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1.
BMC Infect Dis ; 24(1): 948, 2024 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-39256671

RESUMEN

BACKGROUND: Measles remains a major public health burden worldwide. Parents often hesitate to vaccinate children with chronic diseases. We investigated the association between the percentage of vaccination and chronic diseases and explore hospital infections' role in the 2017-2019 measles outbreak across northern Vietnam provinces. METHODS: A total of 2,064 children aged 0-15 years old admitted for measles to the National Children's Hospital during the outbreak were included in the study. Demographic information, clinical characteristics, vaccination statuses and laboratory examination were extracted from electronic medical records, vaccination records, or interviews with parents when other sources were unavailable. RESULTS: The incidence rate that provincial hospitals sent to the National Children's Hospital was proportional to the population density of their provinces of residence. Early nosocomial transmission of measles was observed before community-acquired cases emerged in many provinces. Among patients aged over 18 months, those with chronic diseases had a proportion of vaccination of 9.4%, lower than patients without chronic diseases at 32.4%. Unvaccinated patients had a higher proportion of hospital-acquired infections with aOR = 2.42 (1.65-3.65), p < 0.001 relative to vaccinated patients. The proportion of hospital-acquired infections was higher among children with chronic diseases compared to those without, with aOR = 3.81 (2.90-5.02), p < 0.001. CONCLUSION: Measles spread in healthcare settings prior to community cases that occurred in several provinces. We recommend enhancing hospital infection control by increasing staff training and improving early detection and isolation during non-outbreak periods. Measles patients with chronic diseases exhibited lower proportions of vaccination and faced a higher risk of hospital-acquired infections. It is crucial to establish comprehensive vaccination guidelines and enhance parental awareness regarding the significance and safety of measles vaccination to protect these vulnerable individuals.


Asunto(s)
Infección Hospitalaria , Brotes de Enfermedades , Vacuna Antisarampión , Sarampión , Vacunación , Humanos , Vietnam/epidemiología , Sarampión/epidemiología , Sarampión/prevención & control , Preescolar , Niño , Infección Hospitalaria/epidemiología , Infección Hospitalaria/prevención & control , Masculino , Lactante , Adolescente , Femenino , Enfermedad Crónica/epidemiología , Vacunación/estadística & datos numéricos , Recién Nacido , Vacuna Antisarampión/administración & dosificación , Incidencia
2.
Molecules ; 29(10)2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38792114

RESUMEN

Flavonoids and stilbenoids, crucial secondary metabolites abundant in plants and fungi, display diverse biological and pharmaceutical activities, including potent antioxidant, anti-inflammatory, and antimicrobial effects. However, conventional production methods, such as chemical synthesis and plant extraction, face challenges in sustainability and yield. Hence, there is a notable shift towards biological production using microorganisms like Escherichia coli and yeast. Yet, the drawbacks of using E. coli and yeast as hosts for these compounds persist. For instance, yeast's complex glycosylation profile can lead to intricate protein production scenarios, including hyperglycosylation issues. Consequently, Corynebacterium glutamicum emerges as a promising alternative, given its adaptability and recent advances in metabolic engineering. Although extensively used in biotechnological applications, the potential production of flavonoid and stilbenoid in engineered C. glutamicum remains largely untapped compared to E. coli. This review explores the potential of metabolic engineering in C. glutamicum for biosynthesis, highlighting its versatility as a cell factory and assessing optimization strategies for these pathways. Additionally, various metabolic engineering methods, including genomic editing and biosensors, and cofactor regeneration are evaluated, with a focus on C. glutamicum. Through comprehensive discussion, the review offers insights into future perspectives in production, aiding researchers and industry professionals in the field.


