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1.
J Clin Microbiol ; 62(4): e0128723, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38466092

RESUMEN

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Meníngea , Tuberculosis Resistente a Múltiples Medicamentos , Adulto , Humanos , Tuberculosis Meníngea/diagnóstico , Tuberculosis Meníngea/tratamiento farmacológico , Tuberculosis Meníngea/líquido cefalorraquídeo , Mycobacterium tuberculosis/genética , Pirazinamida , Sensibilidad y Especificidad , Rifampin/farmacología , Rifampin/uso terapéutico , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Líquido Cefalorraquídeo , Pruebas de Sensibilidad Microbiana
2.
Food Chem ; 446: 138815, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38428087

RESUMEN

In this study, we developed a process combining dilute alkali (NaOH or NaHCO3) and physical (disk milling and/or ball milling) treatments to improve the functionality and fermentability of corn fiber. The results showed that combining chemical with physical processes greatly improved the functionality and fermentability of corn fiber. Corn fiber treated with NaOH followed by disk milling (NaOH-DM-CF) had the highest water retention (19.5 g/g), water swelling (38.8 mL/g), and oil holding (15.5 g/g) capacities. Moreover, NaOH-DM-CF produced the largest amount (42.9 mM) of short-chain fatty acid (SCFA) during the 24-hr in vitro fermentation using porcine fecal inoculum. In addition, in vitro fermentation of NaOH-DM-CF led to a targeted microbial shifting to Prevotella (genus level), aligning with a higher fraction of propionic acid. The outstanding functionality and fermentability of NaOH-DM-CF were attributed to its thin and loose structure, decreased ester linkages and acetyl groups, and enriched structural carbohydrate exposure.


Asunto(s)
Fibras de la Dieta , Microbioma Gastrointestinal , Animales , Porcinos , Fibras de la Dieta/análisis , Zea mays/química , Álcalis , Hidróxido de Sodio , Alimentación Animal/análisis , Heces/química , Ácidos Grasos Volátiles/análisis , Agua/análisis , Fermentación
3.
Microbiol Spectr ; 11(6): e0256223, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-37971428

RESUMEN

IMPORTANCE: Drug-resistant tuberculosis (TB) infection is a growing and potent concern, and combating it will be necessary to achieve the WHO's goal of a 95% reduction in TB deaths by 2035. While prior studies have explored the evolution and spread of drug resistance, we still lack a clear understanding of the fitness costs (if any) imposed by resistance-conferring mutations and the role that Mtb genetic lineage plays in determining the likelihood of resistance evolution. This study offers insight into these questions by assessing the dynamics of resistance evolution in a high-burden Southeast Asian setting with a diverse lineage composition. It demonstrates that there are clear lineage-specific differences in the dynamics of resistance acquisition and transmission and shows that different lineages evolve resistance via characteristic mutational pathways.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Mycobacterium tuberculosis/genética , Antituberculosos/farmacología , Antituberculosos/uso terapéutico , Beijing , Vietnam/epidemiología , Genotipo , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Farmacorresistencia Bacteriana Múltiple/genética , Mutación
4.
Commun Biol ; 6(1): 1007, 2023 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-37789208

RESUMEN

Salmonella enterica serotype 1,4,[5],12:i:- (Typhimurium monophasic variant) of sequence type (ST) 34 has emerged as the predominant pandemic genotype in recent decades. Despite increasing reports of resistance to antimicrobials in Southeast Asia, Salmonella ST34 population structure and evolution remained understudied in the region. Here we performed detailed genomic investigations on 454 ST34 genomes collected from Vietnam and diverse geographical sources to elucidate the pathogen's epidemiology, evolution and antimicrobial resistance. We showed that ST34 has been introduced into Vietnam in at least nine occasions since 2000, forming five co-circulating major clones responsible for paediatric diarrhoea and bloodstream infection. Most expansion events were associated with acquisitions of large multidrug resistance plasmids of IncHI2 or IncA/C2. Particularly, the self-conjugative IncA/C2 pST34VN2 (co-transferring blaCTX-M-55, mcr-3.1, and qnrS1) underlies local expansion and intercontinental spread in two separate ST34 clones. At the global scale, Southeast Asia was identified as a potential hub for the emergence and dissemination of multidrug resistant Salmonella ST34, and mutation analysis suggests of selection in antimicrobial responses and key virulence factors.


