Presence and Role of Acanthamoeba in Wound Infections

Methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are the main multi-drug resistant pathogens associated with deep wound infections which then may cause septicaemia. Treatment is problematic and re-infection is quite common. Free Living Amoebae (FLA), such as Acanthamoeba, are widely distributed in the environment and may also contaminate wounds. It is well known that Acanthamoeba feed on and protect bacteria. The role of Acanthamoeba in wound infections is not very well understood. It is possible that the presence of Acanthamoeba in wounds is one of the key factors for such re-infections. In this study, 140 wound swabs were collected to check for the presence of Acanthamoeba spp. Only one sample was positive for Acanthamoeba spp. Sequencing of the highly variable DF3 region of 18S rRNA gene for the sample showed that this isolate belongs to genotype T4. In addition, clinical isolates of MRSA and Pseudomonas from wound infections were used in this study. The results showed that MRSA and Pseudomonas were able to bind with, invade, survive and multiply inside Acanthamoeba species. One of the essential compounds for microorganisms to grow is iron. The role of iron chelators, including deferiprone and selected novel compounds based on hydroxyl pyridine moiety, was studied. Findings revealed that all novel iron chelators have an antimicrobial activity against both bacteria. In addition, all novel iron chelators were able to kill Acanthamoeba. Cytotoxic effects of MRSA, P. aeruginosa and Acanthamoeba were investigated using the KB epithelial cell line and mesenchymal stem cells (MSC) using a general caspase inhibitor. The results revealed that the ability of live bacteria to induce cell death was higher compared with heat-killed bacteria, bacteria conditioned medium (BCM) and Acanthamoeba conditioned media (CM). The exact trigger for the cell death in this study was not investigated but the relative contributions of apoptosis and necrosis were investigated using fluorescent technique, caspase inhibition and LDH assay. In conclusion, presence of Acanthamoeba in wounds could be the reason of prolong treatment and reinfection in wounds

Antimicrobial, Antibiofilm, and Antioxidant Potentials of Four Halophytic Plants, Euphorbia chamaesyce, Bassia arabica, Fagonia mollis, and Haloxylon salicornicum, Growing in Qassim Region of Saudi Arabia: Phytochemical Profile and In Vitro and In Silico Bioactivity Investigations

The current study aimed to investigate the phytochemical contents and antioxidant, antimicrobial, and antibiofilm activities of four halophytic plants, namely, Euphorbia chamaesyce, Bassia arabica, Fagonia mollis, and Haloxylon salicornicum, native to central Saudi Arabia. The alcoholic extract of E. chamaesyce was found to be the most potent in various bioactivities-based evaluations and rich in polyphenols and flavonoid secondary metabolites, with 68.0 mg/g and 39.23 mg/g gallic acid and quercetin equivalents, respectively. Among all plants’ extracts, the alcoholic extract of E. chamaesyce had the highest DPPH scavenging and metal chelating antioxidant activities at 74.15 Trolox equivalents and 16.28 EDTA equivalents, respectively. The highest antimicrobial activity of E. chamaesyce extract was found to be against Shigella flexneri, with a mean zone of inhibition diameter of 18.1 ± 0.2 mm, whereas the minimum inhibitory concentration, minimum biocidal concentration, minimum biofilm inhibitory concentration, and minimum biofilm eradication concentration values were 12.5, 25, 25, and 50 mg/mL, respectively. The LC-ESI-MS/MS analysis of the E. chamaesyce extract showed the presence of six flavonoids and ten phenolic constituents. The in silico binding of the E. chamaesyce extract’s constituents to Staphylococcus aureus tyrosyl-tRNA synthetase enzyme displayed −6.2 to −10.1 kcal/mol binding energy values, suggesting that these constituents can contribute to the antimicrobial properties of the plant extract, making it an essential medicinal ingredient. In conclusion, these results warrant further investigation to standardize the antimicrobial profiles of these plant extracts

Retardation of Bacterial Biofilm Formation by Coating Urinary Catheters with Metal Nanoparticle-Stabilized Polymers

