Background and aim: Leishmaniasis is a group of diseases with various clinical pictures, which is caused by Leishmania spp. This parasite causes disease in human and about one hundred animal species. The disease is widely distributed in Iran and also across the world. One of the best approaches in the development of vaccine against Leishmania is genetically modification of the parasite. Therefore, the aim of this study was to design a novel genetic construct in order to insert Herpes Simplex Virus thimidine kinase (HSV-tk) and YEAST cytosine deaminase (YEAST-cd) suicide genes into the Leishmania genome.Methods: In this work, at the first step, HSV-tk and YEAST-cd fragments along with a gene of Leishmani, a-tubuline were cloned into pBluescript vector and the arrangement of tk-atub-cd was created. Subsequently, these fragments were cut off from the plasmid and sub cloned into the plasmid pF4X1.4.4sat. The final construct was confirmed by digestion with relevant restriction enzymes. Results: The fragments tk- atub-cd was cloned successfully in the plasmid pBluescript and its authenticity was confirmed. Subsequently, this genetic collection was inserted into the plasmid pF4X1.4sat and finally, the orientation of it was checked.Conclusion: The construct designed in this study was able to insert two cellular suicide genes HSV-tk and YEAST-cd into the Leishmanai genome. Thus, this is an approach in achievement of vaccine against Leishmanai in the coming up researches.

In recent science Nanotechnology is a burning field for the researchers. To meet the requirements and growing technological demand, there is a need to develop an eco-friendly approach. In the present effort, the baker’ s YEAST (Saccharomyces cerevisiae) has been taken in order to assess its potential as putative candidate fungal genera for the transformation of silver nanoparticles. Silver nanoparticles were successfully synthesized from Saccharomyces cerevisiae by green synthesis method. The formation of silver nanoparticles and the concentration of YEAST extract required to produce YEAST mediated silver nanoparticles with no aggregation was found out by UV-Visible spectroscopic analysis. The detailed characterization of the Ag NPs was carried out using Scanning Electron Microscopy (SEM), and FTIR. From the UV-visible spectroscopy, the maximum absorption peak was found at 440 nm. From the SEM images, it is confirmed that the sample contains spherical silver nanoparticles at a range of 10 to 60 nm. The silver nanoparticles are crystalline in nature, which was confirmed by the FT-IR peak at 518 cm-1 corresponding to the Ag vibration present in crystalline structure. The water filtration system depicted 5 log reduction for AgNPs [99. 99% reduction]. The antibacterial activity of silver nanoparticles was determined by well diffusion method, and found that silver nanoparticles have significant antibacterial activity against E. coli with an inhibition zone of 2. 1cm. The MIC test was performed to test the inhibitory concentration of AgNPs against the pathogens and was found to be 40 μ g ml-1 for E. coli and comparatively higher for other microorganisms.

Collagens are the most abundant proteins in the human body. Their main function is to provide structural and mechanical support for the tissues, but they are also involved in a number of other biological functions including cell attachment, migration and differentiation. Collagens and gelatins are widely used in pharmaceutical and medical applications. Every year, more than 50, 000 tons of collagen and gelatin are used in medical applications. These materials may have some viral and prion impurity and/or stimulate allergic response in human body. Therefore, scientists have produced human collagen in recombinant systems. In this study we have constructed two YEAST shuttle vectors containing human procollagen genes expression cassette for expression in YEAST. Total RNA was extracted from human skin fibroblast cell line, and cDNA synthesis was done by oligo dt. Then gene fragments were amplified from the cDNA with the necessary changes by Polymerase Chain Reaction (PCR). Finally they were cloned in YEAST vector pPICZaA containing regulatory sequences for expressing and secreting the polypeptide product. Two YEAST shuttle vectors containing human COL1A1 and COL1A2 expression cassettes were created. Final constructs were confirmed by enzymatic digestion, PCR of desired fragment and sequencing. The YEAST shuttle vectors containing human COL1A1 and COL1A2 can be transferred into the YEAST in the later stages to determine the scale of expression.