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Streptomyces , Desarrollo Sostenible , Naciones Unidas , Streptomyces/genética , Descubrimiento de Drogas , HumanosRESUMEN
A 4-month-old female Shar-pei dog was admitted with apathy, anorexia, and vomiting. The patient had an appropriate vaccination protocol, with the last vaccine administered 2.5 weeks prior to the onset of clinical signs. Physical examination revealed tachycardia, fever and swelling of the tibiotarsal joints. Several diagnostic tests including complete blood cell count, biochemistry profile, urinalysis, thoracic radiographs, hind limbs radiographs, abdominal ultrasound, and infectious diseases tests, were conducted to determine the underlying cause. Shar-Pei Auto-inflammatory Disease (SPAID) was diagnosed. Additionally, the patient developed skin necrosis in the inner aspect of the tibiotarsal joints as a complication. A skin biopsy revealed cutaneous vasculopathy causing degeneration, abrupt ulceration, and ischemic necrosis with intense neutrophilic inflammation of the dermis and subcutis. Moreover, a hospital-acquired infection was identified by skin culture. Debridement of the necrotic skin was performed, and due to its' severity and extent, the wound was closed by secondary intention. A diagnostic protocol and the therapeutic dose of acetylsalicylic acid, which led to clinical improvement, are recommended here. The patient has continued to present episodic manifestations of SPAID mainly fever and swelling of the tibiotarsal joints, but there has been no recurrence of necrosis or other cutaneous lesion in the last two years.
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OBJECTIVE: To compare the quality of urinary incontinence (UI) care for women in the safety-net and nonsafety-net settings prior to referral to a specialist. METHODS: We performed a retrospective review of 200 women from two nonsafety-net hospitals and 188 women from two safety-net hospitals who were referred to Urogynecology and Reconstructive Surgery specialists for bothersome UI between March 2017 and March 2020. We evaluated the care that women received 12 months prior to referral, by measuring adherence to a set of previously developed quality indicators (QIs), for example, the performance of a urinalysis or pelvic exam. RESULTS: Women seen in safety-net hospitals were more likely to receive QI-compliant care than women in the nonsafety-net hospitals prior to referral, with 55.53% of appropriate care given in the safety-net vs 40.3% in the nonsafety-net setting (P <.01). Clinicians in the safety-net hospitals were more likely to adhere to QIs in patients with general, stress, and urgency incontinence. CONCLUSION: Women were more likely to receive timely, quality-based UI care in the safety net compared to the nonsafety-net setting. This may be in part due to aspects unique to the safety-net system, including an eConsult referral system, which guides referring clinicians in appropriate management steps that should be taken prior to the specialist visit, as well as women's health-focused primary care clinics.
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BACKGROUND AND AIMS: The relationship between primary biliary cholangitis (PBC) and metabolic dysfunction-associated steatotic liver disease, and its impact on treatment response and prognosis, remains underexplored. METHODS: Patient cohort from two centres comprising long-term follow-up data. All patients had histologically confirmed PBC. Biopsies were classified according to Non-Alcoholic Steatohepatitis Clinical Research Network. Diagnosis of metabolic dysfunction-associated steatotic liver disease was established when steatosis exceeded 5%, along with at least one metabolic risk factor. Patients with specific aetiologies of steatosis, other liver diseases, incomplete results and inadequate treatment with ursodeoxycholic acid were excluded. Data from patients initiating second-line treatment were censored. Treatment response was assessed using the Toronto, Paris II and AST-to-platelet at 12-month criteria. The UK PBC and Globe scores, and liver events were utilized as outcome measures. RESULTS: The study included 129 patients, 36 showing histologically confirmed overlap between PBC and steatosis. Patients with overlap showed worse prognosis according to Paris II (61.1% vs. 33.3%, p = 0.004), Toronto (52.5% vs. 24.7%, p = 0.002), AST-to-platelet 12-month >0.54 (36.1% vs. 17.2%, p = 0.021), Globe >0.30 (49.2% vs. 29.2%, p = 0.033) and UK PBC at 5, 10 and 15 years (p ≤ 0.001). Liver-related mortality and liver transplant were more prevalent in the overlap group (p = 0.001). In the multivariate analysis, steatosis, dyslipidaemia and advanced fibrosis were independently associated to worse outcomes. CONCLUSIONS: Our findings suggest that metabolic dysfunction-associated steatotic liver disease worsens the prognosis of PBC.
