Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 318
Filtrar
1.
Front Cell Infect Microbiol ; 14: 1425624, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39145307

RESUMEN

Type IV pili (T4P) are versatile proteinaceous protrusions that mediate diverse bacterial processes, including adhesion, motility, and biofilm formation. Aeromonas hydrophila, a Gram-negative facultative anaerobe, causes disease in a wide range of hosts. Previously, we reported the presence of a unique Type IV class C pilus, known as tight adherence (Tad), in virulent Aeromonas hydrophila (vAh). In the present study, we sought to functionalize the role of Tad pili in the pathogenicity of A. hydrophila ML09-119. Through a comprehensive comparative genomics analysis of 170 A. hydrophila genomes, the conserved presence of the Tad operon in vAh isolates was confirmed, suggesting its potential contribution to pathogenicity. Herein, the entire Tad operon was knocked out from A. hydrophila ML09-119 to elucidate its specific role in A. hydrophila virulence. The absence of the Tad operon did not affect growth kinetics but significantly reduced virulence in catfish fingerlings, highlighting the essential role of the Tad operon during infection. Biofilm formation of A. hydrophila ML09-119 was significantly decreased in the Tad operon deletant. Absence of the Tad operon had no effect on sensitivity to other environmental stressors, including hydrogen peroxide, osmolarity, alkalinity, and temperature; however, it was more sensitive to low pH conditions. Scanning electron microscopy revealed that the Tad mutant had a rougher surface structure during log phase growth than the wildtype strain, indicating the absence of Tad impacts the outer surface of vAh during cell division, of which the biological consequences are unknown. These findings highlight the role of Tad in vAh pathogenesis and biofilm formation, signifying the importance of T4P in bacterial infections.


Asunto(s)
Aeromonas hydrophila , Biopelículas , Fimbrias Bacterianas , Enfermedades de los Peces , Infecciones por Bacterias Gramnegativas , Operón , Aeromonas hydrophila/genética , Aeromonas hydrophila/patogenicidad , Aeromonas hydrophila/fisiología , Biopelículas/crecimiento & desarrollo , Fimbrias Bacterianas/genética , Fimbrias Bacterianas/metabolismo , Virulencia/genética , Animales , Infecciones por Bacterias Gramnegativas/microbiología , Enfermedades de los Peces/microbiología , Adhesión Bacteriana/genética , Bagres/microbiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Técnicas de Inactivación de Genes
2.
Nat Nanotechnol ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38961248

RESUMEN

Metasurfaces precisely control the amplitude, polarization and phase of light, with applications spanning imaging, sensing, modulation and computing. Three crucial performance metrics of metasurfaces and their constituent resonators are the quality factor (Q factor), mode volume (Vm) and ability to control far-field radiation. Often, resonators face a trade-off between these parameters: a reduction in Vm leads to an equivalent reduction in Q, albeit with more control over radiation. Here we demonstrate that this perceived compromise is not inevitable: high quality factor, subwavelength Vm and controlled dipole-like radiation can be achieved simultaneously. We design high quality factor, very-large-scale-integrated silicon nanoantenna pixels (VINPix) that combine guided mode resonance waveguides with photonic crystal cavities. With optimized nanoantennas, we achieve Q factors exceeding 1,500 with Vm less than 0.1 ( λ / n air ) 3 . Each nanoantenna is individually addressable by free-space light and exhibits dipole-like scattering to the far-field. Resonator densities exceeding a million nanoantennas per cm2 can be achieved. As a proof-of-concept application, we show spectrometer-free, spatially localized, refractive-index sensing, and fabrication of an 8 mm × 8 mm VINPix array. Our platform provides a foundation for compact, densely multiplexed devices such as spatial light modulators, computational spectrometers and in situ environmental sensors.

