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Vibrios, a group of bacteria that are among the most abundant in marine environments, include several species such as Vibrio cholerae and Vibrio parahaemolyticus, which can be pathogenic to humans. Some species of Vibrio contain prophages within their genomes. These prophages can carry genes that code for toxins, such as the zonula occludens toxin (Zot), which contribute to bacterial virulence. Understanding the association between different Vibrio species, prophages and Zot genes can provide insights into their ecological interactions. In this study, we evaluated 4619 Vibrio genomes from 127 species to detect the presence of prophages carrying the Zot toxin. We found 2030 potential prophages with zot-like genes in 43 Vibrio species, showing a non-random association within a primarily modular interaction network. Some prophages, such as CTX or Vf33, were associated with specific species. In contrast, prophages phiVCY and VfO3K6 were found in 28 and 20 Vibrio species, respectively. We also identified six clusters of Zot-like sequences in prophages, with the ZOT2 cluster being the most frequent, present in 34 Vibrio species. This analysis helps to understand the distribution patterns of zot-containing prophages across Vibrio genomes and the potential routes of Zot-like toxin dissemination.
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Endotoxinas , Genoma Bacteriano , Prófagos , Vibrio , Proteínas de Bactérias/genética , Filogenia , Prófagos/genética , Vibrio/genética , Vibrio/virologia , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/virologiaRESUMO
Vibrio parahaemolyticus is an important human pathogen that is currently the leading cause of shellfish-borne gastroenteritis in the world. Particularly, the pandemic strain has the capacity to induce cytotoxicity and enterotoxicity through its Type 3 Secretion System (T3SS2) that leads to massive cell death. However, the specific mechanism by which the T3SS2 induces cell death remains unclear and its contribution to mitochondrial stress is not fully understood. In this work, we evaluated the contribution of the T3SS2 of V. parahaemolyticus in generating mitochondrial stress during infection in human intestinal HT-29 cells. To evaluate the contribution of the T3SS2 of V. parahaemolyticus in mitochondrial stress, infection assays were carried out to evaluate mitochondrial transition pore opening, mitochondrial fragmentation, ATP quantification, and cell viability during infection. Our results showed that the Δvscn1 (T3SS2+) mutant strain contributes to generating the sustained opening of the mitochondrial transition pore. Furthermore, it generates perturbations in the ATP production in infected cells, leading to a significant decrease in cell viability and loss of membrane integrity. Our results suggest that the T3SS2 from V. parahaemolyticus plays a role in generating mitochondrial stress that leads to cell death in human intestinal HT-29 cells. It is important to highlight that this study represents the first report indicating the possible role of the V. parahaemolyticus T3SS2 and its effector proteins involvement in generating mitochondrial stress, its impact on the mitochondrial pore, and its effect on ATP production in human cells.
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Vibrio anguillarum is a pathogen for several fish and shellfish species. Its ecology is influenced by diverse factors, including bacteriophages. Here, we identify and characterize a new temperate bacteriophage (Valp1) of V. anguillarum. Valp1 is a myovirus with a 60 nm head and a 90 nm contractile tail. Its double-stranded DNA genome of 42,988 bp contains 68 genes, including a protelomerase gene, typical of telomeric phages. Valp1 inhibits the growth of the virulent strain of V. anguillarum PF4, while the derived lysogenic strain P1.1 presents a slight reduction in its growth but is not affected by the presence of Valp1. Both strains present similar virulence in a larval zebrafish (Danio rerio) model, and only slight differences have been observed in their biochemical profile. Co-culture assays reveal that PF4 and P1.1 can coexist for 10 h in the presence of naturally induced Valp1, with the proportion of PF4 ranging between 28% and 1.6%. By the end of the assay, the phage reached a concentration of ~108 PFU/mL, and all the non-lysogenic PF4 strains were resistant to Valp1. This equilibrium was maintained even after five successive subcultures, suggesting the existence of a coexistence mechanism between the lysogenic and non-lysogenic populations of V. anguillarum in conjunction with the phage Valp1.