Asunto(s)
Corynebacterium glutamicum , Flavonoides , Ingeniería Metabólica , Estilbenos , Corynebacterium glutamicum/metabolismo , Corynebacterium glutamicum/genética , Ingeniería Metabólica/métodos , Flavonoides/biosíntesis , Flavonoides/metabolismo , Estilbenos/metabolismo
3.
BMC Public Health ; 24(1): 286, 2024 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-38267959

RESUMEN

BACKGROUND: Pertussis is a highly contagious and dangerous respiratory disease that threatens children's health in many countries, including Vietnam, despite vaccine coverage. From 2015 to 2018, Vietnam experienced an increasing number of pertussis patients. Therefore, this study aimed to investigate the trend and examine the seasonal variations of pertussis in North Vietnam. METHODS: Data were collected from medical records of all under-5-year-old inpatients admitted to the National Children's Hospital in Hanoi, Vietnam (VNCH) 2015-2018. A descriptive analysis was performed to describe the distribution of incident cases by year and season. Linear multivariable regression was conducted to investigate the association between the incidence of cases and seasonality adjusted by age and vaccination status. RESULTS: We identified 1063 laboratory-confirmed patients during 2015-2018, including 247 (23.2%) severe patients. The number of pertussis patients admitted to VNCH per 1000 hospitalizations was 3.2 in 2015, compared to 1.9, 3.1, and 2.1 in 2016, 2017, and 2018, respectively. Outbreaks occurred biennially; however, there was no significant difference in the number of severe patients over this period. Most cases occurred in the hot season (509 patients, or nearly half of the study population). With the adjustment of the vaccination rate and average age, the risk of pertussis-associated hospitalization in the mild season and the hot season was 21% (95% CI [0.12; 0.3]) and 15% (95% CI [0.05; 0.25]) higher than that in the warm season, respectively. The rate of hospitalizations was high in the mild season (28.9%) and the warm season (30.8%), nearly twice as much as that in the hot season; nevertheless, the death rate was only striking high in the mild season, about 5-6 times as much as those in the other seasons. CONCLUSION: The pertussis incidence in Northern Vietnam varied between seasons, peaking in the hot season (April-July). However, severe patients and deaths increased in the mild season (December-March). Interventions, for example, communication activities on pertussis and vaccination, are of immense importance in lowering the prevalence of pertussis. In addition, early diagnoses and early warnings performed by health professionals should be encouraged.


Asunto(s)
Tos Ferina , Niño , Humanos , Estaciones del Año , Vietnam/epidemiología , Centros de Atención Terciaria , Tos Ferina/epidemiología , Tos Ferina/prevención & control , Clima
4.
J Innate Immun ; 15(1): 911-924, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37989107

RESUMEN

INTRODUCTION: A role for innate immune memory in protection during COVID-19 infection or vaccination has been recently reported. However, no study so far has shown whether the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can train innate immune cells. The aim of this study was to investigate whether this virus can induce trained immunity in human monocytes. METHODS: Monocytes were exposed to inactivated SARS-CoV-2 (iSARS-CoV-2) for 24 h, followed by a resting period in the medium only and a secondary stimulation on day 6 after which the cytokine/chemokine and transcriptomic profiles were determined. RESULTS: Compared to untrained cells, the iSARS-CoV-2-trained monocytes secreted significantly higher levels of IL-6, TNF-α, CXCL10, CXCL9, and CXCL11 upon restimulation. Transcriptome analysis of iSARS-CoV-2-trained monocytes revealed increased expression of several inflammatory genes. As epigenetic and metabolic modifications are hallmarks of trained immunity, we analyzed the expression of genes related to these processes. Findings indicate that indeed SARS-CoV-2-trained monocytes show changes in the expression of genes involved in metabolic pathways including the tricarboxylic acid cycle, amino acid metabolism, and the expression of several epigenetic regulator genes. Using epigenetic inhibitors that block histone methyl and acetyltransferases, we observed that the capacity of monocytes to be trained by iSARS-CoV-2 was abolished. CONCLUSION: Overall, our findings indicate that iSARS-CoV-2 can induce properties associated with trained immunity in human monocytes. These results contribute to the knowledge required for improving vaccination strategies to prevent infectious diseases.