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Cirrosis Hepática Biliar , Humanos , Femenino , Masculino , Persona de Mediana Edad , Cirrosis Hepática Biliar/complicaciones , Anciano , Pronóstico , Ácido Ursodesoxicólico/uso terapéutico , Hígado Graso/complicaciones , Resultado del Tratamiento , Factores de Riesgo , Enfermedad del Hígado Graso no Alcohólico/complicaciones , Adulto , Estudios Retrospectivos , Estudios de CohortesRESUMEN
BACKGROUND: Volatile compounds are key elements in the interaction and communication between organisms at both interspecific and intraspecific levels. In complex bacterial communities, the emission of these fast-acting chemical messengers allows an exchange of information even at a certain distance that can cause different types of responses in the receiving organisms. The changes in secondary metabolism as a consequence of this interaction arouse great interest in the field of searching for bioactive compounds since they can be used as a tool to activate silenced metabolic pathways. Regarding the great metabolic potential that the Actinobacteria group presents in the production of compounds with attractive properties, we evaluated the reply the emitted volatile compounds can generate in other individuals of the same group. RESULTS: We recently reported that volatile compounds released by different streptomycete species trigger the modulation of biosynthetic gene clusters in Streptomyces spp. which finally leads to the activation/repression of the production of secondary metabolites in the recipient strains. Here we present the application of this rationale in a broader bacterial community to evaluate volatiles as signaling effectors that drive the activation of biosynthesis of bioactive compounds in other members of the Actinobacteria group. Using cocultures of different actinobacteria (where only the volatile compounds reach the recipient strain) we were able to modify the bacterial secondary metabolism that drives overproduction (e.g., granaticins, actiphenol, chromomycins) and/or de novo production (e.g., collismycins, skyllamycins, cosmomycins) of compounds belonging to different chemical species that present important biological activities. CONCLUSIONS: This work shows how the secondary metabolism of different Actinobacteria species can vary significantly when exposed in co-culture to the volatile compounds of other phylum-shared bacteria, these effects being variable depending on strains and culture media. This approach can be applied to the field of new drug discovery to increase the battery of bioactive compounds produced by bacteria that can potentially be used in treatments for humans and animals.
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Actinobacteria , Metabolismo Secundario , Compuestos Orgánicos Volátiles , Actinobacteria/metabolismo , Actinobacteria/genética , Compuestos Orgánicos Volátiles/metabolismo , Streptomyces/metabolismo , Streptomyces/genética , Familia de MultigenesRESUMEN
Fundamento: la aterosclerosis es una enfermedad de origen multifactorial que se agrava a consecuencia de un medio ambiente adverso y de estilos de vida no saludables. Las evidencias confirman su inicio desde las etapas más tempranas de la vida. Objetivo: describir la presencia de lesiones ateroscleróticas tempranas en las aortas de fetos y neonatos fallecidos hijos de madres hipertensas. Método: se realizó un estudio descriptivo de tipo transversal que incluyó a los fetos mayores de 22 semanas y neonatos fallecidos hijos de madres hipertensas, a quienes se les realizó autopsia en el departamento de anatomía patológica, del Hospital Universitario Ginecobstétrico Eusebio Hernández Pérez, en el período comprendido entre enero del 2021 hasta diciembre 2022, con un total de 18. Se recogieron los siguientes datos en las historias clínicas: sexo del fallecido, edad gestacional en el momento del parto, peso postparto, edad materna y antecedentes de hipertensión arterial (crónica o gestacional). Se analizaron las 18 aortas (torácicas y abdominales) de los fallecidos seleccionados. Resultados: del total de fallecidos estudiados el 70,6 % presentó lesiones ateroscleróticas tempranas, caracterizadas por engrosamiento de la íntima a modo de cojinete, presencia de linfocitos en la íntima o en la pared arterial cercana a ella y/o macrófagos. En algunos casos se observó una de estas variantes histológicas y en otros la combinación de dos o tres. Conclusiones: las lesiones ateroscleróticas tempranas están presentes en las aortas de la mayoría de los fetos y neonatos estudiados, con predominio en las que presentaban hipertensión gestacional.
