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Frontiers in Chemistry 2024Non-plasma technologies are being extensively investigated for their potential to mitigate microbial growth through the production of various reactive species....
Non-plasma technologies are being extensively investigated for their potential to mitigate microbial growth through the production of various reactive species. Predominantly, studies utilise atmospheric non-thermal plasma to produce plasma-activated liquids. The advancement of plasma-liquid applications has led to the investigation of plasma-activated aerosols (PAAs). This study aimed to produce a rapid-prototyped plasma-activated aerosol setup and perform chemical and anti-bacterial characterisation on the resultant activated aerosols. The setup was produced using stereolithography 3D printing, and air was used as the carrier gas. The novel design of the device allowed for the direct production of PAAs without the prior generation of plasma-activated water and subsequent aerosolisation. The generated PAAs were assessed for nitrite, hydrogen peroxide and ozone content using colourimetric assays. Anti-bacterial efficacy was tested against three human pathogenic strains: , , and . It was observed that nitrite and ozone contact concentration increased with exposure time, yet no hydrogen peroxide was detected. The generated PAAs showed significant zones of no growth for all bacterial strains. These devices, therefore, show potential to be used as anti-bacterial disinfection technologies.
PubMed: 38947958
DOI: 10.3389/fchem.2024.1416982 -
Critical Care Research and Practice 2024Critically ill COVID-19 patients hospitalized in intensive care units (ICU) are immunosuppressed due to SARSCoV-2-related immunological effects and are administered...
Incidence of Carbapenem-Resistant Gram-Negative Bacterial Infections in Critically Ill Patients with COVID-19 as Compared to Non-COVID-19 Patients: A Prospective Case-Control Study.
INTRODUCTION
Critically ill COVID-19 patients hospitalized in intensive care units (ICU) are immunosuppressed due to SARSCoV-2-related immunological effects and are administered immunomodulatory drugs. This study aimed to determine whether these patients carry an increased risk of multi-drug resistant (MDR) and especially carbapenem-resistant Gram-negative (CRGN) bacterial infections compared to other critically ill patients without COVID-19.
MATERIALS AND METHODS
A prospective case-control study was conducted between January 2022 and August 2023. The ICU patients were divided into two groups (COVID-19 and non-COVID-19). Differences in the incidence of CRGN infections from e, spp., and were investigated. In addition, an indicator of the infection rate of the patients during their ICU stay was calculated. Factors independently related to mortality risk were studied.
RESULTS
Forty-two COVID-19 and 36 non-COVID-19 patients were analyzed. There was no statistically significant difference in the incidence of CRGN between COVID-19 and non-COVID-19 patients. The infection rate was similar in the two groups. Regarding the aetiological agents of CRGN infections, was significantly more common in non-COVID-19 patients (=0.007). COVID-19 patients had longer hospitalisation before ICU admission (=0.003) and shorter ICU length of stay (LOS) (=0.005). ICU COVID-19 patients had significantly higher mortality ( < 0.001) and sequential organ failure assessment (SOFA) score ( < 0.001) compared to non-COVID-19 patients. Μortality secondary to CRGN infections was also higher in COVID-19 patients compared to non-COVID-19 patients (=0.033). Male gender, age, ICU LOS, and hospital LOS before ICU admission were independent risk factors for developing CRGN infections. Independent risk factors for patients' mortality were COVID-19 infection, obesity, SOFA score, total number of comorbidities, WBC count, and CRP, but not infection from CRGN pathogens.
CONCLUSIONS
The incidence of CRGN infections in critically ill COVID-19 patients is not different from that of non-COVID-19 ICU patients. The higher mortality of COVID-19 patients in the ICU is associated with higher disease severity scores, a higher incidence of obesity, and multiple underlying comorbidities, but not with CRGN infections.
PubMed: 38947882
DOI: 10.1155/2024/7102082 -
Heliyon Jun 2024New 3-furan-1-thiophene-based chalcones were synthesized, characterized and pharmacologically evaluated as antibacterial and anticancer agents against two bacterial...
