مقالات رزومه فردین رحیمی

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important pathogens causes of hospital infections in the world, which has become resistant to many common antibiotics. Increasing antibiotic resistance in bacteria has increased attention to herbal medicines and natural antimicrobial substances. Due to its metabolites such as thymoquinone, Nigella sativa has various effects, including antibacterial properties. This research was conducted to determine the antibacterial effect of Nigella sativa extract and the cotrimoxazole, as well as the combined effect of these two substances on the standard MRSA strain in laboratory conditions.

In this study antimicrobial effects of Nigella sativa extract and cotrimoxazole separately and together using the checkerboard method on MRSA (ATCC33591) standard strain were investigated by microdilution method and their minimum growth inhibitory concentration (MIC) were determined.

Cotrimoxazole antibiotic at MIC of 5 μg/ml and Nigella sativa extract at 4.687 mg/ml prevented the growth of the target bacteria. When combining both of them were tested, the MIC concentration for both extract and antibiotic combinations was significantly reduced. These values ​​were reduced to 0.292 mg/ml for the extract and 2 μg/ml for the antibiotic.

According to the obtained results, the antibacterial activity of Nigella sativa ethanolic extract and cotrimoxazole have a synergistic effect on MRSA. Thus, we can use the combination both of antibacterial agents for improving the antimicrobial effect.

Acinetobacter baumannii is a gram-negative opportunistic pathogen and one of the most important hospital pathogens. Antibiotic resistance helps Acinetobacter baumannii to survive in environments under antibiotic stress and complicates treatment. On the other hand, the excessive use of antibiotics causes destructive effects on body organs. Vaccinium arctostaphylus plant is used in the treatment of mental diseases due to its abundant polyphenols, including flavonoids, which have significant antibacterial properties. This research is the first to determine the antibacterial effect of meropenem and the ethanolic extract of vacinium arctostaphylus plant in combination, and it was done separately on the standard strain of Acinetobacter baumannii in laboratory conditions. Firstly, the antimicrobial effect of meropenem and ethanol extract of vaccinium alone on the standard strain of Acinetobacter baumannii (ATCC19606) was determined by the microdilution method, then the inhibitory concentration for the combination of antibiotic and extract was calculated using the checkerboard method and also the relative inhibitory concentration index was also obtained. The growth inhibitory concentration of this extract along with the antibiotic decreased significantly, and in the combination of extract and meropenem, the concentration of meropenem was 0.0156 µg/mLand the concentration of extract was 0.390 µg/ml. Factorial test was used for the statistical comparison of classification variables, which showed that there is a significant relationship between the increase in extract concentration and also the combination with antibiotics. According to the results of this study, the ethanolic extract of arctostaphylus vaccinium has a synergistic effect on Acinetobacter baumannii with meropenem. Due to the good antimicrobial effect of the vaccinium arctostaphylus with the antibiotic meropenem on the standard strain of Acinetobacter baumannii, they can be used in addition to antibiotics.

Niosomes are one of the new drug delivery systems. In this synthesis study, the properties and characteristics of nanosystems loaded amikacin for the aim of slow releasing and antibacterial activity on Pseudomonas aeruginosa were been investigated.

The synthesis nanocarriers were characterized by using DLS, zeta potential, SEM images, and FTIR analysis. The percentage of drug loading in the nanosystems were measured. After that, the release rate of the drug was checked. MIC microbiological tests were performed to determine the minimum inhibitory concentration (MIC) of Pseudomonas aeruginosa. Finally, with MTT method, the toxicity and effectiveness of the system on cell line A549 extracted from lung were evaluated.

In this study, by synthesis and optimization, with the highest loading efficiency of 95.15% at the formulations and the slowest release with a drug release rate of 65.27% in 60 hours to reduce the side effects of amikacin. We were able to increase the antimicrobial activity of amikacin niosomal against Pseudomonas aeruginosa and reduce the side effects compared to the free form and have a slower and more continuous release with greater effectiveness on bacteria. Studying this process on the lung cell lines was successful and free-form of amikacin has a more toxic effect than two drug-free and drug-free niosomal systems. Numerous mathematical models, including realistic and experimental/quasi-experimental mechanistic models, have been successfully introduced to quantitatively define drug release mechanisms and play an important role in designing a drug delivery system for drug release diagrams. That reported in results

Achieving optimal conditions for the preparation of nanosystems carrying amikacin and investigating the effect of this system on bacterial agents is an important step in science, research, and economic efficiency.