Urinary catheter infections remain an issue for many patients and can complicate their health status, especially for individuals who require long-term catheterization. Catheters can be colonized by biofilm-forming bacteria resistant to the administered antibiotics. Therefore, this study aimed to investigate the efficacy of silver nanoparticles (AgNPs) stabilized with different polymeric materials generated via a one-step simple coating technique for their ability to inhibit biofilm formation on urinary catheters. AgNPs were prepared and characterized to confirm their formation and determine their size, charge, morphology, and physical stability. Screening of the antimicrobial activity of nanoparticle formulations and determining minimal inhibitory concentration (MIC) and their cytotoxicity against PC3 cells were performed. Moreover, the antibiofilm activity and efficacy of the AgNPs coated on the urinary catheters under static and flowing conditions were examined against a clinical isolate of Escherichia coli. The results showed that the investigated polymers could form physically stable AgNPs, especially those prepared using polyvinyl pyrrolidone (PVP) and ethyl cellulose (EC). Preliminary screening and MIC determinations suggested that the AgNPs-EC and AgNPs-PVP had superior antibacterial effects against E. coli. AgNPs-EC and AgNPs-PVP inhibited biofilm formation to 58.2% and 50.8% compared with AgNPs-PEG, silver nitrate solution and control samples. In addition, coating urinary catheters with AgNPs-EC and AgNPs-PVP at concentrations lower than the determined IC50 values significantly (p < 0.05; t-test) inhibited bacterial biofilm formation compared with noncoated catheters under both static and static and flowing conditions using two different types of commercial Foley urinary catheters. The data obtained in this study provide evidence that AgNP-coated EC and PVP could be useful as potential antibacterial and antibiofilm catheter coating agents to prevent the development of urinary tract infections caused by E. coli

Synthesis and cytotoxic activity of new indolylpyrrole derivatives

The current approach described the synthesis of a new series of indolylpyrrole derivatives through multicomponent reaction of α-cyano chalcones, appropriate aldehydes, and ammonium acetate in refluxed acetic acid. The chemical structures of the designed compounds were confirmed with spectroscopic data and elemental analysis and then tested for their in vitro cytotoxic activity by SRB assay method towards three cell lines involving human Prostate adenocarcinoma; metastatic cells (PC-3), human ovary adenocarcinoma (SKOV3) and human dukes' type B, colorectal adenocarcinoma (LS 174 T). Most significant activity provided with compounds 5c, 5h and, 5j against prostate cancer cells (PC-3) with IC50s of 3.30 ± 0.20, 3.60 ± 0.10, and 3.60 ± 0.90 µg/ml, respectively. In human ovarian carcinoma (SKOV3), the compounds 5a, and 5i have stronger cytotoxicity with IC50s of 1.20 ± 0.04, 1.90 ± 0.50 µg/ml, respectively than the standard doxorubicin (IC50 = 2.20 ± 0.02 µg/ml). On the other hand, only compound 5a has the ability to diminish the viability of LS174T cells in an active manner with IC50 2.80 ± 0.10 µg/ml. Consequently, this effort offers groundwork for additional examination of nominated indolylpyrroles as antiproliferative agents

Eco-Friendly Synthesis of Silver Nanoparticles by <i>Nitrosalsola vermiculata</i> to Promote Skin Wound Healing

Eco-friendly synthesis of silver nanoparticles (SN) by using a naturally occurring plant, such as Nitrosalsola (Salsola) vermiculata (SV), could be a novel way for appropriate wound healing. AgNO3 was reduced by SV to produce safe SN (SN-SV) extract and hasten the wound healing process. The obtained SN-SV were characterized by size, charge, wavelength, and surface morphology. The optimized formulation was dispersed in O/W cosmetic cream. Then, it was characterized in terms of pH, viscosity, homogeneity, and permeability. The ex vivo and in vivo studies have been conducted in a rat animal model to assess the potential of SN-SV cream on skin tissue regeneration. A skin punch biopsy was obtained to investigate the histopathological (HP) changes in the skin lesions of all rats by the H&E staining and PCNA immunostaining methods. The skin wounds in all subgroups were examined on days 5, 11, and 15 to analyze the effectiveness of SN-SV cream for treating surgical skin wounds. The prepared SN-SV had a particle size of 37.32 ± 1.686 nm, a charge of −1.4 ± 0.7 mV, non-aggregated SN-SV, and a λmax of 396.46 nm. The formed SN-SV cream showed a pH near the skin’s pH, with suitable viscosity and homogeneity and an apparent permeability of 0.009 ± 0.001. The HP changes in the SN-SV subgroups revealed a substantial reduction in wound size and improvement in wound granulation tissue formation and epidermal re-epithelialization (proliferation) compared to the healing in the SN subgroups. The current work revealed that SN-SV could be a novel skin-wound-healing agent with a practical application as a wound-healing platform

