فصلنامه تازه های بیوتکنولوژی سلولی مولکولی
پیاپی 46 (بهار 1401)

Numerous and increasing human progress in the field of various sciences, apart from the positive aspects that it can have for the welfare, comfort, and excellence of human beings, has another dimension, called bioterrorism, which is the abuse of various sciences such as biology and microbiology by various countries or organizations aimed to hit an enemy or rival groups. The purpose of writing this article is to review bioterrorism and its history, as well as to study the various dimensions of the emergence and spread of the emerging coronavirus (SARS-CoV-2) and its negative effects on various issues of human life (health, economic, social, and psychological areas). In this article, we try to review the various related evidence to find out the possibility of an association between the emerging coronavirus, and bioterrorism, and then point out the negative consequences of the Covid-19 pandemic on the economy and order of the world community.

Aim and Background

Enterohemorrhagic E. coli O157: H7 is an important human and animal pathogen that causes hemolytic uremic hemorrhagic diarrhea in humans. The binding to host cells is the first step in stabilizing this bacterium through the secretion system of the type (T3SS) III and through the interactions between secretory proteins. Tir is a protein that is transferred to the host cells after expression in the bacterium and via T3SS and is located in the membrane and plays an important role in the bacterial binding to the host. The purpose of this research is to clone a gene construct that has Tir virulence factors.

Specific primer design for tir gene was performed using oligo softwares and gene amplification was performed by PCR reaction on a DNA template. After the enzyme digestion, the gene was inserted into expression vector pET28a; the construct was transformed to the expression host. After confirmation of gene cloning, the Tir recombinant protein was expressed by induced IPTG induction. The western blot analysis was carried out to confirm Tir protein. The gene of tir was cloned inside pET28a vector.

Cloning of tir gene in pET28a vector was performed appropriately between desired sites and after induction protein, the Tir recombinant protein showed appropriate and significant expression. The antibody used in Western blot was also able to properly detect Tir.

After the induction, the protein of Tir showed a remarkable expression of the recombinant protein. As a result, this structure can be used to produce Tir protein for immunological studies against E.coli O157: H7.

Allergic properties of plants are an important factor in the production of natural herbicides. In this study, the microbial antimicrobial effects of aqueous extract of fennel on wheat germ germination factors were investigated.

In this experimental study, a randomized complete block design was performed in 4 treatments with 3 replications. The treatments of this experiment included 4 different concentrations of fennel aqueous extract (15, 10, 5, 5%). Measured parameters included germination percentage, seedling fresh weight, activity of alpha-amylase, catalase and malondialdehyde concentration.

The results showed that the effect of experimental treatments on all measured traits of wheat grass was significant at the level of 1% probability. There was no significant difference with 5% treatment. With increasing fennel concentration, wheatgrass seedling weight also decreased. The highest weight was observed in control (0.11) and the lowest was observed in 15% fennel concentration (0.06). The highest and lowest alpha enzyme activity was observed. Amylase was observed in control treatment (4.53 nmol / min) and 15% fennel extract (1.67 nmol / min), respectively. The highest concentration of malondialdehyde in seedling tissue in 15% extract was 93% (nmol / gram )was observed. Decreased activity of antioxidant enzyme catalase was affected by increasing the concentration of fennel extract. Although the lowest activity of this enzyme was observed at a concentration of 15% (4.33 mg absorption per minute), this treatment differed from the treatment concentration of 10% (4.47 mg absorption per minute) It did not make sense.

According to the obtained results, it can be said that with increasing the concentration of fennel extract, the concentration of malondialdehyde also increased significantly. Aldehyde and decreased alpha-amylase activity.

Silver nanoparticles (AgNPs) have been considered by researchers as a very strong inhibitor due to their biological properties and have many applications in prevention and treatment. However, there is little information about the effect of nanoparticles on healthy cells.The aim of this study was to investigate the effect of silver nanoparticles on the viability percentage of normal skin cell line MHFB-1.

In this study, during 24, 48 and 72 hours, different concentrations of silver nanoparticles (1.56, 3.125, 6.25, 12.5, 25, 50 and 100 μg / ml on MHFB-1 cell line was evaluated by MTT method.Data obtained from the test were statistically analysed using SPSS software, one-way ANOVA, Tukey test and significance level of P <0.05.

Treatment of normal MHFB-1 cells with different concentrations of silver nanoparticles after 24, 48 and 72 hours by  MTT method showed a significant reduction  in the viability of cells at  concentrations of 25, 50 and 100 μg /ml.

The results of this study showed a dose-dependent inhibitory effect of silver nanoparticles on normal skin cell line (MHFB-1).

Today, microorganisms have become resistant to drugs by causing gene mutations. The aim of this study was to determine the antibiotic resistance of bacteria isolated from urine culture in the laboratory of Savadkuh city.

A cross-sectional descriptive study was performed on bacteria isolated from urinary tract infections in Savadkuh laboratory. Bacteria in the sample were identified by microscopic method, morphological examination and biochemical tests.