Asunto(s)
Antiinfecciosos , Salmonella enterica , Humanos , Niño , Salmonella enterica/genética , Serogrupo , Farmacorresistencia Bacteriana Múltiple/genética , Plásmidos/genética , Salmonella , Asia Sudoriental/epidemiología
5.
Methods Mol Biol ; 2698: 259-275, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37682480

RESUMEN

Single-cell multi-omics technology can be applied to plant cells to characterize gene expression and open chromatin regions in individual cells. In this chapter, we describe a computational pipeline for the analysis of single-cell data to construct gene regulatory networks. The major steps of this pipeline include the following: (1) normalize and integrate scRNA-seq and scATAC-seq data (2) identify cluster maker genes (3) perform motif finding for selected marker genes, and (4) identify regulatory networks with machine learning. The pipeline has been tested using data from the model species Arabidopsis and is generally applicable to other plant and animal species to characterize regulatory networks using single-cell multi-omics data.


Asunto(s)
Arabidopsis , Redes Reguladoras de Genes , Animales , Multiómica , Arabidopsis/genética , Cromatina/genética , Aprendizaje Automático
6.
Taiwan J Ophthalmol ; 13(2): 219-224, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37484613

RESUMEN

PURPOSE: The purpose is to study the 5-year results of aflibercept monotherapy using an individualized regimen in naïve patients with neovascular AMD (nAMD). MATERIALS AND METHODS: This is a prospective observational study including naïve nAMD patients who underwent aflibercept injections with at least 5 years of follow-up. All of them received 3 monthly injections at the loading phase, followed by an observation period, then treated with an individualized treat-and-extend regimen. Visual acuity (VA) measurement and optical coherence tomography were performed at each visit. RESULTS: Forty-eight eyes were included. Of these, 30 were followed up for 5 years. The mean follow-up was 61.7 ± 2.3 months. The mean age was 81 ± 8 years. The visual gain was 7.3 ± 12.7 letters at 1 year, 6.5 ± 12.5 letters at 2 years, 5.2 ± 17 letters at 3 years, 6.2 ± 18.6 letters at 4 years, and 5.6 ± 20 letters at 5 years. At the last observation, 53% of eyes had VA > 70 letters. A complete fluid resolution was obtained in 53% of the eyes. At the 5-year endpoint, the total number of injections was 21.6 ± 13.4. Macular atrophy was observed in 18 eyes (60%) and subretinal fibrosis in 14 eyes (46%). CONCLUSION: Patients with exudative AMD can maintain their visual function at 5 years with aflibercept using an individualized treatment. The loss of visual gain beyond 2 years could be related to the natural progression of the disease than the direct effect of anti-vascular endothelial growth injections.

