Saved Queries

by Sorina Maria Denisa Laitin, Luminita Mirela Baditoiu, Ruxandra Laza, Razvan Sebastian Besliu, Emil Robert Stoicescu, Miruna Gug, Cristina Stefania Dumitru and Raul Patrascu

Medicina 2024, 60(12), 1919; https://doi.org/10.3390/medicina60121919 (registering DOI) - 22 Nov 2024

Abstract

Background and Objectives: The COVID-19 pandemic has had a significant impact on global health, with serious outcomes, such as lung damage, being major determinants of patient morbidity and mortality. Immunization has been essential in attenuating these outcomes. This study aimed to evaluate the impact of COVID-19 vaccination on disease severity, particularly focusing on pulmonary involvement, among hospitalized patients. Materials and Methods: A retrospective cohort study was conducted at Victor Babes Hospital, Timisoara, involving 3005 patients diagnosed with COVID-19 between December 2020 and March 2022. Patients were stratified into vaccinated and unvaccinated groups. Results: The study found that vaccinated patients had significantly lower rates of severe pulmonary involvement compared to unvaccinated patients. Specifically, only 24.24% of vaccinated patients experienced severe lung involvement, compared to 35.64% in the unvaccinated group (p < 0.001). Vaccinated individuals had shorter hospital stays (8.96 ± 6.40 days vs. 10.70 ± 6.29 days), but this difference was not statistically significant (p = 0.219). Additionally, chronic pulmonary diseases and stroke were less prevalent among vaccinated patients, highlighting the protective effect of vaccination. Conclusions: COVID-19 vaccination significantly reduces the severity of disease, particularly in preventing severe pulmonary involvement, which is a major determinant of patient outcomes. These findings underscore the importance of ongoing vaccination efforts and the need for booster doses to maintain immunity, especially as new variants emerge. The study supports the continued prioritization of vaccination in public health strategies to mitigate the long-term impact of COVID-19. Full article

(This article belongs to the Section Infectious Disease)

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Flowchart of patient selection and grouping by vaccination status. Out of 3,005 COVID-19 patients, 623 were vaccinated (grouped by dose) and 2382 were unvaccinated. Full article ">Figure 2
Prevalence of comorbidities and complications in vaccinated vs. unvaccinated COVID-19 patients. This bar chart compares the prevalence of various comorbidities and complications between vaccinated (blue) and unvaccinated (orange) COVID-19 patients. Significant differences were observed in the rates of chronic pulmonary diseases, obesity, and stroke, highlighting the impact of vaccination on reducing certain severe outcomes. Full article ">

22 pages, 5934 KiB

Open AccessArticle

Estimation of the Immunity of an AC/DC Converter of an LED Lamp to a Standardized Electromagnetic Surge

by Wiesław Sabat, Dariusz Klepacki, Kazimierz Kamuda, Kazimierz Kuryło and Piotr Jankowski-Mihułowicz

Electronics 2024, 13(23), 4607; https://doi.org/10.3390/electronics13234607 (registering DOI) - 22 Nov 2024

Abstract

The method for estimating the immunity of an AC/DC converter built in a commercial LED lamp to a 1.2/50 µs (8/20 µs) surge has been presented in this paper. A lamp with a direct drive LED inverter was selected to present the methodology for determining the coefficient of immunity of the test object to a standardized type of surge. The choice of this configuration was important for the testing process and presentation of the methodology to estimate the immunity coefficient of the tested system. In this work, the methodology for determining the deterministic immunity factor of the model inverter to a normalized type of disturbance was presented. Considerations were carried out for a 1.2/50 µs (8/20 µs) surge in accordance with the recommendations of the EN 61000-4-5:2014 standard. This conventional surge is used in laboratory practice to test the immunity of electronic and electrical systems and devices to disturbances that can be generated in the power grid during switching processes, short circuits, and direct and indirect lightning. In the first stage of testing on test benches, the intensity of damage to the integral components of a model inverter was examined with increasing levels of disturbance. Statistical measures characterizing their impact resistance were determined for each of the elements tested. Knowing their values, the value of this coefficient was finally determined for the lamp selected for testing, and the mechanism of its damage was analyzed. Full article

(This article belongs to the Special Issue New Horizons and Recent Advances of Power Electronics)

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17 pages, 9585 KiB

Open AccessArticle

Identification of the Brassinazole-Resistant (BZR) Gene Family in Wheat (Triticum aestivum L.) and the Molecular Cloning and Functional Characterization of TaBZR2.1

by Yan Zhang, Jingzi Qin, Jinna Hou, Congcong Liu, Shenghui Geng, Maomao Qin, Wenxu Li, Ziju Dai, Zhengqing Wu, Zhensheng Lei and Zhengfu Zhou

Int. J. Mol. Sci. 2024, 25(23), 12545; https://doi.org/10.3390/ijms252312545 (registering DOI) - 22 Nov 2024

Abstract

Brassinazole-resistant (BZR) transcription factors are important transcription factors in Brassinosteroid (BR)-responsive gene expression. However, limited knowledge exists regarding the BZR genes in wheat and a limited number of BZR family genes have been previously reported in wheat. In this study, the synteny analyses of the TaBZR genes suggested that gene duplication events have played an essential role in the TaBZR family during evolution. The results of RT-qPCR and transcriptome data analyses exhibited remarkable expression patterns in the BZR genes in different tissues and under different treatments. The yeast two-hybrid (Y2H) screen result showed that the TaBZR2.1 protein interacts with Argonaute 4 (AGO4). Taken together, our results not only provide us a basis for understanding the molecular characteristics and expression patterns of the TaBZR family genes but also offered the functional characterization of TaBZR2.1 in wheat. Full article

(This article belongs to the Special Issue Genetic Engineering of Plants for Stress Tolerance)

