RESUMO
Osteomyelitis (OM) is a progressive, inflammatory infection of bone caused predominately by Staphylococcus aureus. Herein, we engineered an antibiotic-eluting collagen-hydroxyapatite scaffold capable of eliminating infection and facilitating bone healing. An iterative freeze-drying and chemical crosslinking approach was leveraged to modify antibiotic release kinetics, resulting in a layered dual-release system whereby an initial rapid release of antibiotic to clear infection was followed by a sustained controlled release to prevent reoccurrence of infection. We observed that the presence of microbial collagenase accelerated antibiotic release from the crosslinked layer of the scaffold, indicating that the material is responsive to microbial activity. As exemplar drugs, vancomycin and gentamicin-eluting scaffolds were demonstrated to be bactericidal, and supported osteogenesis in vitro. In a pilot murine model of OM, vancomycin-eluting scaffolds were observed to reduce S. aureus infection within the tibia. Finally, in a rabbit model of chronic OM, gentamicin-eluting scaffolds both facilitated radial bone defect healing and eliminated S. aureus infection. These results show that antibiotic-eluting collagen-hydroxyapatite scaffolds are a one-stage therapy for OM, which when implanted into infected bone defects simultaneously eradicate infection and facilitate bone tissue healing.
Assuntos
Antibacterianos , Gentamicinas , Osteomielite , Infecções Estafilocócicas , Staphylococcus aureus , Alicerces Teciduais , Animais , Alicerces Teciduais/química , Antibacterianos/farmacologia , Antibacterianos/química , Infecções Estafilocócicas/tratamento farmacológico , Osteomielite/tratamento farmacológico , Coelhos , Staphylococcus aureus/efeitos dos fármacos , Gentamicinas/farmacologia , Gentamicinas/administração & dosagem , Gentamicinas/química , Gentamicinas/uso terapêutico , Camundongos , Vancomicina/farmacologia , Vancomicina/química , Vancomicina/administração & dosagem , Durapatita/química , Cinética , Cicatrização/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Colágeno/química , FemininoRESUMO
Bacteria-infected wounds pose challenges to healing due to persistent infection and associated damage to nerves and vessels. Although sonodynamic therapy can help kill bacteria, it is limited by the residual oxidative stress, resulting in prolonged inflammation. To tackle these barriers, novel 4 octyl itaconate-coated Li-doped ZnO/PLLA piezoelectric composite microfibers are developed, offering a whole-course "targeted" treatment under ultrasound therapy. The inclusion of Li atoms causes the ZnO lattice distortion and increases the band gap, enhancing the piezoelectric and sonocatalytic properties of the composite microfibers, collaborated by an aligned PLLA conformation design. During the infection and inflammation stages, the piezoelectric microfibers exhibit spatiotemporal-dependent therapeutic effects, swiftly eliminating over 94.2 % of S. aureus within 15 min under sonodynamic therapy. Following this phase, the microfibers capture reactive oxygen species and aid macrophage reprogramming, restoring mitochondrial function, achieving homeostasis, and shortening inflammation cycles. As the wound progresses through the healing stages, bioactive Zn2+ and Li + ions are continuously released, improving cell recruitment, and the piezoelectrical stimulation enhances wound recovery with neuro-vascularization. Compared to commercially available dressings, our microfibers accelerate the closure of rat wounds (Φ = 15 mm) without scarring in 12 days. Overall, this "one stone, four birds" wound management strategy presents a promising avenue for infected wound therapy.