New 3-furan-1-thiophene-based chalcones were synthesized, characterized and pharmacologically evaluated as antibacterial and anticancer agents against two bacterial species; Gram-positive () and Gram-negative (). All tested final compounds were active against the two bacterial species; and . Especially compound AM4 showed large inhibition zone (27.13 and 23.30 mm), respectively. Using the DPPH assay, the new chalcones were evaluated for their free radical scavenging activity and found to reach up to 90 %, accomplished at a test concentration of 200 μg/mL. Furthermore, the chalcone derivatives were investigated against two breast cell lines; MCF-7 (cancerous) and MCF-10A (non-cancerous). Compound AM4 showed potent anticancer activity (IC = 19.354 μg/mL) in comparison to the other tested chalcone derivatives. study was achieved using the PyRx AutoDock Vina software (0.8) to study the interaction types between the new hits and the binding sites of targeted proteins; glucosamine-6-phosphate synthase and tubulin, the target for antibacterial and anticancer drugs, respectively. Based on the molecular docking results the tested chalcones bind to the active pocket of the respective proteins, which support the results. In conclusion, 3-furan-1-thiophene-based chalcones could serve as new hits in the discovery of novel anticancer and/or antibacterial drugs.
PubMed: 38947436
DOI: 10.1016/j.heliyon.2024.e32257 -
Food Chemistry: X Oct 2024Honey is a natural product used since ancient times due to its taste, aroma, and therapeutic properties (antibacterial, antiviral, anti-inflammatory, and antioxidant... (Review)
Review
Honey is a natural product used since ancient times due to its taste, aroma, and therapeutic properties (antibacterial, antiviral, anti-inflammatory, and antioxidant activity). The purpose of this review is to present the species of microorganisms that can survive in honey and the effect they can have on bees and consumers. The techniques for identifying the microorganisms present in honey are also described in this study. Honey contains bacteria, yeasts, molds, and viruses, and some of them may present beneficial properties for humans. The antimicrobial effect of honey is due to its acidity and high viscosity, high sugar concentration, low water content, the presence of hydrogen peroxide and non-peroxidase components, particularly methylglyoxal (MGO), phenolic acids, flavonoids, proteins, peptides, and non-peroxidase glycopeptides. Honey has antibacterial action (it has effectiveness against bacteria, e.g. , , , and etc.), antifungal (effectiveness against spp., spp. spp. spp. and spp.), antiviral (effectiveness against SARS-CoV-2, Herpes simplex virus type 1, Influenza virus A and B, Varicella zoster virus), and antiparasitic action (effectiveness against and ) demonstrated by numerous studies that are comprised and discussed in this review.
PubMed: 38947342
DOI: 10.1016/j.fochx.2024.101524 -
Chemistry & Biodiversity Jun 2024Flavonoids epitomize structural scaffolds in many biologically active synthetic and natural compounds. They showcase a diverse spectrum of biological activities...
Flavonoids epitomize structural scaffolds in many biologically active synthetic and natural compounds. They showcase a diverse spectrum of biological activities including anticancer, antidiabetic, antituberculosis, antimalarial, and antibiofilm activities. The antibiofilm activity of a series of new chalcones and flavonols against clinically significant Pseudomonas aeruginosa PAO1 strain was studied. Antivirulence activities were screened by analysing the effect of compounds on the production of virulence factors like pyocyanin, LasA protease, cell surface hydrophobicity, and rhamnolipid. The best ligands towards the quorum sensing proteins LasR, RhlR, and PqsR were recognised using a molecular docking study. The gene expression in P. aeruginosa after treatment with test compounds was evaluated on quorum sensing genes including rhlA, lasB, and pqsE. The antibiofilm potential of chalcones and flavonols was confirmed by the efficient reduction in the production of virulence factors and downregulation of gene expression.
