Damascus, United States
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Habeeb S.,National Commission for Biotechnology | Yazaji S.,Damascus University | Al-Amir L.,National Commission for Biotechnology
International Food Research Journal | Year: 2016

The effect of environmental factors on glucose isomerase production by Streptomyces roseiscleroticus was studied using the statistics test Response Surface Methodology (RSM). Results of RSM revealed that the highest production of glucose isomerase reached a maximum level of 13.6 U/ml. The optimum conditions for the production of the enzyme by submerged culture were achieved using broth medium containing 1.5% of xylose as a sole source of carbon and as an inducer for enzyme production, in addition to 0.05% magnesium sulfate and 0.05% cobalt chloride as metal ion sources. The initial pH was 6 during an incubation period of 48 hours at 25°C. Applying the optimum conditions obtained 13.6 U/ml enzyme activity, and indicated that the activity increased approximately 175% in comparison with 7.44 U/ml before applying the optimum conditions. © 2008 IFRJ.


Nema N.,Damascus University | Alamir L.,National Commission for Biotechnology | Mohammad M.,Damascus University
International Food Research Journal | Year: 2016

This work describes the partial purification and molecular weight determination of cellulase enzymes produced by submerged fermentation using Bacillus cereus. The enzyme was purified using phenyl-sepharose and sephadex G-100 columns up to 34.6 fold with a specific activity reaching 0.104 IU/mg. The molecular weight of the purified enzyme was determined to be 16.9 kDa by means of SDS-PAGE. This molecular weight is comparable with that of other low molecular mass cellulases produced by Bacillus spp. This finding emphasizes that cellulase produced from Bacillus cereus through submerged fermentation using corn husks belongs to a group of low molecular cellulases. © 2008 IFRJ.


Issa S.,Damascus University | Alhajali A.,Damascus University | Alamir L.,National Commission for Biotechnology
International Food Research Journal | Year: 2016

Rhodotorula yeasts were isolated from various local sources in Damascus, Syria, during 2012 and 2013. Fifty isolates (23 from leaves trees, 13 from different soils, 6 from different meats, 6 from dairy products, 1 pickle and 1 traditional sweet) were identified using API 20C AUX system. Isolated yeasts were classified into three Rhodotorula species: R. mucilaginosa, R. glutinis and R. minuta representing 76%, 20% and 4% of total isolates tested respectively. All isolates were able to produce carotenoid pigments that varied in their quantities ranging from 13.61 μg/g dry biomass for isolate A28 to 658.23 μg/g for isolate A23. The wild strain A23 of R. mucilaginosa was subjected to mutagenesis using UV irradiation at a wavelength of 254 nm. Highest carotenoid production within isolated mutants reached a value of 734.58 μg/g dry biomass after an irradiation period of 4.5 minutes. Overall, UV irradiation. © 2008 IFRJ.


Askoul I.,National Commission for Biotechnology | Gorrah S.A.,Damascus University | Al-Amir L.,National Commission for Biotechnology
International Journal of ChemTech Research | Year: 2014

A total of 25 isolates of lactic acid bacteria from different Syrian dairy products, pickels and a dried plant samples were obtained and tested for their antibacterial activity against four pathogens one gram positive bacteria (Staphylococcus aureus) and three gram negative bacteria (Klebsiella pneumoniae, Escherichiacoli and Pseudomonas aeruginosa). The cell free supernatants of fifteen LAB isolates demonstrated significant antibacterial activity against the four tested pathogens. Results of the standard physiological and biochemical tests identified fourteen isolates as Lactobacillus plantarum and one isolate as Lactobacillus fermentum.All fifteen isolates were mesophilic and were able to grow in the presence of 4% NaCl and in pH values ranging from 4-9.The antibacterial activity of the CFSsof the most active six isolates were significantly influenced after treatment with proteinase K and after neutralization, while no change occurred after heat treatment at 60°C and 80°C for 15 minutes.Two of the tested L. plantarumisolates (SH4 and CK56) had the structural genes for both bacteriocins plantaricin EF and plantaricin N, and two of them (CK57 and CP44) had the structural genes for plantaricin N only.


Rahmo A.,National Commission for Biotechnology | Hamdar Z.,Lebanese University | Kasaa I.,Lebanese University | Dabboussi F.,Lebanese University | Hamze M.,Lebanese University
Journal of Infection and Public Health | Year: 2012

Setting: The incidence of multi- and extensively drug-resistant TB cases is increasing in many countries. Resistance to rifampicin is widely considered a surrogate marker for multiple drug resistant TB. No efforts have been made to identify and quantify the drug-resistant genotypes in the Syrian and Lebanese communities. Objective: The genotypic characterization of rpo B mutations in the rifampicin drug-resistance region (RRDR) of resistant Mycobacterium tuberculosis isolates in Syrian and Lebanese patients. Design: The pyrosequencing technique was applied to DNA derived from the M. tuberculosis isolates of 56 patients. Results: RRDR sequencing identified 97 modified codons representing 35 different mutations; 31 (34%) of the 97 modifications were novel and have not been previously reported. The changes were mostly within codons 531 (37/97: 38%), 533 (28/97: 29%) and 526 (9/97: 9%). Additionally, 30 (54%) isolates had multiple codon changes. Conclusion: This study indicates the importance of the RRDR hotspot region for the detection of rifampicin resistance in MTB clinical isolates from Syrian and Lebanese patients. However, new mutations and mutations in other locations within the RRDR were also observed. The vast majority (95%) of the studied isolates from this pool of patients contained mutations in codons 531 and/or 533. © 2012 King Saud Bin Abdulaziz University for Health Sciences.


