Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 411
Filtrar
2.
Int J Mol Sci ; 25(14)2024 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-39062867

RESUMEN

Entamoeba histolytica is the protozoan causative of human amoebiasis. The EhADH adhesin (687 aa) is a protein involved in tissue invasion, phagocytosis and host-cell lysis. EhADH adheres to the prey and follows its arrival to the multivesicular bodies. It is an accessory protein of the endosomal sorting complexes required for transport (ESCRT) machinery. Here, to study the role of different parts of EhADH during virulence events, we produced trophozoites overexpressing the three domains of EhADH, Bro1 (1-400 aa), Linker (246-446 aa) and Adh (444-687 aa) to evaluate their role in virulence. The TrophozBro11-400 slightly increased adherence and phagocytosis, but these trophozoites showed a higher ability to destroy cell monolayers, augment the permeability of cultured epithelial cells and mouse colon, and produce more damage to hamster livers. The TrophozLinker226-446 also increased the virulence properties, but with lower effect than the TrophozBro11-400. In addition, this fragment participates in cholesterol transport and GTPase binding. Interestingly, the TrophozAdh444-687 produced the highest effect on adherence and phagocytosis, but it poorly influenced the monolayers destruction; nevertheless, they augmented the colon and liver damage. To identify the protein partners of each domain, we used recombinant peptides. Pull-down assays and mass spectrometry showed that Bro1 domain interplays with EhADH, Gal/GalNAc lectin, EhCPs, ESCRT machinery components and cytoskeleton proteins. While EhADH, ubiquitin, EhRabB, EhNPC1 and EhHSP70 were associated to the Linker domain, and EhADH, EhHSP70, EhPrx and metabolic enzymes interacted to the Adh domain. The diverse protein association confirms that EhADH is a versatile molecule with multiple functions probably given by its capacity to form distinct molecular complexes.


Asunto(s)
Entamoeba histolytica , Proteínas Protozoarias , Entamoeba histolytica/patogenicidad , Entamoeba histolytica/metabolismo , Animales , Ratones , Proteínas Protozoarias/metabolismo , Proteínas Protozoarias/química , Proteínas Protozoarias/genética , Humanos , Virulencia , Fagocitosis , Dominios Proteicos , Entamebiasis/parasitología , Entamebiasis/metabolismo , Cricetinae , Trofozoítos/metabolismo
3.
Am J Emerg Med ; 83: 101-108, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39002495

RESUMEN

BACKGROUND: In the context of the COVID-19 pandemic, the early and accurate identification of patients at risk of deterioration was crucial in overcrowded and resource-limited emergency departments. This study conducts an external validation for the evaluation of the performance of the National Early Warning Score 2 (NEWS2), the S/F ratio, and the ROX index at ED admission in a large cohort of COVID-19 patients from Colombia, South America, assessing the net clinical benefit with decision curve analysis. METHODS: A prospective cohort study was conducted on 6907 adult patients with confirmed COVID-19 admitted to a tertiary care ED in Colombia. The study evaluated the diagnostic performance of NEWS2, S/F ratio, and ROX index scores at ED admission using the area under the receiver operating characteristic curve (AUROC) for discrimination, calibration, and decision curve analysis for the prediction of intensive care unit admission, invasive mechanical ventilation, and in-hospital mortality. RESULTS: We included 6907 patients who presented to the ED with confirmed SARS-CoV-2 infection from March 2020 to November 2021. Mean age was 51 (35-65) years and 50.4% of patients were males. The rate of intensive care unit admission was 28%, and in-hospital death was 9.8%. All three scores have good discriminatory performance for the three outcomes based on the AUROC. S/F ratio showed miscalibration at low predicted probabilities and decision curve analysis indicated that the NEWS2 score provided a greater net benefit compared to other scores across at a 10% threshold to decide ED admission at a high-level of care facility. CONCLUSIONS: The NEWS2, S/F ratio, and ROX index at ED admission have good discriminatory performances in COVID-19 patients for the prediction of adverse outcomes, but the NEWS2 score has a higher net benefit underscoring its clinical utility in optimizing patient management and resource allocation in emergency settings.