Asunto(s)
COVID-19 , Monocitos , Humanos , SARS-CoV-2 , Inmunidad Entrenada , Inmunidad Innata , Quimiocina CXCL10/metabolismo
5.
Data Brief ; 49: 109305, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37346928

RESUMEN

This paper presents a dataset from a survey of student perceptions and experiences of quality assurance in Vietnamese higher education institutions. Data were collected from July to September 2020 using the online survey via Google Forms. The survey was sent to students via their email and social media, and there were 1323 valid responses. The data collection instrument was developed based on an international survey administered by UNESCO. The survey was designed to elicit data with respect to students' views on institutional quality policy and model, quality assurance procedures and tools, and student survey. The dataset serves as an insightful reference for institutional practitioners and policymakers in quality assurance to revise internal quality assurance policies and instruments to enhance the quality of teaching and learning. Moreover, the dataset could be of interest to other educational researchers who can use it to investigate students' understanding and viewpoints on quality assurance.

7.
Front Immunol ; 14: 1282859, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38414974

RESUMEN

Introduction: The COVID-19 Disease Map project is a large-scale community effort uniting 277 scientists from 130 Institutions around the globe. We use high-quality, mechanistic content describing SARS-CoV-2-host interactions and develop interoperable bioinformatic pipelines for novel target identification and drug repurposing. Methods: Extensive community work allowed an impressive step forward in building interfaces between Systems Biology tools and platforms. Our framework can link biomolecules from omics data analysis and computational modelling to dysregulated pathways in a cell-, tissue- or patient-specific manner. Drug repurposing using text mining and AI-assisted analysis identified potential drugs, chemicals and microRNAs that could target the identified key factors. Results: Results revealed drugs already tested for anti-COVID-19 efficacy, providing a mechanistic context for their mode of action, and drugs already in clinical trials for treating other diseases, never tested against COVID-19. Discussion: The key advance is that the proposed framework is versatile and expandable, offering a significant upgrade in the arsenal for virus-host interactions and other complex pathologies.


Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Reposicionamiento de Medicamentos , Biología de Sistemas , Simulación por Computador
8.
Adv Respir Med ; 90(6): 500-510, 2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36547011

RESUMEN

Introduction: Despite the theoretical importance of serum immunoglobulin (Ig) in the outcome of COPD exacerbations, the existing evidence for this has not been enough. This study was performed to evaluate changes in serum Ig levels and their relationship with outcomes of acute infectious exacerbations in patients with COPD. Methods: The prospective study was conducted at Military Hospital 103 from August 2017 to April 2019. Group D patients with COPD with infectious exacerbation were selected for participation in the study. The control group consisted of 30 healthy people. The patients were provided clinical examination and laboratory service; simultaneously, we measured their serum Ig levels (total IgG, IgG1, IgG2, IgG3, IgG4) at two time points: at admission (T1) and the final health outcome (T2). Results: The median levels of total IgG in patients at times T1 and T2 were significantly lower compared with those in the healthy group (1119.3 mg/dL and 1150.6 mg/dL compared with 2032.2 mg/dL) (p < 0.001). Regarding changes among IgG subclasses, the IgG1, IgG3, and IgG4 levels measured at T1 and T2 were reduced significantly compared with the control group (p < 0.05); the IgG3 levels at T1 were significantly higher than those at T2. IgG3 levels in patients with life-threatening exacerbations were significantly lower than the remaining ones (24.6 (26.8−155.5) mg/dL and 25.6 (29.5−161.2) mg/dL, respectively, p = 0.023). Conclusions: In group D patients with COPD with infectious exacerbations, there was a decrease in the serum IgG, IgG1, IgG3, and IgG4 levels. IgG3 levels were associated with the severity of COPD exacerbation.


