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Sechium edule (Jacq.) Swartz is a perennial herbaceous climbing plant with tendrils and tuberous roots belonging to the Cucurbitaceae family. Its fruits ("chayote"), stems, roots, and leaves are edible and are commonly ingested by humans. It has shown medicinal properties attributed to its bioactive compounds (vitamins, phenolic acids, flavonoids, carotenoids, triterpenoids, polyphenolic compounds, phytosterols, and cucurbitacins), which together have been associated with the control and prevention of chronic and infectious diseases, highlighting its antibacterial, anti-cardiovascular/antihypertensive, antiepileptic, anti-inflammatory, hepatoprotective, antiproliferative, and antioxidant activities. The objective of the study was to determine the antigenotoxic potential of two types of fresh chayote juice (filtered (FChJ) and unfiltered (UFChJ)) against DNA damage produced by benzo[a]pyrene (B[a]P) using an in vivo mouse peripheral blood micronucleus assay (MN). The juices were consumed freely for 2 weeks. A negative control, a control group of each juice, a positive batch [B[a]P], and two combined batches (B[a]P plus FChJ or UFChJ) were included. Blood smears were stained and observed under a microscope to quantify the number of micronucleated normochromic erythrocytes (MNNEs). The results indicate: (a) B[a]P increased the frequency of MNNEs and reduced the rate of PEs; and (b) no juice produced toxic effects or induced MN. On the contrary, both juices were genoprotective. However, the most significant effect was presented by UFChJ at the end of the experiment (70%). It is suggested that UFChJ has a greater amount of fiber and/or phytochemicals that favor the therapeutic effect. Possibly, the genoprotection is also related to its antioxidant capacity.
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This chapter describes a step-by-step protocol for rapid serological quantification of global DNA methylation by enzyme-linked immunosorbent assay (ELISA) in plant tissue culture specimens. As a case study model, we used the coconut palm (Cocos nucifera), from which plumules were subjected to somatic embryogenesis followed by embryogenic calli multiplication. DNA methylation is one of the most common epigenetic markers in the regulation of gene expression. DNA methylation is generally associated with non-expressed genes, that is, gene silencing under certain conditions, and the degree of DNA methylation can be used as a marker of various physiological processes, both in plants and in animal cells. Methylation consists of adding a methyl radical to carbon 5 of the DNA cytosine base. Herein, the global DNA methylation was quantified by ELISA with antibodies against methylated cytosines using a commercial kit (Zymo-Research™). The method allowed the detection of methylation in total DNA extracts from coconut palm embryogenic calli (arising from somatic embryogenesis) cultivated in liquid or solid media by using antibodies against methylated cytosines and enzymatic development with a colorimetric substrate. Control samples of commercially provided Escherichia coli bacterial DNA with previously known methylation percentages were included in the ELISA test to construct an experimental methylation standard curve. The logarithmic regression of this E. coli standard curve allowed methylation quantification in coconut palm samples. The present ELISA methodology, applied to coconut palm tissue culture specimens, is promising for use in other plant species and botanical families. This chapter is presented in a suitable format for use as a step-by-step laboratory procedure manual, with theoretical introduction information, which makes it easy to apply the protocol in samples of any biological nature to evaluate DNA global methylation associated with any physiological process.