Asunto(s)
COVID-19 , Servicio de Urgencia en Hospital , Mortalidad Hospitalaria , Humanos , COVID-19/mortalidad , COVID-19/terapia , COVID-19/diagnóstico , COVID-19/epidemiología , Masculino , Femenino , Servicio de Urgencia en Hospital/estadística & datos numéricos , Persona de Mediana Edad , Estudios Prospectivos , Adulto , Colombia/epidemiología , Anciano , Puntuación de Alerta Temprana , Curva ROC , Unidades de Cuidados Intensivos/estadística & datos numéricos , SARS-CoV-2 , Respiración Artificial/estadística & datos numéricos , Medición de Riesgo/métodos
4.
Genetics ; 227(4)2024 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-38963803

RESUMEN

Radiotherapy is a key treatment option for a wide variety of human tumors, employed either alone or alongside with other therapeutic interventions. Radiotherapy uses high-energy particles to destroy tumor cells, blocking their ability to divide and proliferate. The effectiveness of radiotherapy is due to genetic and epigenetic factors that determine how tumor cells respond to ionizing radiation. These factors contribute to the establishment of resistance to radiotherapy, which increases the risk of poor clinical prognosis of patients. Although the mechanisms by which tumor cells induce radioresistance are unclear, evidence points out several contributing factors including the overexpression of DNA repair systems, increased levels of reactive oxygen species, alterations in the tumor microenvironment, and enrichment of cancer stem cell populations. In this context, dysregulation of microRNAs or miRNAs, critical regulators of gene expression, may influence how tumors respond to radiation. There is increasing evidence that miRNAs may act as sensitizers or enhancers of radioresistance, regulating key processes such as the DNA damage response and the cell death signaling pathway. Furthermore, expression and activity of miRNAs have shown informative value in overcoming radiotherapy and long-term radiotoxicity, revealing their potential as biomarkers. In this review, we will discuss the molecular mechanisms associated with the response to radiotherapy and highlight the central role of miRNAs in regulating the molecular mechanisms responsible for cellular radioresistance. We will also review radio-miRs, radiotherapy-related miRNAs, either as sensitizers or enhancers of radioresistance that hold promise as biomarkers or pharmacological targets to sensitize radioresistant cells.


Asunto(s)
MicroARNs , Neoplasias , Tolerancia a Radiación , MicroARNs/genética , MicroARNs/metabolismo , Humanos , Tolerancia a Radiación/genética , Neoplasias/radioterapia , Neoplasias/genética , Neoplasias/metabolismo , Reparación del ADN , Animales , Regulación Neoplásica de la Expresión Génica/efectos de la radiación , Daño del ADN
5.
J Med Entomol ; 61(5): 1126-1139, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-38902893

RESUMEN

Leishmaniasis is a zoonoses caused by protozoan parasites belonging to the Leishmania genus that is transmitted to humans through the bite of previously infected phlebotomine sandflies (Diptera:Psychodidae:Phlebotominae). In Brazil, 2 types of leishmaniasis are endemic, tegumentary leishmaniasis (TL) and visceral leishmaniasis (VL). In Baldim, a municipality in the Espinhaço Range Biospere Reserve (ERBR), 5 autochthonous cases of TL, and one autochthonous case of VL were reported from 2017 to 2022. Owing to the lack of data on entomological fauna, we surveyed the occurrence and distribution of phlebotomine sandflies that could act as Leishmania vectors, as well as natural Leishmania infection. During 1 year, 918 sandfly specimens belonging to 12 species were collected. The predominant species was Lutzomyia longipalpis (Lutz & Neiva, 1912) (32.0%), a proven VL agent, followed by Evandromyia evandroi (Costa Lima & Antunes, 1936) (20.7%), Evandromyia cortelezzii (Brèthes, 1923) (17.0%), Nyssomyia whitmani (Antunes & Coutinho, 1939) (12.2%), and Nyssomyia intermedia (Lutz & Neiva, 1912) (10.5%), all putative or proven TL agents. Seasonal fluctuations and endo-exophilic behavior were delineated for the main phlebotomine sandflies. The population of Lu. longipalpis was higher during the coolest and driest months, although different profiles were noted for the other species. Natural Leishmania infection was not detected in any of the 197 phlebotomine sandfly females analyzed. The results were compared with those previously obtained in other municipalities belonging to the ERBR. The presence of Leishmania vectors and human cases of leishmaniasis indicate a risk of Leishmania transmission in the region.