Foundation: atherosclerosis is a disease of multifactorial origin that is aggravated as a result of an adverse environment and unhealthy lifestyles. Evidence confirms its onset from the earliest stages of life. Objective: to describe the presence of early atherosclerotic lesions in the aortas of deceased fetuses and neonates born to hypertensive mothers. Method: a descriptive cross-sectional study was carried out that included fetuses older than 22 weeks and deceased neonates born to hypertensive mothers, who underwent autopsy in the pathological anatomy department of the Eusebio Hernández Pérez Gynecobstetric University Hospital, in the period between January 2021 and December 2022, with a total of 18. The following data were collected in the medical records: sex of the deceased, gestational age at the time of delivery, postpartum weight, maternal age, and history of arterial hypertension (chronic or gestational). The 18 aortas (thoracic and abdominal) of the selected deceased were analyzed. Results: of the total number of deceased studied, 70.6 % presented early atherosclerotic lesions, characterized by thickening of the intima as a cushion, presence of lymphocytes in the intima or in the arterial wall close to it and/or macrophages. In some cases, one of these histological variants was observed and in others a combination of two or three. Conclusions: early atherosclerotic lesions are present in the aortas of the majority of the fetuses and neonates studied, with a predominance in those with gestational hypertension.
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In recent years, the study of volatile compounds has sparked interest due to their implications in signaling and the enormous variety of bioactive properties attributed to them. Despite the absence of analysis methods standardization, there are a multitude of tools and databases that allow the identification and quantification of volatile compounds. These compounds are chemically heterogeneous and their diverse properties are exploited by various fields such as cosmetics, the food industry, agriculture and medicine, some of which will be discussed here. In virtue of volatile compounds being ubiquitous and fast chemical messengers, these molecules mediate a large number of interspecific and intraspecific interactions, which are key at an ecological level to maintaining the balance and correct functioning of ecosystems. This review briefly summarized the role of volatile compounds in inter- and intra-specific relationships as well as industrial applications associated with the use of these compounds that is emerging as a promising field of study.
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Microbiota , Compuestos Orgánicos Volátiles , Humanos , Ecosistema , Compuestos Orgánicos Volátiles/análisis , Compuestos Orgánicos Volátiles/química , Nariz Electrónica , IndustriasRESUMEN
RESUMEN Introducción. El consumo de alimentos industrializados que contienen organismos genéticamente modificados (OGM) se ha incrementado notablemente. Desde su inicio ha generado crecientes controversias debido a que se considera de riesgo para la salud. En Perú se carece de información científica sobre los OGM en alimentos industrializados. Objetivo. Detectar y cuantificar molecularmente los indicadores de transgenicidad P35S y TNOS, y la soya transgénica Roundup Ready en alimentos industrializados de soya; y verificar su mención en la etiqueta. Métodos. Analizamos 30 muestras, para extraer el ADN utilizamos los kits Dneasy Mericon Food y Dneasy Power Soil. Para la detección y cuantificación de las secuencias transgénicas usamos la técnica PCR en tiempo real con los kits Mericon. Resultados. Detectamos transgenicidad en el 100% de las muestras y soya Roundup Ready en el 66,7%. El número de copias/mL o g de muestra osciló entre 1,21E+0 y 8,88E+7. En el etiquetado del 93,3% de las muestras no hubo referencia a componentes transgénicos. Conclusión. Los hallazgos evidencian la urgente necesidad de que la legislación vigente se actualice de acuerdo con los conocimientos científicos y el desarrollo socioeconómico del país, protegiendo la salud y el derecho a la información de la población.
ABSTRACT Introduction. The consumption of industrialized foods that contain genetically modified organisms (GMOs) has increased significantly. Since its inception, it has generated growing controversies because it is considered a health risk. In Peru there is a lack of scientific information on GMOs in industrialized foods. Objetive. Molecularly detect and quantify transgenicity indicators P35S and TNOS, and of Roundup Ready transgenic soybeans in industrialized soy foods and verify their mention on the label. Methods. 30 samples were analyzed; To extract the DNA, the Dneasy Mericon Food and Dneasy Power Soil Kits were used, and for the detection and quantification of the transgenic sequences, the real-time PCR technique with the Mericon kits. In addition, the labeling was reviewed. Results. Transgenicity was detected in 100% of the samples and Soy RR in 66,67%; The number of copies/mL or g of sample ranged between 1,21E+0 and 8,88E+7 and in the labeling of 93,3% of the samples there was no reference to transgenic components. Conclusion. The findings show the urgent need for current legislation to be updated in accordance with the scientific knowledge and the socioeconomic development of the country, protecting health and the right to population information.