Asunto(s)
Inmunoglobulina G , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Estudios Prospectivos
9.
Front Immunol ; 13: 963357, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36189295

RESUMEN

The ACE2 receptors essential for SARS-CoV-2 infections are expressed not only in the lung but also in many other tissues in the human body. To better understand the disease mechanisms and progression, it is essential to understand how the virus affects and alters molecular pathways in the different affected tissues. In this study, we mapped the proteomics data obtained from Nie X. et al. (2021) to the pathway models of the COVID-19 Disease Map project and WikiPathways. The differences in pathway activities between COVID-19 and non-COVID-19 patients were calculated using the Wilcoxon test. As a result, 46% (5,235) of the detected proteins were found to be present in at least one pathway. Only a few pathways were altered in multiple tissues. As an example, the Kinin-Kallikrein pathway, an important inflammation regulatory pathway, was found to be less active in the lung, spleen, testis, and thyroid. We can confirm previously reported changes in COVID-19 patients such as the change in cholesterol, linolenic acid, and arachidonic acid metabolism, complement, and coagulation pathways in most tissues. Of all the tissues, we found the thyroid to be the organ with the most changed pathways. In this tissue, lipid pathways, energy pathways, and many COVID-19 specific pathways such as RAS and bradykinin pathways, thrombosis, and anticoagulation have altered activities in COVID-19 patients. Concluding, our results highlight the systemic nature of COVID-19 and the effect on other tissues besides the lung.


Asunto(s)
COVID-19 , Enzima Convertidora de Angiotensina 2 , Anticoagulantes , Ácido Araquidónico , Bradiquinina/metabolismo , Humanos , Calicreínas/metabolismo , Masculino , Peptidil-Dipeptidasa A/metabolismo , Sistema Renina-Angiotensina , Estudios Retrospectivos , SARS-CoV-2 , Ácido alfa-Linolénico
10.
Methods Enzymol ; 672: 339-368, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35934483

RESUMEN

Break-Induced Replication (BIR) is a homologous recombination (HR) pathway that differentiates itself from all other HR pathways by involving extensive DNA synthesis of up to hundreds of kilobases. This DNA synthesis occurs in G2/M arrested cells by a mechanism distinct from regular DNA replication. BIR initiates by strand invasion of a single end of a DNA double-strand break (DSB) followed by extensive D-loop migration. The main replicative helicase Mcm2-7 is dispensable for BIR, however, Pif1 helicase and its PCNA interaction domain are required. Pif1 helicase was shown to be important for extensive repair-specific DNA synthesis at DSB in budding and fission yeasts, flies, and human cells, implicating conservation of the mechanism. Additionally, Mph1 helicase negatively regulates BIR by unwinding migrating D-loops, and Srs2 promotes BIR by eliminating the toxic joint molecules. Here, we describe the methods that address the following questions in studying BIR: (i) how to distinguish enzymes needed specifically for BIR from enzymes needed for other HR mechanisms that require short patch DNA synthesis, (ii) what are the phenotypes expected for mutants deficient in extensive synthesis during BIR, (iii) how to follow extensive DNA synthesis during BIR? Methods are described using yeast model organism and wild-type cells are compared side-by-side with Pif1 deficient cells.


Asunto(s)
Proteínas de Saccharomyces cerevisiae , Roturas del ADN de Doble Cadena , ADN Helicasas/genética , ADN Helicasas/metabolismo , Reparación del ADN , Replicación del ADN , Humanos , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
11.
Nat Commun ; 13(1): 359, 2022 01 18.
Artículo en Inglés | MEDLINE | ID: mdl-35042867

RESUMEN

Single-stranded DNA (ssDNA) commonly occurs as intermediates in DNA metabolic pathways. The ssDNA binding protein, RPA, not only protects the integrity of ssDNA, but also directs the downstream factor that signals or repairs the ssDNA intermediate. However, it remains unclear how these enzymes/factors outcompete RPA to access ssDNA. Using the budding yeast Saccharomyces cerevisiae as a model system, we find that Dna2 - a key nuclease in DNA replication and repair - employs a bimodal interface to act with RPA both in cis and in trans. The cis-activity makes RPA a processive unit for Dna2-catalyzed ssDNA digestion, where RPA delivers its bound ssDNA to Dna2. On the other hand, activity in trans is mediated by an acidic patch on Dna2, which enables it to function with a sub-optimal amount of RPA, or to overcome DNA secondary structures. The trans-activity mode is not required for cell viability, but is necessary for effective double strand break (DSB) repair.