Asunto(s)
Insectos Vectores , Leishmania , Psychodidae , Brasil , Animales , Psychodidae/parasitología , Insectos Vectores/parasitología , Femenino , Leishmania/aislamiento & purificación , Masculino , Densidad de Población , Distribución Animal , Leishmaniasis/transmisión
6.
Braz J Microbiol ; 55(3): 2321-2334, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-38874746

RESUMEN

Puga geothermal geyser and surrounding area, located in the Himalayan Geothermal Belt of the Trans-Himalayan Plateau in Ladakh, India, are very geographically isolated and considered pristine and free of anthropogenic activities. In this study, we have conducted the first metagenomic investigation of the microbes in and around the geyser. The whole genome sequencing analysis showed the presence of a total of 44.8%, 39.7% and 41.4% bacterial phyla in the PugW, PugS, and PugSo samples respectively, 8.6% of archaeal phyla (in all the samples), unclassified (derived from other sequences, PugW: 27.6%, PugS: 27.6%, and PugSo: 15.5%) and unclassified (derived from bacteria, PugW: 12%, PugS: 13.8%, and PugSo: 13.8%). The majority of archaeal sequences were linked to Euryarchaeota (2.84%) while the majority of the bacterial communities that predominated in most geothermal locations were linked to Pseudomonadota (67.14%) and Bacteroidota (12.52%). The abundant bacterial strains at the species level included Dechloromonas aromatica, Acinetobacter baumannii, and Arcobacter butzleri, in all the samples while the most abundant archaeal species were Methanosaeta thermophile, Methanoregula boonei, and Methanosarcina berkeri. Further, this geothermal geyser metagenome has a large number of unique sequences linked to unidentified and unclassified lineages, suggesting a potential source for novel species of microbes and their products. The present study which only examined one of the many geothermal geysers and springs in the Puga geothermal area, should be regarded as a preliminary investigation of the microbiota that live in the geothermal springs on these remote areas. These findings suggest that further investigations should be undertaken to characterize the ecosystems of the Puga geothermal area, which serve as a repository for unidentified microbial lineages.


Asunto(s)
Archaea , Bacterias , Manantiales de Aguas Termales , Metagenómica , India , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Archaea/genética , Archaea/clasificación , Archaea/aislamiento & purificación , Manantiales de Aguas Termales/microbiología , Filogenia , Microbiota , Metagenoma
7.
medRxiv ; 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38853839

RESUMEN

While incidence of tuberculosis (TB) has decreased globally, in Paraguay, considered a medium-incidence country by the WHO, TB incidence has increased slightly from 42 per 100,000 in 2010 to 46 per 100,000 in 2022. We conducted a retrospective study of TB cases notified to the Paraguay National Program for Tuberculosis Control (NPTC) from 2018 to 2022 and quantified trends in specific populations identified as vulnerable. Of the 13,725 TB cases notified in Paraguay from 2018 to 2022, 2,331 (17%) occurred among incarcerated individuals and 1,743 (12.7%) occurred among self-identified Indigenous individuals. In 2022, the relative risk of TB was 87 and 6.4 among the incarcerated and Indigenous populations, compared with the non-incarcerated and non-Indigenous populations respectively. We found significant heterogeneity in TB incidence across Paraguay's 17 departments. Our findings highlight the urgency of expanding access to TB diagnosis, treatment, and prevention in populations at heightened risk of TB in Paraguay.