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In recent studies, emphasis has been placed on the zonula occludens toxin (Zot) from the non-toxigenic Vibrio parahaemolyticus strain PMC53.7 as an agent inducing alterations in the actin cytoskeleton of infected Caco-2 cells and which appears as a relevant virulence factor. Universal zot primers were designed by the alignment of different types of zot gene and identification of conserved sequences to investigate the presence in diverse environmental and clinical V. parahaemolyticus isolates, in co-occurrence with virulence factors, such a hemolysins and secretion systems. The study screened a total of 390 isolates from environmental sources from Chile and Italy and 95 Chilean clinical isolates. The results revealed that around 37.2% of Chilean environmental strains and 25.9% of Italian strains, and 24.2% of clinical isolates carried the zot gene. The Zot-C2 cluster was present in 71.4% of Chilean environmental strains but absent in clinical isolates, while the Zot-C4 cluster was identified in 28.6% of environmental and 100% of clinical isolates. Understanding the role of zot in V. parahaemolyticus virulence is crucial, especially considering the risk associated with consuming diverse isolates from bivalves and the co-occurrence with virulence factors such as TDH, TRH or T3SS2.
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The gut-brain axis is an essential communication pathway between the central nervous system (CNS) and the gastrointestinal tract. The human microbiota is composed of a diverse and abundant microbial community that compasses more than 100 trillion microorganisms that participate in relevant physiological functions such as host nutrient metabolism, structural integrity, maintenance of the gut mucosal barrier, and immunomodulation. Recent evidence in animal models has been instrumental in demonstrating the possible role of the microbiota in neurodevelopment, neuroinflammation, and behavior. Furthermore, clinical studies suggested that adverse changes in the microbiota can be considered a susceptibility factor for neurological disorders (NDs), such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and amyotrophic lateral sclerosis (ALS). In this review, we will discuss evidence describing the role of gut microbes in health and disease as a relevant risk factor in the pathogenesis of neurodegenerative disorders, including AD, PD, HD, and ALS.
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Doença de Alzheimer , Esclerose Lateral Amiotrófica , Microbioma Gastrointestinal , Doença de Huntington , Doenças Neurodegenerativas , Doença de Parkinson , Animais , Humanos , Eixo Encéfalo-Intestino , Microbioma Gastrointestinal/fisiologia , Doenças Neurodegenerativas/patologia , Sistema Nervoso Central , Doença de Parkinson/patologia , Doença de Huntington/patologiaRESUMO
The bacterial community of the intestinal microbiota influences many host functions, and similar effects have been recently reported for the fungal community (mycobiota). Cobia is a tropical fish that has been studied for its potential in marine aquaculture. However, the study of its bacterial community has been underreported and the mycobiota has not been investigated. We analyzed the gut bacterial and fungal profile present in the intestinal mucosa of reared adult cobias fed two diets (frozen fish pieces (FFPs) and formulated feed (FF)) for 4 months by sequencing the 16S rRNA (V3-V4) and internal transcribed spacer-2 (ITS2) regions using Illumina NovaSeq 6000. No significant differences in the alpha diversity of the bacterial community were observed, which was dominated by the phyla Proteobacteria (~96%) and Firmicutes (~1%). Cobia fed FF showed higher abundance of 10 genera, mainly UCG-002 (Family Oscillospiraceae) and Faecalibacterium, compared to cobia fed FFPs, which showed higher abundance of 7 genera, mainly Methylobacterium-Methylorubrum and Cutibacterium. The inferred bacterial functions were related to metabolism, environmental information processing and cellular processes; and no differences were found between diets. In mycobiota, no differences were observed in the diversity and composition of cobia fed the two diets. The mycobiota was dominated by the phyla Ascomycota (~88%) and Basidiomycota (~11%). This is the first study to describe the gut bacterial and fungal communities in cobia reared under captive conditions and fed on different diets and to identify the genus Ascobulus as a new member of the core fish mycobiota.
