Proposal of a quantitative PCR-based protocol for an optimal Pseudomonas aeruginosa detection in patients with cystic fibrosis

BACKGROUND: The lung of patients with cystic fibrosis (CF) is particularly sensitive to Pseudomonas aeruginosa. This bacterium plays an important role in the poor outcome of CF patients. During the disease progress, first acquisition of P. aeruginosa is the key-step in the management of CF patients. Quantitative PCR (qPCR) offers an opportunity to detect earlier the first acquisition of P. aeruginosa by CF patients. Given the lack of a validated protocol, our goal was to find an optimal molecular protocol for detection of P. aeruginosa in CF patients. METHODS: We compared two formerly described qPCR formats in early detection of P. aeruginosa in CF sputum samples: a qPCR targeting oprL gene, and a multiplex PCR targeting gyrB and ecfX genes. RESULTS: Tested in vitro on a large panel of P. aeruginosa isolates and others gram-negative bacilli, oprL qPCR exhibited a better sensitivity (threshold of 10 CFU/mL versus 730 CFU/mL), whereas the gyrB/ecfX qPCR exhibited a better specificity (90% versus 73%). These results were validated ex vivo on 46 CF sputum samples positive for P. aeruginosa in culture. Ex vivo assays revealed that qPCR detected 100 times more bacterial cells than culture-based method did. CONCLUSION: Based on these results, we proposed a reference molecular protocol combining the two qPCRs, which offers a sensitivity of 100% with a threshold of 10 CFU/mL and a specificity of 100%. This combined qPCR-based protocol can be adapted and used for other future prospective studies

Quorum-sensing activity and related virulence factor expression in clinically pathogenic isolates of Pseudomonas aeruginosa

AbstractRespiratory isolates of Pseudomonas aeruginosa were collected from 58 critically-ill patients with ventilator-associated pneumonia. Expression of elastase and pyocyanin was assessed semi-quantitatively, while quorum-sensing activity was assessed by quantifying the levels of the autoinducers N-3-oxododecanoyl-L-homoserine lactone (C12-HSL) and N-butanoyl-L-homoserine lactone (C4-HSL). Correlations were sought between quorum-sensing activity and the expression of these two virulence factors, and all results were compared to those obtained with the laboratory reference strains PA103, a strain defective in quorum-sensing, and PAO1, a functional quorum-sensing strain. More than two-thirds of clinically pathogenic isolates had increased levels of elastase and/or pyocyanin, and high quorum-sensing activity, as assessed by autoinducer levels. However, a strong correlation between quorum-sensing activity and virulence factor production was revealed only for elastase and not for pyocyanin (C12-HSL/elastase, r = 0.7, p 2 × 10−9; C4-HSL/elastase, r = 0.7, p 2 × 10−9). These data suggest that the pathogenicity of P. aeruginosa isolates from critically-ill patients with ventilator-associated pneumonia is caused, at least in part, by an increase in elastase production regulated by quorum-sensing, while increased pyocyanin production in these isolates may be regulated predominantly by mechanisms other than quorum-sensing

Bereavement : The experience and its shared reception, from the narrative of bereavement to the question of supporting those in mourning

Il s'agit d'étudier la rencontre entre le vécu intime du deuil et sa réception collective. en effet, qu'est-ce que vivre un deuil ? c'est souffrir de la mort d'un être proche et aimé et devoir s'adapter à l'absence, se réorganiser. mais les évolutions possibles d'un deuil sont variées et dépendent largement de facteurs extérieurs. la notion d'attachement dont la perte d'un être cher est la rupture physique laisse subsister une relation vitale d'un genre particulier qui est appelée à évoluer et qui constitue le deuil. le deuil concerne un fait psychologique qui possède sa mécanique et ses enjeux existentiels propres mais il ne nous coupe pas du monde et nous pousse au contraire à aborder autrui de façon différente, nouvelle. cette épreuve qui relève de l'intime, qui bouleverse le moi profond change pourtant notre vision du monde et de ses habitants : la relation moi-autrui change de pôle. mais cette interaction est réciproque : l'autre me regarde et se comporte différemment. la société possède des codes sociaux qui attribuent une place déterminée à chaque membre de la communauté : ainsi, la veuve, le veuf, les orphelins. il est parfois difficile de s'en rendre compte, mais la communauté qui entoure l'endeuillé n'agit pas de façon naturelle : ses actes et ses paroles sont le fruit d'une éducation, d'une série de conventions apprises. mais il en est de même pour la personne en deuil : notre vécu intime cherche ses 'réponses' en autrui, en ceux qui l'entourent et donc dans les codes sociaux qui lui fournissent un modèle de comportement. en quoi le rapport normalisé à autrui fait partie du vécu intime du deuil ? comment la notion de 'faire son deuil' est vitale en tant qu'elle se fait en présence d'autrui ? de même, quelle place le collectif accorde à l'intime, au sentiment personnel et à sa manifestation ?The challenge of this work is to address bereavement as an existential experience in a contemporary social context - living through the lost of a loved one is an abrupt change in a subject's life. Nevertheless, the subject is part of a collective, located in a society that reacts by regulating the experience of bereavement. Faced with the apparent solitude of mourning, the death of a loved one brings us to question identity as fundamentally relational beings. We focus our reflection on the abrupt change change that comes at the sudden news of the death of a loved one in the course of our existence, and which, as such, represents an abrupt change itself. Journeying through a period of mourning means being faced with the intensity and pointlessness of loss, of which no words can be said at the beginning. Starting from the unspeakable and incommunicable nature of bereavement, we address the question of meaning and of implementing practices in response to this situation of abrupt change.Problematising the expression "to be in mourning" reflects the creativity of the human subject when it is called to be a part of a social, economical, political and cultural environment upon the news of a loss. It is therefore important to emphasise the historical and social aspects of our reflection as it analyses the knowledge basis for bereavement. this epistemological analysis tends to consider bereavement as an "object" appropriate for both thought and practice. The objectives here are therefore normative and affect a singular conception of offering support to those in mourning and to those at the end of life in order that those involved in the issue may become involved in experiential continuity

