Vol. 18, September, 2007

1/18 EFFECT OF CHITOSAN UPON HOST CELL WALL DEGRADATION AND SUGAR CONTENTS OF SUGAR BEET PLANT BY SOME PATHOGENIC FUNGI

M. Eweis

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

Chitosan, derived from crab-shell chitin, was applied to soil at (100-400 mg g-1 soil) suppressed infection of two sugar beet cultivars Kaumera and Trirave by the fungal pathogens Rhizoctonia solani, Sclerotium rolfsii and Fusarium solani and acting thus as a fungicide. In absence of chitosan, R. solani was the most virulent against cvs Kaumera and Trirave. Virulence was directly correlated with the activities of cell wall degrading enzymes produced by these pathogens   in vivo. Reduced virulence of R. solani, S. rolfsii and F. solani under chitosan stress was due to decreased inoculum potential of the three pathogens at all utilized concentrations of the fungicide in situ and to reduce production of cell wall degrading enzymes in vivo. Growth parameters including emergence, plant length and dry weight of sugar beet were significantly increased at all utilized fungicide concentrations (100-400 mg g-1 soil). The infection rate was significantly decreased with increasing the fungicidal stress whereas the total reducing value (TRV) and the direct reducing value (DRV) were significantly increased in the tested sugar beet cultivars.

2/18 PRODUCTION, CHARACTERIZATION AND TENSIOACTIVE PROPERTIES OF RHAMNOLIPID BIOSURFACTANT PRODUCED BY PSEUDOMONAS AERUGINOSA -JW1

H.M. M. Ibrahim

Department of Microbiology, National Center for Radiation Research and Technology, Atomic Energy Authority, Nasr city, Cairo, Egypt.

During this study only one isolate out of ten Gram-negative short rods bacterial isolates; previously isolated from soil, was capable of producing biosurfactant, which was identified as rhamnolipid. This isolate was selected and identified as a strain of Pseudomonas aeruginosa. The ability of producing rhamnolipid was confirmed by TLC analysis, with Rf values ranged from 0.71 to 0.76. Furthermore, the FT-IR spectra of the produced rhamnolipid along with standard one were similar. From a variety of carbon substrates; including two hydrophilic substrates, five vegetable oils, and four hydrocarbons, this strain utilized only seven carbon substrates (namely, glucose, glycerol, olive oil, corn oil, sun flower oil, sun flower : soybean mixture 1:1 (v/v), and used frying oil). However, the hydrocarbon substrates (crude oil, diesel oil, n-hexadecane, and naphthalene), inhibited both growth and rhamnolipid production. The vegetable oils were the best carbon and energy source, especially olive- and corn oil; giving 9.63 and 8.42 g/l rhamnolipid respectively, when added by 2% (w/v) to the growth medium. Also, the lowest surface tension of cell free culture broth (24 mN/m) was given by both. The hydrocarbon/CFCB systems showed good emulsification index E24 of 70.97 % for sun flower oil : soy bean oil (1:1) versus kerosene oil, and emulsification capacity (EC) of 18.60 % given by olive oil against kerosene oil. In addition, the relative emulsion volume at 0h ranged from 96.67 % to 106.67 %, while that after 48h ranged from 44.83 % to 58.06 %, which indicated good relative emulsion stability ranging from 43.70 % to 59.04 %. Finally the produced rhamnolipid was highly stable under extreme conditions of temperature (50oC - 90oC for 1h; 120oC for 15 min) and pH (2 - 12).

3/18 MICROBIOLOGICAL STUDIES ON SOME MICROORGANISMS CAUSING SUMMER AND ANTIBIOTIC ASSOCIATED DIARRHEA

M.S.E. Ashour, K.A. El-Garib, F.M. Gomaa and T.A. Helal

Depratment of Microbiology & Immunology, Faculty of Pharmacy,

Al-Azhar University, Nasr City, Cairo, Egypt.

The present study was carried out to investigate the presence of some microorganisms (either aerobic or anaerobic), which cause diarrhea in some hospitals in Egypt and to compare the pattern of resistance of some antimicrobial agents against the isolated species. Suspected etiological agents were detected among acute diarrheal patients during the period from June 2001 to June 2004, 224 stool specimens from patients of different age groups attending Ain shams (84 cases), El-Hussein (85 cases), El-Shohadaa (El-Menoufia) General Hospital (55 cases) were examined. 531 bacterial isolates (aerobic) and 30 isolates Clostridium difficile (anaerobic) in addition another 30 anaerobic bacteria other than Clostridium difficile were isolated from stool of diarrheal patients. E.coli was the most prevalent bacteria; it represented 36.53% of the total number of species isolated from different hospitals. Isolation rates for Klebsiella pneumonia, Citrobacter freundii, Enterobacter aerogenes, Enterobacter cloacae, Providencisa rettgeri and Citrobacter diversus were (17.70%), (11.11%), (20.33%), (3.57%), (0.56%), (2.07%) respectively. The frequency of isolation of Ps. aeruginosa and Ps. cepacia were 7.53% and 0.56% respectively. Clostridium difficile was isolated from patients with antibiotic associated diarrhea with frequency of 50%. Concerning the antimicrobial susceptibility pattern, the most effective antimicrobial agents were amikacin and ofloxacin as they demonstrated 100% activity against all isolates, followed by tobramycin, amoxicillin-clavulanic acid, streptomycin, tetracycline and cefoperazone (in decreasing order). On the other hand all isolated microorganisms were completely resistant to amoxicillin and carbenicillin. The mean Minimum Inhibitory Concentration and the mean Minimum Bactericidal Concentration of different antimicrobial agents against isolated species were determined; it indicated that amikacin (3.12 µg/ml – 25 µg/ml) were the most active agents toward all isolates.

