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Aim and backgrand:Exopolysaccharides (EPS) produced by lactic acid bacteria (LAB) play an important role in taste and texture improvement of fermented dairy products. Additionally, they may be important to the health promoting properties of LAB through host immune stimulation. The aim of this study was exopolysaccharide production of 16 Lactobacillus strains isolated from traditional dairy products of Iran. It was performed to isolate and identify both bound and released exopolysaccharides.

Methods: twenty eight gram positive, catalase negative lactobacillus strains were selected based on their association with fermented dairy products of diverse origin. Colonies were assessed for both microscopic and macroscopic features. The isolates were further evaluated for release and bound EPS we used a phenol/sulfuric acid method. Results were compiled using a glucose standard curve.

Results and discussion: Level of bound EPS production ranged 4-364mg/l and release EPS ranged from 87.25 to 1519 mg/l. The EPS producing strains isolated from dairy products may have properties of emulsification, stabilization, and film formation, to improve flavor, appearance and texture in foods. The EPS produced by LAB may have beneficial effects on human health such as cholesterol-lowering ability, immune modulating, and antitumor activities and prebiotic effects.

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Aim and Background:Non-tuberculous mycobacteria have long been identified as capable of causing human disease. Several reports have suggested increasing trend to available treatment regimes. The aim of this study was to evaluate antibiotic susceptibility of clinically significant NTM using standard micro broth dilution test.

Material and methods:The antimicrobial susceptibility testing was performed following National Committee for Clinical Laboratory Standards (NCCLS) method for 88 clinical isolates of slowly growing mycobacteria (SGM) and 154 clinical isolates of rapidly growing mycobacteria (RGM).

Results:Among the 40 isolates of M. kansasii, all were susceptible to Ethambutol, Isoniazid, Clarithromycin, Moxifloxacin and Linezolid. The isolates also were resistant to Doxycycline and 50% isolates were resistant to Rifampicin and Ciprofloxacin.

Conclusion:The presence of high variations in susceptibility among clinically important NTM to the currently available antimicrobial agents confirms the need for accurate identification as well as performing standard susceptibility testing of any clinically important isolate.

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Aim and Background: Complex structures of asphaltene and paraffin wax are two troublesome components in processing of heavy oils. Nowadays physicochemical processes are used as a resolution for this problem which are both financial and human resource consuming. Exploiting biological methods could open new horizon to solve these problems..

Materials and Method: In this study after sampling from different Lavan’s production wells, initial treatment with paraffin was done. Then screening, enrichment and isolation were done consequently. Biosurfactant production was also investigated. The next step was studying the growth curve of the bacteria that were able to use paraffin as the sole source of carbon and energy and their physiochemical endurance was monitored. After bacterial treatment, paraffin was extracted by n-hexane and was analyzed chemically by gas chromatograph FID. Finally the selected bacterium was identified molecularly.

Results: GC chromatograms suggested a considerable decrease in amount of paraffinic components through the treatment by an indigenous thermophlic, biosurfactant producing bacterium, known as Bacillus thermoleovorans molecularly. This bacterium could grow in temperature rate from 40°C to 65°C, pH from 4 to 10 and salinity from 0.5 to 15%.

Conclusion: A few studies on paraffin degradation in high temperature have been done in Iran. Bacillus thermoleovorans is an Iranian crude oil indigenous thermophilic bacterium with high physicochemical endurance which could be a proper choice environmental of petroleum industry application.

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Aim and Background: Basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are two forms of non-melanoma skin cancer. Recent research indicated that Merkel cell polyomavirus (MCPyV) is associated with Merkel cell Carcinoma (MCC). So, the aim of current study was presence of MCPyV in the tumor tissue and role of large T antigen (LT Ag) mutations that associated with MCPyV oncogenic properties in LTAg region in positive samples that referred to Razi Hospital in Tehran within 2015-2016. Materials and Methods: In this cross-sectional study, 55 tissue samples containing: 30 BCC, 10 SCC and 15 individual healthy samples were collected and genomic DNA was extracted. To finding positive samples, quantitative Real-Time PCR was done and the full-length of Large T antigen region was amplified and sequenced directly for detection of probable mutations. Results: MCPyV genome was detected only 10% of BCC samples. There is no correlation between sex (P-Value=0.33), age (P-Value=0.5), or stage of cancer (P-Value=0.25) and the presence of MCPyV genome in our populations of study. Conclusion: Viral infections are one of the factors in causing cancer. Although, several studies were reported that frame shift mutation at the N-terminus of LT Ag region is associated with tumorigenesis of the virus, but in current study, no any mutations causing stop codons or frame shifting were observed. As our knowledge this is the first study presenting data on the prevalence of MCPyV in non-melanoma skin cancer from Iranian patients. However, further studies with more samples are necessary.