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Piperazic acid is a cyclic nonproteinogenic amino acid that contains a hydrazine N-N bond formed by a piperazate synthase (KtzT-like). This amino acid, found in bioactive natural products synthesized by non-ribosomal peptide synthetases (NRPSs), confers conformational constraint to peptides, an important feature for their biological activities. Genome mining of Streptomyces strains has been revealed as a strategy to identify biosynthetic gene clusters (BGCs) for potentially active compounds. Moreover, the isolation of new strains from underexplored habitats or associated with other organisms has allowed to uncover new BGCs for unknown compounds. The in-house "Carlos Sialer (CS)" strain collection consists of seventy-one Streptomyces strains isolated from the cuticle of leaf-cutting ants of the tribe Attini. Genomes from twelve of these strains have been sequenced and mined using bioinformatics tools, highlighting their potential to encode secondary metabolites. In this work, we have screened in silico those genomes, using KtzT as a hook to identify BGCs encoding piperazic acid-containing compounds. This resulted in uncovering the new BGC dpn in Streptomyces sp. CS113, which encodes the biosynthesis of the hybrid polyketide-depsipeptide diperamycin. Analysis of the diperamycin polyketide synthase (PKS) and NRPS reveals their functional similarity to those from the aurantimycin A biosynthetic pathway. Experimental proof linking the dpn BGC to its encoded compound was achieved by determining the growth conditions for the expression of the cluster and by inactivating the NRPS encoding gene dpnS2 and the piperazate synthase gene dpnZ. The identity of diperamycin was confirmed by High-Resolution Mass Spectrometry (HRMS) and Nuclear Magnetic Resonance (NMR) and by analysis of the domain composition of modules from the DpnP PKS and DpnS NRPS. The identification of the dpn BGC expands the number of BGCs that have been confirmed to encode the relatively scarcely represented BGCs for depsipeptides of the azinothricin family of compounds and will facilitate the generation of new-to-nature analogues by combinatorial biosynthesis.
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Depsipéptidos , Piridazinas , Streptomyces , Streptomyces/genética , Streptomyces/metabolismo , Péptidos Catiónicos Antimicrobianos/metabolismo , Sintasas Poliquetidas/genética , Sintasas Poliquetidas/metabolismo , Familia de Multigenes , Depsipéptidos/genética , Depsipéptidos/metabolismo , Aminoácidos/metabolismoRESUMEN
The incidence of ovarian cancer has been epidemiologically related to female reproductive events and hormone replacement therapy after menopause. This highlights the importance of evaluating the role of sexual steroid hormones in ovarian cancer by the expression of enzymes related to steroid hormone biosynthesis in the tumor cells. This study was aimed to evaluate the presence of 17ß-hydroxysteroid dehydrogenase type 1 (17ß-HSD1), aromatase and estrogen receptor alpha (ERα) in the tumor cells and their association with the overall survival in 111 patients diagnosed with primary ovarian tumors. Positive immunoreactivity for 17ß-HSD1 was observed in 74% of the tumors. In the same samples, aromatase and ERα revealed 66% and 47% positivity, respectively. No association was observed of 17ß-HSD1 expression with the histological subtypes and clinical stages of the tumor. The overall survival of patients was improved in 17ß-HSD1-positive group in Kaplan-Meier analysis (P = 0.028), and 17ß-HSD1 expression had a protective effect from multivariate proportional regression evaluation (HR = 0.44; 95% CI 0.24-0.9; P = 0.040). The improved survival was observed in serous epithelial tumors but not in nonserous ovarian tumors. The expression of 17ß-HSD1 in the cells of the serous epithelial ovarian tumors was associated with an improved overall survival, whereas aromatase and ERα were not related to a better survival. The evaluation of hazard risk factors demonstrated that age and clinical stage showed worse prognosis, and 17ß-HSD1 expression displayed a protective effect with a better survival outcome in patients of epithelial ovarian tumors.