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The 2019 coronavirus disease (COVID-19) pandemic has affected different human populations since March 2020 and challenged healthcare systems, especially in chronic non-communicable diseases such as cancer. The present study aimed to evaluate the mortality, risk factors, and symptoms of cancer patients and control subjects, diagnosed with COVID-19 and admitted to intensive care unit (ICU). This retrospective, observational, non-randomized, controlled study of patients admitted to ICU was conducted between March and August 2020 in an Ecuadorian oncology center. Patient information collected from electronic medical records included sociodemographic information, clinical history, symptoms, laboratory test results, COVID-19 treatment, and discharge status. For patients with neoplasia, diagnosis, type, and status of cancer, as well as antineoplastic treatment received over the past month was also recorded. Descriptive statistics and multiple logistic regression were used to analyze the data. Statistical analysis was performed with SPSS (version 22.0) and R (version 4.1.3). In total, 79 adult COVID-19 patients were studied (40 with cancer and 39 controls). The total mean time until COVID-19 symptoms onset was 6.2â ±â 3.5 days (5.3â ±â 3.2 days in the cancer group vs 7.2â ±â 3.6 days in the control group; Pâ =â .016) but no difference was observed in reported symptoms. All patients received an antibiotic treatment, but only 70% of the cancer group had antivirals (Pâ <â .001). Cancer patients had lower hemoglobin levels than controls (10.7â ±â 2.8 vs 13.3â ±â 1.7 g/dL; Pâ <â .001). In terms of mortality, not statistically significance difference was reported between groups. The study showed that high ferritin (Absolute Odds Ratio of 3.9; 95% CI 1.1-14.6) and mechanical ventilation (Absolute Odds Ratio of 4.9; 95% CI 1.3-18.6) were independent COVID-19 mortality risk factors. COVID-19 infection did not represent an increased risk of mortality in cancer patients, but elevated ferritin levels and the need for mechanical ventilation were identified as mortality risk factors.
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COVID-19 , Neoplasias , Adulto , Humanos , COVID-19/epidemiologia , SARS-CoV-2 , Equador/epidemiologia , Estudos Retrospectivos , Tratamento Farmacológico da COVID-19 , Respiração Artificial , Neoplasias/epidemiologia , Fatores de Risco , FerritinasRESUMO
Introducción: Las enfermedades reumáticas se caracterizan por la presencia de manifestaciones articulares y extraarticulares. Entre estas últimas, uno de los sistemas menos estudiados es el reproductor. Objetivo: Caracterizar las manifestaciones ginecológicas que con mayor frecuencia se presentan en el curso de las enfermedades reumáticas. Métodos: Se realizó una investigación básica, no experimental, descriptiva y longitudinal que incluyó un total de 117 pacientes femeninas con diagnóstico de varias enfermedades reumáticas según los criterios del Colegio Americano de Reumatología. La muestra quedó conformada por 108 pacientes. Durante la realización del estudio se identificó la incidencia de manifestaciones ginecológicas en las pacientes reumáticas y el tipo de manifestación que se notifica con mayor frecuencia. Resultados: Pacientes con un promedio de edad de 61,19 años, predominio de procedencia urbana (61,11 por ciento) y con diagnóstico de artritis reumatoide (61,11 por ciento). El 39,81 por ciento de ellas refirió tiempo de evolución de la enfermedad entre 3 y 5 años. El 62,04 por ciento de las pacientes presentó algún tipo de manifestación extraarticular ginecológica. La secreción vaginal (50,75 por ciento), vulvovaginitis (25,37 por ciento), cervicitis (20,90 por ciento) y la dispareunia (14,92 por ciento) fueron las de mayor frecuencia de presentación. Conclusiones: Las manifestaciones ginecológicas son frecuentes en las pacientes con enfermedades reumáticas. Las manifestaciones ginecológicas de origen inflamatorio fueron las de mayor presentación y fueron más frecuente en la artritis reumatoide y el lupus eritematoso. En la esclerosis sistémica las manifestaciones neoplásicas fueron las más frecuentes(AU)
Introduction: Rheumatic diseases are characterized by the presence of articular and extra-articular manifestations. Within the latter, one of the least studied systems. Objective: To characterize the gynecological manifestations that most frequently occur in the course of rheumatic diseases. Methods: A basic, non-experimental, descriptive and longitudinal research was carried out that included a total of 117 female patients diagnosed with various rheumatic diseases according to the criteria of the American College of Rheumatology. The sample was made up of 108 patients. During the study, the incidence of gynecological manifestations in rheumatic patients and the type of manifestation that is most frequently reported were identified. Result: average age of 61.19 years, predominance of patients of urban origin (61.11%) and with a diagnosis of rheumatoid arthritis (61.11 percent). 39.81 percent of the patients reported disease evolution time between three and five years. 62.04% of the patients presented some type of extra-articular gynecological manifestation. Vaginal secretion (50.75 percent), vulvovaginitis (25.37 percent), cervicitis (20.90 percent) and dyspareunia (14.92 percent) were the ones with the highest frequency of presentation. Conclusions: Gynecological manifestations are frequently found in patients with rheumatic diseases. Gynecological manifestations of inflammatory origin were those with the highest frequency of presentation and were more frequent in rheumatoid arthritis and lupus erythematosus. In systemic sclerosis, neoplastic manifestations were the most frequent(AU)