PubMed: 38946224
DOI: 10.1002/cbdv.202400393 -
Journal of the American Chemical Society Jun 2024bacteria are becoming increasingly resistant against multiple antibiotics. Therefore, the development of vaccines to prevent infections with these bacteria is an urgent...
bacteria are becoming increasingly resistant against multiple antibiotics. Therefore, the development of vaccines to prevent infections with these bacteria is an urgent medical need. While the immunological activity of lipopolysaccharide O-antigens in is well-known, the specific protective epitopes remain unidentified. Herein, we present the first chemical synthesis of highly functionalized aminoglycoside trisaccharide and its acetamido derivative found in the serotype O5 O-antigen. The synthesis of the trisaccharide targets is based on balancing the reactivity of disaccharide acceptors and monosaccharide donors. Glycosylations were analyzed by quantifying the reactivity of the hydroxyl group of the disaccharide acceptor using the orbital-weighted Fukui function and dual descriptor. The stereoselective formation of 1,2--α-fucosylamine linkages was achieved through a combination of remote acyl participation and reagent modulation. The simultaneous S2 substitution of azide groups at C2' and C2″ enabled the efficient synthesis of 1,2--β-linkages for both 2,3-diamino-D-mannuronic acids. Through a strategic orthogonal modification, the five amino groups on target trisaccharide were equipped with a rare acetamidino (Am) and four acetyl (Ac) groups. Glycan microarray analyses of sera from patients infected with indicated that trisaccharides and are key antigenic epitopes of the serotype O5 O-antigen. The acetamidino group is not an essential determinant of antibody binding. The β-D-ManNAc3NAcA residue is a key motif for the antigenicity of serotype O5 O-antigen. These findings serve as a foundation for the development of glycoconjugate vaccines targeting serotype O5.
PubMed: 38946080
DOI: 10.1021/jacs.4c03814 -
International Journal of Biological... Jun 2024The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These...
The article explores the synthesis of network hydrogels derived from moringa gum (MG) through a grafting reaction with poly (vinylsulfonic acid) and carbopol. These hydrogels are designed for use in drug delivery (DD) and wound hydrogels dressing (HYDR) applications. The copolymers were characterized by FESEM, EDX, AFM, FTIR, C NMR, XRD and DSC. Tetracycline release from hydrogel occurred gradually with a non-Fickian diffusion and was best described by the Hixson-Crowell kinetic model in artificial wound fluid. The HYDR demonstrated compatibility with blood, exhibited antioxidant properties and possessed tensile strength, in addition to their mucoadhesive characteristics. The copolymer dressings absorbed approximately 7 g of simulated fluid. The copolymers exhibited significant antioxidant activity, measuring at 84 % free radicals scavenging, during DPPH assay. These dressings demonstrated permeability to HO and O. The hydrogel alone did not reveal antibacterial activities; however, when combined with antibiotic drug tetracycline, the dressings revealed notable antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. The observed biomedical properties suggested that these hydrogels could serve as promising materials for drug delivery HYDR applications.
PubMed: 38945716
DOI: 10.1016/j.ijbiomac.2024.133352 -
International Journal of Antimicrobial... Jun 2024Polymyxin B, with its unique structure and mechanism of action, has emerged as a key therapeutic agent against Gram-negative bacteria. The study aims to explore...
PURPOSE
Polymyxin B, with its unique structure and mechanism of action, has emerged as a key therapeutic agent against Gram-negative bacteria. The study aims to explore potential factors to influence its effectiveness and safety.
METHODS
A Model-Based Meta-Analysis (MBMA) of 96 articles was conducted, focusing on factors like dosage, bacterial species, and combined antibiotic therapy. The analysis evaluated mortality rates and incidence rate of renal dysfunction, also employing parametric survival models to assess 30-day survival rates.
RESULTS
In the study involving 96 articles and 9,716 patients, polymyxin B's daily dose showed minimal effect on overall mortality, with high-dose group mortality at 33.57% (95% CI: 29.15-38.00) compared to the low-dose group at 35.44% (95% CI: 28.99-41.88), p=0.64. Mortality significantly varied by bacterial species, with Pseudomonas aeruginosa infections at 58.50% (95% CI: 55.42-63.58). Monotherapy exhibited the highest mortality at 40.25% (95% CI: 34.75-45.76), p<0.01. Renal dysfunction was more common in high-dose patients at 29.75% (95% CI: 28.52-30.98), with no significant difference across antibiotic regimens, p=0.54. The 30-day Overall Survival rate for monotherapy therapy was 63.6% (95% CI: 59.3-67.5) and 70.2% (95% CI: 64.4-76.2) for association therapy with β-lactam drugs.