3.
J Mol Model ; 30(8): 294, 2024 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-39080111

RESUMEN

CONTEXT: Hydrazones have been studied for a myriad of chemical and physiochemical properties, such as sensors, chelators and numerous biological activities. Experimental data indicates that hydrazones are unstable under cathodic potentials irrespective of the solvent. The single electron reduction of hydrazones to produce radical anions result in unstable species that cleaves at the N-N bond in a heterolytic manner. The literature has proposed a mechanism favouring the radical on the imine moiety, however in this study DFT calculations suggest the radical on the amine product is more likely upon bond cleavage. This has implications on electrochemical mechanisms, and the active molecule in biological studies viz the method of delivery to target areas. METHODS: Density functional theory calculations were carried out using the GAMESS software package. The structures were optimized in the gas phase (B3LYP/6-31G(d,p)) as indicated by the absence of imaginary frequencies in the Hessian, and in CH3CN (B3LYP/6-31G(d,p)/SMD) with the Pople polarization functions. As a comparison, selected pathways were fully optimized using PBE0/6-31G(d,p) and PBE0/6-31G(d,p)/SMD for gas phase and CH3CN, respectively with the Pople polarization functions. The values were not significantly different (< 5% difference). As such only the B3LYP is evaluation is discussed.

4.
JAC Antimicrob Resist ; 6(4): dlae109, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39035015

RESUMEN

Background: Plesiomonas shigelloides strain MS-17-188 was isolated from a deceased catfish from East Mississippi and showed resistance to florfenicol, tetracyclines and a sulphonamide. WGS of strain MS-17-188 revealed three plasmids (pPSMS-171881, pPSMS-171882 and pPSMS-171883). Objectives: To accurately determine the impact of three plasmids found in P. shigelloides strain MS-17-188 on the dissemination of antibiotic resistance genes and to provide insights into the molecular structure of these plasmids. Methods: The genetic features of these plasmids in terms of genes associated with antimicrobial resistance (AMR), virulence, transfer, maintenance and replication were identified using bioinformatic tools. Additionally, we investigated the in vitro mobilization and stability of plasmid-mediated resistance. The Comprehensive Antibiotic Resistance Database and Virulence Factors Database were used to detect the AMR genes and virulence genes of P. shigelloides plasmids. Moreover, plasmid mobility was evaluated by a filter-mating assay using strain MS-17-188 as a donor and azide-resistant Escherichia coli J53 as a recipient strain. A stability experiment was conducted to explore the persistence of plasmid-mediated antibiotic resistance in strain MS-17-188 in the absence and presence of selection. Results: pPSMS-171881 harboured multidrug efflux complex (adeF) and two genes responsible for arsenic resistance (arsB and arsC). pPSMS-171882 had a region of 7085 bp encoding type IV secretion system proteins. pPSMS-171883 carried the tetracycline resistance genes tet(A) and tet(R), and a phenicol resistance gene (floR), which were flanked by two transposable elements and mobilization proteins, suggesting that there is a conjugative mechanism by which this plasmid can be mobilized. Results from the stability experiment indicated that pPSMS-171883 is lost over time in the absence of selective pressure. Moreover, pPSMS-171883 is more stable in P. shigelloides at growth temperatures of 30°C and 37°C compared with 40°C and 43°C. After intraperitoneal injection in catfish, P. shigelloides strain MS-17-188 resulted in no mortalities. Conclusions: This is the first study to report plasmid-mediated AMR in Plesiomonas isolated from cultured fish, which needs continued monitoring. This study will provide an understanding of the genetic mechanisms of AMR and virulence of P. shigelloides.

5.
Nat Food ; 5(7): 557-562, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38977923

RESUMEN

The Codex Alimentarius Commission (Codex) has a substantial influence over the structure and operation of food systems by setting international standards that affect the composition, structure and labelling of food. Despite the dual mandates of Codex to protect public health and ensure fair practices in food trade, food systems are increasingly unhealthy and unsustainable. An ecological reorientation of the decision-making elements that influence how Codex sets food standards-particularly mandates, governance and risk assessment-could help transform food systems towards the UN Sustainable Development Goals.