Assuntos
Terapia por Ultrassom , Cicatrização , Animais , Cicatrização/efeitos dos fármacos , Terapia por Ultrassom/métodos , Ratos Sprague-Dawley , Ratos , Staphylococcus aureus/efeitos dos fármacos , Óxido de Zinco/química , Camundongos , Estimulação Elétrica , Masculino , Infecções Estafilocócicas/terapia , Poliésteres/química , Espécies Reativas de Oxigênio/metabolismo , Terapia por Estimulação Elétrica/métodos , Neovascularização Fisiológica/efeitos dos fármacosRESUMO
Complex tissue damage accompanying with bacterial infection challenges healthcare systems globally. Conventional tissue engineering scaffolds normally generate secondary implantation trauma, mismatched regeneration and infection risks. Herein, we developed an easily implanted scaffold with multistep shape memory and photothermal-chemodynamic properties to exactly match repair requirements of each part from the tissue defect by adjusting its morphology as needed meanwhile inhibiting bacterial infection on demand. Specifically, a thermal-induced shape memory scaffold was prepared using hydroxyethyl methacrylate and polyethylene glycol diacrylate, which was further combined with the photothermal agent iron tannate (FeTA) to produce NIR light-induced shape memory property. By varying ingredients ratios in each segment, this scaffold could perform a stepwise recovery under different NIR periods. This process facilitated implantation after shape fixing to avoid trauma caused by conventional methods and gradually filled irregular defects under NIR to perform suitable tissue regeneration. Moreover, FeTA also catalyzed Fenton reaction at bacterial infections with abundant H2O2, which produced excess ROS for chemodynamic antibacterial therapy. As expected, bacteriostatic rate was further enhanced by additional photothermal therapy under NIR. The in vitro and vivo results showed that our scaffold was able to perform high efficacy in both antibiosis, inflammation reduction and wound healing acceleration, indicating a promising candidate for the regeneration of complex tissue damage with bacterial infection.
Assuntos
Antibacterianos , Alicerces Teciduais , Cicatrização , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/uso terapêutico , Animais , Alicerces Teciduais/química , Camundongos , Cicatrização/efeitos dos fármacos , Raios Infravermelhos , Terapia Fototérmica , Engenharia Tecidual/métodos , Taninos/química , Taninos/farmacologia , Materiais Inteligentes/química , Staphylococcus aureus/efeitos dos fármacos , Masculino , Polietilenoglicóis/químicaRESUMO
Biofilm-associated infections (BAIs) continue to pose a major challenge in the medical field. Nanomedicine, in particular, promises significant advances in combating BAIs through the introduction of a variety of nanomaterials and nano-antimicrobial strategies. However, studies to date have primarily focused on the removal of the bacterial biofilm and neglect the subsequent post-biofilm therapeutic measures for BAIs, rendering pure anti-biofilm strategies insufficient for the holistic recovery of affected patients. Herein, we construct an emerging dual-functional composite nanosheet (SiHx@Ga) that responds to pHs fluctuation in the biofilm microenvironment to enable a sequential therapy of BAIs. In the acidic environment of biofilm, SiHx@Ga employs the self-sensitized photothermal Trojan horse strategy to effectively impair the reactive oxygen species (ROS) defense system while triggering oxidative stress and lipid peroxidation of bacteria, engendering potent antibacterial and anti-biofilm effects. Surprisingly, in the post-treatment phase, SiHx@Ga adsorbs free pathogenic nucleic acids released after biofilm destruction, generates hydrogen with ROS-scavenging and promotes macrophage polarization to the M2 type, effectively mitigating damaging inflammatory burst and promoting tissue healing. This well-orchestrated strategy provides a sequential therapy of BAIs by utilizing microenvironmental variations, offering a conceptual paradigm shift in the field of nanomedicine anti-infectives.
Assuntos
Antibacterianos , Biofilmes , Gálio , Espécies Reativas de Oxigênio , Biofilmes/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Gálio/química , Gálio/farmacologia , Camundongos , Portadores de Fármacos/química , Células RAW 264.7 , Humanos , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologiaRESUMO
Rapid screening for foodborne pathogens is crucial for food safety. A rapid and one-step electrochemical sensor has been developed for the detection of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Salmonella typhimurium (S. typhimurium). Through the construction of aptamer/two-dimensional carboxylated Ti3C2Tx (2D C-Ti3C2Tx)/two-dimensional Zn-MOF (2D Zn-MOF) composites, the recognition elements, signal tags, and signal amplifiers are integrated on the electrode surface. Pathogens are selectively captured using the aptamer, which increases the impedance of the electrode surfaceï¼leads to a decrease in the 2D Zn-MOF current. Bacteria can be rapidly quantified using a one-step detection method and the replacement of aptamers. The detection limits for E. coli, S. aureus, and S. typhimurium are 6, 5, and 5 CFU·mL-1, respectively. The sensor demonstrated reliable detection capabilities in real-sample testing. Therefore, the one-step sensor based on the 2D Zn-MOF and 2D C-Ti3C2Tx has significant application value in the detection of foodborne pathogens.
