Publications by authors named "Dionisio P Amorim Neto"

In this study, the performance of quantitative PCR, combined or not with propidium monoazide (PMA), to recover from peanut products after different storage times was evaluated. The samples were inoculated with 5-6 log cfu g of Typhimurium ATCC 14028 and stored at 28 °C for up to 540 d. The correlation between the threshold cycle number (Ct) and the colony-forming units (cfu) was obtained by a standard curve, which showed a linear correlation (R = 0.

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Article Synopsis
  • - Microbiologically contaminated water poses a risk of infections, especially from Pseudomonas aeruginosa (PSA), which can survive in water and resist disinfectants; this study focuses on how PSA adheres to materials used in mineral water extraction wells.
  • - Water samples were collected from three wells in Brazil, and their physicochemical properties, like strontium and iron concentrations, were analyzed, revealing that PSA adhered more to hydrophobic materials like HDPE and PVC.
  • - The study found that higher concentrations of certain elements (Sr, Fe, Si, SO, Cl) positively correlated with PSA adhesion on hydrophilic materials, while higher oxidation-reduction potential (ORP) negatively affected PSA attachment to PVC,
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Despite the wide variety of native and exotic fruits in Brazil, there is limited understanding of their ability to support pathogens during storage. This study aimed to evaluate the behavior of Salmonella enterica and Listeria monocytogenes inoculated into the pulp of eight fruits native and exotic to Brazil: Jenipapo (Genipa americana L.), Umbu (Spondias tuberosa Arruda), Maná (Solanum sessiliflorum), Cajá-manga (Spondias dulcis), Physalis (Physalis angulata L.

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The production of whole-liquid eggs is of significant economic and nutritional importance. This study aimed to assess the phenotypic and genotypic diversity of mesophilic aerobic spore-forming bacteria (n = 200) isolated from pasteurized whole liquid egg and liquid egg yolk. The majority of the isolates were identified as belonging to the genera Bacillus (86 %), followed by Brevibacillus (10 %) and Lysinibacillus (4 %).

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Sporeforming bacteria are a concern in some food raw materials, such as cocoa powder. Samples (n = 618) were collected on two farms and at several stages during cocoa powder manufacture in three commercial processing lines to determine the impact of each stage on bacterial spore populations. Mesophilic aerobic, mesophilic anaerobic, thermophilic aerobic, and Bacillus cereus spore populations were enumerated in all the samples.

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Gut microbiota influences neurodevelopment, behavior and contributes to neurodegenerative disorders. One possible mechanism is the direct modulation of calcium (Ca) signaling and protein homeostasis in enteroendocrine cells (EECs), a component of the gut epithelium. Here, we present a protocol to isolate fractions of conditioned media (CM) from the anaerobic bacteria and the utilization of this CM to monitor Ca fluctuation in EECs by imaging.

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Parkinson's disease (PD) is a neurodegenerative condition featured by motor dysfunction, death of midbrain dopaminergic neurons and accumulation of α-synuclein (αSyn) aggregates. Growing evidence suggests that PD diagnosis happens late in the disease progression and that the pathology may originate much earlier in the enteric nervous system (ENS) before advancing to the brain, via autonomic fibers. It was recently described that a specific cell type from the gut epithelium named enteroendocrine cells (EECs) possess many neuron-like properties including αSyn expression.

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The gut microbiota influence neurodevelopment, modulate behavior, and contribute to neurodegenerative disorders. Several studies have consistently reported a greater abundance of in Parkinson disease (PD) fecal samples. Therefore, we investigated whether -conditioned medium (CM) could initiate α-synuclein (αSyn) misfolding in enteroendocrine cells (EEC) - a component of the gut epithelium featuring neuron-like properties.

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Current studies estimate that 1-3% of females with unexplained intellectual disability (ID) present splice site, nonsense, frameshift, or missense mutations in the DDX3X protein (DEAD-Box Helicase 3 X-Linked). However, the cellular and molecular mechanisms by which DDX3X mutations impair brain development are not fully comprehended. Here, we show that the ID-linked missense mutation L556S renders DDX3X prone to aggregation.

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The assessment of three-dimensional (3D) brain cytoarchitecture at a cellular resolution remains a great challenge in the field of neuroscience and constant development of imaging techniques has become crucial, particularly when it comes to offering direct and clear obtention of data from macro to nano scales. Magnetic resonance imaging (MRI) and electron or optical microscopy, although valuable, still face some issues such as the lack of contrast and extensive sample preparation protocols. In this context, x-ray microtomography (μCT) has become a promising non-destructive tool for imaging a broad range of samples, from dense materials to soft biological specimens.

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Although Aspergillus flavus and Aspergillus parasiticus are the main microorganisms of concern in peanuts, due to aflatoxin contamination, several Salmonella outbreaks from this product have been reported over the last ten decades. Thus, it is important to understand the relationship between microorganisms to predict, manage and estimate the diversity in the peanut supply chain. The purpose of this study was to evaluate aflatoxin production during the co-cultivation of Aspergillus section Flavi and Salmonella both isolated from peanuts.

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Article Synopsis
  • - A total of thirty-eight Salmonella isolates were collected from various points in the peanut supply chain across three Brazilian states (São Paulo, Minas Gerais, Bahia) and analyzed for antimicrobial resistance and virulence genes using PFGE and other tests.
  • - All isolates showed resistance to sulfonamide, with only one strain demonstrating additional resistance to ampicillin, while intermediary resistance was noted for kanamycin, streptomycin, and ceftazidime.
  • - Six virulence genes were found in all isolates, with a distinct distribution of pulsotypes revealed: pulsotype 1 was exclusive to Minas Gerais and pulsotype 7 was identified in both São Paulo and Bahia, indicating limited multidrug resistance overall.
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Due to recent large outbreaks, peanuts have been considered a product of potential risk for Salmonella. Usually, peanut products show a low water activity (aw) and high fat content, which contribute to increasing the thermal resistance and survival of Salmonella. This study evaluated the long-term kinetics of Salmonella survival on different peanut products under storage at 28°C for 420 days.

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