Vol. 13, January, 2006


M.A. Yassien

Faculty of Pharmacy, King Abdul Aziz University, Jeddah, Saudi Arabia

The postantibiotic effects (PAEs) were induced in Pseudomonas aeruginosa and Escherichia coli clinical isolates after short time (30 min) treatment with 2X- and 4X-MICs of fluoroquinolones (levofloxacin and ciprofloxacin), gentamicin, and β-Lactam antibiotics (cefoperazone, and cefotaxime). The PAEs of fluoroquinolones and gentamicin ( at 2X- and 4X-MICs ) on P. aeruginosa and E coli isolates were in the ranges of 1.0-4.2h and 1.2-4.6h, respectively. In addition, these PAEs induced reduction of elastase activity to the range of 23-54% and 44-63%, and of protease activity to the range of 48-78% and 68-84% in P. aeruginosa, respectively. Concerning E coli, PAEs of these agents reduced the hemolysin activity to the range of 54-83% and 78-88%, respectively. The PAEs of fluoroquinolones on the bacterial regrowth and virulence factor activity were more than that of the gentamicin, and the highest PAE was observed with levofloxacin. The PAEs of β-Lactam antibiotics induced weak effect (ranged between 0.3 and 0.9h) on the regrowth of the tested isolates, in addition, no significant (P≤ 0.05) change in their virulence factors activity was observed. The PAEs of only 4X-MIC fluoroquinolones caused alteration in the outer membrane proteins (OMP) of P. aeruginosa (reduction in the expression of 41 and 42 KDa and overexppression of 38 and 51KDa) and of E coli (reduction in 36 and 38 KDa). According to the obtained results, the PAEs of fluoroquinolones and gentamicin induced significant suppression in the P. aeruginosa elastase and protease activity, and E coli hemolysin activity. In addition, the PAEs of high concentration (4X-MICs) of fluoroquinolones caused alteration in the OMP of P. aeruginosa and E. coli.


M.H.M. Al-Agamy

Microbiology and Immunology department, Faculty of Pharmacy,

Al-Azhar University, Cairo, Egypt.

Out of twenty one broad spectrum β-lactamase (BSBL) producing E. coli strains, eighteen strains (85.71%) were found chloramphenicol (CHL) resistant. Existence of five different CHL resistance genes i.e. catI, catII, catIII, catB and cmlA genes, were checked using polymerase chain reaction (PCR) specific primer pairs. Only catI gene was detected in eight strains (44.44%), whereas cmlA was found alone in one strain (5.55%). The remainder nine strains (50%) showed coexistence of both catI and cmlA genes. These findings proved that the enzymatic inactivation by chloramphenicol acetyltransferase (CAT) due to catI gene was more frequent than non-enzymatic efflux mechanism by cmlA gene. In addition, both mechanisms were more likely to coexist in the strain than to present alone. Absence of catI gene was linked to comparatively low CHL resistance phenotype (MIC = 16 ug/ml), whereas catI existence either in the absence of cmlA or in its existence is tied to high CHL resistance phenotype (MIC 32 to > 128 µg/ml). This investigation is devoted to studying the molecular genetic mechanisms for CHL resistance in BSBL-producing E. coli strains in comparison with those in extended spectrum β-lactamase (ESBL) producing E. coli strains (Al-Agamy, 2004).


M. Yassien and S. Al-Ansari*

Faculty of Pharmacy, Faculty of Medicine*, King abdul Aziz Universaity, Jeddah, Saudi Arabia

The effect of fluoroquinolones (ciprofloxacin, ofloxacin, and levofloxacin), clindamycin, β-lactams (cefoperazone, cefotaxime, cefepime), streptomycin, and vancomycin on the adherence and biofilm formation by Staphylococcus aureus (12 clinical isolates) was studied. In the presence of 1/2 MIC, 1/4 MIC and 1/8 MIC, the optical density of the formed biofilms on plastic surfaces was reduced to 24-59.9%, 32.4-76.7% and 49.7-88.5% of the controls, respectively. Treatment of the preformed biofilms with high concentrations (25-200 μg/ml) of the tested agents caused reduction in the optical density of the adherent biofilms to a range from 52.3 to 87.7% of the control. In an in-vitro model of vascular catheter colonization, the tested subinhibitory concentrations reduced the percentage of the viable adherent cells to 32.1-71.6%, 42.5-85.6%, and 60.3-95.3% of the controls, respectively. The tested fluoroquinolones and clindamycin are significantly more active than the other tested agents, and levofloxacin was the most active one. The vascular catheter segments precolonized with S. aureus for 24 hr and exposed to 50 μg/ml (4-31 times MIC) of the tested fluoroquinolones and clindamycin for 2 hr showed few viable adherent cells (7-13 CFU/segment), while no adherent viable cells were cultured in the presence of 100 μg/ml(8-62 times MIC). Also, the tested subinhibitory concentrations reduced the percentage of the viable bacterial cells adherent to the surface of human lung epithelial A549 cells to the range of 30.1-79.2%, 41.1-89.3%, and 60.9-96.2% of the control, respectively. Treatment of the A549 cells, preattached with bacterial cells, with the tested agents at concentrations of 5, 10, and 20 μg/ml (1/4-50 times MIC) reduced the range of the percentage of the adherent cells to 53.2-88.3%, 33.8-79.2%, and 27.2-68.1% of the control, respectively. The superior activity of the tested fluoroquinolones and clindamycin was also observed. The obtained data show that subinhibitory concentrations of ciprofloxacin, ofloxacin, levofloxacin, and clindamycin efficiently reduced the biofilm formation and adherence of S. aureus to the surfaces of plastics, vascular catheters, and human lung epithelial A549cells. Also, higher concentrations ( MIC) of fluoroquinolones and clindamycin were able to eradicate the adherent S. aureus.