Assuntos
Técnicas Eletroquímicas , Escherichia coli , Salmonella typhimurium , Staphylococcus aureus , Zinco , Staphylococcus aureus/isolamento & purificação , Salmonella typhimurium/isolamento & purificação , Zinco/análise , Escherichia coli/isolamento & purificação , Técnicas Eletroquímicas/instrumentação , Técnicas Biossensoriais/instrumentação , Estruturas Metalorgânicas/química , Microbiologia de Alimentos , Titânio/química , Limite de Detecção , Eletrodos , Contaminação de Alimentos/análiseRESUMO
Aquatic products are highly susceptible to spoilage, and preparing composite edible film with essential oil is an effective solution. In this study, composite edible films were prepared using perilla essential oil (PEO)-glycerol monolaurate emulsions incorporated with chitosan and nisin, and the film formulation was optimized by response surface methodology. These films were applied to ready-to-eat fish balls and evaluated over a period of 12 days. The films with the highest inhibition rate against Staphylococcus aureus were acquired using a polymer composition of 6 µL/mL PEO, 18.4 µg/mL glycerol monolaurate, 14.2 mg/mL chitosan, and 11.0 µg/mL nisin. The fish balls coated with the optimal edible film showed minimal changes in appearance during storage and significantly reduced total bacterial counts and total volatile basic nitrogen compared to the control groups. This work indicated that the composite edible films containing essential oils possess ideal properties as antimicrobial packaging materials for aquatic foods.
Assuntos
Antibacterianos , Quitosana , Filmes Comestíveis , Emulsões , Embalagem de Alimentos , Lauratos , Monoglicerídeos , Nisina , Óleos Voláteis , Staphylococcus aureus , Nisina/farmacologia , Nisina/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Lauratos/química , Lauratos/farmacologia , Embalagem de Alimentos/instrumentação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Emulsões/química , Quitosana/química , Quitosana/farmacologia , Monoglicerídeos/química , Monoglicerídeos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Óleos de Plantas/química , Óleos de Plantas/farmacologia , Perilla/químicaRESUMO
The human milk fat globule membrane (hMFGM) and Lactobacillus modulate the infant's gut and benefit health. Hence, the current study assesses the probiotic potential of Lactiplantibacillus plantarum (MRK3), Limosilactobacillus ferementum (MK1) isolated from infant feces, and its interaction with hMFGM during conditions mimicking infant digestive tract. Both strains showed high tolerance to gastrointestinal conditions, cell surface hydrophobicity, and strong anti-pathogen activity against Staphylococcus aureus. During digestion, hMFGM significantly exhibited xanthine oxidase activity, membrane roughness, and surface topography. In the presence of hMFGM, survival of MRK3 was higher than MK1, and electron microscopic observation revealed successful entrapment of MRK3 in the membrane matrix throughout digestion. Interestingly, probiotic-membrane matrix interaction showed significant synergy to alleviate oxidative stress and damage induced by cell-free supernatant of Escherichia coli in Caco-2 cells. Our results show that a probiotic-encapsulated membrane matrix potentially opens the functional infant formula development pathway.
Assuntos
Glicolipídeos , Glicoproteínas , Gotículas Lipídicas , Leite Humano , Estresse Oxidativo , Probióticos , Humanos , Probióticos/farmacologia , Probióticos/química , Gotículas Lipídicas/química , Gotículas Lipídicas/metabolismo , Glicoproteínas/química , Glicoproteínas/farmacologia , Glicoproteínas/metabolismo , Células CACO-2 , Glicolipídeos/química , Glicolipídeos/farmacologia , Glicolipídeos/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Leite Humano/química , Lactente , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/crescimento & desenvolvimento , Fórmulas Infantis/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Trato Gastrointestinal/microbiologia , Trato Gastrointestinal/metabolismoRESUMO
Osteomyelitis is an osseous infectious disease that primarily affects children and the elderly with high morbidity and recurrence. The conventional treatments of osteomyelitis contain long-term and high-dose systemic antibiotics with debridements, which are not effective and lead to antibiotic resistance with serious side/adverse effects in many cases. Hence, developing novel antibiotic-free interventions against osteomyelitis (especially antibiotic-resistant bacterial infection) is urgent and anticipated. Here, a bone mesenchymal stem cell membrane-constructed nanocell (CFE@CM) was fabricated against osteomyelitis with the characteristics of acid-responsiveness, hydrogen peroxide self-supplying, enhanced chemodynamic therapeutic efficacy, bone marrow targeting and cuproptosis induction. Notably, mRNA sequencing was applied to unveil the underlying biological mechanisms and found that the biological processes related to copper ion binding, oxidative phosphorylation, peptide biosynthesis and metabolism, etc., were disturbed by CFE@CM in bacteria. This work provided an innovative antibiotic-free strategy against osteomyelitis through copper-enhanced Fenton reaction and distinct cuproptosis, promising to complement the current insufficient therapeutic regimen in clinic.