Oncolytic Newcastle Disease Virus Co-Delivered with Modified PLGA Nanoparticles Encapsulating Temozolomide against Glioblastoma Cells: Developing an Effective Treatment Strategy

Glioblastoma multiforme (GBM) is considered to be one of the most serious version of primary malignant tumors. Temozolomide (TMZ), an anti-cancer drug, is the most common chemotherapeutic agent used for patients suffering from GBM. However, due to its inherent instability, short biological half-life, and dose-limiting characteristics, alternatives to TMZ have been sought. In this study, the TMZ-loaded PLGA nanoparticles were prepared by employing the emulsion solvent evaporation technique. The prepared TMZ-PLGA-NPs were characterized using FT-IR, zeta potential analyses, XRD pattern, particle size estimation, TEM, and FE-SEM observations. The virotherapy, being safe, selective, and effective in combating cancer, was employed, and TMZ-PLGA-NPs and oncolytic Newcastle Disease Virus (NDV) were co-administered for the purpose. An AMHA1-attenuated strain of NDV was propagated in chicken embryos, and the virus was titrated in Vero-slammed cells to determine the infective dose. The in vitro cytotoxic effects of the TMZ, NDV, and the TMZ-PLGA-NPs against the human glioblastoma cancer cell line, AMGM5, and the normal cell line of rat embryo fibroblasts (REFs) were evaluated. The synergistic effects of the nano-formulation and viral strain combined therapy was observed on the cell lines in MTT viability assays, together with the Chou&ndash;Talalay tests. The outcomes of the in vitro investigation revealed that the drug combinations of NDV and TMZ, as well as NDV and TMZ-PLGA-NPs exerted the synergistic enhancements of the antitumor activity on the AMGM5 cell lines. The effectiveness of both the mono, and combined treatments on the capability of AMGM5 cells to form colonies were also examined with crystal violet dyeing tests. The morphological features, and apoptotic reactions of the treated cells were investigated by utilizing the phase-contrast inverted microscopic examinations, and acridine orange/propidium iodide double-staining tests. Based on the current findings, the potential for the use of TMZ and NDV as part of a combination treatment of GBM is significant, and may work for patients suffering from GBM

Smart Injectable Chitosan Hydrogels Loaded with 5-Fluorouracil for the Treatment of Breast Cancer

The treatment of breast cancer requires long chemotherapy management, which is accompanied by severe side effects. Localized delivery of anticancer drugs helps to increase the drug concentration at the site of action and overcome such a problem. In the present study, chitosan hydrogel was prepared for local delivery of 5-Fluorouracil. The in vitro release behavior was investigated and the anticancer activity was evaluated against MCF-7 cells using MTT assay. The in vivo studies were investigated via intra-tumoral injection of a 5-FU loaded hydrogel into breast cancer of female rats. The results indicated that the modified hydrogel has excellent physicochemical properties with a sustained in vitro release profile matching a zero-order kinetic for one month. In addition, the hydrogel showed superior inhibition of cell viability compared with the untreated control group. Moreover, the in vivo studies resulted in antitumor activity with minor side effects. The tumor volume and level of tumor markers in blood were inhibited significantly by applying the hydrogel compared with the untreated control group. In conclusion, the designed injectable hydrogels are potential drug delivery systems for the treatment of breast cancer with a controlled drug release profile, which could be suitable for decreasing the side effects of chemotherapy agents

Ciprofloxacin-Loaded Silver Nanoparticles as Potent Nano-Antibiotics against Resistant Pathogenic Bacteria

