Bacterial infection of the wound could potentially cause serious complications and an enormous medical and financial cost to the rapid emergence of drug-resistant bacteria. Nanomaterials are an emerging technology, that has been researched as possible antimicrobial nanomaterials for the inhibition of wound infection and enhancement of wound healing. Graphene is 2-dimensional (2D) sheet of sp2 carbon atoms in a honeycomb structure. It has superior properties, strength, conductivity, antimicrobial, and molecular carrier abilities. Graphene and its derivatives, Graphene oxide (GO) and reduced GO (rGO), have antibacterial activity and could damage bacterial morphology and lead to the leakage of intracellular substances. Besides, for wound infection management, Graphene-platforms could be functionalized by different antibacterial agents such as metal-nanoparticles, natural compounds, and antibiotics. The Graphene structure can absorb near-infrared wavelengths, allowing it to be used as antimicrobial photodynamic therapy. Therefore, Graphene-based material could be used to inhibit pathogens that cause serious skin infections and destroy their biofilm community, which is one of the biggest challenges in treating wound infection. Due to its agglomerated structure, GO hydrogel could entrap and stack the bacteria; thus, it prevents their initial attachment and biofilm formation. The sharp edges of GO could destroy the extracellular polymeric substance surrounding the biofilm and ruin the biofilm biomass structure. As well as, Chitosan and different natural and synthetic polymers such as collagen and polyvinyl alcohol (PVA) also have attracted a great deal of attention for use with GO as wound dressing material. To this end, multi-functional polymers based on Graphene and blends of synthetic and natural polymers can be considered valid non-antibiotic compounds useful against wound infection and improvement of wound healing. Finally, the global wound care market size was valued at USD 20.8 billion in 2022 and is expected to expand at a compound annual growth rate (CAGR) of 5.4% from 2022 to 2027 (USD 27.2 billion). This will encourage academic as well as pharmaceutical and medical device industries to investigate any new materials such as graphene and its derivatives for the treatment of wound healing.
Brucellosis is a zoonotic disease caused by Brucella species. It has been estimated that more than 500,000 new cases of Brucellosis occur annually all around the world. Relapse of the disease is one of the most important challenges. The most important reason for the relapse of brucellosis is the survival of the bacteria inside the macrophages, which makes them safe from the immune system and disrupts drug delivery mechanism. The present study was performed to assess the effects of Doxycycline-loaded Solid Lipid Nanoparticles (DOX-SLN) on the Brucella melitensis inside macrophages. DOX-SLN was prepared using double emulsion method. The technological characterization of DOX-SLN, including particle size, zeta potential, polydispersity index (PDI), drug loading and encapsulation efficiency were used. Fourier-transform infrared spectroscopy (FTIR) and Differential scanning calorimetry (DSC) were used to assess the interactions between Nanoparticles (NPs) components and crystalline form of doxycycline. Moreover, the effect of DOX-SLN on the bacteria were compared with that of the doxycycline using various methods, including well diffusion, Minimum Inhibitory Concentration (MIC), and investigation of their effects on murine macrophage-like cells cell line J774A.1. The means of particle size, zeta potential, PDI, drug loading and encapsulation efficiency were 299 ± 34 nm, − 28.7 ± 3.2 mV, 0.29 ± 0.027, 11.2 ± 1.3%, and 94.9 ± 3.2%, respectively. The morphology of NPs were spherical with a smooth surface. No chemical reaction was occurred between the components. Doxycycline was located within NP matrix in its molecular form. The DOX-SLN significantly decreased the microbial loading within macrophages (3.5 Log) in comparison with the free doxycycline. Since the DOX-SLN showed better effects on B. melitensis enclosed in macrophages than the free doxycycline, it is recommended to use it for treating brucellosis and preventing relapse.
The aims of our study were to evaluate the prevalence of Staphylococcus aureus (S. aureus) strains in food samples of animal origin, examine their antibacterial susceptibility pattern, and to detect staphylococcal enterotoxin (SEs) genes and the mecA gene in isolated S. aureus strains using the polymerase chain reaction (PCR). . A total of 1050 food samples including 671 raw milk and dairy products and 379 raw meats were collected between September 2013 and June 2014 in Hamadan, Iran. Food samples were analyzed for S. aureus identification. The antibiotic susceptibility pattern of all isolates was determined using the disk agar diffusion method followed by detecting mecA resistance gene using PCR. In addition, harboring of SE genes were determined using a multiplex PCR assay targeting nine genes. . A total of 98 (9.3%) S. aureus strains were isolated from 1050 food samples. Of the 98 isolates examined, the most frequent resistance was observed to erythromycin (30.6%), followed by tetracycline (29.6%), gentamicin (27.6%), clindamycin (26.5%), ciprofloxacin and rifampin (24.5%), trimethoprim-sulfamethoxazole (14.3%), and cefoxitin (5.1%). All cefoxitin resistant isolates were positive for mecA. The prevalence of SEs was 77.6% (n=76). Among the genes that code classic enterotoxins, sea was the most frequent and was carried by 25.5% of isolates, followed by see in 18.4%, sed in 11.2%, sec in 5.1%, and seb in 4.1% of isolates. Among the detected enterotoxins, seg was the predominantly identified enterotoxin gene in isolates with prevalence of 35.7%. The seh gene with prevalence of 1% and sei gene with 3.1% were other detected enterotoxins with low frequencies. . The high prevalence of SE genes detected indicates a potential risk for causing animal-originated food poisoning. The increasing prevalence of community-acquired MRSA and its emerging antibiotic resistance in foods is a serious problem for public health.