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Aim and Background: Recent studies have claimed that the genetic variation in cytokine production systems has a major effect on immune system potency and strongly associated with the antiviral treatment response. On the other hand, tumor necrosis factor-alpha (TNF-α), a multifunctional pro-inflammatory cytokine, plays an essential role in host immune response to HCV infection. Therefore, current study was done in order to determine the distribution of the rs1800629 (A/G) polymorphism in the promoter of TNF-α gene in Iranian population. Material and methods: This cross-sectional study, performed on 165 blood samples based on 89 HCV infected patients including 68 SVR positive and 21 negative and 76 healthy individual controls. After DNA extraction the frequency of rs1800629 (A/G) polymorphism was analyzed using PCR-RFLP method. For detection and analysis of the PCR products we used 20% Polyacrylamide gel electrophoresis. Results: Based on analysis of the data, the distribution of the A/G polymorphism between healthy individuals and patients were obtained as AA: 1.1%, AG: 52.6%, GG: 46.1%, and AA: 1.3%, AG: 20.2%, GG: 78.7% respectively. The GG genotype was identified in 70 patients of whom 55 achieved SVR, while the AG heterozygous was found in 18 patients and SVR was achieved in 12. Finally, the AA was detected only in one patient with positive SVR. Conclusion In this study, significant difference between the TNF-α-308 locus SNP (rs1800629) and susceptibility to chronic HCV infection in Iranian population (P value= 0.002) was observed. Moreover, the presence of G allele among SVR positive people and non-SVR group did not show strong statistic difference (P value=0.476). However, further studies with more samples seems to be necessary.

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Aim and Background: Assessing the genetic diversity of natural and protected germplasm is one of the most strategic global activities and as the national capital of each country. Over the years, various mutations and crosses have caused the accumulation of some useful genes in this germplasm and can be used as genetic resources in critical situations. Evaluation of diversity based on morphological and phenotypic traits is not stable due to the influence of the environment and the interaction of genotype in the environment. Therefore, the use of DNA-based markers that have high reproducibility. Codon-based DNA amplifier-based markers have recently been used to translate SCoT in plants due to heritability and reproducibility. The aim of this study was to evaluate the genetic diversity of hazelnut genetic germplasms in the forests of the northwest of the Iran by SCoT markers and it’s accordance to diversity estimates based on national markers of hazelnut differentiation tests.
Materials and Methods: In this study, 77 genotypes from hazelnut forests of Ardabil, Miyaneh and Arasbaran were selected by locating each genotype using GPS. Qualitative traits were evaluated using the national guidelines for uniform differentiation and hazelnut stability tests. after DNA extraction from leaf tissue, their polymorphism diversity was assessed using 15 SCoT-specific primers.
Results: The results showed that the genotypes were classified according to the qualitative traits of differentiation of 17 clusters. Using 15 SCoT markers, 165 polymorphic bands were produced with an average of 11 bands per marker and the average percentage of polymorphisms with an average of 11 bands per marker and the average percentage of polymorphisms for markers 90.2% of genotypes based on these markers in 19 sub-clusters Were grouped.
Discussion: Analysis of qualitative traits based on bands created in SCoT showed that markers 3, 5, 11, 12, 18 and 20 had more genetic diversity and that the degree of  accordance of genotype grouping based on the SCoT markers was 0.87 on The basis of the Mantel test.
Conclusion: Using two genetic markers, 75% (R²) of the variety of hazelnut differentiation descriptors can be accessed.