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Humanos , FemininoRESUMO
Anthropogenic pollution has a huge impact on the water quality of marine ecosystems. Heavy metals and antibiotics are anthropogenic stressors that have a major effect on the health of the marine organisms. Although heavy metals are also associate with volcanic eruptions, wind erosion or evaporation, most of them come from industrial and urban waste. Such contamination, coupled to the use and subsequent misuse of antimicrobials in aquatic environments, is an important stress factor capable of affecting the marine communities in the ecosystem. Bivalves are important ecological components of the oceanic environments and can bioaccumulate pollutants during their feeding through water filtration, acting as environmental sentinels. However, heavy metals and antibiotics pollution can affect several of their physiologic and immunological processes, including their microbiome. In fact, heavy metals and antibiotics have the potential to select resistance genes in bacteria, including those that are part of the microbiota of bivalves, such as Vibrio spp. Worryingly, antibiotic-resistant phenotypes have been shown to be more tolerant to heavy metals, and vice versa, which probably occurs through co- and cross-resistance pathways. In this regard, a crucial role of heavy metal resistance genes in the spread of mobile element-mediated antibiotic resistance has been suggested. Thus, it might be expected that antibiotic resistance of Vibrio spp. associated with bivalves would be higher in contaminated environments. In this review, we focused on co-occurrence of heavy metal and antibiotic resistance in Vibrio spp. In addition, we explore the Chilean situation with respect to the contaminants described above, focusing on the main bivalves-producing region for human consumption, considering bivalves as potential vehicles of antibiotic resistance genes to humans through the ingestion of contaminated seafood.
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Bivalves , Metais Pesados , Microbiota , Agricultura , Animais , Antibacterianos/farmacologia , Bactérias/genética , ChileRESUMO
Kelps or brown algae are a wide group of marine macroalgae that play an important role in aquatic ecosystems and generally have high commercial value. To facilitate brown algal studies, we report the complete genome sequence of the largest kelp Macrocystis pyrifera. The whole genome is â¼428 Mb in size, comprises 44,307 scaffolds with an average GC content of 47%, and is predicted to contain a total of 24,778 genes. 18S sequence-based phylogenetic analysis revealed that littoral brown seaweed Scytosiphon lomentaria is the closest species of M. pyrifera. Numerous genes identified in this dataset are involved in genetic information processing, signaling, and cellular processes, carbohydrate metabolism, and terpenoids biosynthesis.
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Quimioterapia neoadyuvante (NAC) en cáncer de mama permite conocer la sensibilidad del tumor al tratamiento, alcanzar respuesta patológica completa (pRC), está asociada a mejor supervivencia en cáncer de mama localmente avanzado. El objetivo de este estudio fue conocer el impacto de la pRC en la supervivencia en una cohorte de pacientes tratadas con NAC y cirugía. Se realizo un estudio de diseño observacional de tipo retrospectivo, correlacional, con un seguimiento promedio de 90 meses, de una cohorte de pacientes tratadas con NAC y cirugía desde enero del 2009 a diciembre del 2011. El análisis de datos se realizó mediante el software estadístico SPSS v22.0, para el análisis de supervivencia se utilizó el método de Kaplan Meier, para comparar supervivencias se consideró significativa una p<0,05. Entre las características principales de 199 pacientes, se destacan: edad joven a la presentación, elevado índice de proliferación y alta frecuencia del tipo inflamatorio. pRC ocurrió en el 14,1% de pacientes y la supervivencia global (SG) de acuerdo con la respuesta patológica se comparó entre aquellas pacientes que obtuvieron pRC, con las que tuvieron enfermedad residual, con una SG del 71,4% vs 45% respectivamente, con una diferencia significativa (p:0.009). En esta cohorte de pacientes la pRC impactó en la supervivencia en todos los subtipos clínico-patológicos, sobre todo en el subtipo triple negativo. Evaluar los datos en el entorno real es importante para definir estrategias y mejorar los resultados.
Neoadjuvant chemotherapy (NAC) in breast cancer allows knowing the sensitivity of the tumor to treatment, achieving pathological response complete (pRC), and is associated with better survival in locally advanced breast cancer. The objective of this study was to determine the impact of pRC on survival in a cohort of patients treated with NAC and surgery. A retrospective, correlational observational design study was carried out, with an average follow-up of 90 months, of a cohort of patients treated with NAC and surgery from January 2009 to December 2011. Data analysis was performed using the software SPSS v22.0 statistic, for the survival analysis the Kaplan Meier method was used, to compare survivals a p <0.05 was considered significant. Among the main characteristics of 199 patients, the following stand out: young age at presentation, high proliferation index and high frequency of the inflammatory type. pRC occurred in 14.1% of patients and overall survival (OS) according to the pathological response was compared between those patients who obtained pRC, with those who had residual disease, with an OS of 71.4% vs 45% respectively, with a significant difference (p: 0.009). In this cohort of patients, pRC impacted on survival in all clinicopathological subtypes, especially in the triple negative subtype. Evaluating data in the real environment is important to define strategies and improve results.
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Humanos , Feminino , Pessoa de Meia-Idade , Neoplasias da Mama/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante/métodos , Terapia Neoadjuvante/métodos , Prognóstico , Taxa de Sobrevida , Estudos Retrospectivos , Resultado do Tratamento , Correlação de DadosRESUMO
The host microbiome plays an essential role in health and disease. Microbiome modification by pathogens or probiotics has been poorly explored especially in the case of probiotic yeasts. Next-generation sequencing currently provides the best tools for their characterization. Debaryomyces hansenii 97 (D. hansenii 97) and Yarrowia lipolytica 242 (Y. lipolytica 242) are yeasts that protect wildtype zebrafish (Danio rerio) larvae against a Vibrio anguillarum (V. anguillarum) infection, increasing their survival rate. We investigate the effect of these microorganisms on the microbiome and neutrophil response (inflammation) in zebrafish larvae line Tg(Bacmpx:GFP) i114. We postulated that preinoculation of larvae with yeasts would attenuate the intestinal neutrophil response and prevent modification of the larval microbiome induced by the pathogen. Microbiome study was performed by sequencing the V3-V4 region of the 16S rRNA gene and prediction of metabolic pathways by Piphillin in conventionally raised larvae. Survival and the neutrophil response were both evaluated in conventional and germ-free conditions. V. anguillarum infection resulted in higher neutrophil number in the intestinal area compared to non-infected larvae in both conditions. In germ-free conditions, infected larvae pre-inoculated with yeasts showed fewer neutrophil numbers than infected larvae. In both conditions, only D. hansenii 97 increased the survival of infected larvae. Beta diversity of the microbiota was modified by V. anguillarum and both yeasts, compared to non-inoculated larvae. At 3 days post-infection, V. anguillarum modified the relative abundance of 10 genera, and pre-inoculation with D. hansenii 97 and Y. lipolytica 242 prevented the modification of 5 and 6 of these genera, respectively. Both yeasts prevent the increase of Ensifer and Vogesella identified as negative predictors for larval survival (accounting for 40 and 27 of the variance, respectively). In addition, yeast pre-inoculation prevents changes in some metabolic pathways altered by V. anguillarum's infection. These results suggest that both yeasts and V. anguillarum can shape the larval microbiota configuration in the early developmental stage of D. rerio. Moreover, modulation of key taxa or metabolic pathways of the larval microbiome by yeasts can be associated with the survival of infected larvae. This study contributes to the understanding of yeast-pathogen-microbiome interactions, although further studies are needed to elucidate the mechanisms involved.
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Short-chain fatty acids (SCFAs) are carboxylic acids produced as a result of gut microbial anaerobic fermentation. They activate signaling cascades, acting as ligands of G-protein-coupled receptors, such as GPR41, GPR43, and GPR109A, that can modulate the inflammatory response and increase the intestinal barrier integrity by enhancing the tight junction proteins functions. These junctions, located in the most apical zone of epithelial cells, control the diffusion of ions, macromolecules, and the entry of microorganisms from the intestinal lumen into the tissues. In this sense, several enteric pathogens secrete diverse toxins that interrupt tight junction impermeability, allowing them to invade the intestinal tissue and to favor gastrointestinal colonization. It has been recently demonstrated that SCFAs inhibit the virulence of different enteric pathogens and have protective effects against bacterial colonization. Here, we present an overview of SCFAs production by gut microbiota and their effects on the recovery of intestinal barrier integrity during infections by microorganisms that affect tight junctions. These properties make them excellent candidates in the treatment of infectious diseases that cause damage to the intestinal epithelium.
