Phage amplification coupled with loop-mediated isothermal amplification (PA-LAMP) for same-day detection of viable Salmonella Enteritidis in raw poultry meat

Salmonella Enteritidis is the main serotype responsible for human salmonellosis in the European Union. One of the main sources of Salmonella spp. in the food chain are poultry products, such as eggs or chicken meat. In recent years, molecular methods have become an alternative to culture dependent methods for the rapid screening of Salmonella spp. In this work, the strain S. Enteritidis S1400, and previously isolated and characterized bacteriophage PVP-SE2, were used to develop and evaluate a same-day detection method combining Phage Amplification and Loop-mediated isothermal amplification (PA-LAMP) to specifically detect viable S. Enteritidis in chicken breast. This method is based on the detection of the phage DNA rather than bacterial DNA. The virus is added to the sample during pre-enrichment in buffered peptone water, where it replicates in the presence of viable S. Enteritidis. The detection of phage DNA allows, on the one hand to detect viable bacteria, since viruses only replicate in them, and on the other hand to increase the sensitivity of the method since for each infected S. Enteritidis cell, hundreds of new viruses are produced. Two different PA-LAMP detection strategies were evaluated, a real time fluorescence and a naked-eye detection. The present method could down to 0.2 fg/L of pure phage DNA and a concentration of viral particles of 2.2 log PFU/mL. After a short Salmonella recovery step of 3 h and a co-culture of 4 h of the samples with phage particles, both real-time fluorescence and naked-eye method showed a LoD95 of 6.6 CFU/25 g and a LoD50 of 1.5/25 g in spiked chicken breast samples. The entire detection process, including DNA extraction and LAMP analysis, can be completed in around 8 h. In the current proof-of-concept, the novel PA-LAMP obtained comparable results to those of the reference method ISO 6579, to detect Salmonella Enteritidis in poultry meat.Dr. Alexandre Lamas was funded by a postdoctoral fellowship from Xunta de Galicia (Axudas de apoio a étapa de formación posdoutoral IN606B (Modalidade A)). Dr. Alejandro Garrido-Maestu acknowledges funding from the Fundação para a Ciência e Tecnologia through the Scientific Employment Stimulus Program (2021.02810.CEECIND).info:eu-repo/semantics/publishedVersio

Green synthesis of lignin nano- and micro-particles: Physicochemical characterization, bioactive properties and cytotoxicity assessment

Lignin particles (LPs) have gained prominence due to their biodegradability and bioactive properties. LP production at nano and micro scale produced from organosolv lignin and the understanding of size's effect on their properties is unexplored. This work aimed to produce and characterize lignin nanoparticles and microparticles using a green synthesis process, based on ethanol-solubilized lignin and water. Spherical shape LPs, with a mean size of 75 nm and 215 nm and with a low polydispersity were produced, as confirmed by transmission electron microscopy and dynamic light scattering. LPs thermal stability improved over raw lignin, and the chemical structure of lignin was not affected by the production method. The antimicrobial tests proved that LPs presented a bacteriostatic effect on Escherichiacoli and Salmonella enterica. Regarding the antioxidant potential, LPs had a good antioxidant activity that increased with the reaction time and LPs concentration. LPs also presented an antioxidant effect against intracellular ROS, reducing the intracellular ROS levels significantly. Furthermore, the LPs showed a low cytotoxic effect in Caco-2 cell line. These results showed that LPs at different scales (nano and micro) present biological properties and are safe to be used in different high value industrial sectors, such as biomedical, pharmaceutical and food.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit, BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, and MICRODIGEST project (grant agreement 037716) co-funded by FCT and ERDF through COMPETE2020.info:eu-repo/semantics/publishedVersio

Remote Effects of Hippocampal Sclerosis on Effective Connectivity during Working Memory Encoding: A Case of Connectional Diaschisis?

Accumulating evidence suggests a role for the medial temporal lobe (MTL) in working memory (WM). However, little is known concerning its functional interactions with other cortical regions in the distributed neural network subserving WM. To reveal these, we availed of subjects with MTL damage and characterized changes in effective connectivity while subjects engaged in WM task. Specifically, we compared dynamic causal models, extracted from magnetoencephalographic recordings during verbal WM encoding, in temporal lobe epilepsy patients (with left hippocampal sclerosis) and controls. Bayesian model comparison indicated that the best model (across subjects) evidenced bilateral, forward, and backward connections, coupling inferior temporal cortex (ITC), inferior frontal cortex (IFC), and MTL. MTL damage weakened backward connections from left MTL to left ITC, a decrease accompanied by strengthening of (bidirectional) connections between IFC and MTL in the contralesional hemisphere. These findings provide novel evidence concerning functional interactions between nodes of this fundamental cognitive network and sheds light on how these interactions are modified as a result of focal damage to MTL. The findings highlight that a reduced (top-down) influence of the MTL on ipsilateral language regions is accompanied by enhanced reciprocal coupling in the undamaged hemisphere providing a first demonstration of “connectional diaschisis.

Remote Effects of Hippocampal Sclerosis on Effective Connectivity during Working Memory Encoding: A Case of Connectional Diaschisis?