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16 pages, 4694 KiB

Open AccessArticle

Effects of Ethylene Propylene Diene Monomer (EPDM)-Based Polar Macromolecular Compatibilizers on the Low-Temperature Properties of Fluoroelastomer/EPDM Rubber Blends

by Gen Liu, Faxin Du, Zhangjun Yao, Guangzhao Li, Wen Kuang, Chongyu Zhu, Yi Liu, Honglin Chen, Fumei Wang, Ce Zhou, Xueli Wei, Wenyan Wang and Rui Han

Molecules 2024, 29(23), 5522; https://doi.org/10.3390/molecules29235522 (registering DOI) - 22 Nov 2024

Abstract

Integrating rubber with superior low-temperature capabilities, such as ethylene propylene diene monomer (EPDM), is a strategic approach to bolster the low-temperature performance of fluoroelastomer (FKM). However, FKM and EPDM are thermodynamically incompatible. This work synthetized three EPDM-based polar macromolecular compatibilizers, epoxidized EPDM (EPDM-EP), 2,2-trifluoroethylamine-grafted epoxidized EPDM (EPDM-TF), and 2,4-difluorobenzylamine-grafted epoxidized EPDM (EPDM-DF), to enhance the compatibility between FKM and EPDM. These compatibilizers were subsequently incorporated into FKM/EPDM rubber blends. The results revealed that the glass transition temperature (T_g) of FKM/EPDM decreased by 1.3 °C, 2.68 °C, and 2.78 °C, respectively, upon the addition of 10 phr of EPDM-EP, EPDM-TF, or EPDM-DF. Moreover, the T_g of the two phases converged. The tensile strength, elongation at break, and tear strength of the FKM/EPDM rubber blends were also enhanced by the inclusion of these compatibilizers. Notably, EPDM-TF and EPDM-DF exhibited remarkable compatibilization effects due to an increase in polarity. This research not only sheds light on the potential for developing new compatibilizers but also paves the way for innovative applications of FKM and its derivatives. Full article

(This article belongs to the Section Macromolecular Chemistry)

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13 pages, 2898 KiB

Open AccessArticle

Development and Trait-Based Molecular Characterization of Thermosensitive Genic Male-Sterile Rice (Oryza sativa L.) Lines at Texas A&M AgriLife Research

by Darlene L. Sanchez, Stanley Omar PB. Samonte, Kimberly S. Ponce, Zongbu Yan and Lloyd T. Wilson

Agronomy 2024, 14(12), 2773; https://doi.org/10.3390/agronomy14122773 (registering DOI) - 22 Nov 2024

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Abstract

This study aimed to develop and genetically characterize thermosensitive genic male-sterility (TGMS) lines for use in hybrid rice (Oryza sativa L.) breeding. Male-sterile F₂ to F₄ generation lines were screened during the high-temperature summer season, and ratoon crops of selected male-sterile rows were harvested for pure seed. Sixty-six F₅ TGMS lines were genotyped using DNA markers controlling 16 traits from the LSU80 QA/QC Rice PlexSeq SNP Panel. Ten TGMS lines with desirable traits that included semidwarf, glabrous, non-aromatic, long-grain, narrow brown leaf spot resistance, and blast resistance genes were selected for further genotypic characterization using markers for low chalkiness (chalk5), wide compatibility (S5-n), cold tolerance (qSCT-11 and qCST-12), and anaerobic germination (AG1 and AG2). TGMS lines TIL21051S and TIL21052S possess favorable alleles for each of the genes evaluated in this study and are desirable parents for two-line hybrid breeding in the southeast United States. TIL21044S, TIL21095S, TIL21060S, and TIL21066S each contain three blast resistance genes and have potential as parental lines. TIL21014S-2, TIL21015S, and TIL21016S-1 include the fgr allele for aroma and can also be used as parental lines for aromatic two-line hybrids. Full article

(This article belongs to the Special Issue Marker Assisted Selection and Molecular Breeding in Major Crops)

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Pedigree selection used in the development of TGMS lines of Texas A&M AgriLife Research Center in Beaumont. Rice plant images are part of the image collection of the International Rice Research Institute. Full article ">Figure 2
2021 Weather Data at Texas A&M AgriLife Research Center in Beaumont (weather data source: iAIMS Climatic Data of Texas A&M AgriLife Research Center in Beaumont. <a href="https://beaumont/tamu.edu/ClimaticData/" target="_blank">https://beaumont/tamu.edu/ClimaticData/</a>, accessed on 3 September 2023 [<a href="#B50-agronomy-14-02773" class="html-bibr">50</a>,<a href="#B51-agronomy-14-02773" class="html-bibr">51</a>,<a href="#B52-agronomy-14-02773" class="html-bibr">52</a>]). Full article ">Figure 3
Allelic distribution of trait markers in 66 TGMS lines genotyped using the LSU80 QA/QC Rice PlexSeq SNP Panel. Full article ">

17 pages, 939 KiB

Open AccessReview

Optimizing Ultrasound Probe Disinfection for Healthcare-Associated Infection Control: A Comparative Analysis of Disinfectant Efficacy

by Gaetano Ferrara, Giovanni Cangelosi, Sara Morales Palomares, Stefano Mancin, Marianna Melina, Orejeta Diamanti, Marco Sguanci, Antonella Amendola and Fabio Petrelli

Microorganisms 2024, 12(12), 2394; https://doi.org/10.3390/microorganisms12122394 (registering DOI) - 22 Nov 2024