Etude de la prise en charge diagnostique et thérapeutique de 31 ostéites du pied chez des patients diabétiques au CHU de Brest

BREST-BU Médecine-Odontologie (290192102) / SudocSudocFranceF

L’éthique clinique comme expérience démocratique ?

L’objectif de cette étude est d’interroger les enjeux épistémologiques et méthodologiques de l’intervention en éthique. La réflexion s’ancre dans le suivi d’un groupe d’éthique clinique dans un service de réanimation adulte. L’expérience que nous proposons de relater ici part d’un constat d’« échec » quant aux attendus de l’éthique clinique comme méthode d’intervention. L’hypothèse que nous soutenons est celle d’une problématisation nécessaire de la démarche, notamment à la lumière d’une forme de décalage entre l’idéal de délibération collective propre à la méthode d’éthique clinique et la conflictualité du soin.The aim of this study is to question the epistemological and methodological stakes of ethics intervention. The reflection is anchored in the follow-up of a group of clinical ethics in an adult intensive care unit. The experience we relate here is a report of “a failure” as for the reasons adduced for the clinical ethics as method of intervention. The hypothesis which we support is the necessary interrogation of the approach, in particular in the light of a gap between the ideal of collective deliberation which is important to clinical ethics and the conflictuality in care

A Novel Approach to Co-design Tunable Microwave Devices on Silicon

International audienc

Screening of Lactobacillus spp. for the prevention of Pseudomonas aeruginosa pulmonary infections

Background: Pseudomonas aeruginosa is an opportunistic pathogen that significantly increases morbidity and mortality in nosocomial infections and cystic fibrosis patients. Its pathogenicity especially relies on the production of virulence factors or resistances to many antibiotics. Since multiplication of antibiotic resistance can lead to therapeutic impasses, it becomes necessary to develop new tools for fighting P. aeruginosa infections. The use of probiotics is one of the ways currently being explored. Probiotics are microorganisms that exert a positive effect on the host's health and some of them are known to possess antibacterial activities. Since most of their effects have been shown in the digestive tract, experimental data compatible with the respiratory environment are strongly needed. The main goal of this study was then to test the capacity of lactobacilli to inhibit major virulence factors (elastolytic activity and biofilm formation) associated with P. aeruginosa pathogenicity. Results: Sixty-seven lactobacilli were isolated from the oral cavities of healthy volunteers. These isolates together with 20 lactobacilli isolated from raw milks, were tested for their capacity to decrease biofilm formation and activity of the elastase produced by P. aeruginosa PAO1. Ten isolates, particularly efficient, were accurately identified using a polyphasic approach (API 50 CHL, mass-spectrometry and 16S/rpoA/pheS genes sequencing) and typed by pulsed-field gel electrophoresis (PFGE). The 8 remaining strains belonging to the L. fermentum (6), L. zeae (1) and L. paracasei (1) species were sensitive to all antibiotics tested with the exception of the intrinsic resistance to vancomycin. The strains were all able to grow in artificial saliva. Conclusion: Eight strains belonging to L. fermentum, L. zeae and L. paracasei species harbouring anti-elastase and anti-biofilm properties are potential probiotics for fighting P. aeruginosa pulmonary infections. However, further studies are needed in order to test their innocuity and their capacity to behave such as an oropharyngeal barrier against Pseudomonas aeruginosa colonisation in vivo