Asunto(s)
Abastecimiento de Alimentos , Humanos , Abastecimiento de Alimentos/normas , Desarrollo Sostenible , Medición de Riesgo , Etiquetado de Alimentos/legislación & jurisprudencia , Etiquetado de Alimentos/normas , Salud Pública/legislación & jurisprudencia , Inocuidad de los Alimentos
6.
Front Microbiol ; 15: 1403694, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38881664

RESUMEN

Listeria monocytogenes causes listeriosis, an infectious and potentially fatal disease of animals and humans. A diverse network of transcriptional regulators, including LysR-type catabolite control protein C (CcpC), is critical for the survival of L. monocytogenes and its ability to transition into the host environment. In this study, we explored the physiological and genetic consequences of deleting ccpC and the effects of such deletion on the ability of L. monocytogenes to cause disease. We found that ccpC deletion did not impact hemolytic activity, whereas it resulted in significant reductions in phospholipase activities. Western blotting revealed that the ΔccpC strain produced significantly reduced levels of the cholesterol-dependent cytolysin LLO relative to the wildtype F2365 strain. However, the ΔccpC mutant displayed no significant intracellular growth defect in macrophages. Furthermore, ΔccpC strain exhibited reduction in plaque numbers in fibroblasts compared to F2365, but plaque size was not significantly affected by ccpC deletion. In a murine model system, the ΔccpC strain exhibited a significantly reduced bacterial burden in the liver and spleen compared to the wildtype F2365 strain. Interestingly, the deletion of this gene also enhanced the survival of L. monocytogenes under conditions of H2O2-induced oxidative stress. Transcriptomic analyses performed under H2O2-induced oxidative stress conditions revealed that DNA repair, cellular responses to DNA damage and stress, metalloregulatory proteins, and genes involved in the biosynthesis of peptidoglycan and teichoic acids were significantly induced in the ccpC deletion strain relative to F2365. In contrast, genes encoding internalin, 1-phosphatidylinositol phosphodiesterase, and genes associated with sugar-specific phosphotransferase system components, porphyrin, branched-chain amino acids, and pentose phosphate pathway were significantly downregulated in the ccpC deletion strain relative to F2365. This finding highlights CcpC as a key factor that regulates L. monocytogenes physiology and responses to oxidative stress by controlling the expression of important metabolic pathways.

7.
J Bacteriol ; 206(7): e0003324, 2024 07 25.
Artículo en Inglés | MEDLINE | ID: mdl-38899896

RESUMEN

Listeria monocytogenes is a foodborne bacterial pathogen that causes listeriosis. Positive regulatory factor A (PrfA) is a pleiotropic master activator of virulence genes of L. monocytogenes that becomes active upon the entry of the bacterium into the cytosol of infected cells. L. monocytogenes can survive and multiply at low temperatures; this is accomplished through the maintenance of appropriate membrane fluidity via branched-chain fatty acid (BCFA) synthesis. Branched-chain α-keto acid dehydrogenase (BKD), which is composed of four polypeptides encoded by lpd, bkdA1, bkdA2, and bkdB, is known to play a vital role in BCFA biosynthesis. Here, we constructed BKD-deficient Listeria strains by in-frame deletion of lpd, bkdA1, bkdA2, and bkdB genes. To determine the role in in vivo and in vitro, mouse model challenges, plaque assay in murine L2 fibroblast, and intracellular replication in J744A.1 macrophage were conducted. BKD-deficient strains exhibited defects in BCFA composition, virulence, and PrfA-regulon function within the host cells. Transcriptomics analysis revealed that the transcript level of the PrfA-regulon was lower in ΔbkdA1 strain than those in the wild-type. This study demonstrates that L. monocytogenes strains lacking BKD complex components were defective in PrfA-regulon function, and full activation of wild-type prfA may not occur within host cells in the absence of BKD. Further study will investigate the consequences of BKD deletion on PrfA function through altering BCFA catabolism.IMPORTANCEListeria monocytogenes is the causative agent of listeriosis, a disease with a high mortality rate. In this study, we have shown that the deletion of BKD can impact the function of PrfA and the PrfA-regulon. The production of virulence proteins within host cells is necessary for L. monocytogenes to promote its intracellular survival and is likely dependent on membrane integrity. We thus report a link between L. monocytogenes membrane integrity and the function of PrfA. This knowledge will increase our understanding of L. monocytogenes pathogenesis, which may provide insight into the development of antimicrobial agents.


