Enzymatic regulation of CoFe LDH through samarium doping for rapid ROS-induced membrane disruption and inactivation of pathogenic bacteria

Quantitative microbiological risk assessment of complex microbial community in Prawn farm wastewater and applicability of nanoparticles and probiotics for eliminating of antibiotic-resistant bacteria

Antibodies are widely used as recognition elements in sensing and therapy, but they suffer from poor stability, long discovery time, and high cost. Herein, a facile approach to create antibody mimics with flexible recognition phases and luminescent rigid scaffolds for the selective recognition, detection, and inactivation of pathogenic bacteria is reported. Tripeptides with a nitriloacetate-Cu group are spontaneously assembled on transition metal dichalcogenide (TMD) nanosheets via coordination bonding, providing a diversity of TMD-tripeptide assembly (TPA) antibody mimics. TMD-TPA antibody mimics can selectively recognize various pathogenic bacteria with nanomolar affinities. The bacterial binding sites for TMD-TPA are identified by experiments and molecular dynamics simulations, revealing that the dynamic and multivalent interactions of artificial antibodies play a crucial role for their recognition selectivity and affinity. The artificial antibodies allow the rapid and selective detection of pathogenic bacteria at single copy in human serum and urine, and their effective inactivation for therapy of infected mice. This work demonstrates the potential of TMD-TPA antibody mimics as an alternative to natural antibodies for sensing and therapy.

In this work, Cobalt-doped binary metal ferrite nanoparticles were synthesized and evaluated for dual-functionality: the photodegradation of metronidazole (MTZL) antibiotic and the inactivation of pathogenic bacteria. Characterization of the synthesized catalyst revealed a saturation magnetization (Ms) of 80.35 [Formula: see text], a total pore volume of 298 [Formula: see text], and a specific surface area of 70.2 [Formula: see text]. Photocatalytic experiments demonstrated that 10mg of the catalyst achieved 92.8% degradation of MTZL after 6h under UV irradiation in acidic media (pH 3) supplemented with 4 mmol L- 1 hydrogen peroxide (H2O2). To differentiate photocatalysis from physical adsorption-addressing the role of surface interactions-control experiments in the dark yielded 70.2% MTZL removal. Selectivity studies indicated that the presence of tylosin as a co-existing antibiotic (1000 and 500 ppb) reduced MTZL degradation efficiency by approximately 41% and 17.5%, respectively. Furthermore, the material exhibited potent antibacterial activity, inhibiting 1.0 × 107 CFU mL- 1 of Staphylococcus aureus and Escherichia coli within 3h using dosages of 5.0mg and 15.0mg, respectively. Complementing the experimental findings, molecular docking simulations were employed to predict the interaction mechanisms between the Co-doped ferrite cluster and target bacterial proteins. The analysis revealed significant binding affinities (scores of -4.3 and - 4.4kcal mol- 1), driven primarily by hydrogen bonding, electrostatic forces, and metal-residue interactions within the active pocket.

Application of solarization for sanitization of sewage sludge compost

ABSTRACTApplication of biochar to soil to achieve any number of goals should also consider unintended effects upon soil biology, including symbioses such as arbuscular mycorrhizas. We conducted an experiment to examine the interaction of biochar addition and arbuscular mycorrhizal (AM) fungus inoculation upon growth and phosphorus (P) uptake by Allium porrum L. and relate these responses to physicochemical properties of the biochars. A. porrum seedlings were grown with and without Glomus intraradices Schenck & Smith, and either without biochar or in the presence of one of 12 different biochars created by pyrolysis of three biomass feedstocks. Fast pyrolysis biochars greatly reduced colonization of roots by the AM fungus. Among biochars produced by a given pyrolysis method, higher surface areas were accompanied by higher AM fungus colonization. These findings are pertinent in selecting biochars for application to agricultural soils for such purposes as inactivation of pathogenic bacteria while being mindful of potential impacts upon the AM symbiosis.

ABSTRACT: Fresh‐cut lettuce samples inoculated with S. Typhimurium, E. coli O157:H7 or L. monocytogenes were dipped into 300 ppm electrolyzed water (EW) at pH 4 to 9 and 30 °C for 5 min. The effects of treatment pH on bacterial reduction and visual quality of the lettuce were determined. The treatments at pH 4 and 8 resulted in the most effective inactivation of E. coli O157:H7, but the effect of pH was not significant (P > 0.05) for S. Typhimurium and L. monocytogenes. The treatment at pH 7 retained the best visual quality of lettuce, and achieved a reduction of approximately 2 log CFU/g for above 3 bacteria.