Y.A. El-Zawahry; A.M. Galal; M.E. Abou El-Hawa; A.E. El-Sayed; E.A. El-Shirbiny and S. Abd El-Shafi

Botany Department, Faculty of Science, Zagazig University, Egypt

The induced systemic resistance in cucumber plants against zucchini yellow mosaic virus (ZYMV) by bacteria was studied. Ten soil bacteria were purified, identified and grown on soil extract broth to screen their antiviral activity against ZYMV. The virus was identified by ELISA technique. This study included 4 experiments: 1st experiment- equal volumes of each liquid bacterial culture and sap containing virus were mixed then inoculated into first leaf of cucumber (in vitro), 2nd experiment- cucumber leaves treated by bacterial isolate before virus infection (pre inoculation), 3rd experiment- cucumber leaves treated by bacterial isolate after virus infection (post- inoculation) and in the 4th experiment- cucumber seeds were soaked in bacterial culture and cultivated, then cucumber leaves were inoculated with the virus inoculum. Also, optimization factors for growth and antiviral production for the most potent three bacterial isolates were determined. The results of the present study showed that all bacterial treatments increase the cucumber growth and inhibit the viral symptoms in all experiments. Corynebacterium equi, Bacillus firmus and Pseudomonas viridilivida were the most potent bacteria since they showed percentage of viral inhibition in 1st experiment 95, 90 and 90; in pre experiment 83, 55 & 65 and in the post exp. 75, 85 & 85 respectively. Soaking of cucumber seeds in liquid bacterial culture of the same bacteria for 24 hours inhibit the virus infectivity by 80, 70 and 80% respectively. The highest inhibition of virus symptoms was obtained when the bacteria were grown for 3 days at 35-37ْ C and pH 7. The optimum carbon, nitrogen and phosphorous sources for growth of the three isolates and antiviral activity were glucose, yeast extract and K2HPO4 respectively. The maximum increase in chlorophyll content was recorded by C. equi, B. firmus and P. viridilivida cultures where it was 6.60, 6.75 and 6.80 mg total chlorophyll/ g tissue compared to 3.68 for viral control. The application of bacterial isolate to cucumber leaves increase the dry matter, organic matter, crude protein, crude fiber, ether extract, nitrogen free extract and ash in comparison with control. SDS-polyacrylamide gel electrophoresis showed that a new protein band has molecular weight 18.43 kDa was induced in the intercellular fluid of cucumber leaves treated with bacterial culture, cell free supernatant and pellets of P. viridilivida.


F.H. Ahmed*; W.M. Abu El Wafa*; M.S. Sharaf ** and E.A. Saleh **

* Microbiol. Dept., National Organization for Drug Control and Research, Giza, Egypt.

** Agric. Microbiol. Dept., Fac. Agric., Ain Shams Univ., Cairo, Egypt.

Out of 103 local Streptomyces isolates were isolated from different Egyptian soils, only twelve of them were vitamin B12 producers representing 11.65% of total number of Streptomyces isolates and the level of vitamin B12 yield ranged between 0.78 to 1.70 µg ml-1. The maximum production of the vitamin was produced by the Streptomyces isolate SW1, being 1.70 µg ml-1, followed in descending order by Streptomyces isolates SW7, SR1A and SR1, being 1.45, 1.40 and 1.38 µg ml-1, respectively. The four efficient Streptomyces isolates were identified up to species according to the keys proposed by Shirling and Gottlieb (1968 a, b & 1972) and Bergey,s Manual (1974) as Streptomyces baarnensis strain SW1; Streptomyces nigrifaciens strain SR1; Streptomyces halstedii strain SR1A and Streptomyces clavifer strain SW7.


A.A. Zeidan, M.M. Aboulwafa, M.A.M. Yassien and N.A. Hassouna

Department of Microbiology and Immunology, Faculty of Pharmacy,

Ain-Shams University

A total of 650 Streptomyces isolates recovered from 129 Egyptian soil samples were subjected to primary screening for testing their ability to produce glucose isomerase (GI) enzyme. Fourteen isolates were found to produce promising levels of GI and hence were subjected to a more quantitative secondary screening. The highest GI level was produced by the Streptomyces isolate coded S.82-5 which was identified as a strain of S. griseostramineus. For optimization of the enzyme production conditions, the effects of different physiological factors on growth and GI productivity of this isolate were studied. Of the protein sources, corn steep liquor (2.5%, w/v) resulted in the highest GI productivity. Incorporation of yeast extract (1%, w/v) or soy flour extract (2%, w/v) as additional protein sources further increased the microbial growth and GI productivity. Regarding the carbohydrate sources, the highest GI productivity by S. griseostramineus was obtained in the presence of 0.5% (w/v) xylose. The presence of Mg++, Fe++, or Zn++ enhanced the GI production. In addition, the optimum pH range, temperature, and incubation period were 6.0-8.6, 30oC, and 96 h, respectively. Further improvement in GI production was observed after the addition of 0.01% (w/v) L-valine. According to the obtained results, high GI production by S. griseostramineus was achieved by using a complex fermentation medium, designed CYX, which contained corn steep liquor (2.5%), yeast extract (1%) ammonium mono- and dibasic phosphate(0.4% each), L-valine (0.01%), xylose 0.5% and magnesium sulphate (0.1%), and its pH was adjusted to neutrality.


A. Elsawy and M. Mostafa*

Microbiology & Immunology Dept. and Pediatric Dept.*, Faculty of Medicine,

Al-Azhar University

Neonatal bacteremia is a low incidence, high-risk disease with many sepsis work-ups performed to detect a single case. Seventy-two hours of antibiotic therapy have been traditionally recommended pending negative culture results. Improved culture media and new technology integrated into blood culture systems could shorten incubation time required to detect positive culture results. This would then change the length of antibiotic therapy in the management of the newborn infant with suspected sepsis. Blood samples from 150 newborn infants with suspected sepsis were tested to evaluate the time of incubation to detect positive blood cultures using BACTEC 9050 (Becton Dickinson, Sparks,Md.). The vast majority (64%) of infections were caused by Gram-positive organisms. Coagulase negative Staph. "CONS" were the most common late-onset pathogens. The risk of infection increased in patients with increasing duration of ventilator support. So; successful interventions should improve survival, shorten mechanical ventilation and hospital stay, decrease antibiotic usage, and reduce the high cost of caring for very low birth weight (VLBW) infants.