7.
Elife ; 122023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-37158692

RESUMEN

Background: Cellular metabolism is critical for the host immune function against pathogens, and metabolomic analysis may help understand the characteristic immunopathology of tuberculosis. We performed targeted metabolomic analyses in a large cohort of patients with tuberculous meningitis (TBM), the most severe manifestation of tuberculosis, focusing on tryptophan metabolism. Methods: We studied 1069 Indonesian and Vietnamese adults with TBM (26.6% HIV-positive), 54 non-infectious controls, 50 with bacterial meningitis, and 60 with cryptococcal meningitis. Tryptophan and downstream metabolites were measured in cerebrospinal fluid (CSF) and plasma using targeted liquid chromatography-mass spectrometry. Individual metabolite levels were associated with survival, clinical parameters, CSF bacterial load and 92 CSF inflammatory proteins. Results: CSF tryptophan was associated with 60-day mortality from TBM (hazard ratio [HR] = 1.16, 95% confidence interval [CI] = 1.10-1.24, for each doubling in CSF tryptophan) both in HIV-negative and -positive patients. CSF tryptophan concentrations did not correlate with CSF bacterial load nor CSF inflammation but were negatively correlated with CSF interferon-gamma concentrations. Unlike tryptophan, CSF concentrations of an intercorrelating cluster of downstream kynurenine metabolites did not predict mortality. These CSF kynurenine metabolites did however correlate with CSF inflammation and markers of blood-CSF leakage, and plasma kynurenine predicted death (HR 1.54, 95% CI = 1.22-1.93). These findings were mostly specific for TBM, although high CSF tryptophan was also associated with mortality from cryptococcal meningitis. Conclusions: TBM patients with a high baseline CSF tryptophan or high systemic (plasma) kynurenine are at increased risk of death. These findings may reveal new targets for host-directed therapy. Funding: This study was supported by National Institutes of Health (R01AI145781) and the Wellcome Trust (110179/Z/15/Z and 206724/Z/17/Z).


Asunto(s)
Infecciones por VIH , Meningitis Criptocócica , Tuberculosis Meníngea , Adulto , Humanos , Tuberculosis Meníngea/tratamiento farmacológico , Triptófano/metabolismo , Quinurenina , Infecciones por VIH/tratamiento farmacológico , Inflamación/microbiología
8.
medRxiv ; 2023 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-36711829

RESUMEN

Background: Cellular metabolism is critical for the host immune function against pathogens, and metabolomic analysis may help understand the characteristic immunopathology of tuberculosis. We performed targeted metabolomic analyses in a large cohort of patients with tuberculous meningitis (TBM), the most severe manifestation of tuberculosis, focusing on tryptophan metabolism. Methods: We studied 1069 Indonesian and Vietnamese adults with TBM (26.6% HIV-positive), 54 non-infectious controls, 50 with bacterial meningitis, and 60 with cryptococcal meningitis. Tryptophan and downstream metabolites were measured in cerebrospinal fluid (CSF) and plasma using targeted liquid chromatography mass-spectrometry. Individual metabolite levels were associated with survival, clinical parameters, CSF bacterial load and 92 CSF inflammatory proteins. Results: CSF tryptophan was associated with 60-day mortality from tuberculous meningitis (HR=1.16, 95%CI=1.10-1.24, for each doubling in CSF tryptophan) both in HIV-negative and HIV-positive patients. CSF tryptophan concentrations did not correlate with CSF bacterial load nor CSF inflammation but were negatively correlated with CSF interferon-gamma concentrations. Unlike tryptophan, CSF concentrations of an intercorrelating cluster of downstream kynurenine metabolites did not predict mortality. These CSF kynurenine metabolites did however correlate with CSF inflammation and markers of blood-CSF leakage, and plasma kynurenine predicted death (HR 1.54, 95%CI=1.22-1.93). These findings were mostly specific for TBM, although high CSF tryptophan was also associated with mortality from cryptococcal meningitis. Conclusion: TBM patients with a high baseline CSF tryptophan or high systemic (plasma) kynurenine are at increased risk of mortality. These findings may reveal new targets for host-directed therapy. Funding: This study was supported by National Institutes of Health (R01AI145781) and the Wellcome Trust (110179/Z/15/Z and 206724/Z/17/Z).