 

4/18 INDUCTION OF GROWTH PROMOTION AND BIOCONTROL OF FUSARIUM OXYSPORUM AND ALTERNARIA SOLANI ON TOMATO USING MICROBIAL ANTAGONISTS

Z. Kamel, M. Rizk and A. Abdel-Gawad*

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

*Desert Research Center, Ministry of Agriculture, Egypt.

Twenty isolates of Azotobacter spp., eleven Streptomyces species and six Chaetomium spp. were tested for their antagonistic activities against the tomato pathogens Fusarium oxysporum f. sp. lycopersici and Alternaria solani. Plant growth promoting activity of isolates were evaluated on tomato seedlings in vitro. It was found that, only seven Azotobacter isolates showed antagonistic activities against the two tomato pathogens. The antifungal activity and nitrogen fixation were significantly increased when Azotobacter Ma, used as a biocontrol agent compared to the other isolates. Five actinomycetes isolates were able to antagonize F. oxysporum, while six isolates of actinomycetes were antagonistic against A. solani. Streptomyces Mm showed the highest promoting effect on tomato seedlings, where it caused the highest elongation activity 53% and 110% increase for both shoot and root respectively. Also it produced the maximum activity against the two pathogens. Chaetomium isolate Mt showed the highest antifungal activity against both tomato pathogens and highest growth promoting activity. C. globosum was the most active producer of IAA, gibberellines, abcisic and all cytokinine compounds, whereas Streptomyces sp. and Azotobacter chroococcum produced low levels of phytohormones. Benzene: chloroform: ethanol (10:10:3 v/v) at pH 7 proved to be the best organic solvent and the greatest antifungal activities against F. oxysporum, were 35, 42 and 40 mm for A. chroococcum, Streptomyces and C. globosum respectively. The same trend was observed for A. solani.

 

 

5/18 SEROTYPE DEPENDENT CONTRIBUTION OF M PROTEIN IN PATHOGENESIS OF GROUP A STREPTOCOCCUS PYOGENES

M.M. Hafez, W.F.M.A. El- Khatib and A.M. Abdel-Wahab*

Department of Microbiology and Immunology, Faculty of Pharmacy, Ain Shams University.

Department of Microbiology, Faculty of Medicine (girls), Azhar University*

The role of M protein in pathogenesis of group A Streptococcus pyogenes (GAS) was previously investigated, however, it was not clear whether this role is the same among different M protein types or it is serotype dependent. The results of the present study revealed that the M proteins of types 1, 5 and 6 effectively increased the virulence of GAS to mice while the type 22 did not. Regarding dissemination of the pathogen into host tissues, the results indicated that M proteins of types 1, 5 and 22 potentially contributed to such dissemination while the type 6 M protein failed to promote it. In addition, the results indicated that all tested M protein types (types 1, 5, 6 and 22) augmented the adherence of GAS to FaDu and Detroit pharyngeal epithelial cells. It was also revealed that the M proteins of types 1, 5 and 22 but not 6 were crucial for internalization of GAS into FaDu and Detroit cells. Regarding host cytokines, the present study demonstrated that the M proteins of types 6 and 22 played a vital role in IL-6 induction in vitro and in vivo, while neither type 1 nor type 5 M proteins had contribution in the induction of this cytokine. The role of M different types of M protein in cytotoxicity of mammalian cells induced by GAS was also studies. On the contrary to type 22 M protein, the types 1, 5 and 6 potentially contributed to cytotoxicity caused by GAS towards mammalian cells. Taken together, the results of the present study obviously indicated that the contribution of M protein to different pathogenicity determinants of GAS is not always the same but rather it is serotype specific.

6/18 MICROBIOLOGICAL, PHYSICAL AND CHEMICAL QUALITY OF SOME DRINKING WATER SOURCES.