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Abstract

Background/Aims: Ultrasound is a key diagnostic tool in modern medicine due to its ability to provide real-time, high-resolution images of the internal structures of the human body. Despite its undeniable advantages, there are challenges related to the contamination of ultrasound probes, with the risk of healthcare-associated infections. The aim of this review was to identify the most effective disinfectants for disinfecting ultrasound probes to prevent the transmission of pathogens between patients. Methods: A narrative review was conducted using the PubMed, CINAHL, Embase, and Cochrane Library databases, resulting in the inclusion of 16 studies from an initial 1202 records. Results: Hydrogen peroxide (H₂O₂) was the most effective disinfectant, especially in automated systems, achieving a >5-log₁₀ reduction in viral load, including that of resistant pathogens like Human Papillomavirus. Chlorhexidine gluconate (4%) demonstrated strong antibacterial efficacy, eliminating 84.62% of bacterial contamination, but was less effective against viral pathogens. Glutaraldehyde was effective in some cases, though its use carried a higher risk of probe damage. The use of sodium hypochlorite varied across guidelines; some endorsed it for COVID-19 prevention, while others cautioned against its application due to potential probe damage. Conclusions: This study highlights the importance of advanced disinfection technologies and strict adherence to protocols in improving infection control. Automated systems utilizing H₂O₂ strike an ideal balance between antimicrobial efficacy and equipment preservation. Future research should focus on developing disinfection methods that prioritize safety, cost-effectiveness, and environmental sustainability in various clinical environments. Full article

(This article belongs to the Special Issue Latest Review Papers in Medical Microbiology 2024)

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Flow chart of included record selection. Full article ">Figure 2
Process of ultrasound probe-associated infection Prevention. Legend: The figure illustrates the steps involved in the proper disinfection of ultrasound probes to prevent infections, ensuring the elimination of pathogens and reducing the risk of cross-contamination between patients. Full article ">

17 pages, 5639 KiB

Open AccessArticle

Comprehensive Transcriptomic and Physiological Insights into the Response of Root Growth Dynamics During the Germination of Diverse Sesame Varieties to Heat Stress

by Xiaoyu Su, Chunming Li, Yongliang Yu, Lei Li, Lina Wang, Dandan Lu, Yulong Zhao, Yao Sun, Zhengwei Tan and Huizhen Liang

Curr. Issues Mol. Biol. 2024, 46(12), 13311-13327; https://doi.org/10.3390/cimb46120794 (registering DOI) - 22 Nov 2024

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Abstract

Heat stress constitutes a serious threat to sesame (Sesamum indicum L.). Root development during seed germination plays an essential role in plant growth and development. Nevertheless, the regulatory mechanisms underlying heat stress remain poorly understood. In this study, two sesame varieties differing in leaf heat tolerance (Zheng Taizhi 3 (heat-tolerant) and SP19 (heat-sensitive)) have been employed to investigate the impact of heat stress on root growth during germination. The results showed that heat stress significantly reduced the radicle length by 35.71% and 67.02% in Zheng Taizhi 3 and SP19, respectively, while germination rates remained unchanged. In addition, heat stress induced oxidative stress, as evidenced by increased reactive oxygen species (ROS) production, malondialdehyde (MDA) content, and reduced indole-3-acetic acid (IAA) content, accompanied by enhanced antioxidant enzyme activities, including those of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and the abscisic acid (ABA) content significantly increased in both varieties. However, the oxidation resistance in the roots of Zheng Taizhi 3 was enhanced compared to that of SP19 under heat stress, while IAA production was maintained and ABA content was reduced. A comparative transcriptome analysis identified 6164 and 6933 differentially expressed genes (DEGs) in Zheng Taizhi 3 and SP19, respectively, with 4346 overlapping DEGs. These DEGs included those related to stress tolerance, such as heat-shock proteins (HSPs), the antioxidant defense system, hormone signal transduction, and the biosynthetic pathway of phenylpropanoid. These findings provide insights into the physiological and molecular mechanisms underlying the adaptation of sesame to heat stress, which could inform breeding strategies for developing heat-tolerant sesame varieties. Full article

(This article belongs to the Special Issue Advances in Multi-Omics for Functional Genomics Studies and Molecular Breeding)

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Analysis of the phenotype and physiological effects of heat stress on two contrasting sesame varieties, Zheng Taizhi 3 (heat-tolerant) and SP19 (heat-sensitive). Phenotypes of Zheng Taizhi 3 and SP19 before heat stress treatment (left) and after heat stress treatment (right) (A,B); germination rate (C), radicle length (D), relative electronical conductivity (E), MDA content (F), H2O2 content (G), O2·− production rate (H), SOD activity (I), POD activity (J), CAT activity (K), IAA and ABA content (L) were analyzed in Zheng Taizhi 3 and SP19 under heat stress. TH, heat treatment of the tolerant variety, Zhengtaizhi 3; TC, control of the tolerant variety, Zhengtaizhi 3; SH, heat treatment of the sensitive variety, SP19; SC, control of the sensitive variety, SP19. Different letters indicate significant differences between groups at p < 0.05 according to Duncan’s multiple range test. Full article ">Figure 2
Transcriptomic responses to heat stress in sesame. (A) Volcano plot of TH vs. TC; (B) volcano plot of SH vs. SC; C, column chart of the DEGs; (C) Venn diagrams displaying DEGs in diverse treatments. TH, heat treatment of the tolerant variety, Zhengtaizhi 3; TC, control of the tolerant variety, Zhengtaizhi 3; SH, heat treatment of the sensitive variety, SP19; SC, control of the sensitive variety, SP19. Full article ">Figure 3
Transcriptome enrichment analysis. (A) GO analysis of DEGs in different groups. (B) KEGG analysis of DEGs in diverse comparisons. Circle size and color suggest the number of DEGs associated with each KEGG pathway and p-values, respectively. TH, heat treatment of the tolerant variety, Zhengtaizhi 3; TC, control of the tolerant variety, Zhengtaizhi 3; SH, heat treatment of the sensitive variety, SP19; SC, control of the sensitive variety, SP19. Full article ">Figure 4
Expression of antioxidant enzyme system related enzyme genes in sesame root under heat stress. Full article ">Figure 5
Expression of phenylpropanoid biosynthesis-related enzyme genes in sesame root under high heat stress. Full article ">Figure 6
Comparison of heat-responsive HSP family encoded genes’ expression in heat-sensitive (S) and heat-tolerant (T) sesame varieties. Full article ">Figure 7
The response in plant hormone signal transduction to high-temperature treatment. Full article ">Figure 8
Model of the differential responses of two sesame cultivars with different heat tolerances under high-temperature stress found by comparative physiological and transcriptome analysis. Full article ">