9.
Environ Monit Assess ; 194(12): 859, 2022 Oct 08.
Artículo en Inglés | MEDLINE | ID: mdl-36208347

RESUMEN

In this study, total phosphorus (P) and P released forms were measured in core sediments from the areas affected by human settlement and shrimp farming activities and the core zone of the Can Gio Biosphere Reserve, a coastal district in south Vietnam. Furthermore, ecological risk assessment and parameters controlling P release from sediments were investigated, including pH, major elements (Al-Ca-Mg-Fe), and fine fraction. The average total amount of P in the sediments varied from 287 to 669 mg/kg, with significantly lower values being observed in the mangrove biosphere reserve area. According to the results of the correlation analysis, organic matter was the primary source of P in the sediments, but the majority of the P released was inorganic. Positive correlations were found between Fe and non-apatite inorganic P (NAIP) and apatite P (AP), as well as intercorrelations between P fractions (r = 0.40-0.79, p < 0.05), suggesting that Fe might be the controlling factor of P release in the investigated sediments. The rank orders of concentrations of P forms were significantly different between the areas. The range of P forms was AP (35-248 mg/kg) > NAIP (63-201 mg/kg) > LP (labile P) (4-25 mg/kg) in the human settlement and aquaculture areas and NAIP (84-99 mg/kg) > AP (20-38 mg/kg) > LP (7-12 mg/kg) in the mangrove biosphere reserve area. Risk assessment based on the total concentration of P and the availability of P from a single extraction suggested a relatively low risk of P from sediment as an internal load in the studied areas.


Asunto(s)
Fósforo , Contaminantes Químicos del Agua , China , Monitoreo del Ambiente , Sedimentos Geológicos/análisis , Humanos , Fósforo/análisis , Medición de Riesgo , Vietnam , Contaminantes Químicos del Agua/análisis
11.
Microb Genom ; 8(5)2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35511231

RESUMEN

Non-typhoidal Salmonella (NTS) is a major cause of bacterial enterocolitis globally but also causes invasive bloodstream infections. Antimicrobial resistance (AMR) hampers the treatment of these infections and understanding how AMR spreads between NTS may help in developing effective strategies. We investigated NTS isolates associated with invasive disease, diarrhoeal disease and asymptomatic carriage in animals and humans from Vietnam. Isolates included multiple serovars and both common and rare phenotypic AMR profiles; long- and short-read sequencing was used to investigate the genetic mechanisms and genomic backgrounds associated with phenotypic AMR profiles. We demonstrate concordance between most AMR genotypes and phenotypes but identified large genotypic diversity in clinically relevant phenotypes and the high mobility potential of AMR genes (ARGs) in this setting. We found that 84 % of ARGs identified were located on plasmids, most commonly those containing IncHI1A_1 and IncHI1B(R27)_1_R27 replicons (33%), and those containing IncHI2_1 and IncHI2A_1 replicons (31%). The vast majority (95%) of ARGS were found within 10 kbp of IS6/IS26 elements, which provide plasmids with a mechanism to exchange ARGs between plasmids and other parts of the genome. Whole genome sequencing with targeted long-read sequencing applied in a One Health context identified a comparatively limited number of insertion sequences and plasmid replicons associated with AMR. Therefore, in the context of NTS from Vietnam and likely for other settings as well, the mechanisms by which ARGs move contribute to a more successful AMR profile than the specific ARGs, facilitating the adaptation of bacteria to different environments or selection pressures.


Asunto(s)
Antibacterianos , Fiebre Tifoidea , Animales , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Humanos , Salmonella , Serogrupo , Vietnam
12.
Cureus ; 14(1): e21347, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-35186603

RESUMEN

Introduction Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. Early detection and accurate diagnosis of HCC play an important role in patient management. This study aimed to develop a convolutional neural network-based model to identify and segment HCC lesions utilizing dynamic contrast agent-enhanced computed tomography (CT). Methods This retrospective study used CT image sets of histopathology-confirmed hepatocellular carcinoma over three phases (arterial, venous, and delayed). The proposed convolutional neural network (CNN) segmentation method was based on the U-Net architecture and trained using the domain adaptation technique. The proposed method was evaluated using 115 liver masses of 110 patients (87 men and 23 women; mean age, 56.9 years ± 11.9 (SD); mean mass size, 6.0 cm ± 3.6). The sensitivity for identifying HCC of the model and Dice score for segmentation of liver masses between radiologists and the CNN model were calculated for the test set. Results The sensitivity for HCC identification of the model was 100%. The median Dice score for HCC segmenting between radiologists and the CNN model was 0.81 for the test set. Conclusion Deep learning with CNN had high performance in the identification and segmentation of HCC on dynamic CT.