Asunto(s)
ADN Helicasas/metabolismo , ADN de Hongos/metabolismo , ADN de Cadena Simple/metabolismo , Proteína de Replicación A/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Biocatálisis , Supervivencia Celular/efectos de los fármacos , Roturas del ADN de Doble Cadena , Reparación del ADN , Modelos Biológicos , Mutación/genética , Péptidos/metabolismo , Fleomicinas/farmacología , Unión Proteica , Dominios Proteicos , Proteínas de Saccharomyces cerevisiae/química , Tirosina/metabolismo
12.
Environ Geochem Health ; 44(6): 1893-1909, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34480233

RESUMEN

Potentially toxic elements (PTEs), such as Cu, Zn, Pb, Ni, Cr, and Co, can accumulate in vineyard soils due to repeated uses of inorganic pesticides and chemical or organic fertilizers. In sloping vineyards, PTEs can also be moved by soil erosion resulting in their accumulation in low-energy zones within the landscape, adversely affecting the soil environment. Our study evaluated the ecological risk related to the pseudo-total and bioavailable PTE contents (Zn, Pb, Co, Ni, Cr, and Cu) in the soil and eroded sediment samples from an organic vineyard in Tokaj (NE Hungary). The contamination status and the ecological risk of target PTEs were assessed by calculating the contamination factor, the pollution load index, the ecological risk factor, and the ecological risk index. The median pollution load indices of 1.15, 1.81, and 1.10 for the topsoil, the sediments, and the subsoil, respectively, demonstrate a moderate multi-element contamination case in the organic vineyard. Target PTEs tented to show increased concentrations in eroded sediments with the highest enrichment ratio (3.36) observed for Cu (Cu in the sediment/Cu in the topsoil), revealing a preferential movement of Cu-rich soil particles by overland flow. Moreover, PTEs were present in the sediments in more bioavailable forms (except Ni, Cr), assessed by an extraction procedure with EDTA. The ecological risk index (< 90) based on the studied PTEs showed an overall low ecological risk in the vineyard. Copper was the predominant factor of the ecological risk. Moreover, the highest ecological risk factor (24.6) observed for the bioavailable Cu content in an eroded sediment sample (representing 82% of the total ecological risk) shows that Cu accumulation in sloping vineyards is an ecological risk, particularly in the sedimentation zones. The high proportions of bioavailable Cu in the vineyard's soil represent an increasing ecological risk over time, related to repeated treatments of vine plants with Cu-based pesticides.


Asunto(s)
Metales Pesados , Plaguicidas , Contaminantes del Suelo , Monitoreo del Ambiente/métodos , Granjas , Hungría , Plomo , Metales Pesados/análisis , Medición de Riesgo , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/toxicidad
14.
EMBO J ; 40(10): e104847, 2021 05 17.
Artículo en Inglés | MEDLINE | ID: mdl-33844333

RESUMEN

DNA synthesis during homologous recombination is highly mutagenic and prone to template switches. Two-ended DNA double-strand breaks (DSBs) are usually repaired by gene conversion with a short patch of DNA synthesis, thus limiting the mutation load to the vicinity of the DSB. Single-ended DSBs are repaired by break-induced replication (BIR), which involves extensive and mutagenic DNA synthesis spanning up to hundreds of kilobases. It remains unknown how mutagenic BIR is suppressed at two-ended DSBs. Here, we demonstrate that BIR is suppressed at two-ended DSBs by proteins coordinating the usage of two ends of a DSB: (i) ssDNA annealing proteins Rad52 and Rad59 that promote second end capture, (ii) D-loop unwinding helicase Mph1, and (iii) Mre11-Rad50-Xrs2 complex that promotes synchronous resection of two ends of a DSB. Finally, BIR is also suppressed when Sir2 silences a normally heterochromatic repair template. All of these proteins are particularly important for limiting BIR when recombination occurs between short repetitive sequences, emphasizing the significance of these mechanisms for species carrying many repetitive elements such as humans.