Assuntos
Cobre , Osteomielite , Osteomielite/tratamento farmacológico , Animais , Cobre/química , Cobre/farmacologia , Concentração de Íons de Hidrogênio , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/citologia , Camundongos , Peróxido de Hidrogênio/metabolismo , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Antibacterianos/química , Humanos , Staphylococcus aureus/efeitos dos fármacosRESUMO
The skin microbiome is essential for skin barrier function because it inhibits pathogen colonization, and decreased microbiome diversity correlates with increased Staphylococcus aureus (S. aureus) burden and atopic dermatitis (AD) severity. Managing S. aureuss-driven AD in clinical practice remains problematic due to complications such as AD exacerbation, impetigo, abscesses, and invasive infections. This project used a modified Delphi process comprising face-to-face discussions followed by a blinded vote to define 5 final consensus statements. A panel of 6 pediatric dermatologists developed a consensus on S. aureus-driven AD exacerbation, challenges in current treatments for AD with secondary bacterial infections, and new developments to improve patient care and outcomes. The panel's 5 consensus statements provide recommendations for dermatologists, pediatricians, and healthcare providers treating patients with secondary infected AD. These recommendations underscore the importance of recognizing and managing S. aureus skin infection in AD clinical practice and promoting antibiotic stewardship to mitigate resistance. The panel defined a significant unmet need for a single topical AD therapy effective against all symptoms, including pruritus, S. aureus-driven AD exacerbation, infection, and inflammation, across AD severity levels. J Drugs Dermatol. 2024;23(10):825-832. doi:10.36849/JDD.8240.
Assuntos
Antibacterianos , Consenso , Técnica Delphi , Dermatite Atópica , Infecções Cutâneas Estafilocócicas , Staphylococcus aureus , Dermatite Atópica/microbiologia , Dermatite Atópica/diagnóstico , Dermatite Atópica/tratamento farmacológico , Dermatite Atópica/terapia , Humanos , Staphylococcus aureus/isolamento & purificação , Infecções Cutâneas Estafilocócicas/diagnóstico , Infecções Cutâneas Estafilocócicas/tratamento farmacológico , Infecções Cutâneas Estafilocócicas/microbiologia , Infecções Cutâneas Estafilocócicas/terapia , Antibacterianos/uso terapêutico , Antibacterianos/administração & dosagem , Índice de Gravidade de Doença , Administração Cutânea , Pele/microbiologia , Pele/patologia , Gestão de Antimicrobianos/normas , Progressão da DoençaRESUMO
Staphylococcus aureus (S. aureus), particularly Methicillin-resistant S. aureus (MRSA), poses a significant global public health threat, necessitating advanced methodologies to enhance our understanding of this organism at the omics levels. This study introduces a refined protocol for constructing and curing high-density transposon mutant (tn-mutant) libraries in S. aureus, addressing the challenges associated with low transductant yields, and the complex genetic manipulation mechanism in Gram-positive bacteria. Our methodology employs a Himar1 transposon based on a two-plasmid system, leveraging Himar1's high insertional efficiency in AT-rich organisms. Enhanced transduction efficiency was achieved through chloramphenicol pre-treatment and the use of modified enriched media. Complementing this, an optimized plasmid curing procedure ensured a representative and stable tn-mutant library. The protocol was successfully applied to multiple S. aureus strains, demonstrating an increase in mutant recovery and reduced post-curing impact. The method offers a robust approach for Transposon Insertion Sequencing (TIS) applications in S. aureus, enabling deeper insights into survival, resistance, and pathogenicity mechanisms. This protocol holds a significant potential for accelerating the construction of tn-mutant libraries in various S. aureus strains.