8.
Food Sci Technol Int ; : 10820132241259055, 2024 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-38856150

RESUMEN

Mangoes contain several components that are beneficial for health, in addition to being potential sources of starch for the food industry. However, a substantial amount of fruit is lost in the field because it does not meet commercial standards, resulting in food losses and environmental damage. Herein, the physicochemical properties of mango flours and starches obtained from different parts of the fruit of two cultivars were evaluated. Mango peel flours have higher levels of proteins, fibers, minerals, carotenoids, ascorbic acid, and antioxidant activity than pulp flours, in addition to a higher yellowing index and water and oil-holding capacity, and can be used as a functional flour. The pulp flours, with the higher starch content, showed characteristics that make them valuable as a potential ingredient in soft baking and gluten-free products. Mango starches have circular and oval shapes, with a bimodal distribution. All starches showed an A-type crystallinity pattern. Pulp starches showed a higher peak viscosity and breakdown, with a lower setback, and can be used as a thickening or gelling agent. The higher thermal stability of kernel starch suggests its application in sauces, baking, dairy products, and canned foods.

9.
Front Chem ; 12: 1338614, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38807978

RESUMEN

[Cu(NN1)2]ClO4 is a copper (I) complex, where NN1 is an imine ligand 6-((quinolin-2-ylmethylene) amino)-2H-chromen-2-one obtained by derivatization of natural compound coumarin, developed for the treatment of infectious diseases that affect salmonids. In previous research, we showed that the Cu(I) coordination complex possesses antibacterial activity against Flavobacterium psychrophilum, providing protection against this pathogen in rainbow trout during challenge assays (with an RPS of 50%). In the present study, the effects of administering [Cu(NN1)2]ClO4 to Oncorhynchus mykiss over a 60-days period were evaluated with regard to systemic immune response and its potential to alter intestinal microbiota composition. In O. mykiss, an immunostimulatory effect was evident at days 30 and 45 after administration, resulting in an increment of transcript levels of IFN-γ, IL-12, TNF-α, lysozyme and perforin. To determine whether these immunomodulatory effects correlated with changes in the intestinal microbiota, we analyzed the metagenome diversity by V4 16S rRNA sequencing. In O. mykiss, both [Cu(NN1)2]ClO4 and commercial antibiotic florfenicol had comparable effects at the phylum level, resulting in a predominance of proteobacteria and firmicutes. Nonetheless, at the genus level, florfenicol and [Cu(NN1)2]ClO4 complex exhibited distinct effects on the intestinal microbiota of O. mykiss. In conclusion, our findings demonstrate that [Cu(NN1)2]ClO4 is capable of stimulating the immune system at a systemic level, while inducing alterations in the composition of the intestinal microbiota in O. mykiss.

10.
Vet Sci ; 11(5)2024 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-38787197

RESUMEN

The present study aimed to evaluate the influence of the autonomic nervous system on cardiovascular function during the first 35 days of life in different types of delivery, using heart rate variability (HRV) indices. Thirty newborns were equally divided into two groups based on delivery type: eutocic delivery (EG) and emergency cesarean section (CG). Electrocardiographic evaluation was performed at birth (T0), 24 h postpartum (T1), and at 7, 14, 21, 28, and 35 days of life (T2 to T6). Physical parameters, neonatal reflexes, and Apgar scores were recorded. Over 35 days, the values of the time domain indices were higher in the GE group and increased with age. In the frequency domain, the low frequency (LF) index was higher in the CG, and the opposite occurred for the high frequency (HF) index. Since the CG presented lower HRV than the EG, it was shown that the type of delivery should be considered for the assessment of autonomic nervous system activity in neonates. Thus, as predictive factors of vitality, HRV and Apgar scores can help in the face of neonatal depression, demonstrating that delivery by emergency cesarean section can predispose newborns to delays in the autonomic influence on the heart.

