Induced mutagenesis causes an increase variation of some products with limited genetic resources. In this study, the antioxidant enzymes activity, biochemical properties and glycoside content of Stevia were assessed by EMS (chemical mutagen) based on two experiments as factorial with completely randomized design with three replications. The results of the first experiment showed that some prope...

AcrAB-TolC is a major efflux pump in Escherichia coli. It was reported that tolC is overexpressed and involves in improving the organic solvent tolerance level in Escherichia coli marR mutants that are resistant to several antibiotics, such as ciprofloxacin. Low and intermediate levels resistance did not improve organic solvent tolerance. Thus, in this descriptive-experimental study it was deci...

MarA activates two membrane dependent mechanisms of resistance to different antibiotics, such as ciprofloxacin and tetracycline, including promotion of outflux and inhibition of influx of antibiotics. Thus, MarA causes multiple antibiotic resistance phenotype. The activation of these mechanisms needs overexpression of marA. This could happen through mutation in marR. Thus, the aim of this study...

fusarium solain is the most important pathogen of huge range of plant hosts, especially potato in the word, which causes tuber rot in storage and root rot of potato plants in fields. fifty four isolates from potato, bean, chickpea and cucurbit (melon, watermelon and cucumber) was subjected in a study through analysis of vegetative compatibility groups (vcgs) and rep-pcr dna fingerprinting. nit ...

hepatitis b vaccination is safe and effective, although breakthrough infection occasionally occurs in those who receive the vaccine and hepatitis b immunoglobulin (hbig) prophylaxis. sequence variation in their antigenic regions is one of the most powerful strategies that are used by viruses to escape recognition by b and t cell-mediated immune responses. the aim of this study was to explore th...

objective (s):the aim of this study was to determine the correlation between vaccine therapy and appearance of mutations in hepatitis b surface antigen (hbsag)-positive chronic hepatitis b virus (hbv) patients. materials and methods: 16 patients received the hbv vaccine and another 16 individuals from the control group did not. the surface gene was amplified and directly sequenced from samples ...

appearance of bacteria resistant to antibacterial agents puts physicians in trouble and threatens the health of the world. the rapid development of bacterial resistance in escherichia coli to ciprofloxacin makes difficult the treatment of infectious diseases. so, detection of the locations of possible mutations in gyrase a gene ( gyra ) in these mutants is very important to determine the mechan...

photoproteins are excellent reporter systems because they don’t have virtually background signal. aequorin is the most well-known photoprotein. three improved engineered photoproteins photina, i-photina and c-photina, were also recently developed and optimized for generation of ca2+ mobilization assays precisely. the total light emission is greater than aequorin and their reaction kinetics is a...

in this study techniques for laboratory identification of dermatophyte fungi through protoplast hybridization were established. firstly, auxotrophic mutants of different species of microsporum and trichophyton were induced and identified. secondly, protoplasts from these mutants were isolated by digestion of their mycelium with novozyme 234 using caci, (o.4m) as an osmotic stabilizer and glycin...

quinolones are a large and widely consumed class of synthetic drugs. expanded-spectrum quinolones, like ciprofloxacin are highly effective against gram-negative bacteria, especially escherichia coli. in e. coli the major target for quinolones is dna gyrase. this enzyme is composed of two subunits, gyra and gyrb encoding by gyra and gyrb, respectively. mutations in either of these genes cause qu...