staph. aureus (MRSA), and 17.55% were methicillin resistant Staph. epidermidis (MRSE). The resistance of Staph. aureus and Staph. epidermidis to vancomycin were 22.9% and 16.51% respectively. β-lactamase detection was carried out on 54 different strains resistant to amoxycillin, (18 Staph. aureus, 6 Staph. epidermidis, 12 E. coli, 7 Ps. aeruginosa, and 9 Kleb. pneumoniae and 2 Kleb. oxytoca isolates). From the tested strains 57.7% were β-lactamase producers. Plasmid isolation for β-lactamase producing & highly resistant isolates was carried out. It was found that some of these strains were harbouring plasmids that may be responsible for the increased resistance to many antibiotics.

 

 

30/12 EFFECT OF EXCESSIVE EXPOSURE OF FUSARIUM OXYSPORUM F.SP.LYCOPERSICI AND ALTERNARIA ALTERNATA TO HERBICIDE METRIBUZIN ON ACQUIRED TOLERANCE TO FUNGICIDE DIFENOCONAZOLE

M.B. Mahmoud and H.M.S. Khalifa

Plant Protection Department, Faculty of Agriculture, Al-Azhar University,

Nasr City, Cairo.

The side effect of excessive exposure of fungi to the herbicide metribuzin on the acquired tolerance to fungicide difenoconazole was investigated. The results indicated that Fusarium oxysporum f.sp.lycopersici and Alternaria alternata, obtained from diseased tomato, were sensitive to fungicide difenoconazole, according to the EC50 values, i.e. 0.163 and 0.134mg a.i for F.oxysporum F.sp.lycopersici and A.alternata, respectively. Quite contrary, metribuzin did not affect the growth of these fungi on medium containing 100 or 200 mg/ml of the herbicide. Continuous exposure of these fungi to gradual increasing concentration 300, 400, 500 and 600 mg/ml of metribuzin resulted in isolates of these fungi tolerated difenoconazole. The tolerance levels were 165.2-and 6290.07-fold for F.oxysporum f.sp.lycopersici and A.alternata, respectively. The image analysis showed that the mycelium of both fungi tolerant to difenoconazole were thinner than the sensitive one, also contained olive-green droplets which may play a part in tolerance mechanism. The tolerance was lost by subcultering the tolerant isolates on metribuzin- or difenoconazole-free medium up to 10 subcultering, indicating that the tolerance may be due to physiological adaptation.

 

 

31/12 OPTICAL IMMUNOASSAY TEST FOR RAPID DETECTION OF GROUP B STREPTOCOCCUS IN PREGNANT WOMEN AT DELIVERY

A.A. Abd-Elmonem*; H.A. Abd El-Hafeez** and G.F.M. Gad***

Department of Microbiology and Immunology*, Department of Obestetrics and Gynecology**, Beni-Suef Faculty of Medicine, Department of Microbiology, Minia Faculty of Pharmacy ***

This study was prospectively evaluated the accuracy of the standard culture method and the Strep B optical immunoassay (OIA) test for detection of light and heavy group B streptococcus (GBS) colonizationin pregnant women at time of delivery. The study included 107 pregnantwomen admitted to the labor ward at time of delivery. Specimens of anal,vaginal, and combined vaginal and anal secretions were obtainedfrom all the women soon after admission. The specimens were tested for groupB streptococci by the Strep B optical immunoassay (OIA) test in comparison with culture in a standard selective broth medium. Compared to culture, the overall sensitivity, specificity, positive predictive value, and negative predictive value of Strep B OIA test for detecting anyGBS colonization were 25%, 93.7%, 33.3%, and 90.8% respectively. For lightly colonized women, sensitivity, specificity, positive predictive value, and negative predictive value of Strep B OIA test were 13.3%, 98.4%, 37.9%, and 94.1% respectively. For Heavily colonized women, sensitivity, specificity, positive predictive value, and negative predictive value of Strep B OIA test were 41.5%, 97.7%, 48.2%, and 97% respectively. For dense colonized women, sensitivity, specificity, positive predictive value, and negative predictive value of Strep B OIA test were 68.4%, 96.5%, 24.5%, and 99.5% respectively.While considering the culture as a reference method, the prevalence of the group B streptococcus (GBS) isolation with the pregnant women was of 11.2%. As a conclusion, colonization with group B streptococci can be identifiedrapidly and reliably by a Strep B optical immunoassay test in pregnant women in labor. However, the low sensitivity of the Strep B OIA test may limitits usefulness, althoughthe best performance of the test is in women who are heavilycolonized and who therefore may be at highest risk for complicationsdue to GBS infection. Aaat the time being, culture ofspecimens from the rectum and lower vagina remains the gold standardfor detecting GBS colonization in pregnant women even if the time necessary to obtaining the result is definitely longer.