11.
Braz J Microbiol ; 55(2): 1465-1476, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38662153

RESUMEN

Due to their distinctive physicochemical characteristics, hot springs are extremely important. The whole genome metagenomic sequencing technology can be utilized to analyze the diverse microbial community that thrives in this habitat due to the particular selection pressure that prevails there. The current investigation emphasizes on culture-independent metagenomic study of the Panamik hot spring and its nearby areas from Ladakh, India. Based on different diversity indices, sequence analysis of the soil reservoir showed higher species richness and diversity in comparison to water and sediment samples. The mineral content and various physicochemical pameters like temperature, pH had an impact on the composition of the microbial community of the geothermal springs. The phyla Proteobacteria, Cyanobacteria, Bacteroidetes, Actinobacter, Firmicutes, and Verrucomicrobia in bacterial domain dominate the thermos-alkaline spring at Panamik in different concentrations. Economically significant microbes from the genera Actinobacter, Thermosynechoccus, Candidatus Solibacter, Chthoniobacter, Synechoccus, Pseudomonas and Sphingomonas, were prevalent in hot spring. In the archaeal domain, the most dominant phylum and genera were Euryarchaeota and Thermococcus in all the samples. Further, the most abundant species were Methanosarcina barkeri, Nitrospumilus maritimus and Methanosarcina acetivorans. The present study which only examined one of the several thermal springs present in the Himalayan geothermal area, should be regarded as a preliminary investigation of the microbiota that live in the hot springs on these remote areas. These findings suggest that further investigations should be undertaken to characterize the ecosystems of the Panamik hot spring, which serve as a repository for unidentified microbial lineages.


Asunto(s)
Archaea , Bacterias , Secuenciación de Nucleótidos de Alto Rendimiento , Manantiales de Aguas Termales , Metagenómica , Microbiota , Manantiales de Aguas Termales/microbiología , India , Bacterias/genética , Bacterias/clasificación , Bacterias/aislamiento & purificación , Archaea/genética , Archaea/clasificación , Archaea/aislamiento & purificación , Filogenia , Biodiversidad
12.
Int J Mol Sci ; 25(7)2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38612511

RESUMEN

Piscirickettsia salmonis is the pathogen that most affects the salmon industry in Chile. Large quantities of antibiotics have been used to control it. In search of alternatives, we have developed [Cu(NN1)2]ClO4 where NN1 = 6-((quinolin-2-ylmethylene)amino)-2H-chromen-2-one. The antibacterial capacity of [Cu(NN1)2]ClO4 was determined. Subsequently, the effect of the administration of [Cu(NN1)2]ClO4 on the growth of S. salar, modulation of the immune system and the intestinal microbiota was studied. Finally, the ability to protect against a challenge with P. salmonis was evaluated. The results obtained showed that the compound has an MIC between 15 and 33.9 µg/mL in four isolates. On the other hand, the compound did not affect the growth of the fish; however, an increase in the transcript levels of IFN-γ, IL-12, IL-1ß, CD4, lysozyme and perforin was observed in fish treated with 40 µg/g of fish. Furthermore, modulation of the intestinal microbiota was observed, increasing the genera of beneficial bacteria such as Lactobacillus and Bacillus as well as potential pathogens such as Vibrio and Piscirickettsia. Finally, the treatment increased survival in fish challenged with P. salmonis by more than 60%. These results demonstrate that the compound is capable of protecting fish against P. salmonis, probably by modulating the immune system and the composition of the intestinal microbiota.


Asunto(s)
Antiinfecciosos , Infecciones por Piscirickettsiaceae , Salmo salar , Animales , Cobre , Infecciones por Piscirickettsiaceae/tratamiento farmacológico , Infecciones por Piscirickettsiaceae/veterinaria , Antibacterianos/farmacología
13.
Braz J Infect Dis ; 28(2): 103737, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38484781