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Metilação de DNA , Ensaio de Imunoadsorção Enzimática , Epigênese Genética , Ensaio de Imunoadsorção Enzimática/métodos , DNA de Plantas/genética , Cocos/genética , Técnicas de Cultura de Tecidos/métodos , Técnicas de Embriogênese Somática de Plantas/métodosRESUMO
Biofilms are known to be critical for Legionella settlement in engineered water systems and are often associated with Legionnaire's Disease events. One of the key features of biofilms is their heterogeneous three-dimensional structure which supports the establishment of microbial interactions and confers protection to microorganisms. This work addresses the impact of Legionella pneumophila colonization of a Pseudomonas fluorescens biofilm, as information about the interactions between Legionella and biofilm structures is scarce. It combines a set of meso- and microscale biofilm analyses (Optical Coherence Tomography, Episcopic Differential Interference Contrast coupled with Epifluorescence Microscopy and Confocal Laser Scanning Microscopy) with PNA-FISH labelled L. pneumophila to tackle the following questions: (a) does the biofilm structure change upon L. pneumophila biofilm colonization?; (b) what happens to L. pneumophila within the biofilm over time and (c) where is L. pneumophila preferentially located within the biofilm? Results showed that P. fluorescens structure did not significantly change upon L. pneumophila colonization, indicating the competitive advantage of the first colonizer. Imaging of PNA-labelled L. pneumophila showed that compared to standard culture recovery it colonized to a greater extent the 3-day-old P. fluorescens biofilms, presumably entering in VBNC state by the end of the experiment. L. pneumophila was mostly located in the bottom regions of the biofilm, which is consistent with the physiological requirements of both bacteria and confers enhanced Legionella protection against external aggressions. The present study provides an expedited methodological approach to address specific systematic laboratory studies concerning the interactions between L. pneumophila and biofilm structure that can provide, in the future, insights for public health Legionella management of water systems.
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Biofilmes , Legionella pneumophila , Pseudomonas fluorescens , Biofilmes/crescimento & desenvolvimento , Legionella pneumophila/fisiologia , Pseudomonas fluorescens/fisiologia , Legionella/fisiologia , Microscopia Confocal , Tomografia de Coerência ÓpticaRESUMO
In nature, bacteria often survive in a stationary state with low metabolic activity. Phages use the metabolic machinery of the host cell to replicate, and, therefore, their efficacy against non-dividing cells is usually limited. Nevertheless, it was previously shown that the Staphylococcus epidermidis phage SEP1 has the remarkable capacity to actively replicate in stationary-phase cells, reducing their numbers. Here, we studied for the first time the transcriptomic profiles of both exponential and stationary cells infected with SEP1 phage using RNA-seq to gain a better understanding of this rare phenomenon. We showed that SEP1 successfully takes over the transcriptional apparatus of both exponential and stationary cells. Infection was, however, delayed in stationary cells, with genes within the gp142-gp154 module putatively implicated in host takeover. S. epidermidis responded to SEP1 infection by upregulating three genes involved in a DNA modification system, with this being observed already 5 min after infection in exponential cells and later in stationary cells. In stationary cells, a significant number of genes involved in translation and RNA metabolic and biosynthetic processes were upregulated after 15 and 30 min of SEP1 infection in comparison with the uninfected control, showing that SEP1 activates metabolic and biosynthetic pathways necessary to its successful replication.IMPORTANCEMost phage-host interaction studies are performed with exponentially growing cells. However, this cell state is not representative of what happens in natural environments. Additionally, most phages fail to replicate in stationary cells. The Staphylococcus epidermidis phage SEP1 is one of the few phages reported to date to be able to infect stationary cells. Here, we unveiled the interaction of SEP1 with its host in both exponential and stationary states of growth at the transcriptomic level. The findings of this study provide valuable insights for a better implementation of phage therapy since phages able to infect stationary cells could be more efficient in the treatment of recalcitrant infections.
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Fagos de Staphylococcus , Staphylococcus epidermidis , Staphylococcus epidermidis/virologia , Staphylococcus epidermidis/metabolismo , Staphylococcus epidermidis/genética , Fagos de Staphylococcus/genética , Fagos de Staphylococcus/metabolismo , Replicação Viral , Transcriptoma , Regulação Bacteriana da Expressão GênicaRESUMO
Mycoplasmas are atypical bacteria with small genomes that necessitate colonization of their respective animal or plant hosts as obligate parasites, whether as pathogens, or commensals. Some can grow axenically in specialized complex media yet show only host-cell-dependent growth in cell culture, where they can survive chronically and often through interactions involving surface colonization or internalization. To develop a mycoplasma-based system to identify genes mediating such interactions, we exploited genetically tractable strains of the goat pathogen Mycoplasma mycoides (Mmc) with synthetic designer genomes representing the complete natural organism (minus virulence factors; JCVI-syn1.0) or its reduced counterpart (JCVI-syn3B) containing only those genes supporting axenic growth. By measuring growth of surviving organisms, physical association with cultured human cells (HEK-293T, HeLa), and induction of phagocytosis by human myeloid cells (dHL-60), we determined that JCVI-syn1.0 contained a set of eight genes (MMSYN1-0179 to MMSYN1-0186, dispensable for axenic growth) conferring survival, attachment, and phagocytosis phenotypes. JCVI-syn3B lacked these phenotypes, but insertion of these genes restored cell attachment and phagocytosis, although not survival. These results indicate that JCVI-syn3B may be a powerful living platform to analyze the role of specific gene sets, from any organism, on the interaction with diverse mammalian cells in culture.