13.
J Immunol ; 208(6): 1352-1361, 2022 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-35217585

RESUMEN

The major human genes regulating Mycobacterium tuberculosis-induced immune responses and tuberculosis (TB) susceptibility are poorly understood. Although IL-12 and IL-10 are critical for TB pathogenesis, the genetic factors that regulate their expression in humans are unknown. CNBP, REL, and BHLHE40 are master regulators of IL-12 and IL-10 signaling. We hypothesized that common variants in CNBP, REL, and BHLHE40 were associated with IL-12 and IL-10 production from dendritic cells, and that these variants also influence adaptive immune responses to bacillus Calmette-Guérin (BCG) vaccination and TB susceptibility. We characterized the association between common variants in CNBP, REL, and BHLHE40, innate immune responses in dendritic cells and monocyte-derived macrophages, BCG-specific T cell responses, and susceptibility to pediatric and adult TB in human populations. BHLHE40 single-nucleotide polymorphism (SNP) rs4496464 was associated with increased BHLHE40 expression in monocyte-derived macrophages and increased IL-10 from peripheral blood dendritic cells and monocyte-derived macrophages after LPS and TB whole-cell lysate stimulation. SNP BHLHE40 rs11130215, in linkage disequilibrium with rs4496464, was associated with increased BCG-specific IL-2+CD4+ T cell responses and decreased risk for pediatric TB in South Africa. SNPs REL rs842634 and rs842618 were associated with increased IL-12 production from dendritic cells, and SNP REL rs842618 was associated with increased risk for TB meningitis. In summary, we found that genetic variations in REL and BHLHE40 are associated with IL-12 and IL-10 cytokine responses and TB clinical outcomes. Common human genetic regulation of well-defined intermediate cellular traits provides insights into mechanisms of TB pathogenesis.


Asunto(s)
Mycobacterium bovis , Mycobacterium tuberculosis , Proteínas Proto-Oncogénicas c-rel/genética , Tuberculosis , Adulto , Vacuna BCG , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Niño , Proteínas de Homeodominio , Humanos , Interleucina-10/genética , Interleucina-12/genética , Tuberculosis/genética
14.
Asian Pac J Allergy Immunol ; 40(2): 162-171, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31586490

RESUMEN

BACKGROUND: Secondary fungal infection is a major complication in patients with sepsis-associated immunosuppression. However, sepsis-induced immune alterations related to fungal susceptibility have not been well characterized. OBJECTIVES: To determine kinetic changes in the immune phenotype by determining the proportion of T cells, B cells and macrophages, and especially the expression of an immune exhaustion marker PD-1, in murine sepsis. In addition, sepsis -induced alterations of these immune cells were assessed in relation to susceptibility to secondary fungal infection. METHODS: Cecal ligation and puncture (CLP) was used as a mouse sepsis model, with Candida albicans as the secondary systemic fungal infection. Splenic T cells, B cells and macrophages were assessed by flow cytometry. RESULTS: Alterations in T cell and B cell numbers and the proportion of PD-1 expressing T cells and B cells in CLP mice were not clearly related to susceptibility to secondary Candida infection. By contrast, changes in levels of CD86+-activated macrophages, and the proportion of the PD-1+ population among the CD86+ macrophages in CLP mice were found to be related to secondary fungal infection susceptibility. CONCLUSIONS: Macrophage activation and exhaustion might be a significant determinant in susceptibility to fungal infection, and outcomes of infection. This study provided more comprehensive knowledge pertinent to patient evaluation and therapeutics design in restoring host defenses against secondary fungal infection in those with sepsis.


Asunto(s)
Micosis , Sepsis , Animales , Modelos Animales de Enfermedad , Humanos , Macrófagos , Ratones , Ratones Endogámicos C57BL , Fenotipo , Receptor de Muerte Celular Programada 1/metabolismo
15.
Clin Infect Dis ; 73(7): e2338-e2341, 2021 10 05.
Artículo en Inglés | MEDLINE | ID: mdl-33051650

RESUMEN

We investigated the value of susceptibility testing in predicting response in AIDS-associated cryptococcal meningitis using clinical isolates from a randomized controlled trial of antifungal treatment (amphotericin monotherapy, amphotericin with flucytosine, or amphotericin with fluconazole). We found no correlation between antifungal susceptibility and either early or late survival, or fungal clearance.