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Vibrio parahaemolyticus is the leading cause of seafood-associated bacterial gastroenteritis worldwide. Although different studies have focused on its pattern of variation over time, knowledge about the environmental factors driving the dynamics of this pathogen, within the Chilean territory, is still lacking. This study determined the prevalence of total and pathogenic V. parahaemolyticus strains (tdh and/or trh genes) in mussels (Mytilus chilensis) collected from two natural growing areas between 2017 and 2018, using selective agar and PCR analysis. V. parahaemolyticus was detected in 45.6% (93/204) of pooled samples from the Valdivia River Estuary. The pathogenic strains carrying the tdh and/or trh gene were detected in 11.8% (24/204): tdh in 9.8% (20/204), trh in 0.5% (1/204), and 1.5% (3/204) presented both genes. In Reloncaví Fjord, V. parahaemolyticus was detected in 14.4% (30/209) of the samples, pathogenic V. parahaemolyticus carrying the trh gene was detected in 0.5% (1/209) of the samples, while the tdh gene was not detected in the samples from this area. The total count of mauve-purple colonies typical of V. parahaemolyticus on CHROMagar was positively associated by multivariate analysis with area, water temperature, and salinity. Similarly, V. parahaemolyticus detection rates by PCR had a positive correlation with the area and water temperature. The chances of detecting total V. parahaemolyticus in the Valdivia River Estuary are significantly higher than in the Reloncaví Fjord, but inversely, during spring-summer months, the interaction factor between the area and temperature indicated that the chances of detecting V. parahaemolyticus are higher in the Reloncaví Fjord. Interestingly, this period coincides with the season when commercial and natural-growing shellfish are harvested. On the other hand, pathogenic V. parahaemolyticus tdh+ was significantly correlated with an increase of water temperature. These environmental parameters could be used to trigger a warning on potential hazard, which would influence human health and economic losses in aquaculture systems.
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Vibrio parahaemolyticus non-toxigenic strains are responsible for about 10% of acute gastroenteritis associated with this species, suggesting they harbor unique virulence factors. Zonula occludens toxin (Zot), firstly described in Vibrio cholerae, is a secreted toxin that increases intestinal permeability. Recently, we identified Zot-encoding genes in the genomes of highly cytotoxic Chilean V. parahaemolyticus strains, including the non-toxigenic clinical strain PMC53.7. To gain insights into a possible role of Zot in V. parahaemolyticus, we analyzed whether it could be responsible for cytotoxicity. However, we observed a barely positive correlation between Caco-2 cell membrane damage and Zot mRNA expression during PMC53.7 infection and non-cytotoxicity induction in response to purified PMC53.7-Zot. Unusually, we observed a particular actin disturbance on cells infected with PMC53.7. Based on this observation, we decided to compare the sequence of PMC53.7-Zot with Zot of human pathogenic species such as V. cholerae, Campylobacter concisus, Neisseria meningitidis, and other V. parahaemolyticus strains, using computational tools. The PMC53.7-Zot was compared with other toxins and identified as an endotoxin with conserved motifs in the N-terminus and a variable C-terminal region and without FCIGRL peptide. Notably, the C-terminal diversity among Zots meant that not all of them could be identified as toxins. Structurally, PMC53.7-Zot was modeled as a transmembrane protein. Our results suggested that it has partial 3D structure similarity with V. cholerae-Zot. Probably, the PMC53.7-Zot would affect the actin cytoskeletal, but, in the absence of FCIGRL, the mechanisms of actions must be elucidated.
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Toxina da Cólera , Vibrio parahaemolyticus , Células CACO-2 , Campylobacter , Chile , Endotoxinas , Humanos , Vibrio parahaemolyticus/genéticaRESUMO
Sweet cherry is a valuable non-climacteric fruit with elevated phytonutrients, whose fruit quality attributes are prone to rapid deterioration after harvest, especially peel damage and water loss of stem. Here the metabolic and transcriptional response of exogenous melatonin was assessed in two commercial cultivars of sweet cherry (Santina and Royal Rainier) during cold storage. Gene expression profiling revealed that cuticle composition and water movement may underlie the effect of melatonin in delaying weight loss. An effect of melatonin on total soluble solids and lower respiration rate was observed in both cultivars. Melatonin induces overexpression of genes related to anthocyanin biosynthesis, which correlates with increased anthocyanin levels and changes in skin color (Chroma). Our results indicate that along with modulating antioxidant metabolism, melatonin improves fruit quality traits by triggering a range of metabolic and gene expression changes, which ultimately contribute to extend sweet cherry postharvest storability.