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Mycoplasma mycoides , Mycoplasma , Animais , Humanos , Mycoplasma/genética , Mycoplasma mycoides/genética , Células HeLa , MamíferosRESUMO
Inflammation is the immune system's first biological response to infection, injury, or irritation. Evidence suggests that the anti-inflammatory effect is mediated by the regulation of various inflammatory cytokines, such as nitric oxide, interleukins, tumor necrosis factor alpha-α, interferon gamma-γ, as well as the non-cytokine mediator, prostaglandin E2. Currently, the mechanism of action and clinical usefulness of phytochemicals is known; their action on the activity of cytokines, free radicals, and oxidative stress. The latter are of great relevance in the development of diseases, such that the evidence collected demonstrates the beneficial effects of phytochemicals in maintaining health. Epidemiological evidence indicates that regular consumption of fruits and vegetables is related to a low risk of developing cancer and other chronic diseases.
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Industrial biocides aim to keep water systems microbiologically controlled and to minimize biofouling. However, the resulting dead cells are usually not removed from the water streams and can influence the growth of the remaining live cells in planktonic and sessile states. This study aims to understand the effect of dead Pseudomonas fluorescens cells killed by industrial biocides-benzalkonium chloride (BAC) and 2,2-dibromo-3-nitrilopropionamide (DBNPA)-on biofilm formation. Additionally, the effect of different dead/live cell ratios (50.00% and 99.99%) was studied. The inoculum was recirculated in a Parallel Plate Flow Cell (PPFC). The overall results indicate that dead cells greatly affect biofilm properties. Inoculum with DBNPA-dead cells led to more active (higher ATP content and metabolic activity) and thicker biofilm layers in comparison to BAC-dead cells, which seems to be linked to the mechanism of action by which the cells were killed. Furthermore, higher dead cell ratios (99.99%) in the inoculum led to more active (higher culturability, metabolic activity and ATP content) and cohesive/compact and uniformly distributed biofilms in comparison with the 50.00% dead cell ratio. The design of future disinfection strategies must consider the contribution of dead cells to the biofilm build-up, as they might negatively affect water system operations.
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MOTIVATION: BISCAP is a state-of-the-art tool for automatically characterizing biofilm images obtained from Optical Coherence Tomography. Limited availability of other software tools is reported in the field. BISCAP's first version processes 2D images only. Processing 3D images is a problem of greater scientific relevance since it deals with the entire structure of biofilms instead of their 2D slices. RESULTS: Building on the image-processing principles and algorithms proposed earlier for 2D images, these were adapted to the 3D case, and a more general implementation of BISCAP was developed. The primary goal concerns the extension of the initial methodology to incorporate the depth axis in 3D images; multiple improvements were also made to boost computational performance. The calculation of structural properties and visual outputs was extended to offer new insights into the 3D structure of biofilms. BISCAP was tested using 3D images of biofilms with different morphologies, consistently delivering accurate characterizations of 3D structures in a few minutes using standard laptop machines. Low user dependency is required for image analysis. AVAILABILITY AND IMPLEMENTATION: BISCAP is available from https://github.com/diogonarciso/BISCAP. All images used in the tutorials and the validation examples are available from https://web.fe.up.pt/â¼fgm/biscap3d.