Asunto(s)
Síndrome de Inmunodeficiencia Adquirida , Meningitis Criptocócica , Síndrome de Inmunodeficiencia Adquirida/complicaciones , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Antifúngicos/farmacología , Antifúngicos/uso terapéutico , Fluconazol/farmacología , Fluconazol/uso terapéutico , Flucitosina/uso terapéutico , Humanos , Meningitis Criptocócica/tratamiento farmacológico
16.
J Clin Microbiol ; 58(12)2020 11 18.
Artículo en Inglés | MEDLINE | ID: mdl-32907994

RESUMEN

Nontyphoidal Salmonella (NTS) are among the most common etiological agents of diarrheal diseases worldwide and have become the most commonly detected bacterial pathogen in children hospitalized with diarrhea in Vietnam. Aiming to better understand the epidemiology, serovar distribution, antimicrobial resistance (AMR), and clinical manifestation of NTS gastroenteritis in Vietnam, we conducted a clinical genomics investigation of NTS isolated from diarrheal children admitted to one of three tertiary hospitals in Ho Chi Minh City. Between May 2014 and April 2016, 3,166 children hospitalized with dysentery were recruited into the study; 478 (∼15%) children were found to be infected with NTS by stool culture. Molecular serotyping of the 450 generated genomes identified a diverse collection of serogroups (B, C1, C2 to C3, D1, E1, G, I, K, N, O, and Q); however, Salmonella enterica serovar Typhimurium was the most predominant serovar, accounting for 41.8% (188/450) of NTS isolates. We observed a high prevalence of AMR to first-line treatments recommended by WHO, and more than half (53.8%; 242/450) of NTS isolates were multidrug resistant (MDR; resistant to ≥3 antimicrobial classes). AMR gene detection positively correlated with phenotypic AMR testing, and resistance to empirical antimicrobials was associated with a significantly longer hospitalization (0.91 days; P = 0.04). Our work shows that genome sequencing is a powerful epidemiological tool to characterize the serovar diversity and AMR profiles in NTS. We propose a revaluation of empirical antimicrobials for dysenteric diarrhea and endorse the use of whole-genome sequencing for sustained surveillance of NTS internationally.


Asunto(s)
Antiinfecciosos , Gastroenteritis , Antibacterianos/farmacología , Antiinfecciosos/farmacología , Niño , Niño Hospitalizado , Farmacorresistencia Bacteriana , Farmacorresistencia Bacteriana Múltiple/genética , Gastroenteritis/epidemiología , Genómica , Humanos , Pruebas de Sensibilidad Microbiana , Serotipificación , Vietnam/epidemiología
17.
BMC Microbiol ; 20(1): 192, 2020 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-32620076

RESUMEN

BACKGROUND: Diarrhoeagenic Escherichia coli (DEC) infections are common in children in low-middle income countries (LMICs). However, detecting the various DEC pathotypes is complex as they cannot be differentiated by classical microbiology. We developed four multiplex real-time PCR assays were to detect virulence markers of six DEC pathotypes; specificity was tested using DEC controls and other enteric pathogens. PCR amplicons from the six E. coli pathotypes were purified and amplified to be used to optimize PCR reactions and to calculate reproducibility. After validation, these assays were applied to clinical samples from healthy and diarrhoeal Vietnamese children and associated with clinical data. RESULTS: The multiplex real-time PCRs were found to be reproducible, and specific. At least one DEC variant was detected in 34.7% (978/2815) of the faecal samples from diarrhoeal children; EAEC, EIEC and atypical EPEC were most frequent Notably, 41.2% (205/498) of samples from non-diarrhoeal children was positive with a DEC pathotype. In this population, only EIEC, which was detected in 34.3% (99/289) of diarrhoeal samples vs. 0.8% (4/498) non-diarrhoeal samples (p < 0.001), was significantly associated with diarrhoea. Multiplex real-time PCR when applied to clinical samples is an efficient and high-throughput approach to DEC pathotypes. CONCLUSIONS: This approach revealed high carriage rates of DEC pathotypes among Vietnamese children. We describe a novel diagnostic approach for DEC, which provides baseline data for future surveillance studies assessing DEC burden in LMICs.