 

 

32/12 CYTOMEGALOVIRUS AND HELICOBACTER PYLORI INFECTIONS AS PREDICTORS OF ACUTE CORONARY SYNDROME

Ali A. Abdelrahman, *Asmaa M. El-Gendy, **Ossama Al-Amoudy, ***Abdelaziz Basheer and ****Abdellah Refeai

FROM

Medical Microbiology and Immunology Dept., Faculty of Medicine,
Taibah University, **,***,****King Fahd Hospital, Madinah Monawarh, Saudi Arabia

Known risk factors for coronary heart disease do not explain all clinical and epidemiological features of the disease and additional environmental factors probably contribute to clinical atherothrombotic events. The present work studied the association of Helicobacter pylori (H. pylori) and cytomegalovirus infection with acute coronary syndrome. We also studied C-reactive protein (CRP) as a marker of chronic inflammation and its correlation with coronary artery disease. Sera were obtained from 58 patients with acute coronary syndrome (ACS) and from 30 control subjects. Sera were then investigated for IgG antibodies to H. pylori and IgG antibodies for cytomegalovirus using elisa method. Serum samples were assayed for CRP using latex-enhanced agglutination immunoassay. The findings of the present study revealed a highly significant rate of positivity of H. pylori (56.9%) and cytomegalovirus infection (91.3%) in patients with acute coronary syndrome compared to control group (3.3% and 36.7% respectively) (P value <0.001 and <0.001 respectively). Also highly significant levels of CRP in serum of patients with acute coronary syndrome versus that of the control group (3.09 + 4 and 0.22 + 0.19 mg/dl respectively) (P value <0.001) was detected. The above mentioned data suggest that infection with H. pylori and cytomegalovirus might play a role as a trigger factor in acute cardiovascular events. These findings highlight the importance of associated infections in acute coronary disease, and give hope for its specific treatment.

 

 

33/12 EFFECT OF SALINITY ON GROWTH, SOME MACROMOLECULES AND ULTRASTRACTURE OF THE GREEN ALGA DUNALIELLA SALINA.

M.S. Abdelhameed, O. Hammouda, I. Kobbia* and S. Hassan

Botany Dept., Faculty of Science, Beni Suef University.

* Botany Dept., Faculty of Science, Cairo University

The green alga Dunaliella salina was cultured under two concentrations of sodium chloride (2 ML-1 and 3.5 ML-1). Low NaCl concentration induced significant increase by 94% and 430% in the total count and chlorophyll a content of the alga, respectively. On the contrary, high concentration (3.5 ML-1) of NaCl had an inhibitory effect on the growth of the alga. On the same pattern, high salinity reduced the total soluble carbohydrates and proteins of Dunaliella by 64 and 40%, respectively. The unsaturated fatty acids of Dunaliella increased by 122% after treatment with 3.5 ML-1 NaCl. The ultrastructure of the green alga revealed the appearance of more vacuoles and irregular arrangement of the thylakoid as a result of high salinity.

 

34/12 COMPARATIVE EFFECTIVENESS OF GAMMA RADIATION AND ELECTRON BEAM RADIATION ON SOME FOODBORNE PATHOGENS

D.A. Zahran and H.N. El-Hifnawi *

Health Radiation Research Department and *Drug Radiation Research Department National Center For Radiation Research and Technology (NCRRT)
Egyptian Atomic Energy Authority, Nasr City P.O. Box 29