Candida albicans is the most common human fungal pathogen and one of the major causes of drug-resistant, life-threatening fungal infections. The Neosartorya (Aspergillus) fischeri antifungal protein 2 (NFAP2), exhibits potent antifungal activity in both planktonic and biofilm-forming Candida cells in vitro and in vivo. However, the exact antifungal mechanism of NFAP2 remains unelucidated, limiting its therapeutic application. Based on our observations, we posit that NFAP2 is internalized in Candida cells and slows the growth over time, in addition to its previously characterized rapid plasma membrane disruption effect. This study aimed to understand the molecular mechanism of the long-term growth-slowing effect of NFAP2 on C. albicans. Transcriptomic analyses indicated downregulation of genes involved in metabolism and upregulation of genes associated with the cell cycle and filamentous growth. Moreover, in vivo protein-protein interaction analysis identified glutamate decarboxylase (Gad1p), ATP synthase subunit alpha (Atp1p), and enolase 1 (Eno1p) as intracellular protein targets of NFAP2. Our results support a dual mechanism of action of NFAP2. Specifically, when NFAP2 is applied below the minimum inhibitory concentration (<MIC), it enters the cells and reduces the metabolic activity by interacting with Gad1p, Atp1p, and Eno1p, resulting in slow growth. Furthermore, NFAP2 induces the yeast-hypha transition. However, when NFAP2 is applied at the MIC, it rapidly disrupts the plasma membrane.

Background and Objectives: A photochemical process has been tested for the inactivation of viruses and bacteria in buffy–coat derived platelet concentrates (BC PCs). Materials and Methods: BC PCs in 35% CPD plasma and 65% platelet–additive solution (PAS III) were exposed to photochemical treatment (PCT) with 150 μM of the psoralen S–59 and a 3 J/cm² treatment with long–wavelength ultraviolet light (UVA, 320–400 nm). Platelet function was evaluated following PCT using a panel of in vitro assays. Results: This PCT process was highly effective at inactivating gram–positive bacteria (Staphylococcus epidermidis, Staphylococcus aureus, Enterococcus faecalis) and gram–negative bacteria (Enterobacter aerogenes, Pseudomonas aeruginosa, Serratia marcescens). No viable bacteria were detected following PCT and 7 days of platelet storage while bacterial growth was detected in paired untreated control BC PCs. Complete inactivation of the gram–positive Bacillus cereus was achieved only in one of two replicate experiments with BC PCs. PCT was also highly effective for inactivation of human immunodeficiency virus HIV–1 in BC PCs inoculated with approximately 10⁶ tissue culture infectious doses per milliliter (TCID₅₀/ml) of cell–associated HIV–1. Rapid inactivation was observed with increasing UVA doses: with 150 μM S–59 and a 1 J/cm² treatment of UVA, a reduction of 5.6±0.5 log TCID₅₀/ml was achieved, and a reduction of >6.4 log TCID₅₀/ml was achieved with 150 μM S–59 and a 3 J/cm² treatment of UVA. No physiologically relevant differences in platelet functions were found between the test and the control BC PCs during 7 days of storage. Conclusion: PCT with 150 μM S–59 and a 3 J/cm² UVA treatment does not adversely affect in vitro properties of BC PCs stored at 22°C for 7 days. The PCT process inactivated bacteria and HIV–1 inoculated into the BC PCs. These results extend the earlier reported efficacy of PCT apheresis PCs to BC PCs.

Heparin prevents the cytotoxic activity of Bothrops jararacussu and Apis mellifera venoms in renal cells

Photodynamic treatment combining light and a photosensitizer molecule can be an effective method to inactivate pathogenic bacteria. This study identified vitamin K5 as an efficient photosensitizer for ultraviolet light A (UVA)-induced bacterial inactivation. Six bacterial species, Bacillus cereus (vegetative form), Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and two species of antibiotic-resistant bacteria, Pseudomonas aeruginosa* and Staphylococcus aureus*, were suspended in aqueous solutions with or without vitamin K5 and exposed to UVA irradiation. UVA irradiation (5.8 J cm-2) with vitamin K5 (1600 μmol l-1) reduced the colony forming units (CFU) of these bacteria by three to seven logs. Antibiotic resistant bacteria were also susceptible to the bactericidal effects of UVA and vitamin K5 combination treatment. Inactivation of bacteria in human plasma required higher doses of UVA light and vitamin K5. UVA irradiation (30 J cm-2) with vitamin K5 (2000 μmol l-1) reduced E. coli and S. aureus spiked into human plasma by seven logs CFU/ml. Reactive oxygen species, such as superoxide anion radicals and hydroxyl radicals, were found to be generated in vitamin K5 aqueous solution after UVA irradiation, suggesting these oxygen species may mediate the inactivation of the bacteria.

Efficacy of Instant Hand Sanitizers against Foodborne Pathogens Compared with Hand Washing with Soap and Water in Food Preparation Settings: A Systematic Review

Graphitic carbon nitride loaded with FeOOH quantum dots for synergistic photocatalysis-Fenton inactivation of pathogenic marine bacteria: Mechanisms and coupling coefficients

Seawater used in mariculture has been suspected of being a potential source of infection. In this study, the lethal effects of low-amperage electric treatment on microorganisms were examined in natural seawater and in seawater inoculated with Vibrio parahaemolyticus. In both cases, bacteria including V. parahaemolyticus in seawater were completely eliminated in 100 ms by a 0.5-A, 12-V direct current. Electron microscopic investigation of the electrically treated bacteria revealed substantial structural damage at the cellular level. In conclusion, our results indicate that low-amperage electric treatment is effective for rapid inactivation of microorganisms in seawater.

There is a great demand for novel disinfection technologies to inactivate various pathogenic viruses and bacteria. In this situation, ultraviolet (UVC) disinfection technologies seem to be promising because biocontaminated air and surfaces are the major media for disease transmission. However, UVC is strongly absorbed by human cells and protein components; therefore, there are concerns about damaging plasma components and causing dermatitis and skin cancer. To avoid these concerns, in this study, we demonstrate that the efficient inactivation of bacteria is achieved by visible pulsed light irradiation. The principle of inactivation is based on transient photothermal heating. First, we provide experimental confirmation that extremely high temperatures above 1000 K can be achieved by pulsed laser irradiation. Evidence of this high temperature is directly confirmed by melting gold nanoparticles (GNPs). Inorganic GNPs are used because of their well-established thermophysical properties. Second, we show inactivation behaviour by pulsed laser irradiation. This inactivation behaviour cannot be explained by a simple optical absorption effect. We experimentally and theoretically clarify this inactivation mechanism based on both optical absorption and scattering effects. We find that scattering and absorption play an important role in inactivation because the input irradiation is inherently scattered by the bacteria; therefore, the dose that bacteria feel is reduced. This scattering effect can be clearly shown by a technique that combines stained Escherichia coli and site selective irradiation obtained by a wavelength tunable pulsed laser. By measuring Live/Dead fluorescence microscopy images, we show that the inactivation attained by the transient photothermal heating is possible to instantaneously and selectively kill microorganisms such as Escherichia coli bacteria. Thus, this method is promising for the site selective inactivation of various pathogenic viruses and bacteria in a safe and simple manner.

Analysis of neuropathological findings in human infants poisoned by maternal ingestion of methylmercury-contaminated food during pregnancy reveals that the principal histopathologic changes are represented by the outcome of disturbance in brain development, more specifically abnormal neuronal migration, deranged cortical differentiation and exuberant white matter astrocytosis. Although these changes are by no means specific, the striking similarity of the pathologic anatoiriy of the brain of all infants reported in Japan and Iraq and the detailed account of clinical and toxicological data is highly suggestive of a common pathogenetic link to methylmercury poisoning in utero. Thus, the critical periods of vulnerability of developing CNS for sublethal exposure to methylmercury appear to be the late embryonic and fetal periods when neuronal migration and histogenetic development of brain are taking place actively. In order to test this hypothesis, experimental studies using cultures of human fetal brain cells were carried out. Using time-lapse cinematography, phase and electron microscopy and immunocytochemistry, we have been able to observe the cessation of migratory activity of cultured human fetal neurons and astrocytes due to cytotoxic actions of methylmercury. Methylmercury not only caused rapid disruption and degeneration of membranes but also caused specific damage to microtubules in neurons and astrocytes in culture. We have also demonstrated inhibitory effect of methylmercury on DNA synthesis of human fetal astrocytes by radioautography and showed beneficial effect of meso–2,3- dimercaptosuccinic acid on methylmercury-damaged human fetal astrocytes by time-lapse cinematography. Studies of developing mouse brain revealed significant reduction in dendritic arborization of neurons (Jacobson, 1978)• However, there are still many uncertainties regarding the time of origin of different types of neurons and glial cells in various regions of the developing human CNS. Contrary to the general belief that neuronal development precedes glial development (Fujita, 1963, 1967), our studies (Choi, 1981) and those of others (Levitt et al., 1980, 1981) suggest the likelihood of concomitant generation of both types of cells in the early developing human embryo. Until these and other uncertainties regarding neurogenesis are resolved, therefore, it will be difficult to ascertain precisely the molecular mechanisms and stages of development that are applicable to methylmercury poisoning in utero.