staphylococcus aureus

Copper oxide is one of the most important metal oxides that has unique properties in various technological applications, such as superconductors, and has been used as an antimicrobial agent against numerous bacterial species. In the present study, CuO Nps was synthesized using chemical methods and its antimicrobial activity was investigated.

Copper oxide nanoparticles were synthesized using the microwave method, and XRD, EDX, SEM, FTIR, and UV-vis analyses were performed to investigate the physical and chemical properties. The antimicrobial and antifungal effects of copper oxide nanoparticles on pathogenic bacteria including Staphylococcus aureus, Escherichia coli, and Fusarium solani were evaluated using MIC and MBC tests and well diffusion assay.

The results showed that at a concentration of 20 mg/mL, copper oxide nanoparticles inhibited the growth of Staphylococcus aureus. Similarly, growth inhibition of Escherichia coli was observed at a concentration of 4 mg/mL of nanoparticles. Furthermore, Fusarium solani exhibited increased sensitivity to copper oxide nanoparticles at concentrations higher than 50 mg/mL, with a growth inhibition zone diameter of 18 mm at a concentration of 100 mg/mL.

 Discussion and Conclusion:

Copper oxide nanoparticles can be introduced as a strong antimicrobial agent.

Inhibition of key enzymes in bacteria that exert low evolutionary pressure can be a drug development strategy for bacterial antibiotic resistance. Sortase A (Srt A) is a transpeptidase that is widely used in site-specific protein modification. This enzyme has a key function in the interactions between Staphylococcus aureus and the host and has been considered a promising target for the drug development of resistant bacteria. To date, some Srt A inhibitors have been discovered most of them are derived from flavonoid compounds, like myricetin.

Since computational methods for monitoring the behavior of biomolecules at the microscopic level are more accurate and cost-effective, therefore, in this research, our goal is to use computational methods to find similar molecules but with higher binding and inhibitory effect than myricetin.

In this study, we used computational methods such as structure-based virtual screening, molecular docking, MM-PBSA approach, and MD simulation. A molecular docking approach was used to understand protein-ligand interactions and inhibition constants in terms of affinity. MD simulation technique was used to monitor the conformational changes of Srt A enzyme. After the MD simulation studies, the MM-PBSA approach was used to interpret the binding free energy.

First, Chemspider's chemical library was screened by the "Similarity search" method, in which myricetin was placed as a reference molecule. The second stage of screening was done using PyRx software, so that the top 10 compounds were carefully selected based on their inhibitory potential from the set of ligands obtained from the previous stage. These compounds were subjected to Autodock4.2 for molecular docking. As a result, it was observed that compound-73945561 has a higher inhibitory effect than myrsteine. To investigate the stability and efficiency of ligand binding mode, free Srt A, its complexes with myrsteine and the best selected compound were subjected to 50s molecular dynamics simulation. MD simulation results showed that compound-73945561 had better binding profiles and interactions than myrsteine as a reference inhibitor, and steadily unstable behavior was observed in the docking complex.

Overall, compound-73945561 may serve as a new inhibitor or provide a scaffold for further optimization toward the design of more potent SortA inhibitors. The development of such inhibitors would be an essential strategy against resistant bacteria.

Traditional cheese is one of the most popular types of cheese in the western regions of Iran. Contamination of cheese with pathogenic microorganisms can pose a risk to human health and result in significant economic losses. The aim of the present study was to investigate the presence of Escherichia coli and Staphylococcus aureus and to determine their antibiotic resistance patterns in traditional cheeses produced in Jolfa County. 60 samples of traditional cheese were randomly collected from shops in Jolfa County. To examine the presence of the targeted microorganisms according to national food standards, the study utilized Giolitti-Cantoni broth, Baird-Parker agar, blood agar, and Mueller-Hinton agar, as well as diagnostic and biochemical tests for bacterial species confirmation. The antibiotic resistance pattern against six antibiotics was determined. The results indicated that all samples were contaminated with Staphylococcus aureus and Escherichia coli. Additionally, among the Staphylococcus aureus isolates, the highest antibiotic sensitivity was to amikacin at 66.67%, while the highest resistance was to cefixime at 75%. In case of Escherichia coli, the highest antibiotic sensitivity was also to amikacin at 100%, and the highest resistance frequency for this bacterium was reported for azithromycin at 25%. The results of the present study showed that the condition of traditional cheeses in Jolfa County is highly undesirable, and awareness regarding the proper use of traditional products is essential in preventing health and treatment issues, including gastrointestinal diseases.