26 pages, 4366 KiB

Open AccessArticle

Green Synthesis of Silver Oxide Nanoparticles from Mauritia flexuosa Fruit Extract: Characterization and Bioactivity Assessment

by Johana Zúñiga-Miranda, David Vaca-Vega, Karla Vizuete, Saskya E. Carrera-Pacheco, Rebeca Gonzalez-Pastor, Jorge Heredia-Moya, Arianna Mayorga-Ramos, Carlos Barba-Ostria, Elena Coyago-Cruz, Alexis Debut and Linda P. Guamán

Nanomaterials 2024, 14(23), 1875; https://doi.org/10.3390/nano14231875 (registering DOI) - 22 Nov 2024

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Abstract

The increasing prevalence of multidrug-resistant (MDR) pathogens, persistent biofilms, oxidative stress, and cancerous cell proliferation poses significant challenges in healthcare and environmental settings, highlighting the urgent need for innovative and sustainable therapeutic solutions. The exploration of nanotechnology, particularly the use of green-synthesized nanoparticles, offers a promising avenue to address these complex biological challenges due to their multifunctional properties and biocompatibility. Utilizing a green synthesis approach, Mauritia flexuosa Mf-Ag₂ONPs were synthesized and characterized using dynamic light scattering (DLS), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy coupled with scanning electron microscopy (EDS-SEM), UV-Vis spectroscopy, and Fourier transform infrared spectroscopy (FTIR). The Mf-Ag₂ONPs exhibited potent antibacterial effects against both non-resistant and MDR bacterial strains, with minimum inhibitory concentrations (MICs) ranging from 11.25 to 45 µg/mL. Mf-Ag₂ONPs also demonstrated significant antifungal efficacy, particularly against Candida glabrata, with an MIC of 5.63 µg/mL. Moreover, the nanoparticles showed strong biofilm inhibition capabilities and substantial antioxidant properties, underscoring their potential to combat oxidative stress. Additionally, Mf-Ag₂ONPs exhibited pronounced anticancer properties against various cancer cell lines, displaying low IC₅₀ values across various cancer cell lines while maintaining minimal hemolytic activity at therapeutic concentrations. These findings suggest that Mf-Ag₂ONPs synthesized via an eco-friendly approach offer a promising alternative for biomedical applications, including antimicrobial, antifungal, antioxidant, and anticancer therapies, warranting further in vivo studies to fully exploit their therapeutic potential. Full article

(This article belongs to the Special Issue Biosynthesis and Green Synthesis of Nanomaterials: New Methodologies and Results, 2nd Edition)

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25 pages, 5231 KiB

Open AccessArticle

Retrograded Resistant Starch Improves Emulsion Stability and Emulsion Gel Properties Stabilized by Myofibrillar Proteins Without Degrading In Vitro Protein Digestibility

by Jinyu Chen, Fangyang Hu, Jiaqi Guo, Wen Zhang and Zijian Wu

Foods 2024, 13(23), 3739; https://doi.org/10.3390/foods13233739 (registering DOI) - 22 Nov 2024

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Abstract

The objective of this study was to investigate the effects of retrograded resistant starch (RS3) (0, 2%, 4% and 6%; w/v) on the emulsion gel properties stabilized by myofibrillar proteins (MPs) and in vitro protein digestibility of the gels. The RS3 was prepared from corn or potato starch using the gelatinization–ultrasound–retrogradation method. The results showed that the addition of RS3 decreased the surface hydrophobicity (p < 0.05) and increased the fluorescence intensity of MPs, indicating enhanced protein–protein interactions. More stable emulsions stabilized by MP/RS3 mixtures were formed, along with higher electronegativity, a smaller droplet size and reduced creaming index. These changes promoted the formation of better gel networks with the oil droplets evenly dispersed, thus improving gel strength, water holding capacity (WHC) and texture, especially at the concentration of 6% RS3 added. The gel force results indicated that the addition of RS3 enhanced the hydrophobic interaction and disulfide bonds between MPs. LF-NMR and MRI data further confirmed that RS3 addition facilitated the migration of free water to immobilized water. Furthermore, the incorporation of RS3 caused a relatively lower pepsin digestibility but did not change the overall in vitro protein digestibility of the gels. This paper provides a method to produce high-quality low-GI meat products without degrading protein digestibility. Full article

(This article belongs to the Section Meat)

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15 pages, 1912 KiB

Open AccessArticle

Cell Wall-Mediated Antifungal Activity of the Aqueous Extract of Hedera helix L. Leaves Against Diplodia corticola

by Christina Crisóstomo, Luara Simões, Lillian Barros, Tiane C. Finimundy, Ana Cunha and Rui Oliveira

Antibiotics 2024, 13(12), 1116; https://doi.org/10.3390/antibiotics13121116 (registering DOI) - 22 Nov 2024

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Abstract

Background/Objectives: Cork oak forests have been declining due to fungal pathogens such as Diplodia corticola. However, the preventive fungicides against this fungus have restricted use due to the deleterious effects on human health and the environment, prompting the need for sustainable alternatives. Here, we describe the antifungal activity of an aqueous extract of Hedera helix L. leaves (HAE) against D. corticola and the possible mechanism of action. Results/Methods: The chemical analysis revealed compounds like the saponin hederacoside C, quinic acid, 5-O-caffeoylquinic acid, rutin, and glycoside derivatives of quercetin and kaempferol, all of which have been previously reported to possess antimicrobial activity. Remarkable in vitro antifungal activity was observed, reducing radial mycelial growth by 70% after 3 days of inoculation. Saccharomyces cerevisiae mutants, bck1 and mkk1/mkk2, affected the cell wall integrity signaling pathway were more resistant to HAE than the wild-type strain, suggesting that the extract targets kinases of the signaling pathway, which triggers toxicity. The viability under osmotic stress with 0.75 M NaCl was lower in the presence of HAE, suggesting the deficiency of osmotic protection by the cell wall. Conclusions: These results suggest that ivy extracts can be a source of new natural antifungal agents targeting the cell wall, opening the possibility of preventing fungal infections in cork oaks and improving the cork production sector using safer and more sustainable approaches. Full article