Asunto(s)
Diarrea/microbiología , Escherichia coli Enteropatógena/clasificación , Infecciones por Escherichia coli/diagnóstico , Infecciones por Escherichia coli/epidemiología , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Adolescente , Niño , Preescolar , Diarrea/epidemiología , Escherichia coli Enteropatógena/genética , Escherichia coli Enteropatógena/aislamiento & purificación , Escherichia coli Enteropatógena/patogenicidad , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Reacción en Cadena de la Polimerasa Multiplex , Prevalencia , Sensibilidad y Especificidad , Vietnam/epidemiología , Factores de Virulencia de Bordetella
18.
N Engl J Med ; 382(18): 1687-1695, 2020 04 30.
Artículo en Inglés | MEDLINE | ID: mdl-32286748

RESUMEN

BACKGROUND: Nonophthalmologist physicians do not confidently perform direct ophthalmoscopy. The use of artificial intelligence to detect papilledema and other optic-disk abnormalities from fundus photographs has not been well studied. METHODS: We trained, validated, and externally tested a deep-learning system to classify optic disks as being normal or having papilledema or other abnormalities from 15,846 retrospectively collected ocular fundus photographs that had been obtained with pharmacologic pupillary dilation and various digital cameras in persons from multiple ethnic populations. Of these photographs, 14,341 from 19 sites in 11 countries were used for training and validation, and 1505 photographs from 5 other sites were used for external testing. Performance at classifying the optic-disk appearance was evaluated by calculating the area under the receiver-operating-characteristic curve (AUC), sensitivity, and specificity, as compared with a reference standard of clinical diagnoses by neuro-ophthalmologists. RESULTS: The training and validation data sets from 6779 patients included 14,341 photographs: 9156 of normal disks, 2148 of disks with papilledema, and 3037 of disks with other abnormalities. The percentage classified as being normal ranged across sites from 9.8 to 100%; the percentage classified as having papilledema ranged across sites from zero to 59.5%. In the validation set, the system discriminated disks with papilledema from normal disks and disks with nonpapilledema abnormalities with an AUC of 0.99 (95% confidence interval [CI], 0.98 to 0.99) and normal from abnormal disks with an AUC of 0.99 (95% CI, 0.99 to 0.99). In the external-testing data set of 1505 photographs, the system had an AUC for the detection of papilledema of 0.96 (95% CI, 0.95 to 0.97), a sensitivity of 96.4% (95% CI, 93.9 to 98.3), and a specificity of 84.7% (95% CI, 82.3 to 87.1). CONCLUSIONS: A deep-learning system using fundus photographs with pharmacologically dilated pupils differentiated among optic disks with papilledema, normal disks, and disks with nonpapilledema abnormalities. (Funded by the Singapore National Medical Research Council and the SingHealth Duke-NUS Ophthalmology and Visual Sciences Academic Clinical Program.).


Asunto(s)
Aprendizaje Profundo , Fondo de Ojo , Redes Neurales de la Computación , Oftalmoscopía/métodos , Papiledema/diagnóstico , Fotograbar , Retina/diagnóstico por imagen , Algoritmos , Área Bajo la Curva , Conjuntos de Datos como Asunto , Diagnóstico Diferencial , Humanos , Valor Predictivo de las Pruebas , Curva ROC , Retina/patología , Estudios Retrospectivos , Sensibilidad y Especificidad
19.
Clin Infect Dis ; 71(9): e465-e470, 2020 12 03.
Artículo en Inglés | MEDLINE | ID: mdl-32107527