Asunto(s)
Proteínas Bacterianas , Listeria monocytogenes , Listeriosis , Listeria monocytogenes/genética , Listeria monocytogenes/patogenicidad , Listeria monocytogenes/enzimología , Listeria monocytogenes/metabolismo , Ratones , Animales , Virulencia , Listeriosis/microbiología , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Ácidos Grasos/biosíntesis , Ácidos Grasos/metabolismo , 3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida)/metabolismo , 3-Metil-2-Oxobutanoato Deshidrogenasa (Lipoamida)/genética , Regulación Bacteriana de la Expresión Génica , Macrófagos/microbiología , Femenino , Línea Celular
8.
Foods ; 13(9)2024 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-38731673

RESUMEN

Listeria monocytogenes is the causative agent of listeriosis, a severe foodborne illness characterized by septicemia, meningitis, encephalitis, abortions, and occasional death in infants and immunocompromised individuals. L. monocytogenes is composed of four genetic lineages (I, II, III, and IV) and fourteen serotypes. The aim of the current study was to identify proteins that can serve as biomarkers for detection of genetic lineage III strains based on simple antibody-based methods. Liquid chromatography (LC) with electrospray ionization tandem mass spectrometry (ESI MS/MS) followed by bioinformatics and computational analysis were performed on three L. monocytogenes strains (NRRL B-33007, NRRL B-33014, and NRRL B-33077), which were used as reference strains for lineages I, II, and III, respectively. Results from ESI MS/MS revealed 42 unique proteins present in NRRL B-33077 and absent in NRRL B-33007 and NRRL B-33014 strains. BLAST analysis of the 42 proteins against a broader panel of >80 sequenced strains from lineages I and II revealed four proteins [TM2 domain-containing protein (NRRL B-33077_2770), DUF3916 domain-containing protein (NRRL B-33077_1897), DNA adenine methylase (NRRL B-33077_1926), and protein RhsA (NRRL B-33077_1129)] that have no homology with any sequenced strains in lineages I and II. The four genes that encode these proteins were expressed in Escherichia coli strain DE3 and purified. Polyclonal antibodies were prepared against purified recombinant proteins. ELISA using the polyclonal antibodies against 12 L. monocytogenes lineage I, II, and III isolates indicated that TM2 protein and DNA adenine methylase (Dam) detected all lineage III strains with no reaction to lineage I and II strains. In conclusion, two proteins including TM2 protein and Dam are potentially useful biomarkers for detection and differentiation of L. monocytogenes lineage III strains in clinical, environmental, and food processing facilities. Furthermore, these results validate the approach of using a combination of proteomics and bioinformatics to identify useful protein biomarkers.