Out of 693 samples, the result of urine culture test was 462 positive. Staphylococcus 45.4%, E.Coli (34.6%), Streptococcus (12.9%) and Klebsiella (7.1%) were the most common isolated bacteria, respectively. In the study performed on the pattern of antibiotic resistance, the most cases of resistance were related to the antibiotics ampicillin, cefazolin, trimethoprim, sulfamethoxazole and ciprofloxacin, respectively. On the other hand, the highest susceptibility of bacteria is related to the antibiotics nitrofurantoin, cephalexin, cefotaxime, gentamicin and ceftriaxone, respectively.

According to the results of the study, the most common microorganisms that cause urinary tract infections have been identified and the most appropriate antibiotics have been introduced for treatment, which is very effective in reducing the resistance of bacteria to antibiotics. Treatment costs are also reduced with the use of appropriate antibiotics in the early stages of infection.

High metabolism occurs in the presence of oxygen with rapid growth rate in a wide range of organisms including bacteria, yeasts or cancer cells. The ability to grow at high yields plays an important role in biotechnology, especially during the production of proteins (preferably recombinant) or metabolic compounds such as organic acids and secondary metabolites. Increasing the growth efficiency of bacteria, especially Escherichia coli, which is the engine of research and industrial activities, is a noble goal in microbial biotechnology. In this study, we sought to find a solution to reduce the amount of CO2 produced and thus increase the production efficiency of cell mass from organic matter in the process of growth and proliferation by examining the metabolic pathways of E. coli.

Metabolic pathways documented on the KEGG site were examined with a view to reducing the CO2 production efficiency of formic acid. Two strains of knockout bacteria of K12 origin were obtained from Keio microbial bank. Then, selected strains were cultured in complex (LB) and simple (M9 + Glycerol) media. Cell mass production in different treatments were compared with the standard BL21 strain based on optical absorption at 600 nm.

In the LB complex medium, Escherichia coli mutants (W3866 and W4040) grew faster than BL21 (approximately 5-fold at 8 and 10 h and 3 times at 12 h compared to samples with the dehydrogenase formate gene). However, this difference was more pronounced in the simple M9 medium, as we observed more than 6-fold growth in 24 hours of incubation in mutant samples lacking the FDH gene compared to the BL21 maternal strain.

The experiments were completely in line with metabolic predictions and the growth of mutant bacteria was higher than that of BL21. Interestingly, most mutants grew in a simple medium containing glycerol, which showed that glycerol is a very good source for the growth of Escherichia coli bacteria. These results explain the inconsistency of predictions of previous metabolic models that declared glycerol a suitable carbon source for the growth of E. coli, but did not achieve it in practice.

Under normal physiological conditions, E. coli is not able to grow high in glycerol medium. Deletion of formate dehydrogenase gene caused fundamental changes in metabolic process and increased growth rate compared to BL21 strain, which indicates the inhibitory role of this enzyme in increased growth efficiency of E. coli in the presence of glycerol. In addition, the resulting strain can be used to express recombinant proteins with higher efficiency

This study investigates the biological properties of cyclic RGD peptides being covalently immobilized via click chemistry onto alkyne terminated silicon surfaces.

At first cyclic RGD peptides were reacted with 4-azidophenyl isothiocyanate via a specific reaction. The azidated peptide was then covalently immobilized on an alkyne-terminated monolayer on silicon surfaces via the Cu (I)-catalyzed 1, 3-dipolarcycloaddition reaction. The surface structures of the attached peptide and control surfaces were characterized using X-ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared (ATR-FTIR) Spectroscopy. Then after seeding human fibroblast cells on the peptide and control substrates, Scanning electron microscopy (SEM) and Laser scanning confocal microscopy (LSCM) was used to examine the morphology of human fibroblast cells. Adhesion and proliferation of human fibroblast cells on control and modified surfaces were analyzed by cell adhesion and (MTS) assay.

XPS and ATR-FTIR analysis showed the cyclic RGD peptides were successfully immobilized on silicon surfaces. Scanning electron microscopy (SEM) and Laser scanning confocal microscopy (LSCM) demonstrated that human fibroblast cells homogenously distributed across the peptide-modified substrates and had a uniform appearance. Peptide-modified surfaces exhibited substantially superior cellular responses compared to those on control surfaces.

The research may suggest a procedure for the fabrication of biologically active surfaces in biosensor platforms.

One of the most malignant and common brain tumors is glioblastoma multiforme (GBM). Patient survival is relatively poor, and due to the difficulty of early diagnosis, most patients die within one year of diagnosis. The aim of this study was to investigate the expression of YKL39 as a possible biomarker in glioblastoma multiforme and to evaluate the miR of this gene.

In this study, 25 tissue samples with glioblastoma multiforme before treatment and 25 samples of healthy tissue with glioblastoma multiforme tumor were collected as a control sample. RNA extraction and cDNA synthesis were performed. YKL39 gene expression was assessed using real-time PCR and ACTB gene was used as internal control. Statistical analysis of data was performed using GraphPad Prism software version 8. The Roc curve was used to evaluate the biomarker value of YKL39 gene.

High expression of YKL39 (P **** <0.0001) was observed in glioblastoma tissue samples. Expression showed that YKL39 gene was not statistically significant with the age of patients with P value = 0.2971 and gender with P value = 0.888.

The increase in YKL39 gene expression in glioblastoma tissue samples is significant compared to healthy tumor margin tissue. The Roc curve showed that the YKL39 gene could not have biomarker value.