Accumulating evidence suggests a role for the medial temporal lobe (MTL) in working memory (WM). However, little is known concerning its functional interactions with other cortical regions in the distributed neural network subserving WM. To reveal these, we availed of subjects with MTL damage and characterized changes in effective connectivity while subjects engaged in WM task. Specifically, we compared dynamic causal models, extracted from magnetoencephalographic recordings during verbal WM encoding, in temporal lobe epilepsy patients (with left hippocampal sclerosis) and controls. Bayesian model comparison indicated that the best model (across subjects) evidenced bilateral, forward, and backward connections, coupling inferior temporal cortex (ITC), inferior frontal cortex (IFC), and MTL. MTL damage weakened backward connections from left MTL to left ITC, a decrease accompanied by strengthening of (bidirectional) connections between IFC and MTL in the contralesional hemisphere. These findings provide novel evidence concerning functional interactions between nodes of this fundamental cognitive network and sheds light on how these interactions are modified as a result of focal damage to MTL. The findings highlight that a reduced (top-down) influence of the MTL on ipsilateral language regions is accompanied by enhanced reciprocal coupling in the undamaged hemisphere providing a first demonstration of “connectional diaschisis.

Evaluation of the Antimicrobial Activity of Chitosan Nanoparticles against <i>Listeria monocytogenes</i>

Chitosan is obtained from the deacetylation of chitin, and it is known to possess antimicrobial activity. It has attracted attention as it may be used for treating infections caused by different types of microorganisms due to its broad spectrum. Its application in the form of micro- or nanoparticles (CM/CN) has expanded its usage, as in this form, it retains its activity, and remain stable in aqueous solutions. However, inconsistencies in the results reported by different authors have been identified. In this communication, the antimicrobial activity of CN produced from different starting materials was tested against Listeria monocytogenes. It was observed that, even though all the starting materials were reported to have a molecular weight (MW) below 200 kDa and degree of deacetylation (DD) > 75%, the size of the CNs were significantly different (263 nm vs. 607 nm). Furthermore, these differences in sizes exerted a direct effect on the antimicrobial properties of the particles, as when testing the ones with the smallest size, i.e., 263 nm, a lower Minimum Inhibitory Concentration (MIC) was achieved, i.e., 0.04 mg/mL. Even though the largest particles, i.e., 607 nm, in individual experiments were able to achieve an MIC of 0.03 mg/mL, the results with CN presented great variation among replicates and up to 0.2 mg/mL were needed in other replicates. The starting material has a critical impact on the properties of the CN, and it must be carefully characterized and selected for the intended application, and MW and DD solely do not fully account for these properties

Time trends in coronary revascularization procedures among people with COPD: analysis of the Spanish national hospital discharge data (2001&ndash;2011)

Javier de Miguel-D&iacute;ez,1 Rodrigo Jim&eacute;nez-Garc&iacute;a,2 Valent&iacute;n Hern&aacute;ndez-Barrera,2 Pilar Carrasco-Garrido,2 H&eacute;ctor Bueno,3 Luis Puente-Maestu,1 Isabel Jimenez-Trujillo,2 Alejandro Alvaro-Meca,2 Jes&uacute;s Esteban-Hernandez,2 Ana L&oacute;pez de Andr&eacute;s21Pneumology Department, Hospital General Universitario Gregorio Mara&ntilde;&oacute;n, Universidad Complutense de Madrid, Madrid, Spain; 2Preventive Medicine and Public Health Teaching and Research Unit, Department of Health Sciences, Health Sciences Faculty, Rey Juan Carlos University, Alcorc&oacute;n, Madrid, Spain; 3Centro Nacional de Investigaciones Cardiovasculares, Instituto de investigaci&oacute;n i+12, Cardiology Department, Hospital Universitario 12&nbsp;de Octubre, Universidad Complutense de Madrid, Madrid, SpainBackground: People with COPD suffering from coronary artery disease are frequently treated with revascularization procedures. We aim to compare trends in the use and outcomes of these procedures in COPD and non-COPD patients in Spain between 2001 and 2011.Methods: We identified all patients who had undergone percutaneous coronary interventions (PCIs) and coronary artery bypass graft (CABG) surgeries, using national hospital discharge data. Discharges were grouped into: COPD and no COPD.Results: From 2001 to 2011, 428,516 PCIs and 79,619 CABGs were performed. The sex and age-adjusted use of PCI increased by 21.27% per year from 2001 to 2004 and by 5.47% per year from 2004 to 2011 in patients with COPD. In-hospital mortality (IHM) among patients with COPD who underwent a PCI increased significantly from 2001 to 2011 (odds ratio 1.11; 95% confidence interval 1.03&ndash;1.20). Among patients with COPD who underwent a CABG, the sex and age-adjusted CABG incidence rate increased by 9.77% per year from 2001 to 2003, and then decreased by 3.15% through 2011. The probability of dying during hospitalization in patients who underwent a CABG did not change significantly in patients with and without COPD (odds ratio, 1.06; 95% confidence interval 0.96&ndash;1.17).Conclusion: The annual percent change in PCI procedures increased in COPD and non-COPD patients. We found a decrease in the use of CABG procedures in both groups. IHM was higher in patients with COPD who underwent a PCI than in those without COPD. However, COPD did not increase the probability of dying during hospitalization in patients who underwent a CABG.Keywords: COPD, percutaneous coronary intervention, coronary artery bypass graft surgery, hospitalization, length of stay, in-hospital mortalit