This study was conducted to evaluate the microbiological quality of twenty packs of minced chicken meat sold in local meat markets at Giza. The survey revealed that the mean counts of total aerobic bacteria (TAB), total mold, total yeast, staphylococci and Staph. aureus were     4.7x106, 6.6x102, 1.6x103, 5.1x104 and 9.2x103, MPN /g, respectively. The average most probable number (MPN) of coliform bacteria and E. coli was 8.8 x 102 CFU /g. Nearly all samples (90%) contained Salmonella. Estimation of D10 values for Salmonella typhimurium, Staph. aureus (ATCC 25923) and E. coli using two forms of electromagnetic radiation that are used in food irradiation (gamma rays and accelerated electrons) were determined. The results revealed that D10 value for Salmonella typhimurium was 0.4 and 0.3 kGy; for Staph. aureus (ATCC 25923) was 0.8 and 0.6 kGy and for E. coli was 0.3 and 0.5 kGy, respectively. Irradiation by gamma rays resulted in higher D10 values than irradiation by electron beam except for E. coli, indicating that pathogenic bacteria under investigation were more radiosensitive to electron beam irradiation in comparison with gamma irradiation

 

35/12 TRANSMISSIBLE RESISTANCE TO ANTIMICROBIALS AND HEAVY METALS AMONG ENVIRONMENTAL ENTERIC ISOLATES IN GHARBIA REGION, EGYPT

A. Abo Kamar and W. Awarra*

Dept. of Microbiology, Dept. of Pharmacology and Toxicology*,

Faculty of pharmacy, Tanta University.

In the present study, a total of 85 environmental enteric bacterial isolates including (26 Escherichia coli, 9 Shigella flexneri, 30 Pseudomonas aeruginosa and 20 Klebsiella pneumoniae) were recovered from the effluents of different factories in Gharbia governrate, Egypt, and were tested to 8 antimicrobials and 4 heavy metals High incidence of resistance was observed among the tested isolates. The highest incidence of resistance was to ampicillin, chloramphenicol and cefradin which ranged from 44 to 100%. The isolates were also resistant to 2-4 of the tested heavy metals and the incidence of resistance to nickel sulphate (Ni+2) and mercuric chloride (Hg+2) ranged between 61% and 100% while cobalt chloride (Co+2) showed lower incidence of resistance (40-63%). Organic mercury thiomersal was highly effective against all tested isolates. Seven multiple antimicrobial and heavy metal resistant isolates were selected and subjected to study the role of plasmid in development of resistance and to what extent such resistance is transmissible. Conjugation with Escherichia coli K-12 strain (UB 5202) was achieved. The plasmid analysis of parent isolates and the resultant transconjugants showed that the tested isolates harboured plasmids with different sizes that ranged from 2.7 – 163 MDa. All these plasmids were conjugative. Each plasmid mediated more than one resistance markers for antimicrobial and heavy metals. It was indicated that the resistance to the tested antimicrobials and heavy metals were plasmid mediated and these plasmids were conjugative. The presence of such plasmids might enhance the spread of both types of resistance among different bacterial isolates.

 

 

36/12 MICROBIOLOGICAL AND MOLECULAR STUDIES ON DIARRHEAGENIC ESCHERICHIA COLI

M.S.E. Ashour, A.A. El-Moghazy, M.A.B. Gamal, A. El-Sharif and A.F. Ahmed

Microbiology and Immunology Department, Faculty of Pharmacy,

Al-Azhar University

A total of 124 E.coli isolates were recovered from stool specimens collected from ‘Imbaba General Hospital’, Giza, Egypt. Specimens were collected from different departments as Internal medicine, Pediatrics, Gynecologydepartments and internal medicine outpatient clinic. All were suffered from diarrhea. The highest frequency of E.coli (63.17%) was detected in the Internal medicine department. Identification of E. coli isolates was confirmed using API 20E test strips. Testing the susceptibility of isolated E. coli against 12 different antimicrobials revealed that; resistance to Penicillin-G and the first generation cephalosporin; Cephalexin was 100%. Meanwhile resistance to Erythromycin, Ampicillin, Sulphamethoxazole/ Trimethoprim (SXT), Chloramphenicol and Cefepime was 87.9%, 75.8%, 66.9, 41.9 and 3.2 respectively. However all isolates were susceptible by different degrees to Amikacin, Kanamycin, Nitrofurantoin, and Ofloxacin. The presence of multiple drug resistance to 3-7 antimicrobial agents was very clear in most isolates (93%). The isolates were screened for β-Iactamase production by the Iodometric method, where 79.03% of the examined E.coli was found to be β-lactamase producers. In the present study plasmid profile analysis was performed. Five different species of plasmids were obtained. The number of plasmids per isolate ranged from 2 to 4 and the distribution of plasmid sizes ranged between 2.8 to 12.0 kbp. The most common plasmids were found at 2.8 and 6.0 Kbp among the five different groups. The classical TEM enzyme is one of the predominant plasmid-mediated β-lactamases. Polymerase chain reaction (PCR) assay for detection of TEM encoding gene was carried out. The result revealed that 90% of the examined E.coli isolates contain TEM gene responsible for the production of β-lactamases. This finding prove that TEM hyperproduction is a frequently described mechanism by which resistance to the β-lactam antibiotics is mediated in E. coli.