N.H. Aziz and A.A. Hassan
Department of Microbiology, National Center for Radiation Research and Technology, Nasr City, Cairo, Egypt

This study evaluated drinking water quality collected from some different resources. All chlorine-treated drinking water samples were microbiologcally, chemically and physically unstastifactory during the first 4 weeks of collecting samples. After 5weeks in chlorine – treated samples there was a significant decrease in the total bacterial counts and the water samples were free from total coliform, E. coli, St. faecalis and P. aeruginosa with no off odour and a decrease in ammonia, nitrite and nitrate concentrations. The water samples of Nile water alone or mixed with under groundwater from hand pumps were heavily contaminated with all microbial indicators under investigation and samples were unsatisfactory physically and chemically during the 5 weeks of collection. The results indicate that chlorine process actively reduce greatly the bacterial load and the pathogenic bacteria in all water samples which were physically and chemically safe. Further refinements and evaluations of efforts to purify and store water are needed.

 

7/18 DETECTION OF MUTATIONS IN THE GYR A AND PAR C GENES IN QUINOLONE-RESISTANT CLINICAL ISOLATES OF ESCHERICHIA COLI.

M.H. Al-Agamy, I. Wiegand*, B. Wiedemann*, M.S.E. Ashour, A-S.A-H. Helal and K.A. El-Gareeb

Department of Microbiology and Immunology, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt and *Department of Pharmaceutical Microbiology, Bonn University, Bonn, Germany.

In order to investigate the molecular bases for fluoroquinolone resistance in E. coli strains from inpatiens attending Sayed Galal and Al-Hussien hospitals. We have amplified and determined partial sequence of the quinolone-resistant determining region (QRDR) of the gyrA and parC genes responsible for fluoroquinolone resistance in E. coli. A single mutation in gyrA (Ser83→Leu) of some E. coli isolates was detected with a reduced susceptibility to ciprofloxacin (MIC 2µg/m;). Three other mutation in E. coli isolate i.e.E43, E5 and E8 with high MICs of ciprofloxacin; 16µg/mL, 32µg/mL and> 32µg/mL respectively were detected. Double mutation of gyrA (Ser83→Leu and Asp87→Asn) and a single mutation in parC (Ser80→Ile), which were responsible for full resistance to fluoroquinolone (MIC≥16µg/ml). the highest level of E. coli resistance to fluoroquinolone (MIC>64→g/ml) wasn't detected in the present study, since that resistance generally results from four mutations: two in gyrA and two in parC the conjugation experiments revealed no role of plasmid-mediated resistance gene, qnr, in quinolones-resistance in the Egyptian E. coli isolates.

 

 

8/18 PHOTOINSECTICIDAL EFFECTS OF PHLOXINE-B ON PEACH FRUIT FLY, BACTROCERA ZONATA AND ITS SYMBIOTIC BACTERIA.

A.A. El-Adly, M.M. Abdelrahman* and I.A. Khalifa

National Institute of Laser Enhanced Science, Cairo University, Egypt

*Plant Protection Research Institute, Dokki, Giza, Egypt

The insecticidal properties of the photosensitizer phloxine-B (PH-B) were evaluated against peach fruit fly, Bactrocera Zonata in laboratory bioassays. Groups of B. zonata flies were fed on sugar media containing range of concentrations of PH-B for 24 hours in dark, and then exposed to solar simulator light at fluence rate of 400 W/m2 for 2 hours at 25 ± 1ºC. It has been found that PH-B had no detectable lethal effect on adults of B. zonata in the absence of light. Under the influence of light, high rates of mortality were achieved among flies fed on PH-B, with LC50 values of 0.0024%. In addition, it was found that PH-B had strong bactericidal effect on Klebsiella pneumonia, the symbiotic bacteria, essential for life and reproduction of B. zonata. Main factors affecting the degree of toxicity of PH-B against both   B. zonataadults and K. pneumonia were also explored.

 

 

9/18 INTERLEUKIN-8 (IL-8) AND VASCULAR ENDOTHELIAL GROWTH FACTOR (VEGF) SERUM LEVELS IN PATIENTS WITH HEPATOCELLULAR CARCINOMA AND THEIR RELATION TO HEPATITIS C INFECTION.

S.M. EL-Maghraby; S.A. Zaki*; A. Khairy*; M.M. Mounir**

and G.M. Abd-EL Moniem

Clinical Pathology Department, National Cancer Institute, Cairo University; *Microbiology and Immunology Department, Faculty of Pharmacy, AL-Azhar University;** and Epidemiology and Biostatistics Department, National Cancer Institute, Cairo University.

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide, being the third largest cause of cancer deaths. Tumor angiogenesis may be regulated by angiogenic factors as interleukin–8 (IL-8) and vascular endothelial growth factor (VEGF).The aim of this study is to measure the serum levels of IL-8 and VEGF in HCC patients and compare them to healthy controls. Also to find if hepatitis C virus (HCV) infection positively affects their serum levels. Fifty HCC patients and 40 healthy adults were enrolled in this study. Serum levels of IL-8 and VEGF were measured by ELISA in both groups. HCV infection was detected in HCC patients by Reverse-transcriptase PCR (RT-PCR). Results revealed that serum levels of both IL-8 and VEGF were significantly higher in HCC patients than in controls with p-value <0.001. HCV infection in HCC patients positively affects serum level of IL-8 but not VEGF. In conclusion, HCC was associated with high serum levels of IL-8 and VEGF, which may reflect active angiogenesis in HCC patients. Therefore controlling them can be a potential approach to control angiogenesis and invasion of HCC. HCV infection in HCC patients positively affects serum levels of IL-8 but not VEGF.

 

10/18 Isolation and characterization of Potent bacterial Hydrocarbon Degraders

H.M. Hussein, Y.A. El-Zawahry*, A.M. Shawky and R.A. Amer

Environmental Biotechnology Department , Genetic Engineering and Biotechnology Research Institute (GEBRI), Mubarak City for Scientific Research & Technology Applications, New Burg El-Arab City, Alexandria, Egypt.

* Botany Department Faculty of Science, Zagazig University

Around 30 bacterial isolates with different microbial morphology were isolated from soil and water samples contaminated with oil, all samples from oil well located at Red Sea area, Egypt. Eight isolates proved to be promising candidates for naphthalene degradation, Isolate No 5 (Na5) proved to be the most potent isolate capable of naphthalene resistance and degradation. Na5 has high potency in degrading naphthalene up to 2500 mg/L. On the other hand, five isolates found to be good toluene degrader, three of them, T1, T2, and T3, have relatively similar potency for toluene degradations since there is no great difference in its degradation efficiency. These isolates proved to have a great potency for the degradation of higher concentrations of toluene (22000 mg/L). While six isolates have high potency for phenol degradation up to 2000 mg/L, isolates P1, P2 proved to be the most potent isolates in the phenol degradation efficiency. The biochemical identification of the different isolates indicated that, isolates P1, P2, T1, T2 & T3 expected to be Bacillus spp., where isolates Na5 expected to be Pseudomonas spp. This identification will be confirmed genetically in other study.

 

 

11/18 MOLECULAR IDENTIFICATION OF CARBAPENEMASE-MEDIATED blaOXA-TYPE GENES IN MULTIPLE-RESISTANT ACINETOBACTER BAUMANNII ISOLATED FROM BURNS

H.A. Abdel-Salam

Department of Microbiology, Faculty of Pharmacy, Zagazig University

Acinetobacter baumannii has been recognized as an opportunistic nosocomial pathogen in recent years. A total of 38 isolates of A. baumannii were discriminated from burn wounds and their antibiogram was determined using disk diffusion method. A multiplex-PCR was used to detect four subgroups of blaOXA-type carbapenemase genes. The prevalence of MDR and pan-drug resistance against tested drugs were 63% (n= 24) and 24% (n= 9), respectively. The most effective drugs were colistin 87% (n= 33) and tigecycline 76 % (n= 29) of isolates. The susceptibility of isolates to meropenem, imipenem, piperacillin-tazobactam and amikacin was 47%, 45%, 39% and 32%, in respective manner. The tested resistant isolates possessed at least two genes encoding OXA-type enzymes. Hence, due to a high prevalence of multiple resistant isolates of A. baumannii in burns, tigecycline and colistin can be considered choices of treatment. Moreover, correct identification and drug susceptibility testing prior to antibiotic therapy is essential.

 

 

12/18 ISOLATION AND CHARACTERIZATION OF HALOGEOMETRICUM SP. SS1, A NOVEL HALOALKALIPHILIC ARCHAEON FROM SOLAR SALTERN, ALEXANDRIA, EGYPT

H.A. Ghozlan

Microbiology Section, Botany Department, Faculty of Science, University of Alexandria, Egypt

Strain SS1 was isolated from the water of solar saltern in west Alexandria (Egypt). Morphology, physiology, biochemical features, polar lipid composition, G+C content and 16S rDNA were characterized in order to elucidate its taxonomy. The organism was pleomorphic, Gram-negative, motile and required at least 100 gL-1 NaCl to grow. The highest gowth rate (1.6 h-1) was recorded at 200 gL-1 NaCl, pH 9, 40ºC and 10 gL-1 Mg2+. Growth and acid production were observed with a wide range of tested carbon sources. Hydrolysed gelatine. Resistant to penicillin, kanamycin, ampicillin, vancomycin, tetracycline and chloramphenicol. The G+C content of the DNA was 59 mol%. Polar lipid composition revealed the presence of phosphatidylglycerol (PG), phosphatidyl-glycerophosphate (PGP) and a single glycolipid while no phosphatidyl-glycerosulfate (PGS) was detected. According to data of 16S rDNA sequence homology, strain SS1 was affiliated to the genus Halogeometricum. The differences between strain SS1 and the only recognized species H. borinquense isolated from Puerto Rico suggest that this strain represents a new species.

 

 

13/18 IN VITRO DETERMINATION OF ANTIBIOTIC SUSCEPTIBILITY AND RESISTANCE PATTERNS OF E. COLI CLINICAL ISOLATES USING DISK DIFFUSION, BROTH MICRODILUTION AND E-TEST

H.A. Abdel-Salam

Department of Microbiology, Faculty of Pharmacy, Zagazig University, Egypt

Currently: Riyadh Collage of Dentistry and Pharmacy, Riyadh, Kingdom of Saudi Arabia

The antibiotic susceptibility and resistance patterns of 124 clinical isolates of Escherichia coli obtained from community-acquired outpatients were determined by disk diffusion, borth microdilution and E-test. As regular, E. coli was the most prevalent pathogen (67%) followed by Proteus (4%) then Staphylococci (2.7%) and Klebsiella (1.1%) in the urinary tract infections. A comparison of the E-test, the disk diffusion method and the broth microdilution test results, the most active drug against the isolates was cefotaxim (85%) and less effective is Co-trimoxazole 63% by disk diffusion method. By broth microdilution method, ciprofloxacin and cefotaxim are the most effective with MIC range, MIC50 and MIC90 of 1-0.25 and 8-1, 0.5 and 4 and 2 and 16 µg/ ml, respectively. In addition, chloramphenicol and tetracycline showed high MICs particularly, MIC90; 64 µg/ ml. Except cefotaxim and gentamicin, minor discrepancy and very major discrepancy were detected in the tested antibiotics by 1 (0.8%) and 2 isolates (1.6%), respectively. Major discrepancy was mainly detected in cefotaxim (2.4%), rifampicin (2.4%) and ampicillin/ sulbactam (0.8%) in comparison disk diffusion with broth microdilution results. The results of E-test showed 100% agreement with broth microdilution reference method and the regression analysis revealed significant correlation coefficient (r = 0.559 - 0.798) for the used antibiotics against the tested E. coli isolates. Hence, there is increase in Co-trimoxazole, chrolramphenicol and augmentin resistance and E-test is characterized with accurate quantitative and qualitative results and it is reliable, effective, fast and cost effective method of antibiotics susceptibility and it is useful for clinician in order to improve the empiric treatment.

14/18 STREPTOKINASE PRODUCTION BY DIFFERENT ISOLATES OF Β-HEMOLYTIC STREPTOCOCCI

M.S. Ashour; S.S. El-Louboudy*; O.A. Abd El-Rahman; R.W. Sharkawy**

and H.M. Ashour***

Microbiology and Immunology Department, Faculty of Pharmacy and *Microbiology and Botany Department, Faculty of Science, Al-Azhar University, Cairo, Egypt

**Quality Control Department, Egyptian Holding Company for Vaccines and Biological Products (VACSERA), Giza, Egypt.

***Microbiology and Immunology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt

From 13 β-hemolytic streptococci obtained from clinical cases suffering of tonsillitis or pharyngitis, it was found that four isolates, identified as Streptococcus dysgalactiae subsp. Equisimilis, produce streptokinase in detectable amounts. Different factors (nutritional and environmental factors) were studied to optimize streptokinase production by using the highest streptokinase producer isolates. Brain heart infusion broth medium with 1% glucose concentration added to this medium gave the best results for streptokinase production. On studying the effect of initial pHs and aeration level, it was found that pH 7 and 50 rpm agitation speed was the most favorable for streptokinase production. The streptokinase produced by using all optimum conditions was isolated and purified. By using vertical gel electrophoresis, it was found that the observed band corresponded to streptokinase with relative molecular weight 49 KDa. The purified streptokinase was tested for its ability to lyses the blood clot.

 

15/18 FEATHER DEGRADATION BY A NEW KERATINOLYTIC STREPTOMYCES SP.MS-2

M.E. Mabrouk

Department of Botany, Faculty of Science, Damnhour Branch,

Alexandria University, Egypt

Seventy different actinomycete isolates were evaluated for their ability to produce keratinase enzyme using a keratin-salt agar medium containing ball-milled feather as substrate. A novel feather degrading isolate obtained from marine sediment produced the highest keratinolytic activity when cultured on broth containing whole feather as a primary source of carbon, nitrogen and energy. Based on phenotypic characterization and analysis of 16S rDNA sequencing the isolate was identified as Streptomyces sp. MS-2. Maximum keratinase activity (11.2 U/mg protein) was achieved when cells were grown on mineral salt liquid medium containing 1% whole chicken feather adjusted to pH 8 and incubated at 35 °C for 72 h at 150 rpm. Reduction of disulphide bridges was also detected, increasing with incubation time. Feather degradation led to an increase in free amino acids such as alanine, leucine, valine and isoleucine. Moreover, methionine and phenylalanine were also produced as microbial metabolites.

16/18 PHYTOPLANKTON STRUCTURE IN THE AQUATIC DEPRESSIONS AT ABOU-ZABAL QUARRIES (EGYPT), ITS IMPACT ON DEVELOPING THE AREA

A.M. Abdel-Monem, A.D. El-Gamal*, E.A. Kobbiah** and A.M. Hussian

National Institute of Oceanography and Fisheries-Egypt.

* Faculty of Science, Botany Dep., Al-Azhar Univ. Cairo. Egypt.

** Faculty of Science, Botany Dep., Cairo Univ. Egypt.

Abou-Zabal aquatic depressions are three neighboring basins, created through the end of last century at Qalyoubiyah Governorate, 30 km northern east to Cairo, (Egypt). It filled with seepage and ground waters after basalt stone pit stopped. The present study was done to help its management program. Its physical, chemical and biological variables investigated through 5 successive seasons (2003-2004). Biological status concerned in phytoplankton structure, density, species composition and biomass (Chl a). Those variables correlated and interrupted deducing the trophic status for each depression. It is the priority of illustration for topography, climate and environmental status of those depressions. Water budget in the depressions is suffering from direct discharge of domestic wastewater, which can be associated with ecological threats. Recommendations and future prospects was decided for successfully mitigation and to define the best way for developing the area through the employment of those sustainable aquatic depressions, have been discussed.

17/18 MICROBIAL QUALITY OF RIVER NILE WATER AT DAMEITTA BRANCH, EGYPT

M.F. Fareed

Home Economic Department, Faculty of Specific Education, Tanta University,

Tanta, Egypt.

The present investigation was carried out to study the microbial quality of water samples collected from seven stations selected along Dameitta branch of Nile River during Winter 2006 to Autumn 2006. Some physico-chemical parameters such as temperature, transparency, and pH were monitored. Water temperatures of the examined water ranged between 17.5 during Winter and 29.5°C during Summer. Station 1 (El-Qanater) maintained the highest value of water transparency, while station 7 (Damietta) maintained the lowest one. The pH values were in alkaline side ranging from 7.5 during Winter to 8.5 during Spring. On the other hand, Gram-negative bacteria recorded the lowest count at El-Qanater (station 1) during Winter, while the highest was at station 7 (Damietta) during Summer. In addition some pathogenic G-negative bacteria namely; E. coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella cholerasuis, Shigella sp., Proteus vulgaris and Serratia liquefaciens were identified and enumerated. All bacteriological parameters studied showed that there was gradual increase in the bacterial counts from up-to down stream that is from El-Qanater to Damietta, which might indicate that Damietta Branch of River Nile was subjected to sewage pollution and this may cause many health problems for human and animals.

 

18/18 INFLUENCE OF AQUEOUS HERBAL EXTRACTS ON THE ANTIMICROBIAL ACTIVITY OF SOME ANTIBIOTICS AGAINST CLINICAL MICROBIAL ISOLATES

M.A. Kassem, N.H. Fanaki, M.A. Fawzi and F.S.E. Dabbous

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

The extracts of thyme and sweet marjoram are among the herbal plants having antimicrobial activity. The biostatic activitiesof thyme and sweet marjoram extracts against 35 isolates (Staphylococcus spp, E. coli, Ent. sakazakii, Ps. aeruginosa and C. albicans) was evaluated using agar dilution technique. The isolates were found to be variably susceptible. The strains of Staphylococcus spp were more susceptible compared to E. coli, Ent. sakazakii, Ps. aeruginosa and C. albicans. However, thyme extract was found to be more active against the tested Staphylococcus spp. Examining the growth patterns of S. aureus isolates in the presence of subinhibitory concentrations of thyme or sweet marjoram extracts showed that the isolates responded in a concentration-dependant manner. However, microbial cells regrowth after 2h contact occurred mostly when the growth patterns of the Gram negative isolates strains were tested. The sensitivity of Staphylococcus spp and Gram negative bacteria (28 isolates) to different antibiotics in absence and presence of 1/4 MIC and 10 mg/mL of thyme and sweet marjoram extract, respectively, was determined using disc agar diffusion technique. The presence of thyme extract enhanced (up to 81%) the activity of most of the tested β-lactam antibiotics against both Staphylococcus spp and Gram negative bacteria tested. This enhancement reached 100% when the activity of some β-lactam antibiotics was tested in presence of sweet marjoram extract. The bactericidal activity of tetracycline HCl, nitrofurantoin and cefoperazone sodium was evaluated separately in the presence of thyme extract and that of ampicillin sodium and cefuroxime sodium in presence of sweet marjoram, by time-kill method. It was always shown that the combined effect of the herbal extract and the antibiotic under test is better than that of the antibiotic alone where thyme-cefoperazone sodium combination exhibited the highest bactericidal action especially after 4h contact. In conclusion, the coadministration of aqueous thyme extract or aqueous sweet marjoram extract with antibiotic therapy could be highly recommended.

 

19/18 PRODUCTION AND PROPERTIES OF AN EXTRA-CELLULAR NEUTRAL PROTEASE FROM BACILLUS SPECIES

M.A. Mahmoud, M.H.M. Al-Agamy, S.S. El-Loboudy* and M.S. Ashour

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

The purpose of the present research was to investigate protease producing microorganism isolated from Egyptian soils obtained from different localities. Eighty nine out of 450 isolates (19.77%) were exhibited various degrees of proteolytic activities while 16 (17.97%) out of 89 protease-producing bacterial isolates were showed higher yield of protease. The most three potent isolates were identified as Bacillus sphereicus B-5, Bacillus subtilis B-6, and Bacillus cereus B-10 with activity of 326.1, 522.9 and 448.3 u/mg protein/ml respectively. The maximum biosynthesis of protease enzyme(s) was found to be optimal at 36-48 h incubation period, medium pH was adjusted at 7.2, optimal incubation temperature was at 30 0C, 1% gelatin and 1% casein were optimal substrate concentration.The tested carbon sources exhibited a remarkable inhibitory effect except glycerol, which stimulates the production of protease(s). The studied vitamins exerted a remarkable inhibitory effect on productivity of protease(s) except at 0.25, 0.5, 1, and 1% concentrations of cyanocobalamine, folic acid, biotin and nicotinic acid respectively showed similar effect in comparison with control. However, the tested amino acids exhibited variable effects on protease productivity.

 

20/18 PREVALENCE OF MULTIDRUG RESISTANT ENTEROCOCCI IN NOSOCOMIAL INFECTION

Sh.M. Husseiny, A.Kh. Jarousha* and A.M. Afifi*

Botany Department, Faculty of Science , Girls College for Art, Education & Science , Ain Shams University.

*Faculty of Applied Science, Al-Azhar University, GAZA.

This study showed that Enterococci are the leading causes of nosocomial infection like bacteremia, surgical wound infection, lower respiratory tract infection (LRTI), and urinary tract infection (UTI). These organisms are becoming resistant to many and sometimes all standard antibiotics. Most enterococcal infections are caused by Enterococcus faecales which are more likely to express traits related to over virulence. The remaining infections are mostly caused by Enterococcus faecium, a species virtually devoid of known overt pathogenic traits but more likely to be resistant to even antibiotics. Various clinical specimens were processed to find the prevalence rate of Enterococci and identify the species of clinical isolates of them. Enterococci were prevalent in 1.9% of the total nosocomial cases. The most active agents were linzolid, nitrofurantoin, chloramphenicol and ciprofloxacin, while amikacin, gentamicin, erythromycin and lincomycin showed moderate activities. As well as methicillin, ampicillin, tetracycline, aztreonam, cefuroxime and cefotaxim showed inactive effects. The available cephalosporins, such as monobactams, aztreonam or semisynthetic penicillins (naficillin, oxacillin) had no activity against Enterococci. The distribution of enterococcal cases showed the highest rate in LRTI (4.5%), blood stream infection (3%), surgical wound infection (1.9%), and UTI (0.8%) respectively.

21/18 BEHAVIOUR OF UREA AND UREA DERIVATIVES IN SOILS

B.A. Hamed*, O.E. Hammouda*, M.N.A. Hegazy and S.S. El-Sayied

* Plant Physiol., Botany Depart., Fac. of Sci., Beni Suef Univ.

Soil, Water and Environ. Instit., Agric. Res. Center, Giza

This work was carried out to investigate the effect of urea (U) and three of its derivatives [urea formaldehyde (UF), urea nitrate (UN) and urea phosphate (UP)] and the rates of their application (50, 100 and 200 mg N/kg soil) on the available content of nitrogen in the studied soils (clay or sandy soil) during five periods of incubation (1, 2, 4, 6 and 8 weeks). The experiment was carried out in Water and Environment Research Institute (SWERI), Agricultural Research Center (ARC), Giza. The results can be summarized in the following: 1- In all treatments, the application of the nitrogenous fertilizers increased the amounts of NH4-N and NO3-N extracted from clay and sandy soils. The effect of the used nitrogenous fertilizers on the concentration of NH4-N and NO3-N extracted from clay and sandy soils followed the descending order: U > UN > UP > UF. 2- The average values of NH4-N and NO3-N extracted from the clay soil increased in the second week of incubation then decreased gradually up to the end of the experiment (the 8th week of incubation). On the other hand, the corresponding values of the sandy soil increased up to the 4th week of incubation, then decreased up to the end of the experiment. 3- According to type of the fertilizer added, urea recorded in both the studied soils the maximum average of mineralization in both the forms of NH4-N and NO3-N. On the other hand, UF recorded, in both soils, the minimum average of mineralization whether in the form of NH4-N or the form of NO3-N. Collectively, the mineralization of the applied fertilizers was positively affected by the fertilizer type, the rate of application and the period of its incubation.