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Regulação da Expressão Gênica/efeitos dos fármacos , Melatonina/farmacologia , Prunus avium/efeitos dos fármacos , Antocianinas/metabolismo , Frutas/metabolismo , Prunus avium/metabolismoRESUMO
Bacteriophages are an important factor in bacterial evolution. Some reports suggest that lytic bacteriophages can select for resistant mutant strains with reduced virulence. The present study explores the role of the CHOED bacteriophage in the diversification and virulence of its host Vibrio anguillarum. Nine phage-resistant strains were analyzed for their phenotype and different virulence factors, showing alterations in their fitness, motility, biofilm formation, lipopolysaccharide profiles and/or protease activity. Seven of the nine phage-resistant strains showed virulence reduction in a Sparus aurata larvae model. However, this is not generalized since two of the resistant strains show equal virulence compared with the parental strain. The genomic analysis of representative resistant strains displayed that the majority of the mutations are specific for each isolate, affecting genes related to lipopolysaccharide biosynthesis, quorum sensing, motility, toxin and membrane transport. The observed mutations were coherent with the phenotypic and virulence differences observed. These results suggest that the CHOED phage acts as a selective pressure on V. anguillarum, allowing proliferation of resistant strains with different genotypes, phenotypes and degrees of virulence, contributing to bacterial diversification.
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The use of bacteriophages has been proposed as an alternative method to control pathogenic bacteria. During recent years several reports have been published about the successful use of bacteriophages in different fields such as food safety, agriculture, aquaculture, and even human health. Several companies are now commercializing bacteriophages or bacteriophage-based products for therapeutic purposes. However, this technology is still in development and there are challenges to overcome before bacteriophages can be widely used to control pathogenic bacteria. One big hurdle is the development of efficient methods for bacteriophage production. To date, several models for bacteriophage production have been reported, some of them evaluated experimentally. This mini-review offers an overview of different models and methods for bacteriophage production, contrasting their principal differences.
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Small regulatory RNAs (sRNAs) are molecules that play an important role in the regulation of gene expression. sRNAs in bacteria can affect important processes, such as metabolism and virulence. Previous studies showed a significant role of sRNAs in the Vibrio species, but knowledge about Vibrio parahaemolyticus is limited. Here, we examined the conservation of sRNAs between V. parahaemolyticus and other human Vibrio species, in addition to investigating the conservation between V. parahaemolyticus strains differing in pandemic origin. Our results showed that only 7% of sRNAs were conserved between V. parahaemolyticus and other species, but 88% of sRNAs were highly conserved within species. Nonetheless, two sRNAs coding to RNA-OUT, a component of the Tn10/IS10 system, were exclusively present in pandemic strains. Subsequent analysis showed that both RNA-OUT were located in pathogenicity island-7 and would interact with transposase VPA1379, according to the model of pairing of IS10-encoded antisense RNAs. According to the location of RNA-OUT/VPA1379, we also investigated if they were expressed during infection. We observed that the transcriptional level of VPA1379 was significantly increased, while RNA-OUT was decreased at three hours post-infection. We suggest that IS10 transcription increases in pandemic strains during infection, probably to favor IS10 transposition and improve their fitness when they are facing adverse conditions.
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Ilhas Genômicas , RNA não Traduzido/genética , Vibrio parahaemolyticus/genética , Células CACO-2 , Sequência Conservada , Humanos , Transposases/genética , Transposases/metabolismo , Vibrio parahaemolyticus/patogenicidadeRESUMO
Gastrointestinal episodes associated with Vibrio species have been rising worldwide in the last few years. Consequently, it is important to comprehend how occurs the production of diarrhea, to establish new preventive and therapeutic measures. Besides the classical CT and TCP toxins, Zot, RTX, and Ace among others have been deeply studied in V. cholerae. However, in other Vibrio species of clinical interest, where some of these toxins have been reported, there is practically no information. Zot activates a cascade of signals inside of the cell that increase the permeability of epithelial barrier, while RTX causes depolymerization of the actin cytoskeleton and Ace increases the permeability of intestinal cell monolayers. The goal of this study is to acquire information about the distribution of these toxins in human pathogenic Vibrios and to review the progress in the study of their role in the intestinal epithelium during infection.