 

37/12 ISOLATION AND IDENTIFICATION OF YERSINIA SPECIES FROM WATER AND FISHES OF MANZALA LAKE, EGYPT

BY

A. Ismail, M. Abu doubara*, F.A. Mansour* and M. Zaki

FROM

Biology Department, faculty of Education,   Suez Canal University, Egypt.

*Botany Department, faculty of Science, Monsoura University, Egypt.

Water samples were collected from 4 sites while fish samples were collected from 2 sites of Manzala Lake. The sities represented high impact of human and animals activity of the lake. Yersinia spp were counted on the Yersinia selective agar plates which reached the highest counts in water samples from El Mataryia area (3.4x 103 c.f.u / ml) and (9x 103 c.f.u / g) in the intestine of fishes. 50 isolates were identified using the recommended API 20 E system. Results revealed that 46% of total isolates were recorded to belong to the species: Y. Enterocolitica (20%), Y. Pseudotuberculosis (12%), Y. entermedia (12%) and Y. Kristensenii (2%).

 

38/12 PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR CHITINASE FROM

ALTERNARIA ALTERNATA

E.F. Sharaf

Botany Department, Faculty of Science, Cairo University

Chitinase from culture filtrate of Alternaria alternata was purified with 8.97 purity fold after precipitation by ammonium sulfate followed by gel filtration on sephadex G200. Further purification on sephadex G100 gel chromatography increased the purity of the enzyme by 19.37-fold. The purified enzyme (molecular mass ~ 38 kDa) showed highest activity towards colloidal chitin at reaction temperature 60oC and pH value of 5.0. The enzyme was thermostable for 120 min at 50oC and it was activated by Ca2+,Fe2+ and Mn2+. Atomic absorption revealed that the enzyme contained these metal ions in its molecule with the highest quantity achieved by Ca2+. EDTA, Hg2+ and Cu2+ retarted the enzyme activity. The stability of the enzyme was maintained after two months storage period at -4oC. The purified enzyme exhibited antifungal activity against some food spoilage moulds.

 


39/12 THE ANTIMICROBIAL ACTIVITY AND MODE OF ACTION OF SOME NEWLY SYNTHESIZED COMPOUNDS ON SOME MICROORGANISMS

S.M. El-Sabbagh

Department of Botany, Faculty of Science, Minoufiya University

The antimicrobial activity of synthetic furanones bearing an arylazo group has been examined against the tested microorganisms using the cut plug and agar dilution methods. The synthetic compound (no.120a) showed a broad antimicrobial activity against Gram negative (Escherichia coli) and Gram positive (Staphylococcus aureus) bacteria as well as the yeast (Candida albicans), but it did not show any antagonistic activity against the fungus Fusarium oxysporum. The minimal inhibitory concentrations (MIC's) against E. coli, Staphylococcus aureus and Candida albicans were 50 mg/ml. The studies on the mode of action of this synthetic compound revealed that it didn't affect DNA synthesis of the susceptible organisms. There were also no changes in the cell morphology of E. coli, Staphylococcus aureus and Candida albicans treated with this compound. The compound proved to be non toxic and its LD50 was 500mg/ml. However it degraded cell wall of B. subtilis, increased the out flow of K+ ion from all the tested organisms and decreased respiration as well as the total amount of cellular protein. The sublethal dose of this compound showed no effect on the ergosterol content of the cell membrane. The synthetic compound has no effect on the activity of a-glucosidase and proteinase in treated and untreated cells. a-amylase was not inducing using two types of media.

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