10.
Radiat Res ; 201(5): 460-470, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38376474

RESUMEN

With the current volatile geopolitical climate, the threat of nuclear assault is high. Exposure to ionizing radiation from either nuclear incidents or radiological accidents often lead to major harmful consequences to human health. Depending on the absorbed dose, the symptoms of the acute radiation syndrome and delayed effects of acute radiation exposure (DEARE) can appear within hours, weeks to months. The lung is a relatively radiosensitive organ with manifestation of radiation pneumonitis as an acute effect, followed by apparent fibrosis in weeks or even months. A recently developed, first-of-its-kind murine model for partial-body irradiation (PBI) injury, which can be used to test potential countermeasures against multi-organ damage such as gastrointestinal (GI) tract and lungs was used for irradiation, with 2.5% bone marrow spared (BM2.5-PBI) from radiation exposure. Long-term damage to lungs from radiation was evaluated using µ-CT scans, pulmonary function testing, histopathological parameters and molecular biomarkers. Pulmonary fibrosis was detected by ground glass opacity observed in µ-CT scans of male and female C57BL/6J mice 6-7 months after BM2.5-PBI. Lung mechanics assessments pertaining to peripheral airways suggested fibrotic lungs with stiffer parenchymal lung tissue and reduced inspiratory capacity in irradiated animals 6-7 months after BM2.5-PBI. Histopathological evaluation of the irradiated lungs revealed presence of focal and diffuse pleural, and parenchymal inflammatory and fibrotic lesions. Fibrosis was confirmed by elevated levels of collagen when compared to lungs of age-matched naïve mice. These findings were validated by findings of elevated levels of pro-fibrotic biomarkers and reduction in anti-inflammatory proteins. In conclusion, a long-term model for radiation-induced pulmonary fibrosis was established, and countermeasures could be screened in this model for survival and protection/mitigation or recovery from radiation-induced pulmonary damage.


Asunto(s)
Modelos Animales de Enfermedad , Ratones Endogámicos C57BL , Fibrosis Pulmonar , Animales , Fibrosis Pulmonar/etiología , Fibrosis Pulmonar/patología , Ratones , Masculino , Femenino , Pulmón/efectos de la radiación , Pulmón/patología , Neumonitis por Radiación/patología , Neumonitis por Radiación/etiología , Traumatismos Experimentales por Radiación/patología , Traumatismos Experimentales por Radiación/etiología
11.
BMJ ; 384: e077310, 2024 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-38418082

RESUMEN

OBJECTIVE: To evaluate the existing meta-analytic evidence of associations between exposure to ultra-processed foods, as defined by the Nova food classification system, and adverse health outcomes. DESIGN: Systematic umbrella review of existing meta-analyses. DATA SOURCES: MEDLINE, PsycINFO, Embase, and the Cochrane Database of Systematic Reviews, as well as manual searches of reference lists from 2009 to June 2023. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: Systematic reviews and meta-analyses of cohort, case-control, and/or cross sectional study designs. To evaluate the credibility of evidence, pre-specified evidence classification criteria were applied, graded as convincing ("class I"), highly suggestive ("class II"), suggestive ("class III"), weak ("class IV"), or no evidence ("class V"). The quality of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) framework, categorised as "high," "moderate," "low," or "very low" quality. RESULTS: The search identified 45 unique pooled analyses, including 13 dose-response associations and 32 non-dose-response associations (n=9 888 373). Overall, direct associations were found between exposure to ultra-processed foods and 32 (71%) health parameters spanning mortality, cancer, and mental, respiratory, cardiovascular, gastrointestinal, and metabolic health outcomes. Based on the pre-specified evidence classification criteria, convincing evidence (class I) supported direct associations between greater ultra-processed food exposure and higher risks of incident cardiovascular disease related mortality (risk ratio 1.50, 95% confidence interval 1.37 to 1.63; GRADE=very low) and type 2 diabetes (dose-response risk ratio 1.12, 1.11 to 1.13; moderate), as well as higher risks of prevalent anxiety outcomes (odds ratio 1.48, 1.37 to 1.59; low) and combined common mental disorder outcomes (odds ratio 1.53, 1.43 to 1.63; low). Highly suggestive (class II) evidence indicated that greater exposure to ultra-processed foods was directly associated with higher risks of incident all cause mortality (risk ratio 1.21, 1.15 to 1.27; low), heart disease related mortality (hazard ratio 1.66, 1.51 to 1.84; low), type 2 diabetes (odds ratio 1.40, 1.23 to 1.59; very low), and depressive outcomes (hazard ratio 1.22, 1.16 to 1.28; low), together with higher risks of prevalent adverse sleep related outcomes (odds ratio 1.41, 1.24 to 1.61; low), wheezing (risk ratio 1.40, 1.27 to 1.55; low), and obesity (odds ratio 1.55, 1.36 to 1.77; low). Of the remaining 34 pooled analyses, 21 were graded as suggestive or weak strength (class III-IV) and 13 were graded as no evidence (class V). Overall, using the GRADE framework, 22 pooled analyses were rated as low quality, with 19 rated as very low quality and four rated as moderate quality. CONCLUSIONS: Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes. These findings provide a rationale to develop and evaluate the effectiveness of using population based and public health measures to target and reduce dietary exposure to ultra-processed foods for improved human health. They also inform and provide support for urgent mechanistic research. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023412732.