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Three novel lipopeptides, PM130391 (1), PM130392 (2), and PM140293 (3) were obtained from cultures of Streptomyces tuirus PHM034 isolated from a marine sediment. Structural elucidation of the three compounds showed they belong to the nonribosomal peptides family, and they all contain an acylated alanine, three piperazic acids, a methylated glycine, and an N-hydroxylated alanine. The difference between the three compounds resides in the acyl chain bound to the alanine residue. All three compounds showed cytotoxic activity against human cancer cell lines. Genome sequence and bioinformatics analysis allowed the identification of the gene cluster responsible for the biosynthesis. Inactivation of a nonribosomal peptide synthase of this cluster abolished the biosynthesis of the three compounds, thus demonstrating the involvement of this cluster in the biosynthesis of these lipopeptides.
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Introducción. El consumo de alimentos transgénicos constituye un riesgo potencial para la salud. Sin embargo, en el Perú se carece de información actualizada y confiable sobre la presencia de transgénicos en los alimentos y sobre los datos pertinentes en su etiquetado; de igual manera sobre los alimentos que consumen los animales de abasto, cuyos productos van a ser ingeridos por el humano. Objetivo. Determinar la transgenicidad, mediante la detección del promotor 35S, en productos alimenticios industrializados de maíz para consumo humano y animal, que se comercializan en Lima y verificar sí en el etiquetado se menciona si contiene o no secuencias transgénicas. Métodos. Se analizaron 30 muestras de alimentos para consumo humano y 10 para consumo de animales de abasto; y se revisó el etiquetado. Para la extracción del ADN se utilizó el kit Dneasy Mericon Food, para la detección del P35S el método Real Time-PCR empleando el kit Mericon Screen 35S y para determinar la concentración de copias el kit Mericon Quant Mon 810. Resultados. Se detectó el P35S en el 66,66% de las muestras para consumo humano, y en el 90,00% de las muestras para consumo animal. En el etiquetado del 100% de las muestras para consumo humano y animal no se menciona si contiene o no componentes transgénicos. Conclusiones. La detección de contenido transgénico en la mayoría de los alimentos industrializados de maíz para humanos y animales evidencian la necesidad de su mención en el etiquetado y de la implementación de una política exigente en bioseguridad alimentaria.
Introduction. Consumption of transgenic foods constitutes a potential health risk. However, in Peru there is a lack of updated and reliable information on the presence of transgenics in food and on the relevant data on their labeling; in the same way about the food consumed by animals for supply, whose products are going to be ingested by humans. Objetive. To determine the transgenicity, through the detection of the 35S promoter, in industrialized corn food products for human and animal consumption, which are marketed in Lima and to verify if the labeling mentions whether or not it contains transgenic sequences. Methods. 30 food samples for human consumption and 10 for consumption by animals for production were analyzed; and the labeling was revised. The Dneasy Mericon Food kit was used for DNA extraction, the Real Time-PCR method for P35S detection using the Mericon Screen 35S kit, and the Mericon Quant Mon 810 kit to determine the copy concentration. Results. P35S was detected in 66,66% of the samples for human consumption, and in 90.00% of the samples for animal consumption. The labeling of 100% of the samples for human and animal consumption does not mention whether or not it contains transgenic components. Conclusions. The detection of transgenic content in the majority of industrialized corn foods for humans and animals demonstrates the need to mention them on the label and the implementation of a demanding policy on food biosafety.
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The study of volatile organic compounds (VOCs) has expanded because of the growing need to search for new bioactive compounds that could be used as therapeutic alternatives. These small molecules serve as signals to establish interactions with other nearby organisms in the environment. In this work, we evaluated the antifungal effect of VOCs produced by different Streptomyces spp. This study was performed using VOC chamber devices that allow for the free exchange of VOCs without physical contact between microorganisms or the diffusible compounds they produce. Antifungal activity was tested against Escovopsis weberi, a fungal pathogen that affects ant nest stability, and the results showed that Streptomyces spp. CS014, CS057, CS131, CS147, CS159, CS207, and CS227 inhibit or reduce the fungal growth with their emitted VOCs. A GS-MS analysis of volatiles produced and captured by activated charcoal suggested that these Streptomyces strains synthesize several antifungal VOCs, many of them produced because of the presence of E. weberi, with the accumulation of various VOCs determining the growth inhibition effect.