RESUMEN

INTRODUCTION: Understanding the intricate dynamics between different waves of the COVID-19 pandemic and the corresponding variations in clinical outcomes is essential for informed public health decision-making. Comprehensive insights into these fluctuations can guide resource allocation, healthcare policies, and the development of effective interventions. This study aimed to compare the characteristics and clinical outcomes of COVID-19 at peak transmission points by including all patients attended during the first four pandemic waves in a referral center in Colombia. MATERIAL AND METHODS: In a prospective observational study of 2733 patients, clinical and demographic data were extracted from the Fundacion Valle de Lili's COVID-19 Registry, focusing on ICU admission, Invasive Mechanical Ventilation (IMV), length of hospital stay, and mortality. RESULTS: Our analysis unveiled substantial shifts in patient care patterns. Notably, the proportion of patients receiving glucocorticoid therapy and experiencing secondary infections exhibited a pronounced decrease across waves (p < 0.001). Remarkably, there was a significant reduction in ICU admissions (62.83% vs. 51.23% vs. 58.23% vs. 46.70 %, p < 0.001), Invasive Mechanical Ventilation (IMV) usage (39.25% vs. 32.22% vs. 31.22% vs. 21.55 %, p < 0.001), and Length of Hospital Stay (LOS) (9 vs. 8 vs. 8 vs. 8 days, p < 0.001) over the successive waves. Surprisingly, hospital mortality remained stable at approximately 18‒20 % (p > 0.05). Notably, vaccination coverage with one or more doses surged from 0 % during the initial waves to 66.71 % in the fourth wave. CONCLUSIONS: Our findings emphasize the critical importance of adapting healthcare strategies to the evolving dynamics of the pandemic. The reduction in ICU admissions, IMV utilization, and LOS, coupled with the rise in vaccination rates, underscores the adaptability of healthcare systems. Hospital mortality's persistence may warrant further exploration of treatment strategies. These insights can inform public health responses, helping policymakers allocate resources effectively and tailor interventions to specific phases of the pandemic.


Asunto(s)
COVID-19 , Unidades de Cuidados Intensivos , Tiempo de Internación , Respiración Artificial , Humanos , COVID-19/epidemiología , Colombia/epidemiología , Masculino , Femenino , Estudios Prospectivos , Persona de Mediana Edad , Tiempo de Internación/estadística & datos numéricos , Respiración Artificial/estadística & datos numéricos , Unidades de Cuidados Intensivos/estadística & datos numéricos , Pandemias , Hospitalización/estadística & datos numéricos , Anciano , Adulto , Mortalidad Hospitalaria , SARS-CoV-2 , Estudios de Cohortes
14.
Lancet Reg Health Am ; 31: 100668, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38500958

RESUMEN

Background: The increased risk of tuberculosis (TB) among people deprived of liberty (PDL) is due to individual and institution-level factors. We followed a cohort of PDL from 5 prisons in Paraguay to describe the risk of TB during incarceration and after they were released. Methods: We linked a 2013 national census of prisons with TB records from the TB Program from 2010 to 2021 to identify TB notifications among incarcerated and formerly incarcerated individuals. We used multivariable Cox regression models to quantify the risk of TB during and following incarceration and to identify risk factors associated with TB. Findings: Among 2996 individuals incarcerated, 451 (15.1%) were diagnosed with TB. Of these, 262 (58.1%) cases occurred during incarceration and 189 (41.9%) occurred in the community after release. In prison, the hazard ratio of developing TB was 1.97 (95% CI: 1.52-2.61) after six months of incarceration and increased to 2.78 (95% CI: 1.82-4.24) after 36 months compared with the first six months. The overall TB notification rate was 2940 per 100,000 person-years. This rate increased with the duration of incarceration from 1335 per 100,000 person-years in the first year to 8455 per 100,000 person-years after 8 years. Among former prisoners, the rate of TB decreased from 1717 in the first year after release to 593 per 100 000 person-years after 8 years of follow up. Interpretation: Our study shows the alarming risk of TB associated with prison environments in Paraguay, and how this risk persists for years following incarceration. Effective TB control measures to protect the health of people during and following incarceration are urgently needed. Funding: Paraguay National Commission of Science and Technology grant CONACYT PIN 15-705 (GS, GES, SA).