A.A. Zeidan, M.M. Aboulwafa, M.A.M. Yassien and N.A. Hassouna

Department of Microbiology and Immunology, Faculty of Pharmacy,

Ain-Shams University

Improvement of glucose isomerase (GI) productivity by Streptomyces griseostramineus S.82-5, isolated in our previous study from Egyptian soil, was carried out through genetic manipulation. Mutants were selected on the bases of resistant to 2-deoxyglucose (2-DG) by the gradient plate technique. Seven mutants resistant to 2-DG were obtained. From these, five mutants (UVDGr-1 – UVDGr-5) have resulted from UV light treatment and the others (DGr-1 & DGr-2) are spontaneous mutants. Only the mutant strain coded UVDGr-3 could constitutively produce high levels of GI when cultivated in a xylose-free medium. Maximum specific GI production by the selected mutant was obtained in the presence of 1% (w/v) glucose as a carbohydrate source after 96 h of incubation. Production of GI by mutant S. griseostramineus UVDGr-3 was scaled up from 50-ml broth in shake flask to 7-liters laboratory fermentor. An attempt was carried out to immobilize the GI-containing cells of the S. griseostramineus UVDGr-3. Cross-linking of the cell concentrate, the cell homogenate, and the whole culture broth of the selected mutant strain with 0.5% (w/v) glutaraldehyde resulted in formation of immobilized GI preparations that could be used successfully for isomerization of glucose to fructose several times. Addition of polyethyleneimine to the culture broth after glutaraldehyde treatment significantly increased the activity yield of the immobilized preparation and enhanced its recovery from the culture. According to the obtained data, the S. griseostramineus UVDGr-3 is particularly valuable in large-scale production of the enzyme in a cost-effective process. Direct treatment of the culture broth of this strain with glutaraldehyde and polyethyleneimine could be considered an extremely simple and economic method for obtaining an immobilized GI preparation.




E.M. Hoballah*, L.I. Zohdy* and I. Hosny**

* Agricultural Microbiology Department, National Research Center, Cairo, Egypt.

** Agricultural Microbiology Department, Faculty of Agriculture, Cairo University.

The antimicrobial potency of hexane extracts of 32 Egyptian medicinal plants selected on concepts included anti-infectious effect, common distribution and the commercial considers was bio-assayed against 22-test microorganisms, 13-bacteria, and 9-fungi. Bacterial test organisms included phytopathogenic and non- phytopathogenic, Gram-positive and Gram- negative strains. The tested fungi included strains affiliated to Zygomycetes; Ascomycetes and Deuteromycetes classes. Hexane solvent was selected for extracting low polar medicinal plant constituents and then tested for its antimicrobial effects using diffusion and dilution agar methods. Results signified that the probed different parts of the tested medicinal plants exerted varied antimicrobial potency, however, at dissimilar intensities. The most effective extracts against non-phytopathogenic bacteria were C. proximus, J. phoenicea and A. herba-alba, whereas, A. majus, D. peregrinum and C. droserifolia which showed moderate antibacterial potency toward the non-phytopathogenic tested bacteria. The phytopathogenic bacteria provided resistant responds toward most of extracts tested except A. herba-alba, C. proximus and C. rotundus extracts that, showed low potent effects against the investigated phytopathogenic bacteria. The anti-phytopathogenic fungal effects of the investigated medicinal plant extracts showed high active potency toward Fusarium solani, Aspergillus flavus, A. niger and Penicillium digitatum by A. majus, P. harmala, G. capillaris and C. proximus respectively. On the other hand, C. albicans inhibited only by A. herba-alba and A. majus extracts. MICs were determined for the most six medicinal plant extracts that showed highest activities against six phytopathogenic microorganisms included 3-bacteria i.e. Erwinia carotovora, E. chrysanthemiand Xanthomonas campestris and 3-fungi i.e. F. solani, P. digitatum and Rhizopus sp. The results show that, A. herba-alba, C. proximus and J. phoenicea had effects against E. carotovora by 9.4, 8.6 and 79 g/L respectively. Also, C. proximus extract showed MIC value with 21.5 g/L against the tested fungi.


M. Nasr*, M.Z.Sedik**, Z.S. Tawfik* and I. Hosny**

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

** Agricultural Microbiology Department, Faculty of Agriculture, Cairo University.

The effect of soil pollution with heavy metals (Pb2+, Cd2+, Cu2+, Zn2+, Cr5+, Ni2+ and Hg2+) on soil microorganisms and soil organic matter decomposition was studied. Periodical changes in total microbial population and total cellulose decomposers, as affected by three concentrations (T1, T2 and T3) of each metal, were determined. The intrinsically metal-tolerant microorganisms and/or adapted ones were determined. The decomposition of organic soil matter was followed up. Low-metal concentration (T1) resulted in slight suppression in the microbial population in soil treated with either Pb2+, Cd2+, Cu2+, Zn2+, Cr5+ or Ni2+, while 75-91% reduction in microbial counts was recorded in Hg2+-treated soil. A drastic reduction in counts of 92-98 was recorded in both T2and T3of each metal. 3% of the initial population were Pb2+- and Cr5+-intrinsically resistant, while <0.1% were intrinsically resistant to the other five metals. Concerning the adapted microorganisms, 17-62% of the initial microbial counts successfully developed at T1 of Pb2+, while few numbers were developed with Cd2+, Cu2+, Zn2+, Cr5+ or Ni2+. No acquired resistance was recorded in presence of Hg2+-treated soil. Total cellulose decomposers of 104 MPN.g-1 were initially present in control soil and remained fairly constant through the experiment. These microbes proved to be sensitive towards the three concentrations of each of the tested metals. About 93% of the initial organic carbon was oxidized in control soil. Application of each of the tested metals caused a marked reduction in organic matter decomposition. Pb2+ was less toxic when compared with other metals, while the highest suppressive oxidation reduction was recorded for Cd2+, Cu2+, Cr5+ or Hg2+. According to their toxicity, heavy metals could be arranged as follow: Hg2+ ≥ Cr5+ ≥ Cu2+ >   Cd2+ > Zn2+ > Pb2+ ≥ Ni2+.