The use of nanotechnology in various fields of biomedicine and pharmaceutical is expanding rapidly. The aim of the current study was to analyze the biosynthesis of samarium oxide nanoparticles (Sm2O3 NPs) using curcumin and to investigate its antimicrobial effects. In this study, curcumin was used as a reducing agent for the synthesis of samarium oxide nanoparticles. The synthesized NPs were examined using Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Energy Dispersive X-Ray (EDX), light dynamic diffraction (DLS), and zeta potential methods. Antimicrobial effects of Sm2O3 NPs against clinical and standard strains of Pseudomonas aeruginosa PTCC 1430 and Staphylococcus aureus PTCC 1431 were investigated by disk diffusion methods with Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). Also, the effect of NPs on the production of virulence factors of pyocyanin pigment and alginate in Pseudomonas aeruginosa was investigated. Characterization of the synthesized Sm2O3NPs showed that the NPs had a cubic structure with an average size of 32.61 nm and a pure crystalline phase. Also, DLS and zeta potential analysis showed that the produced NPs had an average diameter of 90 nm and a charge of -9.4 mV. The disk diffusion method displayed the significant antibacterial activity of Sm2O3 NPs against studied strains. According to the broth microdilution method, the lowest MIC value was obtained for the standard strain of S. aureus and the highest MIC value was obtained for the clinical strain of P. aeruginosa with concentrations of 3.12 and 25 μg/mL, respectively. Also, the study of the effect of nanoparticles on the production of pyocyanin and alginate showed promising results. In the present study, the antibacterial effect of Sm2O3 NPs against multidrug-resistant strains of P. aeruginosa and S. aureus was investigated. Based on the results of this study, Sm2O3 NPs synthesized using curcumin can be used as an effective antibacterial agent against clinical pathogens.

Staphylococcus aureus is one of the pathogens that can easily infect meat. The present study was performed to evaluate the antimicrobial resistance and distribution of enterotoxin genes in Staphylococcus aureus isolates isolated from raw meat and meat products. 440 samples of raw meat and meat products were collected from suppliers in Shahrekord city and the presence of Staphylococcus aureus was examined using biochemical and molecular tests. The most common enterotoxin genes and genes encoding antibiotic resistance were examined in the presence of specific primers. In this study, out of 440 samples, 61 samples (13.86%) were positive for Staphylococcus aureus. Biofilm reaction was observed in 56 isolates (91.8%). The highest resistance to penicillin (83.60%) and the lowest resistance to vancomycin (0%). The frequency of the presence of sea, seb, sec and sed genes in the studied isolates were reported 39.34%, 27.86%, 26.22% and 37.70%, respectively. Considering that there was a statistically significant relationship between antibiotic resistance genes and biofilm production, it is clear that antibiotic resistance in strains that are able to produce biofilm compared to strains that are not able to produce biofilms are more

In this study, 50 Staphylococcus aureus samples from Baghdad Hospital were collected and examined, 17 samples were infected with methicillin-resistant Staphylococcus aureus (MRSA) and 5 samples were infected with vancomycin-resistant Staphylococcus aureus (VRSA). The sensitivity of the isolates against different antimicrobial agents was evaluated using the VITEK2 standard system. According to CLSI, the minimum inhibitory concentration (MIC) values of zinc oxide quantum dots (ZnO-QDs) were also tested by the Muller-Hinton dilution method. In addition, polymerase chain reaction (PCR) was performed to identify vanA and mecA genes. The antibacterial effects of ZnO-QDs on VRSA were higher than MRSA isolates.