Assuntos
Elementos de DNA Transponíveis , Biblioteca Gênica , Mutagênese Insercional , Staphylococcus aureus , Elementos de DNA Transponíveis/genética , Staphylococcus aureus/genética , Mutagênese Insercional/métodos , Mutação , Plasmídeos/genética , Bacteriófagos/genética , Temperatura Alta , Staphylococcus aureus Resistente à Meticilina/genéticaRESUMO
Isogenic bacterial cell populations are phenotypically heterogenous and may include subpopulations of antibiotic tolerant or heteroresistant cells. The reversibility of these phenotypes and lack of biomarkers to differentiate functionally different, but morphologically identical cells is a challenge for research and clinical detection. To overcome this, we present ´Cellular Phenotypic Profiling and backTracing (CPPT)´, a fluorescence-activated cell sorting platform that uses fluorescent probes to visualize and quantify cellular traits and connects this phenotypic profile with a cell´s experimentally determined fate in single cell-derived growth and antibiotic susceptibility analysis. By applying CPPT on Staphylococcus aureus we phenotypically characterized dormant cells, exposed bimodal growth patterns in colony-derived cells and revealed different culturability of single cells on solid compared to liquid media. We demonstrate that a fluorescent vancomycin conjugate marks cellular subpopulations of vancomycin-intermediate S. aureus with increased likelihood to survive antibiotic exposure, showcasing the value of CPPT for discovery of clinically relevant biomarkers.
Assuntos
Antibacterianos , Fenótipo , Análise de Célula Única , Staphylococcus aureus , Staphylococcus aureus/genética , Staphylococcus aureus/efeitos dos fármacos , Análise de Célula Única/métodos , Antibacterianos/farmacologia , Citometria de Fluxo/métodos , Vancomicina/farmacologia , Testes de Sensibilidade Microbiana , Humanos , Infecções Estafilocócicas/microbiologiaRESUMO
In this study, an environmentally-friendly, simple, and low-cost approach was developed for the production of silver nanoparticles (Ag NPs) accelerated by Salvia mirzayanii plant. The identification process involved ultraviolet-visible (UV-Vis) spectrophotometry, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). The UV-Vis spectrum exhibited a peak at 450 nm which is a characteristic surface plasmon resonance of Ag NPs. The XRD and EDS analyses confirmed the crystalline nature and the presence of silver element, while the SEM analysis displayed the production of almost spherical nanoparticles. The FTIR spectrum exhibited that the Ag NPs were functionalized with biomolecules found in the extract, which are involved in the production and stabilization of the NPs. The antibacterial activity of the essential oil, the hydroalcoholic extract and Ag NPs was examined against antibiotic-resistant bacteria, Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). The anti-Giardia activity was tested on Giardia lamblia cysts at different time intervals. The results exhibited that the MIC values for essential oil, hydroalcoholic extract and Ag NPs against S. aureus were 1.65 µL/mL, 75 mg/mL, and 0.125 mg/mL respectively. The MBC was attained 6.25 µL/mL, 300 mg/mL, and 0.25 mg/mL, for essential oil, hydroalcoholic extract and Ag NPs, respectively. The MIC values for essential oil, hydroalcoholic extract and NPs against E. coli were 3.12 µL/mL, 150 mg/mL, and 0.06 mg/mL, respectively. The MBC was determined to be 50 µL/mL, 300 mg/mL, and 0.25 mg/mL for essential oil, hydroalcoholic extract and Ag NPs, respectively. In addition, the antioxidant activity was determined using the ferric reducing antioxidant power (FRAP) test. The results indicated that the essential oil of this plant exhibited the highest antibacterial and anti-giardial properties, whereas its extract demonstrated the strongest antioxidant properties.