Asunto(s)
Alimentos Procesados , Humanos , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/epidemiología , Alimentos Procesados/estadística & datos numéricos , Metaanálisis como Asunto
12.
Global Health ; 20(1): 16, 2024 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-38388413

RESUMEN

BACKGROUND: A major challenge to transforming food systems to promote human health and sustainable development is the global rise in the manufacture and consumption of ultra-processed foods (UPFs). A key driver of this dietary transition is the globalization of UPF corporations, and their organized corporate political activity (CPA) intended to counter opposition and block government regulation. UPF industry CPA and the corporate interest groups who lobby on their behalf have been well described at the national level, however, at the global level, this network has not been systematically characterized. This study aims to map, analyse, and describe this network, and discuss the implications for global food policy action on UPFs, global food governance (GFG), and food systems transformation. METHODS: We conducted a network analysis of the declared interest group memberships of the world's leading UPF corporations, extracted from web sources, company reports, and relevant academic and grey literature. Data on the characteristics of these interest groups were further extracted for analysis, including year founded, level, type, and headquarter location. RESULTS: We identified 268 interest groups affiliated with the UPF industry. The UPF manufacturers Nestlé (n = 171), The Coca-Cola Company (n = 147), Unilever (n = 142), PepsiCo (n = 138), and Danone (n = 113) had the greatest number of memberships, indicating strong centrality in coordinating the network. We found that this network operates at all levels, yet key actors now predominantly coordinate globally through multistakeholder channels in GFG. The most common interest group types were sustainability/corporate social responsibility/multistakeholder initiatives, followed by branding and advertising, and food manufacturing and retail. Most corporate interest groups are headquartered where they can access powerful government and GFG decision-makers, nearly one-third in Washington DC and Brussels, and the rest in capital cities of major national markets for UPFs. CONCLUSIONS: The UPF industry, and especially its leading corporations, coordinate a global network of interest groups spanning multiple levels, jurisdictions, and governance spaces. This represents a major structural feature of global food and health governance systems, which arguably poses major challenges for actions to attenuate the harms of UPFs, and to realising of healthy and sustainable food systems.


Asunto(s)
Alimentos Procesados , Opinión Pública , Humanos , Industrias , Alimentos , Política , Industria de Alimentos
13.
Public Health Nutr ; 27(1): e75, 2024 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-38374798

RESUMEN

OBJECTIVE: Despite commitment by many countries to promote food system transformation, Australia has yet to adopt a national food policy. This study aimed to evaluate Australian Federal Government's (AFG) food policies and policy actions potential to promote healthy and sustainable food systems. DESIGN: This study is a desk-based policy mapping followed by a theoretically guided evaluation of policy actions. This involved three steps: (1) identification of government departments and agencies that could influence Australia's food system; (2) identification of food policies and policy actions within these departments and (3) use of a conceptual framework to evaluate policy actions' potential of changing the food system as adjust (first-order change), reform (second-order change) or transform (third-order change). SETTING: Australia. PARTICIPANTS: None. RESULTS: Twenty-four food policies and sixty-two policy actions were identified across eight AFG departments and the Food Regulation System and evaluated based on the order of change they represented. Most policies were led by individual departments, reflecting the absence of a joined-up approach to food policy in Australia. Most policy actions (n 25/ 56·5 %) were evaluated as having adjust potential, whereas no transformative policy action was identified. CONCLUSIONS: These findings suggest that Australia is likely to proceed incrementally towards achieving food system change through adjustments and reforms but lacking transformative impact. To promote transformative change, all three orders of change must be strategically implemented in a coherent and coordinated matter. A comprehensive national food policy and a national coordinating body are needed to ensure a cohesive approach to policy.