(This article belongs to the Section Plant-Derived Antibiotics)

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Percentage of growth inhibition of D. corticola by H. helix aqueous extract (HAE). Radial growth of D. corticola mycelium was measured in Petri dishes with PDA medium containing 50, 100, 500, 1000, or 1500 µg/mL of HAE. Representative images of HAE antifungal activity against D. corticola after 6 days of incubation (A). In the negative control (C-), the highest volume of extract used on the assays was replaced by sterilized deionized water (extract solvent). The diameter was measured after 3 (black bars; (B)) and 6 (grey bars; (B)) days of incubation at 25 °C in the dark. Each bar represents the mean ± SD of three independent experiments. A two-way ANOVA was used for the analysis and different letters represent statistical significance. Capital letters were used for comparisons of extract concentrations within the same time of incubation and lowercase letters were used for comparisons of different times of incubation for each concentration tested. Full article ">Figure 2
Viability of S. cerevisiae BY4741 (A) and the mutant strains erg2 (B), bck1 (C), and mkk1/mkk2 (D) in the presence of aqueous extract of H. helix (HAE). Cells from exponentially growing cultures were exposed to 10 µg/mL (white squares), 50 µg/mL (black triangles), 75 µg/mL (white inverted triangles), 100 µg/mL (black diamonds), or 250 µg/mL (white circles) of HAE and incubated at 30 °C, 200 rpm. Viability was assessed using CFU after 0, 30, 60, and 90 min of incubation upon spreading 10−4 dilutions on YPDA plates and incubation at 30 °C, 200 rpm. The negative control (black circles) was prepared by replacing the extract by the solvent at the highest volume of extract used in the assays. The data represent the mean ± SD of three independent experiments. A one-way ANOVA and Dunnett’s post hoc test were used for the analysis, and concentrations were compared at each time-point. For clarity of graphical representation, significance is shown only for the 90 min timepoint, where ** means 0.001 < p ≤ 0.01 and **** means p < 0.0001; the absence of significance is not marked with any symbol. Other relevant significances are presented in the text. Full article ">Figure 3
Viability of S. cerevisiae BY4741 in the presence of aqueous extract of H. helix (HAE) and osmotic stress. Cells from exponentially growing cultures were exposed to 10 µg/mL (grey bars) or 50 µg/mL (dark grey bars) of HAE at 30 °C, 200 rpm, for 30 min. The viability was assessed using CFU by plating 10−4 dilutions on YPDA plates containing different concentrations of NaCl (0, 0.25, 0.5, or 0.75 M) and further incubation at 30 °C for 48 h. The negative control (black bars) was prepared by replacing the extract with the solvent at the highest volume of extract used in the assays. The data represent the mean ± SD of three independent experiments. A two-way ANOVA and Tukey’s post hoc test were used for the analysis. A letter code was used. Lowercase letters are used for comparisons of extract concentration effects within each salt concentration (p < 0.0001) and capital letters are used for comparisons between salt concentrations for each extract concentration (p < 0.01). Mean values followed by the same letters are not statistically different. Full article ">Figure 4
Percentage of growth inhibition of D. corticola by H. helix aqueous extract (HAE) in the absence and presence of osmotic stress. Radial growth of D. corticola mycelium was measured in Petri dishes with PDA medium containing 50, 500, or 1500 µg/mL HAE in the absence or presence of 0.4 M of NaCl. Representative images of HAE antifungal activity against D. corticola after 6 days of incubation (A). In the negative control (C-), the highest volume of extract used on the assays was replaced by sterilized deionized water (extract solvent). The diameter was measured after 6 days of incubation at 25 °C in the dark and the percentage of growth inhibition was calculated, taking C- as a reference (B). Each bar represents the mean ± SD of three independent experiments. A one-way ANOVA and Dunnett’s post hoc test were used for the analysis, where *** means 0.0001 < p ≤ 0.001 and **** means p < 0.0001. Full article ">

15 pages, 3088 KiB

Open AccessArticle

A Recombinant Shigella flexneri Strain Expressing ETEC Heat-Labile Enterotoxin B Subunit Shows Promise for Vaccine Development via OMVs

by Josune Salvador-Erro, Yadira Pastor and Carlos Gamazo

Int. J. Mol. Sci. 2024, 25(23), 12535; https://doi.org/10.3390/ijms252312535 (registering DOI) - 22 Nov 2024

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Abstract

Diarrheal diseases caused by Shigella and enterotoxigenic Escherichia coli (ETEC) are significant health burdens, especially in resource-limited regions with high child mortality. In response to the lack of licensed vaccines and rising antibiotic resistance for these pathogens, this study developed a recombinant Shigella flexneri strain with the novel incorporation of the eltb gene for the heat-labile enterotoxin B (LTB) subunit of ETEC directly into Shigella’s genome, enhancing stability and consistent production. This approach combines the immunogenic potential of LTB with the antigen delivery properties of S. flexneri outer membrane vesicles (OMVs), aiming to provide cross-protection against both bacterial pathogens in a stable, non-replicating vaccine platform. We confirmed successful expression through GM1-capture ELISA, achieving levels comparable to ETEC. Additionally, proteomic analysis verified that the isolated vesicles from the recombinant strains contain the LTB protein and the main outer membrane proteins and virulence factors from Shigella, including OmpA, OmpC, IcsA, SepA, and Ipa proteins, and increased expression of Slp and OmpX. Thus, our newly designed S. flexneri OMVs, engineered to carry ETEC’s LTB toxin, represent a promising strategy to be considered as a subunit vaccine candidate against S. flexneri and ETEC. Full article

(This article belongs to the Special Issue Current Research on the Role of the Gut Microbiota in Human Diseases and Health)

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LTB detection in ETEC and different parental or transgenic Shigella flexneri strains using a GM1 capture-ELISA. (A) The presence of LTB was confirmed on ETEC and S. flexneri::eltb and ΔtolR::eltb strains. (B) In LTB-positive samples, no significant differences were observed between cell-associated and bacterial culture supernatant fractions. [ns, not significant (p ≥ 0.05)]. Full article ">Figure 2
Representative transmission electron microscopy (TEM) images of OMVs and HT-OMVs isolated from parental Shigella flexneri, S. flexneri ΔtolR mutant, and their respective recombinant containing eltb (scale bar = 200 nm). Full article ">Figure 3
Proteomic analysis identified LTB abundance in the different OMV and HT products from ETEC and Shigella flexneri or mutant (ΔtolR), with and without the eltb insertion. Samples were analyzed in triplicates and the protein abundance was normalized to the total protein (*, p < 0.05; ***, p < 0.001; ns, non-significant; a.u.: arbitrary units). Full article ">Figure 4
Differential expression of the main outer membrane proteins and virulence factors included in OMV and HT products from Shigella flexneri wild-type (A,B) or mutant ΔtolR (C,D) before (black) and after eltb mutation (white). Proteins were clustered in two groups based on their expression profile. Samples were analyzed in triplicates and the Log2 of the fold change is represented (*, p < 0.05, **, p < 0.01, ***, p < 0.001; ns, non-significant). Full article ">Figure 5
Bacterial growth curves of Shigella flexneri wt, S. flexneri::eltb, S. flexneri ΔtolR, and S. flexneri ΔtolR::eltb. Bacterial suspensions were inoculated on Bioscreen C multi-well plates and incubated with continuous shaking at 37 °C. Absorbance values (O.D.580 nm) were automatically read at regular intervals of 10 min for 22 h. An arbitrary position of the stationary phase is indicated according to the growth curve kinetics. Full article ">Figure 6
Biofilm formation assay results. (A) Comparison of biofilm formation among recombinant and parental Shigella flexneri strains, showing significant increases in biofilm production for the S. flexneri::eltb and S. flexneri ΔtolR::eltb strains (**, p < 0.01) compared to the parental strains. (B) Evaluation of LTB involvement in biofilm formation, showing a significant decrease in biofilm formation capacity after the addition of GM1, the natural receptor of LTB (*, p < 0.05), with no significant differences observed in the parental strain (ns). Full article ">Figure 7
Effect of OMVs and HT-OMVs on the mitochondrial activity (MTT assay) on HeLa cells. Figures indicate the percentage (%) of mitochondrial activity after treatment for 2 or 24 h with different concentrations of OMVs and HT-OMVs (μg/mL) compared to untreated cells. Experiment was performed in triplicate. Error bars represent SEM. Full article ">

9 pages, 1053 KiB

Open AccessArticle

Enhanced Effect of Patient Room Disinfection Against Carbapenem-Resistant Enterobacter cloacae and Methicillin-Resistant Staphylococcus aureus Using UV-C Irradiation in Conjunction with UV-C Containment Unit

by Shiori Kitaya, Kentarou Takei, Yoshitomo Honda, Risako Kakuta and Hajime Kanamori

Antibiotics 2024, 13(12), 1115; https://doi.org/10.3390/antibiotics13121115 (registering DOI) - 22 Nov 2024

Viewed by 68

Abstract

Background/Objectives: In environments with high-frequency contact surfaces, drug-resistant bacteria, such as carbapenem-resistant Enterobacterales and methicillin-resistant Staphylococcus aureus (MRSA), can survive for extended periods, contributing to healthcare-associated infections. Ultraviolet (UV)-C irradiation often fails to adequately disinfect shadowed areas, leading to a persistent contamination risk. We evaluated the effectiveness of using a UV-C containment unit (UVCCU) in conjunction with UV-C irradiation to improve the sterilization effects on both direct and indirect surfaces, including shadowed areas, and to assess the leakage of UV radiation to the surroundings. Methods: In a model patient room, agar media inoculated with carbapenem-resistant Enterobacter cloacae and MRSA were placed at multiple locations on direct and indirect surfaces around the bed. We used the UV-C irradiation system, UVDI-360, to irradiate the bedroom-environment surfaces with and without a UVCCU. The reduction in bacterial colony counts with and without the UVCCU was measured by counting colony-forming units and calculating the log reduction values, and the UV radiation leakage outside the UVCCU was measured. Results: The use of the UVCCU led to a significant reduction in MRSA colony counts, even in shadowed areas that had previously been inadequately disinfected (with the UVCCU: 2.7 [2.7–2.8]; without the UVCCU: 0.6 [0.5–0.7]; p < 0.01). Additionally, the use of the UVCCU kept the UV radiation leakage to the surrounding environment within regulated limits. Conclusions: These findings suggest that a UVCCU can enhance the disinfection efficacy for multidrug-resistant organisms on healthcare environmental surfaces. The portability and ease of use of the UVCCU indicate its promise as an auxiliary device for UV-C disinfection in healthcare settings. Full article

(This article belongs to the Special Issue Antibiotics Resistance and Molecular Epidemiology of Carbapenem-Resistance Bacteria)