Assuntos
Antibacterianos , Antioxidantes , Química Verde , Nanopartículas Metálicas , Óleos Voláteis , Extratos Vegetais , Salvia , Prata , Nanopartículas Metálicas/química , Prata/química , Prata/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Antioxidantes/farmacologia , Antioxidantes/química , Salvia/química , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Química Verde/métodos , Testes de Sensibilidade Microbiana , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacosRESUMO
BACKGROUND: The contribution of interspecies interactions between coinfecting pathogens to chronic refractory infection by affecting pathogenicity is well established. However, little is known about the impact of intraspecific interactions on infection relapse, despite the cross-talk of different strains within one species is more common in clinical infection. We reported a case of chronic refractory pulmonary infection relapse, caused by two methicillin-sensitive S. aureus (MSSA) strains (SA01 and SA02) and revealed a novel strategy for relapse via intraspecific cooperation. METHODS: The hemolytic ability, growth curve, biofilm formation, virulence genes and response of G. mellonella larvae to S. aureus infection were analysed to confirm this hypothesis. RESULTS: SA02 hemolytic activity was inhibited by SA01, along with the expression of hemolysin genes and the virulence factor Hla. Additionally, SA01 significantly enhanced the biofilm formation of SA02. AIP-RNAIII may be a possible pathway for this interaction. Compared with mono-infection, a worse outcome (decreased larval survival and increased microbial burden) of the two MSSA strains coinfected with G. mellonella confirmed that intraspecific interactions indeed enhanced bacterial survival in vivo. CONCLUSION: The intraspecific interaction of S. aureus could lead to chronic refractory infection via pathogenicity changes.
Assuntos
Biofilmes , Larva , Infecções Estafilocócicas , Staphylococcus aureus , Fatores de Virulência , Animais , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Staphylococcus aureus/fisiologia , Staphylococcus aureus/patogenicidade , Biofilmes/crescimento & desenvolvimento , Humanos , Larva/microbiologia , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Recidiva , Virulência , Mariposas/microbiologiaRESUMO
Bacterial infections often involve more than one pathogen. While it is well established that polymicrobial infections can impact disease outcomes, we know little about how pathogens interact and affect each other's behaviour and fitness. Here, we used a microscopy approach to explore interactions between Pseudomonas aeruginosa and six human opportunistic pathogens that often co-occur in polymicrobial infections: Acinetobacter baumannii, Burkholderia cenocepacia, Escherichia coli, Enterococcus faecium, Klebsiella pneumoniae, and Staphylococcus aureus. When following growing microcolonies on agarose pads over time, we observed a broad spectrum of species-specific ecological interactions, ranging from mutualism to antagonism. For example, P. aeruginosa engaged in a mutually beneficial interaction with E. faecium but suffered from antagonism by E. coli. While we found little evidence for active directional growth towards or away from cohabitants, we observed that some pathogens increased growth in double layers in response to competition and that physical forces due to fast colony expansion had a major impact on fitness. Overall, our work provides an atlas of pathogen interactions, highlighting the diversity of potential species dynamics that may occur in polymicrobial infections. We discuss possible mechanisms driving pathogen interactions and offer predictions of how the different ecological interactions could affect virulence.
Assuntos
Interações Microbianas , Pseudomonas aeruginosa , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/crescimento & desenvolvimento , Pseudomonas aeruginosa/genética , Humanos , Simbiose , Antibiose , Klebsiella pneumoniae/crescimento & desenvolvimento , Klebsiella pneumoniae/fisiologia , Klebsiella pneumoniae/patogenicidade , Staphylococcus aureus/fisiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/genética , Enterococcus faecium/fisiologia , Enterococcus faecium/crescimento & desenvolvimento , Escherichia coli/fisiologia , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/genética , Coinfecção/microbiologia , Acinetobacter baumannii/fisiologia , Acinetobacter baumannii/crescimento & desenvolvimento , Infecções Oportunistas/microbiologia , Burkholderia cenocepacia/genética , Burkholderia cenocepacia/fisiologia , Burkholderia cenocepacia/crescimento & desenvolvimentoRESUMO
Infections originating from pathogenic microorganisms can significantly impede the natural wound-healing process. To address this obstacle, innovative bio-active nanomaterials have been developed to enhance antibacterial capabilities. This study focuses on the preparation of nanocomposites from thermally reduced graphene oxide and zinc oxide (TRGO/ZnO). The hydrothermal method was employed to synthesize these nanocomposites, and their physicochemical properties were comprehensively characterized using X-ray diffraction analysis (XRD), High-resolution transmission electron microscopy (HR-TEM), Fourier-transform infrared (FT-IR), Raman spectroscopy, UV-vis, and field-emission scanning electron microscopy (FE-SEM) techniques. Subsequently, the potential of TRGO/ZnO nanocomposites as bio-active materials against wound infection-causing bacteria, including Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, was evaluated. Furthermore, the investigated samples show disrupted bacterial biofilm formation. A reactive oxygen species (ROS) assay was conducted to investigate the mechanism of nanocomposite inhibition against bacteria and for further in-vivo determination of antimicrobial activity. The MTT assay was performed to ensure the safety and biocompatibility of nanocomposite. The results suggest that TRGO/ZnO nanocomposites have the potential to serve as effective bio-active nanomaterials for combating pathogenic microorganisms present in wounds.