Asunto(s)
Política Nutricional , Humanos , Australia
15.
J Aquat Anim Health ; 36(1): 3-15, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37859458

RESUMEN

OBJECTIVE: Columnaris disease is a leading cause of disease-related losses in the catfish industry of the southeastern United States. The term "columnaris-causing bacteria" (CCB) has been coined in reference to the four described species that cause columnaris disease: Flavobacterium columnare, F. covae, F. davisii, and F. oreochromis. Historically, F. columnare, F. covae, and F. davisii have been isolated from columnaris disease cases in the catfish industry; however, there is a lack of knowledge of which CCB species are most prevalent in farm-raised catfish. The current research objectives were to (1) sample columnaris disease cases from the U.S. catfish industry and identify the species of CCB involved and (2) determine the virulence of the four CCB species in Channel Catfish Ictalurus punctatus in controlled laboratory challenges. METHODS: Bacterial isolates or swabs of external lesions from catfish were collected from 259 columnaris disease cases in Mississippi and Alabama during 2015-2019. The DNA extracted from the samples was analyzed using a CCB-specific multiplex polymerase chain reaction to identify the CCB present in each diagnostic case. Channel Catfish were challenged by immersion with isolates belonging to each CCB species to determine virulence at ~28°C and 20°C. RESULT: Flavobacterium covae was identified as the predominant CCB species impacting the U.S. catfish industry, as it was present in 94.2% (n = 244) of diagnostic case submissions. Challenge experiments demonstrated that F. covae and F. oreochromis were highly virulent to Channel Catfish, with most isolates resulting in near 100% mortality. In contrast, F. columnare and F. davisii were less virulent, with most isolates resulting in less than 40% mortality. CONCLUSION: Collectively, these results demonstrate that F. covae is the predominant CCB in the U.S. catfish industry, and research aimed at developing new control and prevention strategies should target this bacterial species. The methods described herein can be used to continue monitoring the prevalence of CCB in the catfish industry and can be easily applied to other industries to identify which Flavobacterium species have the greatest impact.


Asunto(s)
Bagres , Enfermedades de los Peces , Infecciones por Flavobacteriaceae , Ictaluridae , Animales , Ictaluridae/microbiología , Flavobacterium/genética , Infecciones por Flavobacteriaceae/epidemiología , Infecciones por Flavobacteriaceae/veterinaria , Infecciones por Flavobacteriaceae/microbiología , Sudeste de Estados Unidos/epidemiología , Enfermedades de los Peces/epidemiología , Enfermedades de los Peces/microbiología
17.
Aust N Z J Psychiatry ; 58(1): 82-91, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37122137

RESUMEN

OBJECTIVE: To explore the views of psychiatrists (including trainees) regarding the current state and future direction of specialist mental health and addictions services in Aotearoa New Zealand. METHODS: Psychiatrists and trainee psychiatrists (registrars) in Aotearoa New Zealand were surveyed in August 2021. Of 879 eligible doctors, 540 participated (83% qualified and 17% trainee psychiatrists), a response rate of over 60%. Data were analysed quantitatively and with content analysis. RESULTS: Psychiatrists thought specialist mental health and addictions services had been neglected during recent reforms, with 94% believing current resourcing was insufficient, and only 3% considering future planning was heading in the right direction. The demand and complexity of on-call work had markedly increased in the preceding 2 years. Ninety-eight percent reported that people needing specialist treatment were often (85%) or sometimes (13%) unable to access the right care due to resourcing constraints. The pressures were similar across sub-specialties. A key theme was the distress (sometimes termed 'moral injury') experienced by psychiatrists unable to provide adequate care due to resource limitations, 'knowing what would be a good thing to do and being unable to do it . . . is soul destroying'. Recommendations were made for addressing workforce, service design and wider issues. CONCLUSION: Most psychiatrists in Aotearoa New Zealand believe the mental health system is not currently fit for purpose and that it is not heading in the right direction. Remedies include urgently addressing identified staffing challenges and boosting designated funding to adequately care for the 5% of New Zealanders with severe mental health and addiction needs.