The role of previous treatment in the dynamics of tuberculosis transmission has not been adequately investigated. Mycobacterium tuberculosis isolates from previously treated patients (n = 88) from all regions of Syrian Arab Republic were characterized in terms of antibiotic sensitivity and genotyping using double-repetitiveelement polymerase chain reaction (DRE-PCR) method for the proximity of the repetitive DNA elements IS6110 (a mobile genetic element) and PGRS. The 88 isolates resulted in 59 different DRE-PCR patterns. Correlations related to age, sex, region, sensitivity and genotype were examined. All regions of the country showed high levels of genotype diversity, suggesting a low level of transmission of M. tuberculosis strains in previously treated patients.


Hamze M.,University of Tripoli | Rahmo A.,National Commission for Biotechnology | Saade M.,Ministry of Public Health
Eastern Mediterranean Health Journal | Year: 2010

Molecular studies have been successfully applied in evaluating epidemiological linkages in tuberculosis. A total of 87 isolates of Mycobacterium tuberculosis were collected from patients in all regions of Lebanon and characterized in terms of drug sensitivity. Double-repetitive-element polymerase chain reaction was used to differentiate between strains. Various correlations related to age, sex, region, sensitivity and genotype were examined. Several genotypes were more common in certain age ranges. Male patients appeared more likely either to be infected by or to develop multi-drug resistant strains. There was also evidence for a distribution of genotype groups indicating some level of geographical isolation and hence separate evolution of M. tuberculosis strains.


PubMed | Lebanese University and National Commission for Biotechnology
Type: Journal Article | Journal: International journal of mycobacteriology | Year: 2016

Rapid and accurate techniques are always welcomed for the detection of resistant strains of Mycobacterium tuberculosis MTB.The objective of this study is to evaluate the pyrosequencing technology for the detection of MTB resistance to Rifampicin (RIF) and Isoniazid (INH) in Syrian and Lebanese clinical strains; 66 strains resistant to INH, among them 56 resistant also to RIF, were tested.Four pyrosequencing assays were optimized and applied to the following loci: rpoBrpoB RIF resistance-determining region, katG, the promoter regions of inhA and ahpC-oxyR intergenic region.The prevalence of mutations on codon 315 of the katG gene, inhA and ahpc-oxyR were 42.4%, 21.2% and 9.0%, respectively, which make an overall sensitivity of 72.6% for INH resistance. All RIF-resistant strains contained at least one non-synonymous codon change in the sequenced rpoB region (507-533) relative to the ATCC reference strain. The RIF drug resistance region (RRDR) sequencing identified 96 modified codons representing 34 different mutations.The high sensitivity and the short turnaround time combined with multilocus sequencing of several isolates in parallel make pyrosequencing an attractive method for drug resistance screening for MTB.


PubMed | Reference Tuberculosis Laboratory and National Commission for Biotechnology
Type: Journal Article | Journal: International journal of mycobacteriology | Year: 2016

The Beijing family of Mycobacterium tuberculosis (MTB) has been reported to have an exceptional capacity to spread tuberculosis (TB) and induce multi-drug resistance. A method has been developed to distinguish this family from the rest of the MTB families through real-time DNA amplification and subsequent analysis of the melting point of an amplicon. Two pools of multi-drug resistant (MDR) MTB samples collected at two different time periods from various regions in Syria have been selected. This preliminary screening indicated a complete absence of the Beijing family in all samples. This research presents an effective differentiation of bacterial Beijing strains, with minimal effort and cost through analysis of differential amplicon melting points.


PubMed | Lebanese University and National Commission for Biotechnology
Type: Journal Article | Journal: International journal of mycobacteriology | Year: 2016

To characterize by spoligotyping clinical isolates of Mycobacterium tuberculosis (MTB) collected between July 2003 and October 2005 from all Syrian provinces (muhafazat).All isolates (n=96) were cultured and identified by biochemical characteristics. DNA extracts of these samples were amplified by PCR and genotyped by spoligotyping.Twelve patterns were identified: 46.8% of the strains belonged to T 1 family; 20.8% to LAM 9; 10.4% to CAS; 9.3% to Haarlem 3; 4.1% to Haarlem 1; 2.1% to Family 34; and 1% to each of Family 36, EAI 5, LAM 1, LAM 8, T 3, and X 3 families. The noticeable absence of the Beijing family was not consistent with the patterns reported in most neighboring countries.A more inclusive study of the Syrian population is necessary to more accurately identify most of the prevailing families in the country.

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