Assuntos
Antibacterianos , Grafite , Nanocompostos , Cicatrização , Óxido de Zinco , Grafite/química , Grafite/farmacologia , Óxido de Zinco/química , Óxido de Zinco/farmacologia , Nanocompostos/química , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Testes de Sensibilidade Microbiana , Animais , Espectroscopia de Infravermelho com Transformada de Fourier , Humanos , Difração de Raios X , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologiaRESUMO
This work aimed to fabricate a Cloisite 30B-incorporated carboxymethyl cellulose graft copolymer of acrylic acid and itaconic acid hydrogel (Hyd) via a free radical polymerization method for controlled release of Sunitinib malate anticancer drug. The synthesized samples were characterized by FTIR, XRD, TEM, and SEM-dot mapping analyses. The encapsulation efficiency of Hyd and Hyd/Cloisite 30B (6 wt%) was 81 and 93%, respectively, showing the effectiveness of Cloisite 30B in drug loading. An in vitro drug release study showed that drug release from all samples in a buffer solution with pH 7.4 was higher than in a buffer solution with pH 5.5. During 240 min, the cumulative drug release from Hyd/Cloisite 30B (94.97% at pH 7.4) is lower than Hyd (53.71% at pH 7.4). Also, drug-loaded Hyd/Cloisite 30B (6 wt%) demonstrated better antibacterial activity towards S. Aureus bacteria and E. Coli. High anticancer activity of Hyd/Cloisite 30B against MCF-7 human breast cancer cells was shown by the MTT assay, with a MCF-7 cell viability of 23.82 ± 1.23% after 72-hour incubation. Our results suggest that Hyd/Cloisite 30B could be used as a pH-controlled carrier to deliver anticancer Sunitinib malate.
Assuntos
Carboximetilcelulose Sódica , Portadores de Fármacos , Hidrogéis , Indóis , Nanocompostos , Pirróis , Succinatos , Sunitinibe , Sunitinibe/química , Sunitinibe/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Succinatos/química , Succinatos/farmacologia , Carboximetilcelulose Sódica/química , Hidrogéis/química , Indóis/química , Indóis/farmacologia , Nanocompostos/química , Pirróis/química , Pirróis/farmacologia , Portadores de Fármacos/química , Células MCF-7 , Antineoplásicos/farmacologia , Antineoplásicos/química , Resinas Acrílicas/química , Administração Oral , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/administração & dosagem , Liberação Controlada de Fármacos , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacosAssuntos
Antibacterianos , Infecções Estafilocócicas , Humanos , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Antibacterianos/farmacologia , Staphylococcus aureus/genética , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Farmacorresistência Bacteriana/genéticaRESUMO
Drug-resistant bacteria such as Escherichia coli and Staphylococcus aureus represent a global health problem that requires priority attention. Due to the current situation, there is an urgent need to develop new, more effective and safe antimicrobial agents. Biotechnological approaches can provide a possible alternative control through the production of new generation antimicrobial agents, such as silver nanoparticles (AgNPs) and bacteriocins. AgNPs stand out for their antimicrobial potential by employing several mechanisms of action that can act simultaneously on the target cell such as the production of reactive oxygen species and cell wall rupture. On the other hand, bacteriocins are natural peptides synthesized ribosomally that have antimicrobial activity and are produced, among others, by lactic acid bacteria (LAB), whose main mechanism of action is to produce pores at the level of the cell membrane of bacterial cells. However, these agents have disadvantages. Nanoparticles also have limitations such as the tendency to form aggregates, which decreases their antibacterial activity and possible cytotoxic effects, and bacteriocins have a narrow spectrum of action, require high doses to be effective, and can be degraded by proteases. Given these limitations, nanoconjugates of these two agents have been developed that can act synergistically in the control of pathogenic bacteria resistant to antibiotics. This review focuses on knowing relevant aspects of the antibiotic resistance of E. coli and S. aureus, the characteristics of these new generation antibacterial agents, and their effect alone or forming nanoconjugates that are more effective against the multiresistant mentioned bacteria.