RESUMEN

BACKGROUND: Approximately 6% of children hospitalized with severe falciparum malaria in Africa are also bacteremic. It is therefore recommended that all children with severe malaria should receive broad-spectrum antibiotics in addition to parenteral artesunate. Empirical antibiotics are not recommended currently for adults with severe malaria. METHODS: Blood cultures were performed on sequential prospectively studied adult patients with strictly defined severe falciparum malaria admitted to a single referral center in Vietnam between 1991 and 2003. RESULTS: In 845 Vietnamese adults with severe falciparum malaria admission blood cultures were positive in 9 (1.07%: 95% confidence interval [CI], .37-1.76%); Staphylococcus aureus in 2, Streptococcus pyogenes in 1, Salmonella Typhi in 3, Non-typhoid Salmonella in 1, Klebsiella pneumoniae in 1, and Haemophilus influenzae type b in 1. Bacteremic patients presented usually with a combination of jaundice, acute renal failure, and high malaria parasitemia. Four bacteremic patients died compared with 108 (12.9%) of 836 nonbacteremic severe malaria patients (risk ratio, 3.44; 95% CI, 1.62-7.29). In patients with >20% parasitemia the prevalence of concomitant bacteremia was 5.2% (4/76; 95% CI, .2-10.3%) compared with 0.65% (5/769; 0.08-1.2%) in patients with <20% parasitemia, a risk ratio of 8.1 (2.2-29.5). CONCLUSIONS: In contrast to children, the prevalence of concomitant bacteremia in adults with severe malaria is low. Administration of empirical antibiotics, in addition to artesunate, is warranted in the small subgroup of patients with very high parasitemias, emphasizing the importance of quantitative blood smear microscopy assessment, but it is not indicated in most adults with severe falciparum malaria.


Asunto(s)
Antimaláricos , Artemisininas , Bacteriemia , Malaria Falciparum , Malaria , Adulto , África , Antimaláricos/uso terapéutico , Artemisininas/uso terapéutico , Bacteriemia/complicaciones , Bacteriemia/tratamiento farmacológico , Bacteriemia/epidemiología , Niño , Humanos , Malaria/tratamiento farmacológico , Malaria Falciparum/complicaciones , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Plasmodium falciparum , Vietnam/epidemiología
20.
Clin Infect Dis ; 70(5): 827-834, 2020 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-30944929

RESUMEN

BACKGROUND: Pretreatment predictors of death from tuberculous meningitis (TBM) are well established, but whether outcome can be predicted more accurately after the start of treatment by updated clinical variables is unknown. Hence, we developed and validated models that dynamically predict mortality using time-updated Glasgow Coma Scale (GCS) and plasma sodium measurements, together with patient baseline characteristics. METHODS: We included 1048 adults from 4 TBM studies conducted in southern Vietnam from 2004 to 2016. We used a landmarking approach to predict death within 120 days after treatment initiation using time-updated data during the first 30 days of treatment. Separate models were built for patients with and without human immunodeficiency virus (HIV) infection. We used the area under the receiver operating characteristic curve (AUC) to evaluate performance of the models at days 10, 20, and 30 of treatment to predict mortality by 60, 90, and 120 days. Our internal validation was corrected for overoptimism using bootstrap. We provide a web-based application that computes mortality risk within 120 days. RESULTS: Higher GCS indicated better prognosis in all patients. In HIV-infected patients, higher plasma sodium was uniformly associated with good prognosis, whereas in HIV-uninfected patients the association was heterogeneous over time. The bias-corrected AUC of the models ranged from 0.82 to 0.92 and 0.81 to 0.85 in HIV-uninfected and HIV-infected individuals, respectively. The models outperformed the previously published baseline models. CONCLUSIONS: Time-updated GCS and plasma sodium measurements improved predictions based solely on information obtained at diagnosis. Our models may be used in practice to define those with poor prognosis during treatment.


Asunto(s)
Tuberculosis Meníngea , Adulto , Escala de Coma de Glasgow , Humanos , Plasma , Pronóstico , Sodio , Tuberculosis Meníngea/diagnóstico , Vietnam
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