15.
Braz J Microbiol ; 55(2): 1545-1555, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38421596

RESUMEN

In light of their unique and challenging environment, the high-altitude Chumathang geothermal springs in Ladakh, India, are undeniably intriguing for microbiological study. The purpose of this study was to employ a culture-independent sequencing approach to give a comprehensive characterization of the unknown bacterial and archaeal community structure, composition and networks in water and soil from the Chumathang geothermal spring. A total of 50%, and 42.86% bacterial phyla were found in the water, and soil samples respectively and this analysis also showed a total of 9.62% and 7.94% of archaeal phyla in both the samples, respectively. Further, the presence of unclassified (derived from other sequences, water: 17.31%, and soil: 19.05%) and unclassified (derived from bacteria, water: 13.46%, and soil: 12.70%) were also observed in the current metagenomics investigation. Firmicutes and Proteobacteria were the most abundant bacterial phyla in water, whereas Proteobacteria and Bacteroidetes were the most abundant bacterial phyla in geothermal soil. Crenarchaeota and Euryarchaeota dominated archeal communities in soil and water, respectively. This metagenomic study gave a detailed insight into the microbial diversity found in Chumathang geothermal spring and surrounding area, located in Ladakh, India. Surprisingly, this finding indicated the existence of geographically distinct microbial communities that were suited to various geothermal water habitats along the Himalayan Geothermal Belt. Future studies must take into account the metabolic pathways of these microbial communities that exist in these extreme environments. This will allow us to obtain a better knowledge of the microbial metabolisms that are common at these geothermal locations, which have a lot of potential for biotechnological applications. They will also enable us to establish links between the microbial community composition and the physicochemical environment of geothermal water and area.


Asunto(s)
Archaea , Bacterias , Biodiversidad , Manantiales de Aguas Termales , Metagenómica , Filogenia , Microbiología del Suelo , Manantiales de Aguas Termales/microbiología , India , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Archaea/clasificación , Archaea/genética , Archaea/aislamiento & purificación , ARN Ribosómico 16S/genética , Microbiota , Microbiología del Agua
16.
Front Bioeng Biotechnol ; 12: 1321466, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38361789

RESUMEN

Context: The development of porous devices using materials modified with various natural agents has become a priority for bone healing processes in the oral and maxillofacial field. There must be a balance between the proliferation of eukaryotic and the inhibition of prokaryotic cells to achieve proper bone health. Infections might inhibit the formation of new alveolar bone during bone graft augmentation. Objective: This study aimed to evaluate the in vitro osteogenic behavior of human bone marrow stem cells and assess the antimicrobial response to 3D-printed porous scaffolds using propolis-modified wollastonite. Methodology: A fractional factorial design of experiments was used to obtain a 3D printing paste for developing scaffolds with a triply periodic minimal surface (TPMS) gyroid geometry based on wollastonite and modified with an ethanolic propolis extract. The antioxidant activity of the extracts was characterized using free radical scavenging methods (DPPH and ABTS). Cell proliferation and osteogenic potential using Human Bone Marrow Stem Cells (bmMSCs) were assessed at different culture time points up to 28 days. MIC and inhibition zones were studied from single strain cultures, and biofilm formation was evaluated on the scaffolds under co-culture conditions. The mechanical strength of the scaffolds was evaluated. Results: Through statistical design of experiments, a paste suitable for printing scaffolds with the desired geometry was obtained. Propolis extracts modifying the TPMS gyroid scaffolds showed favorable cell proliferation and metabolic activity with osteogenic potential after 21 days. Additionally, propolis exhibited antioxidant activity, which may be related to the antimicrobial effectiveness of the scaffolds against S. aureus and S. epidermidis cultures. The mechanical properties of the scaffolds were not affected by propolis impregnation. Conclusion: These results demonstrate that propolis-impregnated porous wollastonite scaffolds might have the potential to stimulate bone repair in maxillofacial tissue engineering applications.

