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Journal of Food Protection Jul 2024Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls...
Salmonella is capable of surviving dehydration within various foods, such as dried fruit. Dried fruit, including apple slices, have been the subject of product recalls due to contamination with Salmonella. A study was conducted to determine the fate of Salmonella on apple slices, following immersion in three antimicrobial solutions (viz., ε-polylysine [epsilon-polylysine or EP], sodium bisulfate [SBS], or peracetic acid [PAA]), and subsequent hot air dehydration. Gala apples were aseptically cored and sliced into 0.4 cm thick rings, bisected, and inoculated with a five-strain composite of desiccation-resistant Salmonella, to a population of 8.28 log CFU/slice. Slices were then immersed for 2 min in various concentrations of antimicrobial solutions, including EP (0.005, 0.02, 0.05, and 0.1%), SBS (0.05, 0.1, 0.2, and 0.3%), PAA (18 or 42 ppm), or varying concentrations of PAA + EP, and then dehydrated at 60°C for 5 h. Salmonella populations in positive control samples (inoculated apple slices washed in sterile water) declined by 2.64 log after drying. In the present study, the inactivation of Salmonella, following EP and SBS treatments, increased with increasing concentrations, with maximum reductions of 3.87 and 6.20 log (with 0.1 and 0.3% of the two compounds, respectively). Based on preliminary studies, EP concentrations greater than 0.1% did not result in lower populations of Salmonella. Pretreatment washes with either 18 or 42 ppm of PAA inactivated Salmonella populations by 4.62 and 5.63 log, respectively, following desiccation. Combining PAA with up to 0.1% EP induced no greater population reductions of Salmonella than washing with PAA alone. The addition of EP to PAA solutions appeared to destabilize PAA concentrations, reducing its biocidal efficacy. These results may provide antimicrobial predrying treatment alternatives to promote the reduction of Salmonella during commercial or consumer hot air drying of apple slices.
Topics: Malus; Peracetic Acid; Salmonella; Polylysine; Food Microbiology; Humans; Colony Count, Microbial; Sulfates; Food Preservation; Dose-Response Relationship, Drug; Desiccation; Food Contamination; Food Handling; Consumer Product Safety
PubMed: 38734414
DOI: 10.1016/j.jfp.2024.100297 -
Journal of Clinical and Experimental... Apr 2024The aim of this review was to assess the evidence regarding the most commonly used chelating agents in terms of efficacy, erosive potential, cytotoxicity, interaction,... (Review)
Review
BACKGROUND
The aim of this review was to assess the evidence regarding the most commonly used chelating agents in terms of efficacy, erosive potential, cytotoxicity, interaction, antimicrobial effect, impact on sealers adhesion, and release of growth factors.
MATERIAL AND METHODS
MEDLINE (PubMed) database, Cochrane Library and Scopus were searched up to January 14, 2023, including studies with one or more of the following chelating agents: 17% EDTA, 9% and 18% HEDP, 10% and 20% citric acid, 2%-2.25% peracetic acid and 7% maleic acid. In addition, the reference lists of all selected articles were also checked to identify additional relevant studies. Articles published in English and available in full-text were selected. The quality of studies was assessed using the modified CONSORT checklist guide and the Cochrane Collaboration tool.
RESULTS
The electronic search yielded 538 citations, 56 of which were included. The articles included had moderate and low evidence values. Among 56 articles included, 55 were in vitro studies and one was a randomized clinical trial. Among the in vitro studies, 15 evaluated efficacy and dentin erosion, 12 evaluated interaction with other endodontic irrigants, 9 tested antimicrobial effect, 4 evaluated cytotoxicity in hamster and rat lung cells, 9 evaluated intervention in adhesion of filling materials and 8 focused on release of growth factors and on behavior of stem cells in regenerative endodontic. The RCT tested antimicrobial effect.
CONCLUSIONS
17% EDTA is the most effective in smear layer removal and in releasing growth factors on regenerative endodontics. However, the current incorporation of 9% and 18% etidronic acid has shown optimal results due to its compatibility with sodium hypochlorite and its capability on avoiding smear layer formation through a continuous chelation action. Despite these preliminary findings, methodological standardization between studies is required and in vivo studies are necessary to confirm in vitro studies. Chelating Agents, Smear Layer, Systematic Review, Endodontics, Root Canal Irrigants.
PubMed: 38725809
DOI: 10.4317/jced.60989 -
Journal of Environmental Management May 2024Peracetic acid (PAA) combined with free ammonia (FA) pretreatment can be utilized to promote anaerobic fermentation (AF) of waste activated sludge (WAS) to produce...
Synergistic effects of peracetic acid and free ammonia pretreatment on anaerobic fermentation of waste activated sludge to promote short-chain fatty acid production for polyhydroxyalkanoate biosynthesis: Mechanisms and optimization.
Peracetic acid (PAA) combined with free ammonia (FA) pretreatment can be utilized to promote anaerobic fermentation (AF) of waste activated sludge (WAS) to produce short-chain fatty acids (SCFAs), and the resulting SCFAs are desirable carbon sources (C-sources) for polyhydroxyalkanoate (PHA) biosynthesis. This work aimed to determine the optimum conditions for PAA + FA pretreatment of sludge AF and the feasibility of using anaerobic fermentation liquor (AFL) for PHA production. To reveal the mechanisms of integrated pretreatment, the impacts of PAA + FA pretreatment on different stages of sludge AF and changes in the microbial community structure were explored. The experimental results showed that the maximum SCFA yield reached 491.35 ± 6.02 mg COD/g VSS on day 5 after pretreatment with 0.1 g PAA/g VSS +70 mg FA/L, which was significantly greater than that resulting from PAA or FA pretreatment alone. The mechanism analysis showed that PAA + FA pretreatment promoted sludge solubilization but strongly inhibited methanogenesis. According to the analysis of the microbial community, PAA + FA pretreatment changed the microbial community structure and promoted the enrichment of bacteria related to hydrolysis and acidification, and Proteiniclasticum, Macellibacteroides and Petrimonas became the dominant hydrolytic and acidifying bacteria. Finally, after alkali treatment, the AFL was utilized for batch-mode PHA production, and a maximum PHA yield of 55.05 wt% was achieved after five operation periods.
Topics: Sewage; Polyhydroxyalkanoates; Fermentation; Ammonia; Fatty Acids, Volatile; Anaerobiosis; Waste Disposal, Fluid; Bioreactors
PubMed: 38723503
DOI: 10.1016/j.jenvman.2024.121078 -
PloS One 2024Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant....
Ricin is a highly toxic protein, capable of inhibiting protein synthesis within cells, and is produced from the beans of the Ricinus communis (castor bean) plant. Numerous recent incidents involving ricin have occurred, many in the form of mailed letters resulting in both building and mail sorting facility contamination. The goal of this study was to assess the decontamination efficacy of several commercial off-the-shelf (COTS) cleaners and decontaminants (solutions of sodium hypochlorite [bleach], quaternary ammonium, sodium percarbonate, peracetic acid, and hydrogen peroxide) against a crude preparation of ricin toxin. The ricin was inoculated onto four common building materials (pine wood, drywall joint tape, countertop laminate, and industrial carpet), and the decontaminants were applied to the test coupons using a handheld sprayer. Decontamination efficacy was quantified using an in-vitro cytotoxicity assay to measure the quantity of bioactive ricin toxin extracted from test coupons as compared to the corresponding positive controls (not sprayed with decontaminant). Results showed that decontamination efficacy varied by decontaminant and substrate material, and that efficacy generally improved as the number of spray applications or contact time increased. The solutions of 0.45% peracetic acid and the 20,000-parts per million (ppm) sodium hypochlorite provided the overall best decontamination efficacy. The 0.45% peracetic acid solution achieved 97.8 to 99.8% reduction with a 30-min contact time.
Topics: Ricin; Decontamination; Sodium Hypochlorite; Construction Materials; Peracetic Acid; Hydrogen Peroxide; Animals; Disinfectants
PubMed: 38722908
DOI: 10.1371/journal.pone.0302967 -
Chemosphere Jun 2024Peracetic acid (PAA) has garnered significant attention as a novel disinfectant owing to its remarkable oxidative capacity and minimal potential to generate byproducts....
Peracetic acid (PAA) has garnered significant attention as a novel disinfectant owing to its remarkable oxidative capacity and minimal potential to generate byproducts. In this study, we prepared a novel catalyst, denoted as cobalt modified nitrogen-doped carbon nanotubes (Co@N-CNTs), and evaluated it for PAA activation. Modification with cobalt nanoparticles (∼4.8 nm) changed the morphology and structure of the carbon nanotubes, and greatly improved their ability to activate PAA. Co@N-CNTs/PAA catalytic system shows outstanding catalytic degradation ability of antiviral drugs. Under neutral conditions, with a dosage of 0.05 g/L [email protected] and 0.25 mM PAA, the removal efficiency of acyclovir (ACV) reached 98.3% within a mere 10 min. The primary reactive species responsible for effective pollutant degradation were identified as acetylperoxyl radicals (CHC(O)OO•) and acetyloxyl radicals (CHC(O)O•). In addition, density functional theory (DFT) proved that Co nanoparticles, as the main catalytic sites, were more likely to adsorb PAA and transfer more electrons than N-doped graphene. This study explored the feasibility of PAA degradation of antiviral drugs in sewage, and provided new insights for the application of heterogeneous catalytic PAA in environmental remediation.
Topics: Nanotubes, Carbon; Nitrogen; Cobalt; Peracetic Acid; Catalysis; Antiviral Agents; Water Pollutants, Chemical; Acyclovir; Adsorption
PubMed: 38719118
DOI: 10.1016/j.chemosphere.2024.142277 -
Bioresource Technology Jun 2024The study investigated the inactivation of Microcystis aeruginosa using a combined approach involving thermally activated peroxyacetic acid (Heat/PAA) and thermally...
The study investigated the inactivation of Microcystis aeruginosa using a combined approach involving thermally activated peroxyacetic acid (Heat/PAA) and thermally activated persulfate (Heat/PDS). The Heat/PDS algal inactivation process conforms to first-order reaction kinetics. Both hydroxyl radical (•OH) and sulfate radical (SO•) significantly impact the disruption of cell integrity, with SO• assuming a predominant role. PAA appears to activate organic radicals (RO•), hydroxyl (•OH), and a minimal amount of singlet oxygen (O). A thorough analysis underscores persulfate's superior ability to disrupt algal cell membranes. Additionally, SO• can convert small-molecule proteins into aromatic hydrocarbons, accelerating cell lysis. PAA can accelerate cell death by diffusing into the cell membrane and triggering advanced oxidative reactions within the cell. This study validates the effectiveness of the thermally activated persulfate process and the thermally activated peroxyacetic acid as strategies for algae inactivation.
Topics: Microcystis; Oxidation-Reduction; Reactive Oxygen Species; Sulfates; Peracetic Acid; Hot Temperature; Hydroxyl Radical; Kinetics
PubMed: 38718906
DOI: 10.1016/j.biortech.2024.130806 -
Water Research Jun 2024The effective activation of natural chalcopyrite (CuFeS) on peracetic acid (PAA) to remove organic micropollutants was studied under visible light irradiation. Results...
The effective activation of natural chalcopyrite (CuFeS) on peracetic acid (PAA) to remove organic micropollutants was studied under visible light irradiation. Results showed than an effective sulfamethoxazole (SMX) degradation (95.0 %) was achieved under visible light irradiation for 30 min at pH 7.0. Quenching experiments, electron spin resonance analysis, and LC/MS spectrum demonstrated that HO and CHC(O)OO were the main reactive species for SMX degradation, accounting for 43.3 % and 56.7 % of the contributions, respectively. Combined with X-ray photoelectron spectroscopy analysis, the photoelectrons generated on CuFeS activated by visible light enhanced the Fe/Fe and Cu/Cu cycles on the surface, thereby activating PAA to generate HO/CHC(O)OO. The removal rate of SMX decreased with the increase in wavelengths, due to the formation of low energy photons at longer wavelengths. Besides, the optimal pH for degradation of SMX by CuFeS/PAA/Vis-LED process was neutral, which was attributed to the increasing easily activated anionic form of PAA during the increase in pH and the depletion of Fe species at alkaline conditions. Cl, HCO, and HA slightly inhibited SMX degradation because of reactive species being quenched and/or shielding effect. Furthermore, the degradation efficiency of different pollutants by CuFeS/PAA/Vis-LED was also measured, and the removal efficiency was different owing to the selectivity of CHC(O)OO. Finally, the process exhibited good applicability in real waters. Overall, this study provides new insight into visible light-catalyzed activation of PAA and suggests on further exploration of the intrinsic activation mechanism of PAA.
Topics: Water Pollutants, Chemical; Copper; Peracetic Acid; Light; Hydrogen-Ion Concentration; Sulfamethoxazole
PubMed: 38713937
DOI: 10.1016/j.watres.2024.121699 -
Biofilm Jun 2024is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this...
is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.
PubMed: 38706985
DOI: 10.1016/j.bioflm.2024.100197 -
The Journal of Hospital Infection Jul 2024The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated...
BACKGROUND
The role of the healthcare environment in the transmission of clinical pathogens is well established. EN 17126:2018 was developed to address the need for regulated sporicidal product testing and includes a realistic medical soil to enable validation of products that claim combined cleaning and disinfection efficacy.
AIM
To investigate the chemical stability and sporicidal efficacy of oxidizing disinfectant products in the presence of simulated clean and medical dirty conditions.
METHODS
Disinfectant stability and sporicidal efficacy were evaluated in like-for-like ratios of soil:product. Disinfectants were exposed to simulated test soils and free chlorine, chlorine dioxide or peracetic acid concentrations were measured using standard colorimetric methods. Efficacy of disinfectants against C. difficile R027 endospores was assessed as per EN 17126:2018. Comparisons of performance between clean and medical dirty conditions were performed using one-way analysis of variance. Correlation analysis was performed using Pearson product-moment correlation.
FINDINGS
Performance of chlorine-releasing agents (sodium dichloroisocyanurate, chlorine dioxide and hypochlorous acid) was concentration dependent, with 1000 ppm chlorine showing reduced stability and efficacy in dirty conditions. By contrast, peracetic acid product demonstrated stability and consistently achieved efficacy in dirty conditions.
CONCLUSION
These results have implications for clinical practice, as ineffective environmental decontamination may increase the risk of transmission of pathogens that can cause healthcare-associated infections.
Topics: Disinfectants; Chlorine Compounds; Oxides; Peracetic Acid; Spores, Bacterial; Clostridioides difficile; Humans; Disinfection; Triazines; Hypochlorous Acid
PubMed: 38705474
DOI: 10.1016/j.jhin.2024.04.010 -
Cureus Mar 2024Therapeutic plasma exchange (TPE) is used to manage various life-threatening illnesses. It is widely performed by nephrologists, intensivists, pathologists, or experts...
INTRODUCTION
Therapeutic plasma exchange (TPE) is used to manage various life-threatening illnesses. It is widely performed by nephrologists, intensivists, pathologists, or experts in transfusion medicine worldwide. However, the costs of TPE sessions are exceedingly high, and they have a huge impact on patients' financial burden. Herein, we investigated the outcomes of the reuse of plasma filters in TPE on several occasions.
METHODS
This is a retrospective analysis of patients receiving TPE from January 1, 2020, to April 30, 2023, in the Department of Nephrology. A formulation of 4.5% peracetic acid and 24% hydrogen peroxide acid with RO water dilution was used for reprocessing. Clinical outcomes, risks, and cost-benefit were evaluated and compared between the plasma filter reuse group (GP-1) and the no-reuse group (GP-2).
RESULTS
A total of 70 patients were included in this study. 200 and 112 TPE sessions were performed in GP-1 and GP-2, respectively. The most common indication for TPE in both groups was neurological. The clinical efficacy of TPE was similar in both groups. There was no difference in the clotting of the plasma filter, any allergic reaction, infection, or bleeding in the group. However, there was a significant difference in levels of fibrinogen (p=0.03) pre and post-procedure in both groups. The incidence of hypotension was found to be higher in GP-1 (26%) compared to GP-2 (15.6%), p = 0.05. The cost of overall treatment was 38% less in GP-1.
CONCLUSION
The reuse of plasma filters is a safe and effective method for cost minimization in patients requiring TPE. This method can be effectively utilized in resource-poor settings without any increased risk of adverse effects.
PubMed: 38646327
DOI: 10.7759/cureus.56516