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Figure 1

Figure 1
The bed unit and shielding system UVCCU. (a) A bed unit that mimics an actual hospital room is created in one bed of the model hospital room (4-bed room); (b) a shielding system UV-C containment unit is installed to surround the bed unit. UV, ultraviolet; UVCCU, UV-C containment unit. Full article ">Figure 2
The locations for placing agar media and the position of the UVDI-360 within the bed unit. Agar media coated with carbapenem-resistant Enterobacter cloacae and methicillin-resistant Staphylococcus aureus were placed at seven locations, including surfaces directly hit by UV-C and indirect surfaces that were shaded. The distances from the UVDI-360 installed on the right and left sides of the bed to each directly irradiated surface were as follows: head position of the bed, right (171 cm), left (173 cm); overbed table (tabletop), right (105 cm), left (107 cm); bedside cabinet (tabletop), right (123 cm), left (216 cm); bed rails, right (61 cm), left (142 cm); curtain (pole part), right (87 cm), left (226 cm). On the other hand, the distances from the UVDI-360 installed on the right and left sides of the bed to each indirectly irradiated surface were as follows: footboard (outer side), right 92 cm, left 94 cm; bedside cabinet (left side), right (126 cm), left (232 cm). The UVDI-360 was irradiated at position A for 5 min and then at position B for 5 min, considering this as one cycle, and a total of three cycles were conducted. UV, ultraviolet. Full article ">Figure 3
The positional relationship and irradiation method of the UVDI-360 within the bed unit. The UVDI-360 was installed at two locations, designated as points A and B. The UVDI-360 was irradiated at position A for 5 min and then at position B for 5 min, considering this as one cycle, and a total of three cycles were conducted. Full article ">

19 pages, 1632 KiB

Open AccessArticle

New Conjugates of Vancomycin with Cell-Penetrating Peptides—Synthesis, Antimicrobial Activity, Cytotoxicity, and BBB Permeability Studies

by Jarosław Ruczyński, Katarzyna Prochera, Natalia Kaźmierczak, Katarzyna Kosznik-Kwaśnicka, Lidia Piechowicz, Piotr Mucha and Piotr Rekowski

Molecules 2024, 29(23), 5519; https://doi.org/10.3390/molecules29235519 (registering DOI) - 22 Nov 2024

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Abstract

Vancomycin (Van) is a glycopeptide antibiotic commonly used as a last resort for treating life-threatening infections caused by multidrug-resistant bacterial strains, such as Staphylococcus aureus and Enterococcus spp. However, its effectiveness is currently limited due to the rapidly increasing number of drug-resistant clinical strains and its inherent cytotoxicity and poor penetration into cells and specific regions of the body, such as the brain. One of the most promising strategies to enhance its efficacy appears to be the covalent attachment of cell-penetrating peptides (CPPs) to the Van structure. In this study, a series of vancomycin conjugates with CPPs—such as TP10, Tat (47–57), PTD4, and Arg₉—were designed and synthesized. These conjugates were tested for antimicrobial activity against four reference strains (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, and Pseudomonas aeruginosa) and two clinical drug-resistant strains: methicillin-resistant S. aureus and vancomycin-resistant E. faecium. In addition, cytotoxicity tests (using a human fibroblast cell line) and blood–brain barrier (BBB) permeability tests (using a parallel artificial membrane permeability assay—PAMPA-BBB assay) were conducted for selected compounds. Our research demonstrated that conjugation of Van with CPPs, particularly with Tat (47–57), Arg₉, or TP10, significantly enhances its antimicrobial activity against Gram-positive bacteria such as S. aureus and Enterococcus spp., reduces its cytotoxicity, and improves its access to brain tissues. We conclude that these findings provide a strong foundation for the design of novel antimicrobial agents effective in treating infections caused by drug-resistant staphylococcal and enterococcal strains, while also being capable of crossing the BBB. Full article

(This article belongs to the Special Issue Chemical Biology of Antimicrobial Resistance, 2nd Edition)

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Figure 1

Figure 1
Schematic illustration of the chemical structure of the synthesized Van-CPP conjugates, where VV is the primary amino position in the carbohydrate moiety of vancomycin (green circle, position of PEG4 or Suc-Cystamine linker attachment), VC is the C-terminal carboxylic position of vancomycin (orange circle, position of PEG3 or Cystamine linker attachment), PEG4 is 4,7,10,13-tetraoxopentadecane-1-caboxylate, PEG3 is 1-amino-3,6,9-trioxoundecane, Cystamine is 1-amino-2-(ethyldisulfanyl)ethan, Suc-Cystamine is 4-(2-(ethyldisulfanyl)ethylamino)-4-oxobutane-1-carboxylate, CPP is the N-terminal amino position of cell-penetrating peptides (blue circle, position of CPP attachment): Tat (47–57) and PTD4 (attached via PEG3, PEG4, Cystamine and Suc-Cystamine linker), Arg9 (attached via PEG3, PEG4 and Cystamine linker) or TP10 (attached via PEG3 and PEG4 linker). Full article ">Figure 2
Effects of vancomycin conjugates and their components on the viability of normal human fibroblast cells: (A) TP10 and its conjugates, (B) Tat(47–57) and its conjugates, (C) PTD4 and its conjugates, (D) Arg9 and its conjugates. Cells were incubated with various concentrations of peptides for 24 h and cell viability was assessed by neutral red cytotoxicity assay. Plots present mean ± SD from three independent experiments performed in triplicate. The x-axis represents peptide concentration in µg/mL. The y-axis represents cell viability expressed as a percentage relative to the untreated control cells incubated without peptides as well as control cells treated with 10% DMSO. A one-way ANOVA test was used to test the degree of significance. * statistically significant (p < 0.05) as compared to control. Full article ">Figure 3
The general scheme of the synthesis of vancomycin conjugates with CPPs showing the preparation of one of the representatives of the conjugates—Van-PEG3-Tat (47–57). The syntheses consist of three main steps. (I) In the first step, azido-functionalized Van derivatives are obtained by coupling vancomycin with bifunctional linkers, e.g., H2N-PEG3-N3 (1-amino-11-azido-3,6,9-trioxoundecane); (II) the second step is the solid-phase synthesis (SPPS) of CPP derivatives with a propiolate group attached to the N-terminus, e.g., Prop-Tat (47–57); (III) in the third step, vancomycin derivatives are conjugated with CPP derivatives using the highly effective and chemoselective 1,3-dipolar Huisgen cycloaddition, commonly known as the “click reaction”, which leads to the formation of a 1,2,3-triazole ring and stable Van-CPP conjugates, e.g., Van-PEG3-Tat (47–57). Full article ">

10 pages, 286 KiB

Open AccessArticle

Phylum Firmicutes in the Faecal Microbiota Demonstrates a Direct Association with Arterial Hypertension in Individuals of the Kazakh Population Without Insulin Resistance

by Gulshara Abildinova, Tamara Vochshenkova, Alisher Aitkaliyev, Aizhan Abildinova, Valeriy Benberin, Anna Borovikova, Nazira Bekenova and Balzhan Kassiyeva

Int. J. Environ. Res. Public Health 2024, 21(12), 1546; https://doi.org/10.3390/ijerph21121546 (registering DOI) - 22 Nov 2024

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Abstract

The gut microbiota plays a fundamental role in the host’s energy metabolism and the development of metabolic diseases such as arterial hypertension, insulin resistance, and atherosclerosis. Our study aimed to investigate the potential role of the gut microbiota in arterial hypertension among individuals of the Kazakh population without insulin resistance. 16S rRNA gene sequencing of faecal samples from 197 Kazakh subjects was performed. Preliminary binary comparisons of the faecal microbiota composition depending on the presence of arterial hypertension and insulin resistance revealed statistically significant differences in the abundance of the phylum Firmicutes. Logistic regression analysis showed that only the phylum Firmicutes influenced hypertension risk in individuals without insulin resistance after adjusting for age, sex, BMI, fasting glucose, triglycerides, and triglyceride–glucose index. The higher the abundance of the phylum Firmicutes in faeces, the greater the risk of arterial hypertension (OR = 1.064 [95% CI 1.005–1.125]). Correlation analysis revealed a negative association between the abundance of the phylum Firmicutes and the triglyceride–glucose index, primarily driven by triglyceride levels. These findings suggest the potential role of the gut microbiota, especially the phylum Firmicutes, in the development of hypertension in individuals without insulin resistance. Full article

(This article belongs to the Special Issue New Insights into Understudied Phenomena in Healthcare)

16 pages, 8810 KiB

Open AccessArticle

Streptococcus agalactiae Infection in Wild Trahira (Hoplias malabaricus) and Farmed Arapaima (Arapaima gigas) in Brazil: An Interspecies Transmission in Aquatic Environments Shared with Nile Tilapia (Oreochromis niloticus)

by Carlos Augusto Gomes Leal, Rafael Gariglio Clark Xavier, Guilherme Alves de Queiroz, Tarcísio Martins França Silva, Júnia Pacheco Teixeira, Flávia Figueira Aburjaile and Guilherme Campos Tavares

Microorganisms 2024, 12(12), 2393; https://doi.org/10.3390/microorganisms12122393 (registering DOI) - 22 Nov 2024

Viewed by 79

Abstract

Streptococcus agalactiae is an important pathogen responsible for cases of high mortality in farmed and wild fish worldwide. In Brazil, this bacterium has been commonly associated with outbreaks in Nile tilapia farms, but other native fish species are also susceptible. Since floating cages are one of the most common culture systems used in the country, the close contact between farmed tilapia and native fish species presents a risk concerning the transmission of this pathogen. In this study, we characterized a mortality outbreak in free-living trahira and in farmed arapaima, as well as the genetic and antimicrobial susceptibility patterns of the isolates obtained. During the outbreaks, moribund fish were sampled and subjected to bacterial examination, after which the isolates were identified via MALDI-ToF analysis. Genotyping was evaluated using repetitive sequence-based PCR (REP-PCR) and multilocus sequence typing (MLST). Antimicrobial susceptibility was evaluated using disc diffusion assays. In addition, whole-genome analysis also was performed. S. agalactiae was identified in all diseased fish, all of which belonged to serotype Ib; however, trahira strains were classified as non-typeable lineages in the MLST assay, while arapaima strains were classified as ST260. These isolates were shown to be similar to the main genotype found in Nile tilapia in Brazil, using REP-PCR, MLST and phylogenomic analysis. The pathogenicity of the bacterium was confirmed by Koch’s postulates for both fish species. The antimicrobial susceptibility assay showed variable results to the same antibiotics among the isolates, prompting four of the isolates to be classified as multidrug-resistant. This study represents the first report of a natural outbreak of Streptococcus agalactiae infection in wild trahira and farmed arapaima inhabiting the same aquatic environment as Nile tilapia. Full article

(This article belongs to the Special Issue Infectious Diseases in Aquaculture)

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Figure 1

Figure 1
Natural Streptococcus agalactiae infection in native fish species. (A) Diseased wild trahira with exophthalmia (arrow) found dead during the outbreak; (B) Diseased arapaima with exophtalmia and corneal opacity, alive in the tank. Full article ">Figure 2
REP-PCR results for five Streptococcus agalactiae strains isolated from trahira, arapaima, Amazon catfish and Nile tilapia. The dendrogram was constructed using Dice’s coefficient and the UPGMA method. Full article ">Figure 3
Whole-genome sequence RA × ML phylogenetic tree constructed using SA32-17 and SA45-17 strains together other Brazilian Streptococcus agalactiae strains deposited in the GenBank database (bootstrap test, 1000 replicates). Two distantly related groups of isolates are visualized one on the right side (CC260, marked with *) and one on the left side (NT) of the figure. Bootstrap values are presented as color gradients at the branches for better visualization. Full article ">Figure 4
Mortality rate of the trahira and arapaima challenged with Streptococcus agalactiae during the experimental period. Full article ">Figure 5
Histology of challenged trahira (a–c) and arapaima (d). (a) Brain—meningitis was and obvious sign characterized by thickening with congested blood vessels and inflammatory cells infiltration; (b) Liver—congestion and thrombosis of portal blood vessel accompanied with hepatic sinusoids with marked vacuolar degeneration change of hepatocytes; (c) Heart—Accumulation of inflammatory cells (arrows) and hemorrhagic areas in myocardium and pericardium; (d) Spleen—cellular necrosis (picnosis = arrow) in white pulp associated with the presence of Gram-positive bacteria (arrow head). Full article ">

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