Asunto(s)
Fuerza Laboral en Salud , Servicios de Salud Mental , Psiquiatría , Humanos , Nueva Zelanda , Psiquiatras
18.
Global Health ; 19(1): 64, 2023 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-37653543

RESUMEN

BACKGROUND: Ultra-processed foods (UPF) are associated with adverse health outcomes. This study aimed to analyse the national trends in retail sales, consumer expenditure and nutritional quality of UPFs in Thailand. METHODS: The study used data from the Euromonitor Passport database for analysis of retail sales and consumer expenditure, and from the Mintel Global New Products Database for nutritional analysis using the WHO Southeast Asian Region nutrient profile model. RESULTS: The study found the highest per capita sales volume and value of UPFs in 2021 were sauces, dressings & condiments (8.4 kg/capita) and carbonated soft drinks (27.1 L/capita), respectively. However, functional & flavoured water, ready-made meals and baked goods had the highest observed (2012-2021) and expected (2021-2026) sales growth. Supermarkets were responsible for most of the UPF sales since 2012, but convenience stores had larger growth in retail values. Growth in consumer expenditure per capita on UPFs from 2012 to 2020, ranged between 12.7% and 34%, and till 2026 is forecast to grow between 26% and 30%. More than half of UPFs exceeded at least one nutrient cutoff, 59.3% for total fats, 24.8% for saturated fats, 68.2% for total sugars and 94.3% for sodium. CONCLUSIONS: The findings suggest a need for regulatory and non-regulatory measures such as UPF taxation and marketing restrictions, and market incentives for producing non-UPFs. A system for regularly monitoring and evaluating healthiness (both nutritional and processing aspects) of food products, especially UPFs, is required.


Asunto(s)
Alimentos Procesados , Gastos en Salud , Humanos , Tailandia , Comercio , Valor Nutritivo
19.
Front Nutr ; 10: 1223316, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37469549

RESUMEN

[This corrects the article DOI: 10.3389/fnut.2023.1071356.].

20.
Nat Commun ; 14(1): 4486, 2023 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-37495593

RESUMEN

Genetic analysis methods are foundational to advancing personalized medicine, accelerating disease diagnostics, and monitoring the health of organisms and ecosystems. Current nucleic acid technologies such as polymerase chain reaction (PCR) and next-generation sequencing (NGS) rely on sample amplification and can suffer from inhibition. Here, we introduce a label-free genetic screening platform based on high quality (high-Q) factor silicon nanoantennas functionalized with nucleic acid fragments. Each high-Q nanoantenna exhibits average resonant quality factors of 2,200 in physiological buffer. We quantitatively detect two gene fragments, SARS-CoV-2 envelope (E) and open reading frame 1b (ORF1b), with high-specificity via DNA hybridization. We also demonstrate femtomolar sensitivity in buffer and nanomolar sensitivity in spiked nasopharyngeal eluates within 5 minutes. Nanoantennas are patterned at densities of 160,000 devices per cm2, enabling future work on highly-multiplexed detection. Combined with advances in complex sample processing, our work provides a foundation for rapid, compact, and amplification-free molecular assays.


Asunto(s)
COVID-19 , Ácidos Nucleicos , Humanos , SARS-CoV-2/genética , COVID-19/diagnóstico , COVID-19/genética , Ecosistema , Pruebas Genéticas , Sensibilidad y Especificidad , Técnicas de Amplificación de Ácido Nucleico/métodos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA