Phytochemicals and Their Usefulness in the Maintenance of Health.

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.

Minimal Bacterial Cell JCVI-syn3B as a Chassis to Investigate Interactions between Bacteria and Mammalian Cells.

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.

Influence of Dead Cells Killed by Industrial Biocides (BAC and DBNPA) on Biofilm Formation.

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.

3D Optical Coherence Tomography image processing in BISCAP: characterization of biofilm structure and properties.

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/∼fgm/biscap3d.

Phage-Host Interaction Analysis Using Flow Cytometry.

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.

Microparticles as BDMDAC (Quaternary Ammonium Compound) Carriers for Water Disinfection: A Layer-by-Layer Approach without Biocide Release.

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.

Distribution of diversity of fishes in an Andean fluvial network

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.

Combining phages and antibiotic to enhance antibiofilm efficacy against an in vitro dual species wound biofilm.

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.

Genomic and proteomic characterization of vB_SauM-UFV_DC4, a novel Staphylococcus jumbo phage.

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.

Isolation and Characterization of the Acadevirus Members BigMira and MidiMira Infecting a Highly Pathogenic Proteus mirabilis Strain.

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.

Fighting Methicillin-Resistant Staphylococcus aureus with Targeted Nanoparticles.

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.

Spatial modeling of homicide mortality in the Northeast region of Brazil.

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.

Aptasensor for the Detection of Moraxella catarrhalis Adhesin UspA2.

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.

Advances on diagnosis of Helicobacter pylori infections.

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.

Spatial modeling of homicide mortality in the Northeast region of Brazil / Modelado espacial de la mortalidad por homicidios en la Región Noreste de Brasil / Modelagem espacial da mortalidade por homicídios na Região Nordeste do Brasil

ABSTRACT 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.

RESUMEN Objetivo: Analizar distribución espaciotemporal de mortalidad por homicidios y relación con determinantes sociales de salud en el Noreste brasileño. Métodos: Estudio ecológico con modelado espaciotemporal de óbitos por homicidios entre 2000 y 2019. Las tendencias temporales fueron analizadas por regresión lineal segmentada. La mortalidad brutal fue calculada y acordada por moderación del método bayesiano empírico local y analizadas por Índice de Moran Global/Local y estadística de barrido espaciotemporal. La relación entre determinantes sociales de salud y mortalidad por homicidios fue realizada mediante la regresión lineal múltiple y modelos espaciales autorregresivos. Resultados: Fueron registrados 353.089 óbitos. La mortalidad aumentó de 2000 para 2019, con un incremento anual de 4,37 en el sexo masculino y 3,57 y en el femenino. Aglomeraciones espaciales y espaciotemporales de alto riesgo fueron identificadas en la región costera de los estados. El modelo de regresión espacial demostró relación con las desigualdades socioeconómicas. Conclusiones: Identificamos áreas de alto riesgo para homicídios relacionadas con la desigualdad socioeconómica, debiendo ser consideradas como prioridad para el delineamiento e inversión en políticas públicas en salud.

RESUMO Objetivo: Analisar a distribuição espaçotemporal da mortalidade por homicídios e associação com determinantes sociais da saúde na Região Nordeste do Brasil. Métodos: Estudo ecológico com modelagem espaço temporal dos óbitos por homicídios entre 2000 e 2019. As tendências temporais foram analisadas por regressão linear segmentada. A mortalidade bruta foi calculada e ajustada pela suavização do método bayesiano empírico local e analisadas pelo Índice de Moran Global/Local e estatística de varredura espaço temporal. A associação entre os determinantes sociais da saúde e a mortalidade por homicídios foi realizada por meio da regressão linear múltipla e modelos espaciais autorregressivos. Resultados: Foram registrados 353.089 óbitos. A mortalidade aumentou de 2000 para 2019, com um acréscimo anual de 4,37 no sexo masculino e 3,57 no feminino. Aglomerações espaciais e espaçotemporais de alto risco foram identificadas na região costeira dos estados. O modelo de regressão espacial demonstrou associação com as desigualdades socioeconômicas. Conclusões: Identificamos áreas de alto risco para homicídios associadas com a desigualdade socioeconômica, devendo ser consideradas como prioridade para o delineamento e investimento em políticas públicas em saúde.

O que mudou entre os períodos de pico e de platô durante a primeira onda do SARS-CoV-2? Estudo multicêntrico português em unidades de cuidados intensivos / What changed between the peak and plateau periods of the first COVID-19 pandemic wave? A multicentric Portuguese cohort study in intensive care

RESUMO Objetivo: Analisar e comparar as características de pacientes críticos com a COVID-19, a abordagem clínica e os resultados entre os períodos de pico e de platô na primeira onda pandêmica em Portugal. Métodos: Este foi um estudo de coorte multicêntrico ambispectivo, que incluiu pacientes consecutivos com a forma grave da COVID-19 entre março e agosto de 2020 de 16 unidades de terapia intensiva portuguesas. Definiram-se as semanas 10 - 16 e 17 - 34 como os períodos de pico e platô. Resultados: Incluíram-se 541 pacientes adultos com mediana de idade de 65 [57 - 74] anos, a maioria do sexo masculino (71,2%). Não houve diferenças significativas na mediana de idade (p = 0,3), no Simplified Acute Physiology Score II (40 versus 39; p = 0,8), na pressão parcial de oxigênio/fração inspirada de oxigênio (139 versus 136; p = 0,6), na terapia com antibióticos na admissão (57% versus 64%; p = 0,2) ou na mortalidade aos 28 dias (24,4% versus 22,8%; p = 0,7) entre o período de pico e platô. Durante o período de pico, os pacientes tiveram menos comorbidades (1 [0 - 3] versus 2 [0 - 5]; p = 0,002); fizeram mais uso de vasopressores (47% versus 36%; p < 0,001) e ventilação mecânica invasiva na admissão (58,1% versus 49,2%; p < 0,001), e tiveram mais prescrição de hidroxicloroquina (59% versus 10%; p < 0,001), lopinavir/ritonavir (41% versus 10%; p < 0,001) e posição prona (45% versus 36%; p = 0,04). Entretanto, durante o platô, observou-se maior uso de cânulas nasais de alto fluxo (5% versus 16%; p < 0,001) na admissão, remdesivir (0,3% versus 15%; p < 0,001) e corticosteroides (29% versus 52%; p < 0,001), além de menor tempo de internação na unidade de terapia intensiva (12 versus 8 dias; p < 0,001). Conclusão: Houve mudanças significativas nas comorbidades dos pacientes, nos tratamentos da unidade de terapia intensiva e no tempo de internação entre os períodos de pico e platô na primeira onda da COVID-19.

ABSTRACT Objective: To analyze and compare COVID-19 patient characteristics, clinical management and outcomes between the peak and plateau periods of the first pandemic wave in Portugal. Methods: This was a multicentric ambispective cohort study including consecutive severe COVID-19 patients between March and August 2020 from 16 Portuguese intensive care units. The peak and plateau periods, respectively, weeks 10 - 16 and 17 - 34, were defined. Results: Five hundred forty-one adult patients with a median age of 65 [57 - 74] years, mostly male (71.2%), were included. There were no significant differences in median age (p = 0.3), Simplified Acute Physiology Score II (40 versus 39; p = 0.8), partial arterial oxygen pressure/fraction of inspired oxygen ratio (139 versus 136; p = 0.6), antibiotic therapy (57% versus 64%; p = 0.2) at admission, or 28-day mortality (24.4% versus 22.8%; p = 0.7) between the peak and plateau periods. During the peak period, patients had fewer comorbidities (1 [0 - 3] versus 2 [0 - 5]; p = 0.002) and presented a higher use of vasopressors (47% versus 36%; p < 0.001) and invasive mechanical ventilation (58.1 versus 49.2%; p < 0.001) at admission, prone positioning (45% versus 36%; p = 0.04), and hydroxychloroquine (59% versus 10%; p < 0.001) and lopinavir/ritonavir (41% versus 10%; p < 0.001) prescriptions. However, a greater use of high-flow nasal cannulas (5% versus 16%, p < 0.001) on admission, remdesivir (0.3% versus 15%; p < 0.001) and corticosteroid (29% versus 52%, p < 0.001) therapy, and a shorter ICU length of stay (12 days versus 8, p < 0.001) were observed during the plateau. Conclusion: There were significant changes in patient comorbidities, intensive care unit therapies and length of stay between the peak and plateau periods of the first COVID-19 wave.

Development of a Nanostructured Electrochemical Genosensor for the Detection of the K-ras Gene.

In the scientific literature, it has been documented that electrochemical genosensors are novel analytical tools with proven clinical diagnostic potential for the identification of carcinogenic processes due to genetic and epigenetic alterations, as well as infectious diseases due to viruses or bacteria. In the present work, we describe the construction of an electrochemical genosensor for the identification of the k12p.1 mutation; it was based on use of Screen-Printed Gold Electrode (SPGE), Cyclic Voltammetry (CV), and Atomic Force Microscopy (AFM), for the monitoring the electron transfer trough the functionalized nanostructured surface and corresponding morphological changes. The sensitivity of the genosensor showed a linear response for the identification of the k12p.1 mutation of the K-ras gene in the concentration range of 10 fM to 1 µM with a detection limit of 7.96 fM in the presence of doxorubicin (Dox) as DNA intercalating agent and indicator of the hybridization reaction. Thus, the electrochemical genosensor developed could be useful for the identification of diseases related with the K-ras oncogene.

Analysis of intact prophages in genomes of Paenibacillus larvae: An important pathogen for bees.

Paenibacillus larvae is the etiological agent of American Foulbrood (AFB), a highly contagious and worldwide spread bacterial disease that affects honeybee brood. In this study, all complete P. larvae genomes available on the NCBI database were analyzed in order to detect presence of prophages using the PHASTER software. A total of 55 intact prophages were identified in 11 P. larvae genomes (5.0 ± 2.3 per genome) and were further investigated for the presence of genes encoding relevant traits related to P. larvae. A closer look at the prophage genomes revealed the presence of several putative genes such as metabolic and antimicrobial resistance genes, toxins or bacteriocins, potentially influencing host performance. Some of the coding DNA sequences (CDS) were present in all ERIC-genotypes, while others were only found in a specific genotype. While CDS encoding toxins and antitoxins such as HicB and MazE were found in prophages of all bacterial genotypes, others, from the same category, were provided by prophages particularly to ERIC I (enhancin-like toxin), ERIC II (antitoxin SocA) and ERIC V strains (subunit of Panton-Valentine leukocidin system (PVL) LukF-PV). This is the first in-depth analysis of P. larvae prophages. It provides better knowledge on their impact in the evolution of virulence and fitness of P. larvae, by discovering new features assigned by the viruses.

Pseudomonas fluorescens Cells' Recovery after Exposure to BAC and DBNPA Biocides.

A proper assessment of the effects of biocides on bacterial cells is key to the prevention of antimicrobial resistance and the implementation of suitable biocidal programmes. It is particularly relevant regarding the ability of dead-labelled cells to recover their functional processes once the biocide is removed. In the present work, we studied how Pseudomonas fluorescens cells previously exposed to different concentrations of BAC (benzalkonium chloride) and DBNPA (2,2-Dibromo-3-nitrilopropionamide) behave upon the restoration of optimum growth conditions. The following indicators were evaluated: culturability, membrane integrity, metabolic activity (resazurin), cellular energy (ATP), and cell structure and morphology (transmission electron microscopy (TEM)). The results demonstrated that cells previously labelled as 'dead' recovered to a greater extent in all indicators. Only cells previously exposed to BAC at 160 mg/L (concentration above the MBC) showed significant reductions on all the evaluated indicators. However, the obtained values were much higher than the 'death' thresholds found for the autoclaved cells. This suggests that cells exposed to this concentration take more time to rebuild their functional processes. The recovery of DBNPA-treated cells did not seem to be related to the biocide concentration. Finally, a reflection on what kind of cells were able to recover (remaining cells below the detection limit and/or dormant cells) is also presented.