Comparative proteomic analysis of collection and clinical-isolate strains of psudomonas aeruginosa

Comunicaciones a congreso

Abundance of the Quorum-Sensing Factor Ax21 in Four Strains of Stenotrophomonas maltophilia Correlates with Mortality Rate in a New Zebrafish Model of Infection

Stenotrophomonas maltophilia is a Gram-negative pathogen with emerging nosocomial incidence. Little is known about its pathogenesis and the genomic diversity exhibited by clinical isolates complicates the study of pathogenicity and virulence factors. Here, we present a strategy to identify such factors in new clinical isolates of S. maltophilia, incorporating an adult-zebrafish model of S. maltophilia infection to evaluate relative virulence coupled to 2D difference gel electrophoresis to explore underlying differences in protein expression. In this study we report upon three recent clinical isolates and use the collection strain ATCC13637 as a reference. The adult-zebrafish model shows discrimination capacity, i.e. from very low to very high mortality rates, with clinical symptoms very similar to those observed in natural S. maltophilia infections in fish. Strain virulence correlates with resistance to human serum, in agreement with previous studies in mouse and rat and therefore supporting zebrafish as a replacement model. Despite its clinical origin, the collection strain ATCC13637 showed obvious signs of attenuation in zebrafish, with null mortality. Multilocus-sequence-typing analysis revealed that the most virulent strains, UV74 and M30, exhibit the strongest genetic similitude. Differential proteomic analysis led to the identification of 38 proteins with significantly different abundance in the three clinical strains relative to the reference strain. Orthologs of several of these proteins have been already reported to have a role in pathogenesis, virulence or resistance mechanisms thus supporting our strategy. Proof of concept is further provided by protein Ax21, whose abundance is shown here to be directly proportional to mortality in the zebrafish infection model. Indeed, recent studies have demonstrated that this protein is a quorum-sensing-related virulence factor

The FCA* layout design

A proposal for a possible upgrade around the FCA (the FCA*) based on Thin Gap Gas Chambers has been presented to DELPHI. In this note the detailed design of the FCA* layout is described. 1 Introduction The Technical Proposal for a possible upgrade around the FCA (the FCA*) based on Thin Gap Gas Chambers has been presented to DELPHI and it is described in a separate DELPHI note [1]. In this note the detailed design of the FCA* layout is described. 2 FCA geometry From the references [2, 3, 4] we have the following information. The FCA trigger strip width is h = 3:14 cm. There are 64 trigger strips for each coordinate x, u, v, each rotated by 120 ffi with respect to the others. The external radius of the FCA acceptance is then 32 strips that is 32h = 100:48 cm. The internal radius of the FCA acceptance is about 9 strips that is about 9h = 28:26 cm. Starting to count the trigger strips from the center, the strip number n starts at a radial distance from the centre of 3:14 \Delta (..

Low Frequency Brain Oscillations for Brain-Computer Interface applications: from the sources to the scalp domain

Low Frequency Oscillations (LFOs) are brief periods of oscillatory activity in delta and lower theta band localized over the cortical motor areas. Recent animal and human researches have evidenced the LFO power increase, only through the analysis of cortical activity yet, in the preparatory phase of movement. In post-stroke subjects, a decrease in LFOs activity has been observed in the acute phase of the disease with a subsequent re-emergence related to functional recovery. With the ultimate aim to develop a Brain-Computer Interface for post-stroke motor rehabilitation based on LFO, in this study we analyzed LFOs activity on electroencephalographic data (EEG) recorded in a sample of 9 healthy participants during the Motor Execution (ME) and the Motor Imagery (MI) of the finger extension task. We extracted the LFOs activity both in the source and in the scalp domains with the aim of evaluate the reproducibility of the results between domains and analyze the LFO power on the scalp in the MI finger extension task. The results suggest that (i) the LFOs can be observed during the ME of the proposed experimental task in the cortex domain, (ii) the sources’ LFOs activity is reproduced on the scalp level and (iii) the LFOs may be detected also on the scalp during the MI task. In conclusion, in this preliminary study, we verified that LFOs can also be detected directly on the scalp both in the ME and the MI of the finger extension task

Re-Configuration of Resting state brain networks after BCI training in stroke patients

Motor imagery (MI) practice within a BCI-assisted rehabilitative intervention proved to influence brain plasticity phenomena underlying post-stroke motor recovery as outlined by resting state (RS) brain networks analysis based on graph theory (GT) approach. We investigated RS networks in a subgroup of stroke patients recruited within a longitudinal randomized controlled trial evaluating the efficacy of a MI-based BCI on upper limb (UL) motor rehabilitation describing brain re-organization at the single subject level

Long-term effect on EEG sensorimotor responsiveness to motor imagery after a BCI training for stroke rehabilitation

Previous studies demonstrated the efficacy of EEG-Brain-Computer Interfaces based on Motor Imagery (MI-BCI) in post stroke functional motor recovery of upper limbs [1]; however, the maintenance of such effects in the long-term is still partially unexplored. Here we tackled this long-term aspect of MI-BCI induced positive effects on rehabilitation outcomes by analyzing an EEG dataset acquired from subacute stroke patients recruited in the longitudinal Randomized Controlled Trial reported in [2]. The oscillatory activity in the EEG beta band known as related to MI tasks within BCI contexts [1], [3], was studied at different time points in two groups of participants one performing MI practice with BCI assistance (BCI group) while the other performing MI training alone (CTRLgroup). [1] F. Pichiorri et al., “Brain-computer interface boosts motor imagery practice during stroke recovery,” Ann. Neurol., vol. 77, no. 5, pp. 851–865, 2015, doi: 10.1002/ana.24390. [2] D. Mattia et al., “The Promotoer, a brain-computer interface-assisted intervention to promote upper limb functional motor recovery after stroke: A study protocol for a randomized controlled trial to test early and long-term efficacy and to identify determinants of response,” BMC Neurol., vol. 20, no. 1, pp. 1–13, 2020, doi: 10.1186/s12883-020-01826-w. [3] F. Pichiorri et al., “Sensorimotor rhythm-based brain-computer interface training: The impact on motor cortical responsiveness,” J. Neural Eng., vol. 8, no. 2, 2011, doi: 10.1088/1741-2560/8/2/025020

Low Frequency Brain Oscillations during the execution and imagination of simple hand movements for Brain-Computer Interface applications

Low Frequency Brain Oscillations (LFOs) are brief periods of oscillatory activity in delta and lower theta band that appear at motor cortical areas before and around movement onset. It has been shown that LFO power decreases in post-stroke patients and re-emerges with motor functional recovery. To date, LFOs have not yet been explored during the motor execution (ME) and imagination (MI) of simple hand movements, often used in BCI-supported motor rehabilitation protocols post-stroke. This study aims at analyzing the LFOs during the ME and MI of the finger extension task in a sample of 10 healthy subjects and 2 stroke patients in subacute phase. The results showed that LFO power peaks occur in the preparatory phase of both ME and MI tasks on the sensorimotor channels in healthy subjects and their alterations in stroke patients