18.
Heliyon ; 10(1): e23955, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-38205336

RESUMEN

Biocompatible ceramic scaffolds offer a promising approach to address the challenges in bone reconstruction. Wollastonite, well-known for its exceptional biocompatibility, has attracted significant attention in orthopedics and craniofacial fields. However, the antimicrobial properties of wollastonite have contradictory findings, necessitating further research to enhance its antibacterial characteristics. This study aimed to explore a new approach to improve in vitro biological response in terms of antimicrobial activity and cell proliferation by taking advantage of additive manufacturing for the development of scaffolds with complex geometries by 3D printing using propolis-modified wollastonite. The scaffolds were designed with a TPMS (Triply Periodic Minimal Surface) gyroid geometric shape and 3D printed prior to impregnation with propolis extract. The paste formulation was characterized by rheometric measurements, and the presence of propolis was confirmed by FTIR spectroscopy. The scaffolds were comprehensively assessed for their mechanical strength. The biological characterization involved evaluating the antimicrobial effects against Staphylococcus aureus and Staphylococcus epidermidis, employing Minimum Inhibitory Concentration (MIC), Zone of Inhibition (ZOI), and biofilm formation assays. Additionally, SaOs-2 cultures were used to study cell proliferation (Alamar blue assay), and potential osteogenic was tested (von Kossa, Alizarin Red, and ALP stainings) at different time points. Propolis impregnation did not compromise the mechanical properties of the scaffolds, which exhibited values comparable to human trabecular bone. Propolis incorporation conferred antibacterial activity against both Staphylococcus aureus and Staphylococcus epidermidis. The implementation of TPMS gyroid geometry in the scaffold design demonstrated favorable cell proliferation with increased metabolic activity and osteogenic potential after 21 days of cell cultures.

19.
Biotechnol Bioeng ; 121(4): 1314-1324, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38178588

RESUMEN

The integration of first- (1G) and second-generation (2G) ethanol production by adding sugarcane juice or molasses to lignocellulosic hydrolysates offers the possibility to overcome the problem of inhibitors (acetic acid, furfural, hydroxymethylfurfural and phenolic compounds), and add nutrients (such as salts, sugars and nitrogen sources) to the fermentation medium, allowing the production of higher ethanol titers. In this work, an 1G2G production process was developed with hemicellulosic hydrolysate (HH) from a diluted sulfuric acid pretreatment of sugarcane bagasse and sugarcane molasses. The industrial Saccharomyces cerevisiae CAT-1 was genetically modified for xylose consumption and used for co-fermentation of sucrose, fructose, glucose, and xylose. The fed-batch fermentation with high cell density that mimics an industrial fermentation was performed at bench scale fermenter, achieved high volumetric ethanol productivity of 1.59 g L-1 h-1, 0.39 g g-1 of ethanol yield, and 44.5 g L-1 ethanol titer, and shown that the yeast was able to consume all the sugars present in must simultaneously. With the results, it was possible to establish a mass balance for the global process: from pretreatment to the co-fermentation of molasses and HH, and it was possible to establish an effective integrated process (1G2G) with sugarcane molasses and HH co-fermentation employing a recombinant yeast.


Asunto(s)
Celulosa , Polisacáridos , Saccharum , Celulosa/metabolismo , Fermentación , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Xilosa , Melaza , Saccharum/metabolismo , Azúcares , Etanol
20.
Proteins ; 92(2): 302-313, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37864384

RESUMEN

Endosulfan is an organochlorine insecticide widely used for agricultural pest control. Many nations worldwide have restricted or completely banned it due to its extreme toxicity to fish and aquatic invertebrates. Arthrobacter sp. strain KW has the ability to degrade α, ß endosulfan and its intermediate metabolite endosulfate; this degradation is associated with Ese protein, a two-component flavin-dependent monooxygenase (TC-FDM). Employing in silico tools, we obtained the 3D model of Ese protein, and our results suggest that it belongs to the Luciferase Like Monooxygenase family (LLM). Docking studies showed that the residues V59, V315, D316, and T335 interact with α-endosulfan. The residues: V59, T60, V315, D316, and T335 are implicated in the interacting site with ß-endosulfan, and the residues: H17, V315, D316, T335, N364, and Q363 participate in the interaction with endosulfate. Topological analysis of the electron density by means of the Quantum Theory of Atoms in Molecules (QTAIM) and the Non-Covalent Interaction (NCI) index reveals that the Ese-ligands complexes are formed mainly by dispersive forces, where Cl atoms have a predominant role. As Ese is a monooxygenase member, we predict the homodimer formation. However, enzymatic studies must be developed to investigate the Ese protein's enzymatic and catalytic activity.


Asunto(s)
Arthrobacter , Insecticidas , Animales , Endosulfano/química , Endosulfano/metabolismo , Arthrobacter/metabolismo , Biodegradación Ambiental , Insecticidas/química , Insecticidas/metabolismo , Oxigenasas de Función Mixta
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA