Yafteh

Background: Root hair culture is a valuable system to produce recombinant proteins in planta. Antimicrobial peptides (AMPs) are  vital parts of the innate immune response found in almost all forms of life. Precise target activity and limited toxicity towards mammalian cells make them suitable candidate molecules to combat evolving drug-resistant microorganisms. The aim of the present study was to produce a Dermaseptin B1 recombinant antimicrobial peptide in Nicotiana tabacum root hair and assess the antibacterial activity of the protein extract from transgenic root hairs.
Materials and Methods: A Dermaseptin B1 encoding gene sequence was C-terminally fused to a Chitin Binding Domain (CBD) encoding sequence and cloned in a plant binary vector used for Agrobacterium rhizogenes-mediated transformation to generate root hairs in tobacco. Transgenic root hairs were produced, and protein extracts were used to assess antimicrobial activity against a number of microbes.
Results: PCR and RT-PCR analysis confirmed the integration of the Dermaseptin B1 gene in a root hair cell genome and the presence of Dermaseptin B1 mRNA transcripts, respectively. Recombinant protein had a significant (P<0.05) antibacterial effect towards gram-positive and gram-negative bacteria.
Conclusion: Dermaseptine B1 recombinant peptide was successfully produced in tobacco root hair cells and its antibacterial effects was confirmed. These results suggest that the recombinant protein may have a therapeutic effect to control bacterial pathogens. It can be concluded that root hair cells can be used to produce and purify valuable recombinant proteins with pharmaceutical applications.

Background: Antimicrobial peptides are one of the vital components of innate immunity in plants and animals. The identification and introduction of novel and effective peptide molecules to plants is a cost-effective way both to improve the resistance of crop plant species to pathogens, and to produce peptides for pharmaceutical applications by using recombinant DNA technology.
Material and Methods: An expression construct containing the omiganan (MBI-226) antimicrobial gene sequence was cloned and used for tobacco and potato Agrobacterium tumefaciens-mediated transformation. Following tissue culture, Polymerase chain reaction analysis (PCR) confirmed that some kanamycin resistant plants are transgenic. A number of transgenic plants, along with a non-transgenic control, were selected. Total protein was extracted from the transgenic plants, and the non-transgenic control, and was used for antimicrobial activity assay against some human pathogens, including; Escherchia coli, Staphylococcus epidermis, Pseudomonas aeruginosa, Salmonella typh, Staphylococcus aureus, Bacillus cereus, Candida albicans using the disc diffusion method.
Results: Total protein extract from transgenic plants was significantly (P<0.05) able to inhibit the majority of bacteria growth, whereas non-transgenic total protein extract did not inhibit human pathogens growth. There was a significant difference (P<0.05) between transgenic lines with respect to omiganan peptide activity. In contrary to gram-negative bacteria, omiganan peptide did not have a significant effect (P>0.05) on human gram-positive pathogenic bacteria.
Conclusion: The total protein from the omiganan-expressing peptide had a strong antibacterial activity against some human bacterial pathogens. By expression and purification of the omiganan peptide, the peptide could be used as an antibiotic to destroy pathogenic bacteria. This approach could open an opportunity to produce antibacterial peptides in plants for pharmaceutical applications.

Background: Since the application of certain methods to minimize the oxidative and microbial spoilage in meat products is economically and hygienically significant, further studies are required to evaluate the antioxidant and antimicrobial activities of plant extracts in meat and meat products.
Materials and Methods: The aim of the present study was to investigate the antimicrobial effect of sumac extract in ground beef contaminated with multidrug resistance E. coli. Sumac extract was extracted by maceration method. The total phenol content of the extract was measured by Folin-Ciocalteo, and the total flavonoid content was determined by aluminum chloride method. Antioxidant activity was evaluated by iron reduction test (FRAP). The antimicrobial effect of the extract was evaluated using well diffusion method. After the inoculation of the minced meat, the samples were transferred to the refrigerator at 4 ° C, and a six-day storage period for microbial tests including the total count, Pseudomonas, Escherichia coli, mold and yeast started.
Results: The total amount of phenolic compounds was 290.852 mg/g, and the amount of flavonoids was 4.508 mg/g. The antioxidant ability of the extract was reported 380.79-744.04 µmol iron/mg. The results of the antimicrobial tests indicated that the minimum inhibitory and lethal concentrations were 166.66 mg/ml and 333.33 mg/ml, respectively. Adding sumac extract to minced meat samples significantly prevented the growth of all microorganisms. This activity increased with the rise of concentration.
Conclusion: It could be concluded that sumac extract is a remarkable source of antimicrobial and antioxidant compounds and might be used in food products such as meat and meat products.

Background: Microbial resistance is one of the major problems leading to the spread of illness and death in the worldwide. Virginiamycin is one of those antibiotics that have been approved for use in the poultry, but in recent years, attention has been paid to replacing these compounds with natural additives such as powder and extracts of medicinal herbs, in livestock nutrition and poultry.
Materials and Methods: In this experiment, 125 hens of white Leghorn chicken (Hay-line) were used at age 64 weeks. Hens were divided into five groups with five replicate cages containing five hens each for each group. In this study, the effects of garlic and sage powder in the diet of laying hens, alone or in combination, with an emphasis on antimicrobial properties, were evaluated in comparison with antibiotic Virginiamycin, and the effect of these compounds on some biochemical parameters, blood and histomorphology of the intestine were investigated. The experiment was conducted in a completely randomized design with 5 treatments and 5 replications with 5 observations in each replication
Results: The results showed that different experimental treatments, including garlic powder, sage or their mixture, also Virginiamycin resulted in a significant increase in villi height (P<0.05) and villi height to crypt depth ratio (P<0.05), while the effect of sage powder and Virginiamycin on crypt depth was not significant. Furthermore, the addition of different experimental treatments significantly altered the intestinal microflora, and except for Lactobacillus that decreased significantly, the reduction in the number of germs including E. coli, Salmonella and total bacteria was significant.
Conclusion: It seems that a large part of the antimicrobial properties of these compounds in this study can be due to the ability of herbs active compounds or essential oils that are capable of eliminating bacteria due to the instability of membranes, including mitochondria membrane and imbalance in the membrane integrity of bacteria, and possibly reduce the damage to intestinal erythrocytes, also reduced the cellular requirements for the proliferation of new cells in the intestine. So that, the use of experimental treatments led to  higher villi height and less crypt depth.