Assuntos
Antibacterianos , Bacteriocinas , Farmacorresistência Bacteriana Múltipla , Escherichia coli , Nanopartículas Metálicas , Nanocompostos , Prata , Staphylococcus aureus , Bacteriocinas/farmacologia , Bacteriocinas/química , Prata/farmacologia , Prata/química , Escherichia coli/efeitos dos fármacos , Nanopartículas Metálicas/química , Staphylococcus aureus/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Nanocompostos/química , Testes de Sensibilidade Microbiana , Lactobacillales/metabolismo , Lactobacillales/efeitos dos fármacosRESUMO
Microbiologically influenced corrosion (MIC) poses considerable challenges in various industries, prompting the exploration of advanced materials to mitigate microbial threats. This study successfully synthesized nanoscale vermiculite (VMT) from natural seawater and utilized it as a foundation to integrate magnetic nanoparticles (Fe3O4) and chlorhexidine acetate (CA) for inhibiting MIC. A comprehensive investigation encompassing the synthesis, characterization, and application of these VMT/Fe3O4/CA composites was conducted to evaluate their antimicrobial effectiveness against Escherichia coli, Staphylococcus aureus, and sulfate-reducing bacteria (SRB), demonstrating an efficacy exceeding 99.5%. Moreover, the composite material demonstrated the capability to align with a magnetic field, enabling precise drug targeting and release, thereby facilitating biofilm removal. This research makes a significant contribution to the advancement of intelligent, efficient, and eco-friendly corrosion protection solutions.
Assuntos
Biofilmes , Escherichia coli , Staphylococcus aureus , Biofilmes/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Clorexidina/farmacologia , Clorexidina/química , Corrosão , Nanopartículas de Magnetita/química , Testes de Sensibilidade MicrobianaRESUMO
BACKGROUND The environmentally friendly production of silver nanoparticles (AgNPs) has gained significant attention as a sustainable alternative to traditional chemical methods. This study focused on synthesizing AgNPs using extract of Dracocephalum kotschyi (D. kotschyi), a medicinal plant. MATERIAL AND METHODS The biosynthesis of AgNPs was monitored using UV-visible spectrophotometry. The role of phytoconstituents from D. kotschyi in stabilizing AgNPs was analyzed using Fourier-transform infrared (FTIR) spectroscopy. Dynamic light scattering (DLS) spectroscopy was used to determine the size, charge, and polydispersity of the nanoparticles, while scanning electron microscopy (SEM) was employed to assess their morphology. We evaluated the antimicrobial efficacy of the synthesized AgNPs against various bacteria, their antioxidant properties via a 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay, and their cytotoxic activity against the HeLa cervical cancer cell line. RESULTS The formation of AgNPs was indicated by a color change and the emergence of a surface plasmon resonance peak at 418 nm. The nanoparticles demonstrated significant antimicrobial, antioxidant, cytotoxic, and anticancer activities. Morphology, size, and shape analysis revealed nearly spherical particles with an average size of 43 nm. FTIR confirmed the presence of phenolic compounds in the extract, serving as reducing and capping agents. X-ray diffraction (XRD) analysis confirmed the crystalline structure of the nanoparticles. Antimicrobial assessments showed effectiveness against Escherichia coli and Staphylococcus aureus. The DPPH scavenging assay demonstrated efficient antioxidant activity, and potent apoptotic anticancer effects were observed on cervical cancer cells. CONCLUSIONS The extract of D. kotschyi was effective as a reducing agent in the environmentally friendly synthesis of AgNPs, which exhibited noteworthy antimicrobial, antioxidant, and anticancer properties. These findings suggest potential biomedical applications for the synthesized AgNPs.