Asunto(s)
Reparación del ADN/fisiología , Roturas del ADN de Doble Cadena , Roturas del ADN de Cadena Simple , Reparación del ADN/genética , Replicación del ADN/genética , Replicación del ADN/fisiología , Humanos
15.
Biotechnol Biofuels ; 14(1): 2, 2021 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-33407779

RESUMEN

BACKGROUND: Cutaneotrichosporon oleaginosus ATCC 20509 is a fast-growing oleaginous basidiomycete yeast that is able to grow in a wide range of low-cost carbon sources including crude glycerol, a byproduct of biodiesel production. When glycerol is used as a carbon source, this yeast can accumulate more than 50% lipids (w/w) with high concentrations of mono-unsaturated fatty acids. RESULTS: To increase our understanding of this yeast and to provide a knowledge base for further industrial use, a FAIR re-annotated genome was used to build a genome-scale, constraint-based metabolic model containing 1553 reactions involving 1373 metabolites in 11 compartments. A new description of the biomass synthesis reaction was introduced to account for massive lipid accumulation in conditions with high carbon-to-nitrogen (C/N) ratio in the media. This condition-specific biomass objective function is shown to better predict conditions with high lipid accumulation using glucose, fructose, sucrose, xylose, and glycerol as sole carbon source. CONCLUSION: Contributing to the economic viability of biodiesel as renewable fuel, C. oleaginosus ATCC 20509 can effectively convert crude glycerol waste streams in lipids as a potential bioenergy source. Performance simulations are essential to identify optimal production conditions and to develop and fine tune a cost-effective production process. Our model suggests ATP-citrate lyase as a possible target to further improve lipid production.

16.
Front Microbiol ; 12: 785573, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34975808

RESUMEN

Staphylococcus aureus biofilms are poorly responsive to antibiotics. Underlying reasons include a matrix effect preventing drug access to embedded bacteria, or the presence of dormant bacteria with reduced growth rate. Using 18 clinical isolates previously characterized for their moxifloxacin-resistant and moxifloxacin-persister character in stationary-phase culture, we studied their biofilm production and matrix composition and the anti-biofilm activity of moxifloxacin. Biofilms were grown in microtiter plates and their abundance quantified by crystal violet staining and colony counting; their content in polysaccharides, extracellular DNA and proteins was measured. Moxifloxacin activity was assessed after 24 h of incubation with a broad range of concentrations to establish full concentration-response curves. All clinical isolates produced more biofilm biomass than the reference strain ATCC 25923, the difference being more important for those with high relative persister fractions to moxifloxacin, most of which being also resistant. High biofilm producers expressed icaA to higher levels, enriching the matrix in polysaccharides. Moxifloxacin was less potent against biofilms from clinical isolates than from ATCC 25923, especially against moxifloxacin-resistant isolates with high persister fractions, which was ascribed to a lower concentration of moxifloxacin in these biofilms. Time-kill curves in biofilms revealed the presence of a moxifloxacin-tolerant subpopulation, with low multiplication capacity, whatever the persister character of the isolate. Thus, moxifloxacin activity depends on its local concentration in biofilm, which is reduced in most isolates with high-relative persister fractions due to matrix effects, and insufficient to kill resistant isolates due to their high MIC.

17.
Front Microbiol ; 11: 587364, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33329458

RESUMEN

Staphylococcus aureus may cause relapsing infections. We previously showed that S. aureus SH1000 surviving intracellularly to bactericidal antibiotics are persisters. Here, we used 54 non-duplicate clinical isolates to assess links between persistence, resistance evolution, and intracellular survival, using moxifloxacin throughout as test bactericidal antibiotic. The relative persister fraction (RPF: percentage of inoculum surviving to 100× MIC moxifloxacin in stationary phase culture for each isolate relative to ATCC 25923) was determined to categorize isolates with low (≤10) or high (>10) RPF. Evolution to resistance (moxifloxacin MIC ≥ 0.5 mg/L) was triggered by serial passages at 0.5× MIC (with daily concentration readjustments). Intracellular moxifloxacin maximal efficacy (Emax) was determined by 24 h concentration-response experiments [pharmacodynamic model (Hill-Langmuir)] with infected THP-1 monocytes exposed to moxifloxacin (0.01 to 100× MIC) after phagocytosis. Division of intracellular survivors was followed by green fluorescence protein dilution (FACS). Most (30/36) moxifloxacin-susceptible isolates showed low RPF but all moxifloxacin-resistant (n = 18) isolates harbored high RPF. Evolution to resistance of susceptible isolates was faster for those with high vs. low RPF (with SOS response and topoisomerase-encoding genes overexpression). Intracellularly, moxifloxacin Emax was decreased (less negative) for isolates with high vs. low RPF, independently from resistance. Moxifloxacin intracellular survivors were non-dividing. The data demonstrate and quantitate persisters in clinical isolates of S. aureus, and show that this phenotype accelerates resistance evolution and is associated with intracellular survival in spite of high antibiotic concentrations. Isolates with high RPF may represent a possible cause of treatment failure not directly related to resistance in patients receiving active antibiotics.

18.
PLoS Genet ; 16(10): e1008689, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33057349

RESUMEN

The Rad51/RecA family of recombinases perform a critical function in typical repair of double-strand breaks (DSBs): strand invasion of a resected DSB end into a homologous double-stranded DNA (dsDNA) template sequence to initiate repair. However, repair of a DSB using single stranded DNA (ssDNA) as a template, a common method of CRISPR/Cas9-mediated gene editing, is Rad51-independent. We have analyzed the genetic requirements for these Rad51-independent events in Saccharomyces cerevisiae by creating a DSB with the site-specific HO endonuclease and repairing the DSB with 80-nt single-stranded oligonucleotides (ssODNs), and confirmed these results by Cas9-mediated DSBs in combination with a bacterial retron system that produces ssDNA templates in vivo. We show that single strand template repair (SSTR), is dependent on Rad52, Rad59, Srs2 and the Mre11-Rad50-Xrs2 (MRX) complex, but unlike other Rad51-independent recombination events, independent of Rdh54. We show that Rad59 acts to alleviate the inhibition of Rad51 on Rad52's strand annealing activity both in SSTR and in single strand annealing (SSA). Gene editing is Rad51-dependent when double-stranded oligonucleotides of the same size and sequence are introduced as templates. The assimilation of mismatches during gene editing is dependent on the activity of Msh2, which acts very differently on the 3' side of the ssODN which can anneal directly to the resected DSB end compared to the 5' end. In addition DNA polymerase Polδ's 3' to 5' proofreading activity frequently excises a mismatch very close to the 3' end of the template. We further report that SSTR is accompanied by as much as a 600-fold increase in mutations in regions adjacent to the sequences directly undergoing repair. These DNA polymerase ζ-dependent mutations may compromise the accuracy of gene editing.


Asunto(s)
Sistemas CRISPR-Cas/genética , Reparación del ADN/genética , ADN de Cadena Simple/genética , Desoxirribonucleasas de Localización Especificada Tipo II/genética , Endonucleasas/genética , Proteínas de Saccharomyces cerevisiae/genética , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , ADN Polimerasa Dirigida por ADN/genética , Endodesoxirribonucleasas/genética , Exodesoxirribonucleasas/genética , Oligonucleótidos/genética , Recombinasa Rad51/genética , Proteína Recombinante y Reparadora de ADN Rad52/genética , Rec A Recombinasas/genética , Saccharomyces cerevisiae/genética , ADN Polimerasa theta
19.
PLoS One ; 15(7): e0235718, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32639976

RESUMEN

Sugar alcohols (polyols) are abundant carbohydrates in lichen-forming algae and transported to other lichen symbionts, fungi, and bacteria. Particularly, ribitol is an abundant polyol in the lichen Cetraria sp. Polyols have important physiological roles in lichen symbiosis, but polyol utilization in lichen-associated bacteria has been largely unreported. Herein, we purified and characterized a novel ribitol dehydrogenase (RDH) from a Cetraria sp.-associated bacterium Sphingomonas sp. PAMC 26621 grown on a minimal medium containing D-ribitol (the RDH hereafter referred to as SpRDH). SpRDH is present as a trimer in its native form, and the molecular weight of SpRDH was estimated to be 39 kDa by SDS-PAGE and 117 kDa by gel filtration chromatography. SpRDH converted D-ribitol to D-ribulose using NAD+ as a cofactor. As far as we know, SpRDH is the first RDH belonging to the medium-chain dehydrogenase/reductase family. Multiple sequence alignments indicated that the catalytic amino acid residues of SpRDH consist of Cys37, His65, Glu66, and Glu157, whereas those of short-chain RDHs consist of Ser, Tyr, and Lys. Furthermore, unlike other short-chain RDHs, SpRDH did not require divalent metal ions for its catalytic activity. Despite SpRDH originating from a psychrophilic Arctic bacterium, Sphingomonas sp., it had maximum activity at 60°C and exhibited high thermal stability within the 4-50°C range. Further studies on the structure/function relationship and catalytic mechanism of SpRDH will expand our understanding of its role in lichen symbiosis.


Asunto(s)
Proteínas Bacterianas/aislamiento & purificación , Proteínas Bacterianas/metabolismo , Líquenes/microbiología , Ribitol/metabolismo , Sphingomonas/enzimología , Deshidrogenasas del Alcohol de Azúcar/aislamiento & purificación , Deshidrogenasas del Alcohol de Azúcar/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/genética , Homología de Secuencia , Sphingomonas/crecimiento & desarrollo , Especificidad por Sustrato , Deshidrogenasas del Alcohol de Azúcar/genética
20.
Acta Paediatr ; 109(12): 2685-2691, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32181924

RESUMEN

AIM: To evaluate effect and costs of pertussis vaccination at Vietnam National Children's Hospital. METHODS: Pertussis cases were defined by positive laboratory tests of children under 5 years January 2015-June 2018, and data on patient characteristics, clinical data and hospitalisation costs were collected through patient records. RESULTS: Of 909 inpatients, 400 (44%) were <2 months, the age for first DPT vaccination, and mechanical ventilation was more common than in children >2 months (9% vs 4%, OR = 2.3, CI 1.3-3.9), as well as persistent cough (99%), violent cough (87%) and pneumonia (91%). Comparing non-vaccinated (172 cases, 19%) and DPT vaccinated patients >2 months of age hospitalisation was 106-fold higher (149.6 vs 1.39 per 100 000 population), and proportion of severe patients, length of hospital stay and hospitalisation costs were significantly greater (23.9% vs 12.8%; 13 vs 10 days; 826 USD vs 582 USD, CI 23-423, P = .03). CONCLUSION: Incidence and proportion of complications among under 2-month infants were higher than in older patients. DPT vaccination protects children from pertussis infection, and in case of pertussis infection decreases severity. Results indicate that the Ministry of Health should consider adding a booster vaccine for pregnant women in an extended vaccination programme.


Asunto(s)
Tos Ferina , Anciano , Niño , Preescolar , Femenino , Humanos , Programas de Inmunización , Lactante , Vacuna contra la Tos Ferina , Embarazo , Vacunación , Vietnam/epidemiología , Tos Ferina/epidemiología , Tos Ferina/prevención & control
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