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Processamento de Imagem Assistida por Computador , Tomografia de Coerência Óptica , Tomografia de Coerência Óptica/métodos , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Software , Algoritmos , BiofilmesRESUMO
Phage-host interactions are commonly evaluated by culture-based methods. However, these techniques are very laborious and time-consuming. Therefore, other time-efficient, not labor-intensive, and cost-effective methods have been developed.This chapter describes the methodology used to assess the susceptibility of planktonic cultures of bacteria to phage infection and to study their interactions over time by flow cytometry.
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Bacteriófagos , Citometria de Fluxo/métodos , Bactérias , PlânctonRESUMO
Introducción: A partir del Boston Carpal Tunnel Questionnaire, se desarrolló una escala corta de 6 ítems llamada Six-Item Car-pal Tunnel Symptoms Scale (CTS-6). Objetivo: Evaluar la CTS-6 para detectar pacientes con neuropatía periférica del nervio mediano con criterio quirúrgico. materiales y métodos: Se realizó un estudio descriptivo prospectivo observacional en un grupo de pacientes con diagnóstico clínico de síndrome del túnel carpiano. Se utilizó la CTS-6, y se corroboró el diagnóstico mediante electromiografía. Posteriormente, los pacientes fueron operados. Se analizaron las diferencias en el puntaje de la CTS-6 entre los distintos niveles de gravedad determinados por electromiografía. Resultados: Se analizaron 106 pacientes. El 20,75% tenía síndrome del túnel carpiano bilateral. Se evaluaron 126 manos. La mediana del puntaje de la CTS-6 fue de 21 (mín. 16,5; máx. 26). Según los resultados de la electromiografía, el 24,22% de los casos de síndrome del túnel carpiano eran graves. Al comparar el puntaje de la CTS-6 según la gravedad del síndrome del túnel carpiano evaluada por electromiografía, la mediana del puntaje de la CTS-6 fue de 16,5 en los casos leves, de 21 en los casos moderados y de 26 en los casos graves. Conclusiones: El puntaje de la CTS-6 fue mayor en los pacientes con síndrome del túnel carpiano grave según la electromiografía. Esto plantea la hipótesis de que podría ser útil como herramienta diagnóstica no invasiva en el síndrome del túnel carpiano para definir pacientes que se beneficien con el tratamiento quirúrgico. Nivel de Evidencia: IV
Introduction: The Six-Item Carpal Tunnel Symptoms Scale (CTS-6) is a a short 6-item scale based on the Boston Carpal Tunnel Questionnaire (BCTQ). Objective: To evaluate the CTS-6 to identify patients with peripheral neuropathy of the median nerve us-ing surgical criteria. materials and methods: A prospective descriptive observational study was conducted on a group of patients diagnosed with carpal tunnel syndrome. The CTS-6 was employed, and the diagnosis was confirmed with electromyography. The patients then underwent surgery. The differences in the CTS-6 score between the various severity levels measured by electro-myography were examined. Results: 106 patients were analyzed and a total of 126 hands were evaluated. 20.75% had bilateral carpal tunnel syndrome. The median CTS-6 score was 21 (min. 16.5; max. 26). According to electromyography results, 24.22% of CTS cases were severe. When comparing the CTS-6 score according to the severity of carpal tunnel syndrome assessed by electromyography, the median CTS-6 score was 16.5 in mild cases, 21 in moderate cases, and 26 in severe cases. Conclusions: Electromyography revealed a higher CTS-6 score in patients with severe carpal tunnel syndrome. This raises the possibility that it could be used as a noninvasive diagnostic tool in carpal tunnel syndrome to determine which patients would benefit from surgical therapy. Level of Evidence: IV
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Adulto , Medição da Dor , Síndrome do Túnel Carpal/diagnóstico , EletromiografiaRESUMO
This work studies the antimicrobial activity of benzyldimethyldodecyl ammonium chloride (BDMDAC)-coated microparticles with distinct morphological structures. Functionalized microparticles were prepared by the layer-by-layer (LbL) self-assembly technique on hydroxyapatite (Hap), calcium carbonate (CaCO3) and glass beads (GB) cores. All particles were characterized, before and after functionalization, by Fourier-Transform Infrared Spectroscopy (FTIR), Brunner-Emmett-Teller (BET) and Scanning Electron Microscopy (SEM) analyses. Antimicrobial activity was tested against planktonic Pseudomonas fluorescens. Planktonic bacteria were exposed to 100 mg/L, 200 mg/L and 400 mg/L of BDMDAC-coated microparticles for 240 min. This strategy promoted a complete bacteria reduction at 200 mg/L for Hap microparticles after 240 min. No release of biocide was detected through HPLC analyses during 2 weeks, suggesting that bacteria inactivation may be attributed to a contact killing mechanism.
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Introduction: The distribution of freshwater fishes in the Colombian Andes results from the interaction between historical and recent factors. Currently, the Andean landscape is facing rapid transformation processes. However, the knowledge regarding species distribution and environmental requirements is advancing slower than the transformations underway in the fluvial networks. Objective: To understand the conformation of the fish assemblage in the middle and lower Cauca River basin, considering the local environmental context before the construction of the Ituango Dam, and quantifying β diversity and its two components (turnover and nestedness) amongst local fish communities. Methods: 58 localities were monitored during nine years (between February 2010 and November 2018), the period before the dam's operation. The species richness (α-diversity), species turnover (β-diversity), and assemblage composition were estimated for the given localities. Results: 114 species were recorded, representing ~ 49 % of the total richness of known species for the Magdalena basin. The richness distribution showed that the number of species varies among the aquatic environments. Swamps presented the most significant number of species, followed by the Cauca River, while streams had the lowest values of richness. The spatial analyses of β-diversity revealed a high variation component in the study area due to species replacement between the aquatic environments. Conclusions: The implementation of long-term monitoring allowed us to recognize that the Cauca River basin conserves a great variety of species-rich environments. The species turnover indicates a high proportion of endemism or multiple sites with unique species. Finally, our study will serve as a baseline to verify, over time, whether the dam's construction is associated with essential changes in the structure of fish communities.
Introducción: La distribución de los peces de agua dulce en los Andes colombianos es el resultado de la interacción entre factores históricos y recientes. Actualmente, el paisaje Andino enfrenta procesos de rápida transformación. Sin embargo, el conocimiento sobre la distribución de las especies y sus requerimientos ambientales no avanza tan rápido como las transformaciones en curso en las redes fluviales. Objetivo: Comprender la conformación del ensamble de peces en la cuenca media y baja del río Cauca, considerando el contexto ambiental local antes de la construcción de la represa de Ituango, y cuantificar la diversidad beta y sus dos componentes (recambio y anidamiento) entre las comunidades de peces locales. Métodos: Se analizaron 58 localidades durante nueve años (entre febrero 2010 y noviembre 2018), período previo a la operación de la represa. La riqueza de especies (diversidad α), el recambio de especies (diversidad β) y la composición del conjunto se estimaron para las localidades dadas. Resultados: Se registraron 114 especies, que representan ~ 49 % de la riqueza total de especies conocidas para la cuenca del Magdalena. La distribución de la riqueza mostró que el número de especies varía entre los ambientes acuáticos. Las ciénagas presentaron el mayor número de especies, seguidas por el río Cauca, mientras que las quebradas presentaron los valores más bajos de riqueza. Los análisis espaciales de la diversidad β revelaron un alto componente de variación en el área de estudio debido al reemplazo de especies entre los ambientes acuáticos. Conclusiones: La implementación del monitoreo a largo plazo permitió reconocer que la cuenca del río Cauca conserva una gran variedad de ambientes ricos en especies. El recambio de especies indica una alta proporción de endemismo o múltiples sitios con especies únicas. Finalmente, nuestro estudio servirá como línea base para verificar, con el tiempo, si la construcción de la represa está asociada con cambios esenciales en la estructura de las comunidades de peces.
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Chronic wound management is extremely challenging because of the persistence of biofilm-forming pathogens, such as Pseudomonas aeruginosa and Staphylococcus aureus, which are the prevailing bacterial species that co-infect chronic wounds. Phage therapy has gained an increased interest to treat biofilm-associated infections, namely when combined with antibiotics. Here, we tested the effect of gentamicin as a co-adjuvant of phages in a dual species-biofilm wound model formed on artificial dermis. The biofilm-killing capacity of the tested treatments was significantly increased when phages were combined with gentamicin and applied multiple times as multiple dose (three doses, every 8 h). Our results suggest that gentamycin is an effective adjuvant of phage therapy particularly when applied simultaneously with phages and in three consecutive doses. The multiple and simultaneous dose treatment seems to be essential to avoid bacterial resistance development to each of the antimicrobial agents.
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Staphylococcus aureus is one of the most relevant mastitis pathogens in dairy cattle, and the acquisition of antimicrobial resistance genes presents a significant health issue in both veterinary and human fields. Among the different strategies to tackle S. aureus infection in livestock, bacteriophages have been thoroughly investigated in the last decades; however, few specimens of the so-called jumbo phages capable of infecting S. aureus have been described. Herein, we report the biological, genomic, and structural proteomic features of the jumbo phage vB_SauM-UFV_DC4 (DC4). DC4 exhibited a remarkable killing activity against S. aureus isolated from the veterinary environment and stability at alkaline conditions (pH 4 to 12). The complete genome of DC4 is 263,185 bp (GC content: 25%), encodes 263 predicted CDSs (80% without an assigned function), 1 tRNA (Phe-tRNA), multisubunit RNA polymerase, and an RNA-dependent DNA polymerase. Moreover, comparative analysis revealed that DC4 can be considered a new viral species belonging to a new genus DC4 and showed a similar set of lytic proteins and depolymerase activity with closely related jumbo phages. The characterization of a new S. aureus jumbo phage increases our understanding of the diversity of this group and provides insights into the biotechnological potential of these viruses. KEY POINTS: ⢠vB_SauM-UFV_DC4 is a new viral species belonging to a new genus within the class Caudoviricetes. ⢠vB_SauM-UFV_DC4 carries a set of RNA polymerase subunits and an RNA-directed DNA polymerase. ⢠vB_SauM-UFV_DC4 and closely related jumbo phages showed a similar set of lytic proteins.
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Bacteriófagos , Fagos de Staphylococcus , Animais , Bovinos , Feminino , Humanos , Fagos de Staphylococcus/genética , Staphylococcus aureus/genética , Proteômica , Genoma Viral , Genômica , Bacteriófagos/genética , RNA Polimerases Dirigidas por DNA/genética , RNA de TransferênciaRESUMO
Proteus mirabilis is an opportunistic pathogen and is responsible for more than 40% of all cases of catheter-associated urinary tract infections (CAUTIs). Healthcare-associated infections have been aggravated by the constant emergence of antibiotic-resistant bacterial strains. Because of this, the use of phages to combat bacterial infections gained renewed interest. In this study, we describe the biological and genomic features of two P. mirabilis phages, named BigMira and MidiMira. These phages belong to the Acadevirus genus (family Autographiviridae). BigMira and MidiMira are highly similar, differing only in four missense mutations in their phage tail fiber. These mutations are sufficient to impact the phages' depolymerase activity. Subsequently, the comparative genomic analysis of ten clinical P. mirabilis strains revealed differences in their antibiotic resistance profiles and lipopolysaccharide locus, with the latter potentially explaining the host range data of the phages. The massive presence of antimicrobial resistance genes, especially in the phages' isolation strain P. mirabilis MCS, highlights the challenges in treating infections caused by multidrug-resistant bacteria. The findings reinforce BigMira and MidiMira phages as candidates for phage therapy purposes.
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Antimicrobial resistance (AMR) is considered one of the greatest threats to global health. Methicillin-resistant Staphylococcus aureus (MRSA) remains at the core of this threat, accounting for about 90% of S. aureus infections widespread in the community and hospital settings. In recent years, the use of nanoparticles (NPs) has emerged as a promising strategy to treat MRSA infections. NPs can act directly as antibacterial agents via antibiotic-independent activity and/or serve as drug delivery systems (DDSs), releasing loaded antibiotics. Nonetheless, directing NPs to the infection site is fundamental for effective MRSA treatment so that highly concentrated therapeutic agents are delivered to the infection site while directly reducing the toxicity to healthy human cells. This leads to decreased AMR emergence and less disturbance of the individual's healthy microbiota. Hence, this review compiles and discusses the scientific evidence related to targeted NPs developed for MRSA treatment.
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Staphylococcus aureus Resistente à Meticilina , Nanopartículas , Infecções Estafilocócicas , Humanos , Staphylococcus aureus , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Sistemas de Liberação de Medicamentos , Testes de Sensibilidade Microbiana , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologiaRESUMO
Innovative point-of-care (PoC) diagnostic platforms are desirable to surpass the deficiencies of conventional laboratory diagnostic methods for bacterial infections and to tackle the growing antimicrobial resistance crisis. In this study, a workflow was implemented, comprising the identification of new aptamers with high affinity for the ubiquitous surface protein A2 (UspA2) of the bacterial pathogen Moraxella catarrhalis and the development of an electrochemical biosensor functionalized with the best-performing aptamer as a bioreceptor to detect UspA2. After cell-systematic evolution of ligands by exponential enrichment (cell-SELEX) was performed, next-generation sequencing was used to sequence the final aptamer pool. The most frequent aptamer sequences were further evaluated using bioinformatic tools. The two most promising aptamer candidates, Apt1 and Apt1_RC (Apt1 reverse complement), had Kd values of 214.4 and 3.4 nM, respectively. Finally, a simple and label-free electrochemical biosensor was functionalized with Apt1_RC. The aptasensor surface modifications were confirmed by impedance spectroscopy and cyclic voltammetry. The ability to detect UspA2 was evaluated by square wave voltammetry, exhibiting a linear detection range of 4.0 × 104-7.0 × 107 CFU mL-1, a square correlation coefficient superior to 0.99 and a limit of detection of 4.0 × 104 CFU mL-1 at pH 5.0. The workflow described has the potential to be part of a sensitive PoC diagnostic platform to detect and quantify M. catarrhalis from biological samples.
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OBJECTIVE: To analyze the spatiotemporal distribution of homicide mortality and association with social determinants of health in the Northeast Region of Brazil. METHODS: Ecological study with spatiotemporal modeling of homicide deaths between 2000 and 2019. Temporal trends were analyzed by segmented linear regression. Crude mortality was calculated and adjusted by smoothing the local empirical Bayesian method and analyzed by the Global/Local Moran Index and spatiotemporal scan statistics. The association between social determinants of health and homicide mortality was performed using multiple linear regression and autoregressive spatial models. RESULTS: 353,089 deaths were recorded. Mortality increased from 2000 to 2019, with an annual increase of 4.37 in males and 3.57 in females. High risk spatial and spatiotemporal clusters were identified in the coastal region of the states. The spatial regression model showed an association with socioeconomic inequalities. CONCLUSIONS: High risk areas for homicides associated with socioeconomic inequality, which should be considered as a priority for designing and investing in public health policies were investigated.
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Homicídio , Masculino , Feminino , Humanos , Fatores Socioeconômicos , Brasil/epidemiologia , Teorema de Bayes , Análise MultivariadaRESUMO
The association of Helicobacter pylori to several gastric diseases, such as chronic gastritis, peptic ulcer disease, and gastric cancer, and its high prevalence worldwide, raised the necessity to use methods for a proper and fast diagnosis and monitoring the pathogen eradication. Available diagnostic methods can be classified as invasive or non-invasive, and the selection of the best relies on the clinical condition of the patient, as well as on the sensitivity, specificity, and accessibility of the diagnostic test. This review summarises all diagnostic methods currently available, including the invasive methods: endoscopy, histology, culture, and molecular methods, and the rapid urease test (RUT), as well as the non-invasive methods urea breath test (UBT), serological assays, biosensors, and microfluidic devices and the stool antigen test (SAT). Moreover, it lists the diagnostic advantages and limitations, as well as the main advances for each methodology. In the end, research on the development of new diagnostic methods, such as bacteriophage-based H. pylori diagnostic tools, is also discussed.