 

22/18 STUDY OF CD3CD56 NATURAL KILLER T CELLS IN

PERIPHERAL BLOOD IN PATIENTS WITH PSORIASIS

R.Y. Khalil*, F.M. Ali*, N.M. Sayed*, K.I. Mohamed* and R.A. Lotfi**

Microbiology and Immunology* and Dermatology and Venerology** Departments,

Faculty of Medicine, Ain Shams University

Background:Activated effectors memory T cells, NK and NKT cells have been suggested to play an important role in the pathogenesis of psoriasis. Objectives of this study was to evaluate the significance of   measuring T, NK, NKT cells before and after treatment and measuring naïve and memory T cells in peripheral blood of psoriatic patients correlating them with the clinical manifestation of the disease and to investigate their possible role in the pathogenesis of the disease Subjects and methods: Twenty selected psoriatic patients, (Group I) included 20 in exacerbation and (Group II) same 20 patients after treatment and complete remission. (Group III) included 20 healthy age and sex matched controls.Using flowcytometry, peripheral blood T, naïve T, memory T lymphocytes, NK and NKT cells were measured for group I and group III. Also peripheral blood T, NK and NKT cells were measured in group II to correlate the number of these cells in peripheral blood with the occurrence of remission. Results: This study showed a significant statistical difference between group I and group III as regards the mean value of NK cells, NKT cells (which were reduced in patients with psoriasis). While no statistically significant difference was found between the two groups as regards mean value of T lymphocytes. A significant difference was found between group I and group II as regards the mean value of NK cells and NKT cells; which was higher in group II. While no significant difference between the two groups was found as regards mean value of T lymphocytes. An inverse correlation was found between the PASI score (disease severity) and the mean value of total lymphocytes, T lymphocytes, NK and NKT cells among patients. Also there was an increase in the memory T lymphocytes and a decrease in the naïve T cells in the peripheral blood of patients with psoriasis. In conclusion: Deficiency of NK and NKT cells in the peripheral blood of patients with psoriasis with the inverse correlation found between the mean value of NKT cells and the disease severity (PASI score) indicates the role of these cells in the pathogenesis of psoriasis.   An increase in the number of these cells after treatment; however not reaching the normal values makes developing antipsoriatic drugs that can stimulate the immunoregulatory role and the number of these cells may be of help in treatment. Also the increase in the memory T lymphocytes and a decrease in the naïve T cells in the peripheral blood of patients with psoriasis suggest the presence of an antigen that stimulates the immune response.

23/18 EFFECT OF DIFFERENT UREA DERIVATIVES ON LIPID COMPONENTS AND LIPASE ACTIVITY OF SESAME (SESAMUM INDICUM)

B.A. Hamed*, O.E. Hammouda*, M.N.A. Hegazy and S.S. El-Sayied

* Plant Physiol., Botany Depart., Fac. of Sci., Beni Suef Univ.

Soil, Water and Environ. Instit., Agric. Res. Center, Giza

A greenhouse experiment was done to investigate effect of urea (U) and its derivatives [urea formaldehyde (UF), urea nitrate (UN) and urea phosphate (UP)] as well as their rates of application (0, 50, 100 and 200 mg N/kg soil) on lipid components (total fatty acids, total lipids, individual fatty acids, iodine number and oil %) of sesame plants cultivated on clay and sandy soils. The obtained results indicated that, the response of these components depended on type of the applied fertilizer, applied dose and type of the cultivated soil. According to effect of the type, UN recorded the best results followed by UP, UF then U. According to the applied dose, 200 mg N/kg soil recorded an inhibitory effect while the best dose was 100 mg N/kg soil then 50 mg N/kg soil. According to the effect of the soil type, clay soil was better than sandy one. The activity of lipase was affected by the applied dose according to the following descending order: 100 mg N/kg soil > 50 mg N/kg soil > 200 mg N/kg soil. The enzyme recorded higher rate of activity at the early germination stage then slowed down at the vegetative stage. The response of this hydrolyzing enzyme toward the type of the fertilizer used was in the descending order: UN > UP > UF > U. Clay soil scored enzymatic activity higher than the sandy one.

 

24/18 MODIFIED BIOFILM COLORIMETRIC ASSAYS: CORRELATION AND CRITICAL REVIEW WITH OTHER METHODS

M.S. Ali, T.R. Mohamed, S.I. Fouda, H.M. Hafni, and M.S.E. Ashour

Microbiology and Immunology Department, Faculty of Pharmacy Al-Azhur University, Cairo, Egypt

Two hundred and seventy four microbial isolates, including eighty one Candida albicans (C. albicans), seventy six Staphylococcus epidermidis (S. epidermidis), sixty two Pseudomonas aeruginosa (Ps. aeruginosa), and fifty five Staphylococcus aureus (S. aureus), removed from two hundred and fifteen intravenous catheters isolates were assayed for in vitro biofilms formation using modified polystyrene ninety-six microtiter tray (PST) and modified tube biofilms assays. Results were statistically analyzed. Modifications of the two colorimetric assays allowed excellent linear correlation between the two assay methods with reproducible results between runs. This indicates that the capacity to form biofilm by different clinical isolates is a stable trait for each isolate with a relative capabilities between isolates where some isolates were more biofilms forming than others. These results hold not only in case of bacterial clinical isolates but also in case of Candida albicans clinical isolates which probably extends the application of the modified methods to a wide variety of bacterial and yeast clinical isolates. The simplicity and easiness of the modified colorimetric assays in comparison with other bioadherence assays is discussed in the text with their correlation to microbial pathogenicities.

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