CONCLUSIONS
The dosage of Polymyxin B doesn't significantly change death rates, but its effectiveness varies based on the bacterial infection. Certain bacteria like Pseudomonas aeruginosa are associated with higher mortality. Combining Polymyxin B with other antibiotics, especially β-lactam drugs, improves survival rates. Side effects depend on the dose, with lower doses being safer. These findings emphasize the importance of customizing treatment to balance effectiveness and safety.
PubMed: 38945178
DOI: 10.1016/j.ijantimicag.2024.107262 -
International Journal of Antimicrobial... Jun 2024The proliferation of metallo-beta-lactamase-producing Pseudomonas aeruginosa represents a significant public health threat. P. aeruginosa can undergo significant...
OBJECTIVES
The proliferation of metallo-beta-lactamase-producing Pseudomonas aeruginosa represents a significant public health threat. P. aeruginosa can undergo significant phenotypic changes that can drastically impair antibiotic efficacy. This study's objectives were (1) to quantify the time-course of killing of VIM-2-producing P. aeruginosa in response to aztreonam-based therapies (including avibactam for coverage of AmpC), and (2) to document the capacity of P. aeruginosa to undergo morphological transformations that facilitate persistence.
METHODS
A well-characterized, clinical VIM-2-producing P. aeruginosa was studied in the Hollow Fiber Infection Model (HFIM) over 9 days (7 days of active antibiotic therapy, 2 days treatment withdrawal) at a 10 CFU/mL starting inoculum. HFIM treatment arms included: growth control, aztreonam, ceftazidime/avibactam, aztreonam/ceftazidime/avibactam, polymyxin B, and aztreonam/ceftazidime/avibactam/polymyxin B. In addition, real-time imaging studies were conducted under static conditions to determine the time-course of the reversion of persister cells.
RESULTS
A pronounced discrepancy was observed between OD and bacterial counts obtained from plating methods (hereafter referred to as 'OD-count discrepancy'). For aztreonam monotherapy, observed counts were 0 CFU/mL by 120 h. Despite this, there was a significant OD-count discrepancy as compared to the pre-treatment 0h. Between therapy withdrawal at 168h and 216h, all arms with suppressed counts had re-grown to the system carrying capacity. Real-time imaging of the P. aeruginosa filaments after drug removal showed rapid reversion from a long, filamentous phenotype to many individual rods within 2 h.
CONCLUSION
Managing MBL-producing P. aeruginosa will require a multi-faceted approach, focused on maximizing killing and minimizing proliferation of resistant and persistent subpopulations, which will involve eliminating drug-induced phenotypic transformers.
PubMed: 38945177
DOI: 10.1016/j.ijantimicag.2024.107260 -
Mymensingh Medical Journal : MMJ Jul 2024Water related diseases are of great concern in developing countries like Bangladesh. Every year, many people die due to consumption of unsafe drinking water. In order to... (Observational Study)
Observational Study
Water related diseases are of great concern in developing countries like Bangladesh. Every year, many people die due to consumption of unsafe drinking water. In order to protect public health it is compulsory that the accessible drinking water should be maximum quality. In this descriptive observational study 150 samples of bottled water and 150 jar water samples were collected from different shops and restaurants. Each sample were filtered through a membrane filter and then placed on MacConkey agar media for total and fecal coliform count and 0.1 ml of water spread on nutrient agar media for heterotrophic plate count (HPC). Among 150 bottled water samples 11 (7.33%) were culture positive and 92 (61.33%) were culture positive in 150 jar water samples. Out of 150 jar water samples 38 (25.33%) were total coliform and among them 19 (12.67%) were fecal coliform. Among 300 water samples 55 (53.40%) samples showed HPC greater than 500 CFU/ml. A total of 9 bacterial isolates: Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter spp. CONS, Aeromonas spp., Enterobacter spp., Klebsiella spp. and Citrobacter were found.
Topics: Drinking Water; Water Microbiology; Humans; Bangladesh
PubMed: 38944733
DOI: No ID Found