Eugenol is the major constituents of clove oil, which is known as an anti-bacterial and anti-oxidant agent. Staphylococcus aureus is most common pathogens that cause nosocomial infections and some bacterial infections death. In this study, the effect of Eugenol on the expression of mecA gene and the interaction with mecA protein (PBP2a) was evaluated in methicillin resistant isolates of Staphylococcus aureus.

Antibacterial activity of Eugenol was investigated in isolates of Staphylococcus aureus with DISC diffusion, MIC and MBC. Interaction between Eugenol and mecA protein (PBP2) was evaluated with bioinformatic approaches. The expression of mecA gene was assessed in Eugenol treated and untreated isolates by Q-RT-PCR.

results of this study showed that Eugenol inhibited bacterial growth in the DISCs in 80% of Staphylococcus aureus isolates. MIC and MBC of Eugenol in the most isolates were determined 5.22 mg/ml and 10.44 mg/ml, respectively. In silico analysis showed interaction between Eugenol and mecA protein (PBP2). mecA gene downregulated in Eugenol treated isolates (5.22 mg/ml) in compared to control.

It seems that Eugenol led to growth inhibition of Staphylococcus aureus isolates through both interaction with PBP2 and mecA gene downregulation.

Fast and cold foods increase the microbiological risk of consumers due to the lack of cooking time and the contact of restaurant workers' hands during preparation. Staphylococcus aureus is one of the most important causes of foodborne diseases. The purpose of this study is to determine the abundance of Staphylococcus aureus in semi-prepared foods and fast foods and to identify them by PCR method.In this research, 100 food samples (meat products, falafel, pizza, chicken) were randomly collected from the food preparation and serving centers in Borujen, Shahrekord and Farsan cities in a period of one month to investigate the presence of Staphylococcus aureus. Tested. In total, staphylococcus contamination was observed in samples of meat products (64.1%), falafel (21.2%), pizza (20%), chicken (30.8%). The average number of Staphylococcus aureus bacteria in positive samples was reported (39%).Based on the results of the present research, it can be said that since the results of the production steps and preparation of fast food and semi-prepared foods are manual, there is a possibility of food contamination through human labor. Although the percentage of sample contamination is high, the number of bacteria in the sample is low and does not pose a potential risk to the health of the consumer. Therefore, personal and environmental health education is of great importance in order to reduce the amount of Staphylococcus aureus in people who are involved in food preparation and production.

isolates of Staphylococcus aureus from different samples to determine antibiotic resistance and Staphylococcus aureus is a major cause of hospital acquired infections and community. Toxic shock syndrome toxin -1 gene secreted by the bacteria from the categories are important virulence factors and is component super antigens toxins pyrogenic (PTSAgs). The purpose of this study is determine the antibiotic resistance patterns and tsst-1 gene frequency in Staphylococcus aureus strains isolated from patients of Imam Khomeini hospital in Ahvaz. In this study, 133 clinical frequency tsst-1 gene were studied. After genomic DNA extraction using DNA extraction kit was performed the definitive diagnosis of bacteria, Then the gene tsst-1 frequency done in the presence of specific primers and antibiotic resistance was determined by agar disk diffusion method. After PCR amplification and detection of the bacterium, Of 133 isolates sequence tsst-1 gene was observed in 6 strains. In antibiogram test the greatest resistance to cefazolin (3/83%) and the lowest resistance to nitrofurantoin and vancomycin (0%) was observed. Due to the increasing prevalence of resistance to antibiotics of clinical importance tsst-1 gene timely identification and implementation of appropriate therapeutic strategies for controlling infection seems necessary.