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The search for novel bioactive compounds to overcome resistance to current therapeutics has become of utmost importance. Streptomyces spp. are one of the main sources of bioactive compounds currently used in medicine. In this work, five different global transcriptional regulators and five housekeeping genes, known to induce the activation or overproduction of secondary metabolites in Streptomyces coelicolor, were cloned in two separated constructs and expressed in 12 different strains of Streptomyces spp. from the in-house CS collection. These recombinant plasmids were also inserted into streptomycin and rifampicin resistant Streptomyces strains (mutations known to enhance secondary metabolism in Streptomyces). Different media with diverse carbon and nitrogen sources were selected to assess the strains' metabolite production. Cultures were then extracted with different organic solvents and analysed to search for changes in their production profiles. An overproduction of metabolites already known to be produced by the biosynthesis wild-type strains was observed such as germicidin by CS113, collismycins by CS149 and CS014, or colibrimycins by CS147. Additionally, the activation of some compounds such as alteramides in CS090a pSETxkBMRRH and CS065a pSETxkDCABA or inhibition of the biosynthesis of chromomycins in CS065a in pSETxkDCABA when grown in SM10 was demonstrated. Therefore, these genetic constructs are a relatively simple tool to manipulate Streptomyces metabolism and explore their wide secondary metabolites production potential.
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Genome mining using standard bioinformatics tools has allowed for the uncovering of hidden biosynthesis gene clusters for specialized metabolites in Streptomyces genomes. In this work, we have used an alternative approach consisting in seeking "Streptomyces Antibiotic Regulatory Proteins" (SARP) encoding genes and analyzing their surrounding DNA region to unearth cryptic gene clusters that cannot be identified using standard bioinformatics tools. This strategy has allowed the unveiling of the new ahb cluster in Streptomyces argillaceus, which had not been retrieved before using antiSMASH. The ahb cluster is highly preserved in other Streptomyces strains, which suggests a role for their encoding compounds in specific environmental conditions. By combining overexpression of three regulatory genes and generation of different mutants, we were able to activate the ahb cluster, and to identify and chemically characterize the encoded compounds that we have named ahbamycins (AHBs). These constitute a new family of metabolites derived from 3-amino-4-hydroxybenzoate (3,4-AHBA) known for having antibiotic and antitumor activity. Additionally, by overexpressing three genes of the cluster (ahbH, ahbI, and ahbL2) for the synthesis and activation of 3,4-AHBA, a new hybrid compound, AHB18, was identified which had been produced from a metabolic crosstalk between the AHB and the argimycin P pathways. The identification of this new BGC opens the possibility to generate new compounds by combinatorial biosynthesis.
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Antibacterianos , Streptomyces , Antibacterianos/química , Factores de Transcripción/metabolismo , Familia de Multigenes , Genes Reguladores , Streptomyces/genética , Streptomyces/metabolismo , Hidroxibenzoatos/metabolismoRESUMEN
The increasing appearance of multiresistant pathogens, as well as emerging diseases, has highlighted the need for new strategies to discover natural compounds that can be used as therapeutic alternatives, especially in the genus Streptomyces, which is one of the largest producers of bioactive metabolites. In recent years, the study of volatile compounds (VOCs) has raised interest because of the variety of their biological properties in addition to their involvement in cell communication. In this work, we analyze the implications of VOCs as mediating molecules capable of inducing the activation of biosynthetic pathways of bioactive compounds in surrounding Actinomycetes. For this purpose, several strains of Streptomyces were co-cultured in chamber devices that allowed VOC exchange while avoiding physical contact. In several of those strains, secondary metabolism was activated by VOCs emitted by companion strains, resulting in increased antibiotic production and synthesis of new VOCs. This study shows a novel strategy to exploit the metabolic potential of Actinomycetes as well as emphasizes the importance of studying the interactions between different microorganisms sharing the same ecological niche.
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Actinobacteria , Streptomyces , Actinobacteria/genética , Streptomyces/genética , Streptomyces/metabolismo , Familia de Multigenes , Vías Biosintéticas/genética , Descubrimiento de DrogasRESUMEN
Coelimycin P1 and argimycins P are two types of polyketide alkaloids produced by Streptomyces coelicolor and Streptomyces argillaceus, respectively. Their biosynthesis pathways share some early steps that render very similar aminated polyketide chains, diverging the pathways afterwards. By expressing the putative isomerase cpkE and/or the putative epoxidase/dehydrogenase cpkD from the coelimycin P1 gene cluster into S. argillaceus wild type and in argimycin mutant strains, five novel hybrid argimycins were generated. Chemical characterization of those compounds revealed that four of them show unprecedented scaffolds (quinolizidine and pyranopyridine) never found before in the argimycin family of compounds. One of these compounds (argimycin DM104) shows improved antibiotic activity. Noticeable, biosynthesis of these quinolizidine argimycins results from a hybrid pathway created by combining enzymes from two different pathways, which utilizes an aminated polyketide chain as precursor instead of lysine as it occurs for other quinolizidines.
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Plicamicina , Streptomyces , Plicamicina/química , Plicamicina/metabolismo , Familia de Multigenes , Antibacterianos/metabolismoRESUMEN
Objectives: The start of the COVID-19 pandemic led the Los Angeles safety net health system to dramatically reduce in-person visits and transition abruptly to telehealth/telemedicine services to deliver clinical care (remote telephone and video visits). However, safety net patients and the settings that serve them face a "digital divide" that could impact effective implementation of such digital care. The study objective was to examine attitudes and perspectives of leadership and frontline staff regarding telehealth integration in the Los Angeles safety net, with a focus on telemedicine video visits. Methods: This qualitative study took place in the Los Angeles County Department of Health Services (LAC DHS), the second-largest safety net health system in the US. This system disproportionately serves the uninsured, Medicaid, racial/ethnic minority, low-income, and Limited English Proficient (LEP) patient populations of Los Angeles County. Staff and leadership personnel from each of the five major LAC DHS hospital center clinics, and community-based clinics from the LAC DHS Ambulatory Care Network (ACN) were individually interviewed (video or phone calls), and discussions were recorded. Interview guides were based on the Consolidated Framework for Implementation Research (CFIR), and included questions about the video visit technology platform and its usability, staff resources, clinic needs, and facilitators and barriers to general telehealth implementation and use. Interviews were analyzed for summary of major themes. Results: Twenty semi-structured interviews were conducted in August to October 2020. Participants included LAC DHS physicians, nurses, medical assistants, and physical therapists with clinical and/or administrative roles. Narrative themes surrounding telehealth implementation, with video visits as the case study, were identified and then categorized at the patient, clinic (including provider), and health system levels. Conclusions: Patient, clinic, and health system level factors must be considered when disseminating telehealth services across the safety net. Participant discussions illustrated how multilevel facilitators and barriers influenced the feasibility of video visits and other telehealth encounters. Future research should explore proposed solutions from frontline stakeholders as testable interventions towards advancing equity in telehealth implementation: from patient training and support, to standardized workflows that leverage the expertise of multidisciplinary teams.
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Largimycins A1 and A2 are key members of a recently identified family of hybrid nonribosomal peptide polyketides belonging to the scarcely represented group of antitumor leinamycins. They are encoded by the gene cluster lrg of Streptomyces argillaceus. This cluster contains a halogenase gene and two sets of genes for the biosynthesis and incorporation of ß branches at C3 and C9. Noticeably, largimycins A1 and A2 are nonhalogenated compounds and only contain a ß branch at C3. By generating mutants in those genes and characterizing chemically their accumulated compounds, we could confirm the existence of a chlorination step at C19, the introduction of an acetyl-derived olefinic exomethylene group at C9, and a propionyl-derived ß branch at C3 in the biosynthesis pathway. Since the olefinic exomethylene group and the chlorine atom are absent in the final products, those biosynthetic steps can be considered cryptic in the overall pathway but essential to generating keto and epoxide functionalities at C9 and C18/C19, respectively. We propose that chlorination at C19 is utilized as an activation strategy that creates the precursor halohydrin to finally yield the epoxy functionality at C18/C19. This represents a novel strategy to create such functionalities and extends the small number of natural product biosynthetic pathways that include a cryptic chlorination step.