H.A. Abdel-Salam

Department of Microbiology, Faculty of Pharmacy, Zagazig University

The minimum inhibitory concentration for 9 antibiotics against 10 Clostridium difficile, 5 Clostridium perfringens and 5 Clostridium colinum isolates, were determined by E-test and agar dilution methods. In disk diffusion method, the most effective drugs are β–lactams; aztreonam, ampicillin/ sulbactam, imipenem and penicillin G with activity of about 90, 85 and 80%, respectively, while the lesser effective drugs are and gentamicin (55%). The MIC range, MIC50 and MIC90 values by agar dilution method revealed that the most effective drugs are azteronam then ampicillin/ sulbactam but, penicillin G and ciprofloxacin showed lower activity with high MICs values. E-test results showed higher percentage of agreement with agar dilution than disk diffusion method. Moreover, the agreement is 100% with penicillin, aztreonam and imipenem, 95% with ampicillin/ sulbactam, rifampicin and gentamicin, 90% with ciprofloxacin and 80% with cefotaxime and metronidazole by the used methods. In conclusion, E-test is easy to perform and read and yield good results and well-correlates with agar dilution method and being suitable method for anaerobic bacteria. The variability and discrepancy in results might be due to the test conditions, anaerobiosis, type and origin of medium and low number of tested isolates. However, it is recommended, particularly in serious anaerobic infections and considered efficient for anaerobic bacteria even with few isolates.

12/13 ISOLATION AND IDENTIFICATION of purple non-sulfur bacteria (Rhodospirillaceae) from River Nile (Aswan – Egypt)

M.S. Shabeb, M. Younis and A. Shoreit*

Botany Department, Faculty of Science, South Valley University, Aswan, Egypt.

*Botany Department, Faculty of Science, Assiut University, Assiut, Egypt.

Seventy isolates of purple non-sulfur bacteria (Rhodospirillaceae) were isolated from rhizosphere, rhizoplane and water samples in the vicinity of Eichhornia crassipes plant at different localities from River Nile (Aswan- Egypt). These isolates comprise four different genera with eight different species of purple non-sulfer bacteria. Rhodospirillum was the most common genus and represented by two species, Rhodospirillum rubrum and Rhodospirillum molischianum. Rhodopseudomonas was the second in the frequency which represented by three species, Rhodopseudomonas blastica, Rhodopseudomonas palustris and Rhodopseudomonas rutila. Rhodocyclus genus was represented by two species, Rhodocyclus gelatinosus and Rhodocyclus tenuis while Rhodobacter genus was represented only by one species, Rhodobacter capsulatus. The obtained results in this paper considered as A microbial wealth and a key for different applied studies on these ecological distinguished organisms.


E.F. El Ghazzawi, S.M. Kandil*, Gh.F. Helaly**

Department of Microbiology, Medical Research Institute, Alexandria University, Alexandria, Egypt

*Department of cardiology and internal medicine, Medical Research Institute, Alexandria University, Alexandria, Egypt

Cardiovascular disease is one of the leading causes of death worldwide and is responsible for 45% and 24.5% of deaths in the western world and the developing countries respectively. Gender differences play a role in the incidence and prevention of cardiovascular disease. Incidence of myocardial infarction in women increases significantly after the menopause, and mortality through coronary heart disease is higher amongst women than men. Results of several studies have suggested that chronic infection may be a risk factor for cardiovascular disease. However, data concerning that issue particularly among menopausal women are spares. One of these chronic infections is by Helicobacter pylori (H. pylori). Its role as a determinant of cardiovascular disease is controversial. This study was carried outto determine whether previous exposure to H. pylori is associated with increased risk for cardiovascular events in relation to different risk factors and laboratory investigation. A total of 40 menopausal women with incident or prevalent ischemic heart disease and 20 age and sex matched control subjects were included. Patients and controls underwent a standard physical examination and had blood samples taken for serological analysis for H. pylori IgG titers, determined by an enzyme-linked immunosorbent assay (NovaTec Immundiagnostica GmbH, Dietzenbach, Germany). For the cases, measurements of some cardiovascular risk factor levels were done. The mean IgG titer for H. pylori was significantly elevated in the cases than controls (p<0.05). It was higher among patients of low socioeconomic class. Patients suffering from stable or unstable angina have a great prospect to be chronically infected with H. pylori. The overwhelming risk factors were stress, anxiety, depression, obesity, and hypertension. Patients with high body mass index (BMI) were positive for the H. pylori IgG titers compared to 50% of patients with normal body weight, this difference was statistically highly significant (P<0.0001). The mean IgG titers for H. pylori were significantly elevated among hypertensive patients than normotensive ones (P<0.02). Ischemic patients whether diabetic, hypercholesterolemic, anemic, with high levels of triglycerides, uric acid abnormality, detectable C-reactive protein have a certain risk to be chronically infected with H. pylori. In conclusion, there is some evidence of an association between Ischemic heart disease and serological markers of persistent infection with H pylori specially if accompanied with confounding risk factors.


N.E. Yousef, M. Abou Hashem, M.H. Eid* and I. Badawi #

Department of Microbiology- Pharmacognosy, Faculty of Pharmacy,Zagazig University

Pedodontic Department, Faculty of Oral and Dental Medicine, Cairo University*

Department of Pharmacology, Faculty of Medicine, Copenhagen University, Denmark#

Postantifungal effects (PAFE) of natural (latex sap 1 and latex sap 2) and synthetic antifungal agents (nystatin, amphotericin B, fluconazole, ketoconazole and 5- fluorocytosine) were measured against twenty five oral Candida albicans isolates. The natural latex sap antifungals exhibited the highest postantifungal PAFE. A marginal PAFE was observed for ketoconazole and little or none for fluconazole. The mean duration of PAFE of latex sap 1, latex sap 2, nystatin, amphotericin B, 5- fluorocytosine, ketoconazole and fluconazole were 3.8 h, 3.6 h, 3.3 h, 3.0 h, 2.8 h, 0.4 h and o.15 h, respectively. Glycosidic activities of the tested C. albicans isolates and reduction in their adhesion to buccal epithelial cells (BECs) during PAFE following exposure for 1 h to the tested antifungal agents were determined. Latex saps showed marked increase in glycosidic activity while ketoconazole and fluconazole exhibited the little glycosidic activity. The mean percentage reduction in yeast adhesion to BECs during PAFE were 80 %, 79 %, 77 %, 76 %, 76 %, 14 % and 12 % on exposure to latex sap 1, latex sap 2, nystatin, amphotericin B, 5-fluorocytosine, ketoconazole and fluconazole, respectively.


A.A. Abdelrahman and K.M. Biomy*

Department of Microbiology, Faculty of Pharmacy, Suez Canal University.

* Department of Obstetrics and Gynaecology, Faculty of Medicine,

Zagazig University

Pathogenic bacteria such as E. coli, Staph. epidermidis and Bacteroid distasonis were observed to migrate readily along polymeric fibers ( nylon, silk, polypropylene and polyethylene) on the surfaces of nutrient and blood agar.   Migration speed was greatest for E. coli and slowest for Bacteroid distasonis.   Nylon was found to support bacterial migration to lowest extent. Antiseptics such as cetrimide, benzalkonium chloride, chlorhexidine, ethylene diamine tetra-acetic acid (EDTA), polyvinyl pyrolidone and sodium dodecyl sulfate (SDS) were tested for efficacy as inhibitors of microbial migration along polymeric fibers. Cetrimide was the best antiseptic used in reduction of microbial migration along the four polymeric fibers.



N.E. Yousef

Department of Microbiology, Faculty of Pharmacy, Zagazig University

Twenty bacterial isolates capable of degrading polycaprolactone plastic polymer (PCL) by clearing the opacity of the polymer containing basal mineral salt solid medium were isolated, purified and identified as Pseudomonas aeruginosa (12 isolates), Ps. fluorescence (5 isolates) and Alcaligenes faecalis (3 isolates). The isolates exhibited extracellular PCL depolymerase, esterase and lipase activities in crude enzyme preparation. Production of the enzymes was strongly influenced by nutritional factors which acted as inducers or repressors. Depolymerase and esterase enzymes were induced by PCL upon which they acted. However, glucose repressed the enzymes. Lipids activated lipase production with the greatest induction attributable to tween 80 while, fatty acids such as stearate decreased lipase activity. Ps. aeruginosa having the highest depolymerase and esterase activities was selected for studying factors affecting PCL degradation and enzymes activities. Ps. aeruginosa showed optimum depolymerase and esterase activities at temperature 37ºC, pH 7 and PCL as substrate. The enzymes were stable up to 50ºC and were inhibited by surfactants, EDTA and soyabean enzyme inhibitor.


E.H.A. Nashy and A. M. Ahmady *

Department of Chemistry of Tanning materials and proteins, National Research Center, Dokki, Cairo, Egypt

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

Many fungal species can utilize chicken feather as their sole carbon and nitrogen sources. Because enzymatic conversion of native keratin of animal hair and skin is of interest for skin dehairing. Among ten of the tested fungal strains; an Aspergillus nodulans strain was selected for partial characterization of produced keratinase enzyme and the visual evaluation of its effect on skin quality. Optimal requirements for skin dehairing conditions by keratinase included contact time, reaction temperature, pH values and crude enzyme concentration. Experimental results revealed that optimal keratinae activity by standard assay of the selected mold enzyme was exhibited at pH 8.0 for a contact time of 2 hr. at 55 ºC. Also, optimal keratinase dehairing activity on animal hide was achieved at 48 hr. of incubation at pH 8.5, temperature 35 ºC, shaking frequency of 140 rev/min at Crud enzyme concentration of 6%. Scanning electron microscopy (SEM) was applied to confer the good skin quality after treatment with keratinase enzyme. Results suggested the possibility of using this fungal enzyme for skin dehairing instead of the chemical traditional method.


A.M. Ahmady and E.H.A. Nashy*

Department of Microbiology and immunology, Faculty of Pharmacy, Cairo University.

* Departmentof Chemistry of Tanning materials and proteins, National Research Centre, DoKKi, Cairo, Egypt.

The incidence of resistance among Gram-negative bacteria to antibiotics with special reference to β-lactams was determined among 326 uropathogenic strains. E.coli strains was the most predominate bacterial isolates representing about 67% of isolated strains, showed highest sensitivities to β-lactams, aminoglycosides and quinolones, with only about 3% of them showing multiple antibiotic resistance. In contrast, Ps. aeruginosa seemed to generally be the most resistant tested species. The six potent antibiotic tested (≥ 45% active against the tested strains); imipenem (IPM, 73-100%), ciprofloxacin (CIP, 75- 98%), amikacin (AK, 66- 98%), both cefotaxime and cefepime(CTX, FEP, 55- 98%), ceftazidime (CAZ, 50-95%) according the species tested. Ps.aeruginosa being susceptible only to Ak, CIP, CAZ (91,91 and 86% respectively) and IPM only active against 73% of the tested strains. Among Gram-negative bacterial strains; only   53 isolates (about 16%) were resistant to cefotaxime (CTX) with other third or fourth generation cephalosporin, ciprofloxacin (CIP) or amikacin (AK). These CTX resistant strains including Ps. aeruginosa (12 isolates), Pr. mirabilis (11 isolates,), E. cloacae (10 isolates), C. freundii (8 isolates) and each of Kl. pneumoniae and E. coli (6 isolates). Out of 53 CTX resistant isolates only 15 strains (about 28%) were producers of extended spectrum β-lactamases (ESBLs). These included 3 isolates of each of Pr. mirabilis, Ps. aeruginosa and C. freundii and 2 isolates of each of Kl. pneumoniae , E.coli and E. cloacae. All of these isolates were resistant to both CTX and CAZ with MIC range between 32 ->64 μg/ml but were sensitive to cefoxitin (FOX, MIC ≤ 4 μg/ml). AmpC β-lactamases were detected in 16 isolates (about 30%); 7 strains of E.cloacae, 4 strains of Pr.mirabilis, 2 strains of each of C. freundii and E. coli and one strain of Ps. aeruginosa. All of these isolates were resistant to FOX (MIC 64-512 μg/ml)in addition to CTX,CAZ with or without FEP resistance. Induction of β-lactamase was studied on early log-phase cells on the AmpC producing strains and induced with cefoxitin. Only 2 strains of E. cloacae and one Pr. mirabilis were significantly inducible but β-lactamase production by one of them (strain no. 22 of E. clocae) was highly inducible with cefoxitin (25 fold)   suggesting dependence on active protein synthesis. This inducible strain showed resistance to all tested β-lactams except IPM. From the substrate profile, this enzyme displayed a typical cephalosporinase properties. Its activity was fully or highly inhibited by (antibiotics, β-lactams), cabenicillin, cloxacillin, cefoxitin, aztreonam, cefotaxime, cefuroxime, or (ions), Hg++, iodine and Cu++ but weakly inhibited by clavulanic acid. Therefor, this enzyme was considered as belongs a serine protease group 1,    


E.H. Ashour; M.M. Kassem; I.A. Ismail and M.M. El-Gawady

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

The study was performed in a fish farm, as a natural state, located in the Manzala lake zone, northeastern Nile Delta and associated with Bahr El-Baqar drain. Four sites were designed along the direction of water stream in the farm (as farm inlet, stirring point, farm and farm outlet), to follow the changes in abiotic parameters, certain heavy metals and bacterial populations in water samples during summer and winter and their effectiveness on the quality of farming fishes. Farm inlet sample recorded the highest values of TSS, COD, BOD, Ammonia and nitrite that is interpreted high environmental pollution accompanying water effluents. However, salinity, DO and nitrate values were pronounced increased in water farm sample. The results also indicated that the water content of the measured heavy metals was not similar. Zinc was superior contaminant, its value reached to 1130 µg/L. However, maximum lead concentration was 29.70 µg/L followed by copper (14.2 µg/L). Cadmium was inferior of these metals content. Statistically, means differences of metals amounts were highly significant in water samples (p<0.01). Farm inlet water was significantly contained the highest amounts of all metals tested. Among the five types of captured fishes, liver and muscles of Claris spp. was significantly the highest accumulated to measured metals. The detected amounts of heavy metals in fish muscles were clearly lower than the legal limits of different countries and WHO guidelines. Bacterial content determinants appeared significant differences between the four sampling sites where the bacterial loading was reached to the lowest count in either farm or farm outlet water samples. The measured counts of faecal coliform in water samples are mostly within legal limits of the WHOguidelines. Subsequently, the total aerobic bacterial count was not high in the edible skin of fish (up to 7.7X102 cfu g-1) and was also within the legal limits WHO guidelines. Gut of Claris spp. were significantly contained the highest number of bacterial counts (4.5X108 cfu g-1), that is bacterial load in gut 200 times higher than water bacterial content. The highest total coliform counts were seen in gut of Sarotherodon galilaeus, 2.15X107 cfu g-1. Gut of Claris spp. was highly contained faecal coliform, reached to 1.2X107 cfu g-1. Also Claris spp. skin was carried the highest faecal coliform counts (5X10 cfu g-1). The highest count of E. coli (2.2X105 cfu g-1) was observed in the gut of Claris spp. Skin of Claris spp. was the most polluted with E. coli, where it contained 1.35X10 cfu g-1. Enterococci were completely absent in the skin of all fish samples. It is clear that water and fish studied samples contain enteric bacteria, including isolates that are known to be pathogenic for human beings. This may be a threat to public health either when fish are handled, consumed by man or restocked elsewhere.


M.S. Beltagi, H.A. Soliman*, A.M. Diab, W.E. Abdallah

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

*Chemistry Department, Faculty of Science, Suez Canal University, Ismailia, Egypt.

The current investigation was conducted to assess the antimicrobial bioactive fractions of leaf extracts of Avicennia marina (Forssk.) Vierh. sampled from three stands (13 sites) along the Red Sea coast and one stand (7 sites) located in Southern Sinai coastal area of Egypt during August and September, 2000. The phytochemical screening of A. marina leaves revealed the presence of flavonoids, carbohydrates and/or glycosides, sterols/terpenes, saponins, alkaloids and tannins. The results of the bioassay (disc diffusion technique) of the bioactive constituents of the crude extracts (5 solvents) showed variable antimicrobial effects against the tested microorganisms (ATCC bacterial strains and clinical bacterial isolates). Chloroform and ethyl acetate leaf extracts showed high and medium antimicrobial activity, respectively, compared to the low antimicrobial activity of methanol, n-hexane and n-butanol extracts within the applied concentration range (100 – 500 µg/disc). In accordance, a close correlation existsbetween the use of A. marine in folk remediation and its biological activity.


M.A. Ramadan*, A.M. Hashem*, A.K. Ahmady* and A.S. Khairalla**

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

**Department of Microbiology and Immunology, Faculty of Pharmacy, Bani Sweif University.

The study was conducted to determine the Post-antifungal effect (PAFE) induced by polyene and azole antibiotics against clinical isolates of Candida species. A total of 95 clinical Candida isolates were collected from different clinical specimens, and were identified as C. albicans (61); C. tropicalis (16); C. glabrata (15); and C. Krusei (3). The antifungal sensitivity pattern of the tested isolates was determined by the disc diffusion method on RPMI-1640 medium. According to the National Committee for Clinical Laboratory Standards (NCCLS) criteria, 19 isolates (20%) were found to be susceptible to fluconazole;2 (2.1%) were susceptibleــdose dependent (SDD); and 74 (77.9 %)were resistant to fluconazole. While according to the Rosco diagnostics criteria, 80 isolates (84.2%) were found to be susceptible to nystatin;14 (14.7%) were intermediate to nystatin; only one isolate (1.1 %)was resistant to nystatin; 56 (59%) were susceptible to ketoconazole; 12 (12.6%) were intermediate to ketoconazole; 27 (28.4 %)were resistant to ketoconazole, 66 (69.5%) were susceptible to miconazole; 24 (25.3%) were intermediate to miconazole; and 5 (5.2 %)were resistant to miconazole. Determination of the minimum inhibitory concentration (MIC) using the agar dilution method revealed that the MICs ranged from 0.14-37 μg /ml for nystatin; 0.125-128 μg /ml for fluconazole; 0.06-32 μg /ml for ketoconazole; and 0.125-8 μg /ml for miconazole. Four isolates of Candida species were exposed for a period of 1 h to three concentrations (4, 1, and 1/4 MIC) of each of the following: nystatin, fluconazole, ketoconazole, miconazole, and combined (nystatin ـ ketoconazole). Following removal of the antifungal agent, two experiments were conducted. Firstly, the determination of the PAFE using a spectrophotometric method, which revealed that the duration of the PAFEs of nystatin, fluconazole, ketoconazole, miconazole, and the combined (nystatin-ketoconazole) ranged from: (0.3-3 h), (0.3-1.2 h), (-1.4- 1 h), (0.3- 7.7 h), (0.7- 8 h) respectively, depending on the concentration and the species tested. Secondly, the use oftransmission electron microscopy for the investigation of theinhibitory effect of antifungal agents on germ tube formation in C. albicans. After incubating the tested isolates in a germ tube-inducing medium, and comparing the results with the controls, it was found that, exposure to nystatin almost completely inhibited germ tube formation, while ketoconazole suppressed this activity to a lesser degree. However, fluconazole-mediated germ tube suppression was minimal.


E.E. Habib

Microbiology Department, Faculty of Pharmacy, Mansoura University,

Mansoura 35516, EGYPT

The optimum conditions for the production of erythromycin by a UV mutant strain of Saccharopolyspora erythraea NRRL B-24071 in shaking flasks were studied. The selected MUV-12 strain which was initially found to produce 1.6 folds higher erythromycin as compared with the wild strain using S-medium, composed of 2.0 % glucose, 3.0 % starch, 0.5 % peptone, 1.0 % corn steep liquor (C.S.L), 1.0 % soybean flour (S.B.F.), 0.3% NaCl, and 0.3% CaCO3. Different carbon sources were selected at a concentration of 20 g/l. Monosaccharides were found to support erythromycin production. Glucose was the best carbon source for the production of erythromycin (250 mg/ml) at a concentration of 40 g/l. Organic and inorganic nitrogen sources at a concentration of 5 g/l were used. Yeast extract (5 g/l) was selected as the best nitrogen source for erythromycin production. Using the optimum conditions, 40 g/l glucose (carbon source), 5 g/l yeast extract (nitrogen source), 7 days incubation, rotary shaker (150 rpm), 30 oC, and an initial pH value of 7.0., a comparison for erythromycin production by MUV-12 and its wild strain was studied. MUV-12 produce 285 mg/ml of erythromycin while its wild strain produce 175 mg/ml with increasing in the specific activity by 5.8 mg/mg .


W.M. Awara*, A.M. Abo-Kamar** and S.H. El-Nabi***

Departments of Pharmacology & Toxicology*, Microbiology**, College of Pharmacy, University of Tanta, Zoology***, College of Science, University of Menoufia, Egypt.

The contamination of the soil and the ground water with the waste products is one of the etiological factors involved in the development of many diseases including cancer and liver injury. This study was carried out to assess the genotoxic potential resulting from environmental contaminated waste water from four different sources in Gharbia Governorate in Egypt. The assessment of DNA damage is achieved by using Comet assay. In addition, the ability of waste water to induce DNA damage and apoptotic cell death in the liver was evaluated by agarose gel electrophoresis. This is achieved by treatment of rats with the waste water for 6 and 12 weeks. The possibility of involvement of oxidative damage in the apoptotic DNA damage is also assessed by determination of the hepatic tissue content of lipid peroxides (measured as MDA) and reduced glutathione (GSH). Data obtained from Comet assay revealed that treatment of lymphocytes with waste water from different sources showed a significant increase in DNA migration. The degree of DNA damage was at its highest level when lymphocytes were treated with water from the Nile river nearby the fertilizer factory. DNA isolated from liver tissues of rats treated with waste water for 6 or 12 weeks showed loss of genomic DNA and a ladder-like DNA fragmentation pattern as diagnostic of apoptosis. It may be suggested that waste water-containing effluent could exert hepatic apoptosis through induction of oxidative damage as indicated by the significant increase in hepatic lipid peroxides and decrease in hepatic GSH contents. Therefore, this study addressed the mutagenic hazards due to contamination of the environment by the genotoxic chemicals present in waste water. It also recommend the importance of regular health screening to assess the possibility of DNA damage to prevent the appearance of any adverse effects due to this contamination. This study also showed that Comet assay can be used as a valuable, simple and fast technique for measuring and analyzing DNA breakage in mammalian cells due to exposure to polluted waste water.


R.B.A. El-Tantawy; N.A.H. Elewa; M.A. Degheidi and H.M. El-Gahri

Department of Dairy Science, Faculty of Agric. AL-Fayoum, University

Ras cheese was manufactured as follows:-1-from milk free of streptomycin and penicillin and parent starter cultures (L. delbreuckii subsp. bulgaricus and Str. salivarius subsp. thermophilus). This was dealt with as control. 2-From milk treated with 100 μg /ml streptomycin along with induced resistance starter cultures (Str. salivarius subsp. thermophilus and L. delbreuckii subsp. bulgaricus). This was referred to as (IRSs). 3-Milk with 100μg /ml streptomycin and parent starter cultures .Which served as (PSs). 4-Milk with 3.0IU/ml penicillin along with induced resistance starter cultures. This was referred as (IRSp). 5-Milk with 3.0IU/ml penicillin along with parent starter cultures. This served as (PSs). It was observed that the acidity %, SN and NPN were higher in both the control, IRSs and IRSp compared to PSs and PSp during the end of storage period (90days). The PH values got affected in a contrary way. In the case of counting the total bacterial counts (TC), the (TC) were higher in both control and (IRSp) compared to (IRSs) and (PSs), while the (PSp)was still higher during the storage period(90days). The streptococci and lactobacilli counts were higher in both the control, IRSs and IRSp treatments than those of PSs and PSp. Coliform bacteria, Moulds and Yeasts were not detected in all Ras cheese treatments when fresh and throughout the storage period. The results showed that the highest count, of sporeformers was detected in IRSp and PSp treatments, corresponding to the control, IRSs and PSs treatments respectively when fresh, while with the advance of the ripening period, a countinual decrease was observed in all the treatments. Finally IRSs cheese treatment was almost similar to the control, while PSs cheese treatment,had a sweet flavour, weak texture, a pasty body and an odour varid from rancid to putrid at the end of ripening period (90) days.


A.A. El Mougith; Y.A. El Zawahry; F.A. Mohamed* and G.A. Abdel Hamid*

Botany Deprt. Faculty of Science, Zagazig Univristy;

*Plant researches Deprt.; NRC; Atomic Energy Authority, Egypt.

Sharkia Governorate is an important area of Egypt because it include an important places, economically and scientifically as 10th of Ramadan City which is the biggest industrial city and the Nuclear Reactor of the Egyptian Atomic Energy authority (EAEA). So this study was conducted to isolate some fungal bioremediatores to the most famous pollutants heavy metals (Mn2+ and Co+2) and some of the polycyclic aromatic hydrocarbons (PAHs) as textile dyes. The studied soils were sandy, poor in organic matter and almost neutral. The concentrations of Co, Mn, Cs, Ca, Pb and Sr were high in 10th of Ramadan City than the soil of Nuclear Reactor area, but the total fungal count in the two soil samples was lower in number through the incubation periods in the presence of each tested heavy metal and dye. In addition these pollutants caused many malformations in the morphology of the most tolerant isolate A. oryzae.s


Z.M. Fathy, M.H. Yassin*, N.M. Ali* and D.A. Ahmed**

Microbiology Department, Faculty of Medicine, Zagazig university

*Botany Department, Faculty of Science, Benha University

**Botany Department, Faculty of Science, Zagazig University

Urinary tract infection is important health problem especially in diabetic patients. Our study was carried on seventy eight diabetic patients, dependent and undependent on insulin. They were from different age group ranged from 30-70 years of males and 35-60 years of females. Urinary samples were collected from all previous groups and urine examination culture and biochemical reactions were performed to detect different organisms causing urinary tract infection. Also antibiotic sensitivity test was performed to detect the most sensitive antibiotic against these organisms. We detected fifty patients out of seventy eight had urinary tract infection. The most common organisms detected were identified as Escherichia coli, Klebsiella aerogense and Pseudomonas aeroginosa. Also we found that the most sensitive antibiotic were nitrofurrantion (68%) followed by noroxin (60%) septrin sulfatrimero (30%), cephradine (28%), ampicillin (24%) and amikin (20%).


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

Faculty of Applied Scinee, Al-Azhar University, Gaza.

Bacterial and fungal infections are one of the most important causes of life threatening situations of seriously sick patients treated in Gaza Hospitals.     The types and frequencies of pathogenic microorganisms were determined from hospitalized patients which admitted in European Gaza Hospital during the period 2002-2003. Among 7387 patients admitted to the hospital, 309 patients were developed nosocomial infections for overall prevalence of 4.1%. The most frequent isolate pathogenic microorganisms were E. coli (24.9%), Klebsiella spp. (20.1%), Pseudomonas aeruginosa (16.2%), Staphylococcus aureus (10.4%), and the others less than 10% comprised (28.4%) of the total number of isolated pathogens. Gram negative comprised (68.5%), Gram positive comprised (28.2%), and Candida albicans and yeast comprised (3.3%). The highest infection rates are in urinary tract infection (37.5%), followed by wound infections (33.7%), blood stream infections (21.7%), and the lowest percentage of nosocomial infection was in lower respiratory tract infection (7.1%). About(61%) of the nosocomial infection cases were caused by single bacterial pathogens and 39% were caused by multiple pathogens, either bacteria or yeast.


S. Ebaid**, A. Ghazal,*M. Morsi,ª O. AAbdel Kader*, E. Awad#, and N. Ibrahim**

* Microbiology Department, ** Applied Medical Chemistry Department, # General Surgery Department, ª Radiation Science Department, Medical Research Institute, Alexandria University.

            Hepatocellular carcinoma (HCC) is the fifth most common malignancy in the world, and is estimated to cause approximately half a million deaths annually. It usually develops in the setting of chronic hepatitis or cirrhosis. Rapidly accumulated evidence from both epidemiologic and laboratory investigation has suggested that hepatitis C virus infection plays a crucial role in the etiology of HCC. The aim of this study was to determine the value of p53 protein in the sera of both HCC and hepatitis C patients and to compare the amount of p53 protein with healthy controls (negative for both anti HCV and HBsAg). Twenty pathologically proved HCC patients were tested for anti HCV, HBsAg, quantitative determination of P53, alpha fetoprotein by ELISA, and liver enzymes ALT and AST. In addition 30 anti HCV negative and 40anti HCV positive patients were included. Results: 100% of HCC patients were anti HCV positive, 3(15%) out of them were co-infected with HBV (HBsAg positive). 3 (15%) of the HCC patients had values of p53 above 25 U/ml compared to 1(2.5%) case of HCV and none of the control subject. No significant variation in p53 concentration among HCV-RNA positive and negative HCC patients was found. No association between p53 concentration and HCC grading was found. No correlation could be demonstrated between p53 concentration and AFP levels.


R.A. Amer

Department of Environmental Biotechnology, Genetic Engineering and Biotechnology, Research Institute (GEBRI), Mubarak City for Scientific Research and Technology, Alexandria, Egypt.

Phenol is one of highly toxic compounds that can be introduced in the environment accidentally or by man-made. In this study, biodegradation using locally isolated bacteria proved to be an efficient alternative method for phenol decontamination. Oil contaminated soil and water collected from Red Sea were used for the isolation process. Twenty isolates were obtained which were found to have certain phenol resistance and degradation ability. Among the obtained isolates one isolate was found to be resistant to phenol, up to 100mg/L. The strain was physiologically characterized and identified using 16S rDNA amplification gene. The results revealed that the isolate was belonged to genus Bacillus and named Bacillus sp. RA5.

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