Silver nanoparticles (AgNPs) have demonstrated numerous physicochemical, biological, and functional properties suitable for biomedical applications, including antibacterial and drug carrier properties. In the present study, the antibiotic, ciprofloxacin (CIP), was loaded onto AgNPs, which were synthesized via the chemical reduction method, thereby enhancing CIP&rsquo;s antibacterial activity against Gram-negative (Acinetobacter baumannii and Serratia marcescens) and Gram-positive (Staphylococcus aureus) bacterial strains. Polyethylene glycol&ndash;400 (PEG) was used to prepare an AgNPs-PEG conjugate with enhanced stability and to act as the linker between CIP and AgNPs, to produce the novel nanocomposite, AgNPs-PEG-CIP. The prepared AgNPs and their conjugates were characterized by ultraviolet-visible spectrophotometry, Fourier-transform infrared spectroscopy, X-ray diffraction, field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy, transmission electron microscopy, zeta potential analysis, and dynamic light scattering techniques. The inhibitory activity of AgNPs and their conjugates on the growths of pathogenic bacteria was assessed using the well-diffusion method. The results showed the enhanced antibacterial effects of AgNPs-CIP compared to CIP alone. The AgNPs-PEG-CIP nanocomposite showed excellent inhibitory effects against bacterial isolates, with its inhibition zones diameters reaching 39, 36, and 40 mm in S. aureus, A. baumannii, and S. marcescens, respectively. The minimum inhibitory concentration and minimum bactericidal concentration of fogNPs and their conjugates and their antibiofilm effects were also determined. The antioxidant potentials of AgNPs and their conjugates, tested via their 1,1-diphenyl-2-picryl-hydrazyl (DPPH) scavenging ability, showed that the activity increased with increasing AgNPs concentration and the addition of the PEG and/or CIP. Overall, according to the results obtained in the present study, the new nanocomposite, AgNPs-PEG-CIP, showed the highest antibacterial, antibiofilm, and antioxidant activity against the pathogenic bacteria tested, compared to CIP alone. The preparation has high clinical potential for prospective use as an antibacterial agent

Liposome-Mediated Delivery of MERS Antigen Induces Potent Humoral and Cell-Mediated Immune Response in Mice

The advancements in the field of nanotechnology have provided a great platform for the development of effective antiviral vaccines. Liposome-mediated delivery of antigens has been shown to induce the antigen-specific stimulation of the humoral and cell-mediated immune responses. Here, we prepared dried, reconstituted vesicles (DRVs) from DPPC liposomes and used them as the vaccine carrier system for the Middle East respiratory syndrome coronavirus papain-like protease (DRVs-MERS-CoV PLpro). MERS-CoV PLpro emulsified in the Incomplete Freund&rsquo;s Adjuvant (IFA-MERS-CoV PLpro) was used as a control. Immunization of mice with DRVs-MERS-CoV PLpro did not induce any notable toxicity, as revealed by the levels of the serum alanine transaminase (ALT), aspartate transaminase (AST), blood urea nitrogen (BUN) and lactate dehydrogenase (LDH) in the blood of immunized mice. Immunization with DRVs-MERS-CoV PLpro induced greater antigen-specific antibody titer and switching of IgG1 isotyping to IgG2a as compared to immunization with IFA-MERS-CoV PLpro. Moreover, splenocytes from mice immunized with DRVs-MERS-CoV PLpro exhibited greater proliferation in response to antigen stimulation. Moreover, splenocytes from DRVs-MERS-CoV PLpro-immunized mice secreted significantly higher IFN-&gamma; as compared to splenocytes from IFA-MERS-CoV PLpro mice. In summary, DRVs-MERS-CoV PLpro may prove to be an effective prophylactic formulation to prevent MERS-CoV infection

Gold Nanoparticles and Graphene Oxide Flakes Synergistic Partaking in Cytosolic Bactericidal Augmentation: Role of ROS and NOX2 Activity

Gold nanoparticles (GNPs) and graphene oxide flakes (GOFs) exerted significantly (p &lt; 0.0001) supportive roles on the phagocytosis bioactivity of the immune cells of phagocytic nature against the Gram-positive and Gram-negative human pathogenic bacteria Staphylococcus aureus and Escherichia coli. Under experimental conditions, upon bacterial exposure, the combined GNPs and GOFs induced significant clearance of bacteria through phagosome maturation (p &lt; 0.0001) from time-points of 6 to 30 min and production of reactive oxygen species (ROS, p &lt; 0.0001) through the NADPH oxidase 2 (NOX2, p &lt; 0.0001)-based feedback mechanism. The effects of the combined presence of GNPs and GOFs on phagocytosis (p &lt; 0.0001) suggested a synergistic action underway, also achieved through elevated signal transduction activity in the bone-marrow-derived macrophages (BMDM, p &lt; 0.0001). The current study demonstrated that GNPs&rsquo; and GOFs&rsquo; bactericidal assisting potentials could be considered an effective and alternative strategy for treating infections from both positive and negative bacterial strains