Epidemiology of Pseudomomas aeruginosa and Achromobacter xylosoxidans in Belgian cystic fibrosis patients, relying on molecular typing techniques

Pseudomonas aeruginosa is known to be the most important pathogen in CF, and is associated with increased morbidity and reduced life expectancy. Although we are convinced that peer contacts are psychologically beneficial for patients dealing with CF, we wanted to ensure that our patients did not experience more harm than benefit from these contacts, by patient-to-patient transmission of bacteria. Therefore, we set up 2 studies to evaluate the risk of patient-to patient transmission: a pilot study in the rehabilitation centre of De Haan (2001-2002) and a national study, in collaboration of all 7 Belgian CF centres (2003-2004). From both studies we could derive that the majority of P. aeruginosa colonised patients carried a unique genotype, though small clusters of patients with the same genotype could be described. During the study period in the rehabilitation centre there were 3 patients for whom persistent cross-infection could be suspected. We considered this risk comparable with the risk of getting infected from the environment. Both studies showed that, in the individual patient, morphologically different looking colonies often had the same genotype. The national study revealed that most patients (80%) continue to carry the same strain, when genotyped one year later. The patients carrying a ‘cluster’genotype, had a significantly higher questionnaire score for social contacts than those with a ‘unique’ P. aeruginosa genotype. This led to the conclusion that the ‘cluster’genotypes are acquired from patient contacts in the past, which supports the need for segregation. We also described probable patient-to-patient transmission of A. xylosoxidans in the rehabilitation centre population, with only four genotypes that were identified from 102 isolates of 13 patients. A. xylosoxidans is an emerging pathogen in older CF patients. Because litlle is known about the pathogenicty of the organism, we studied the prevalence of A. xylosoxidans in our CF population and the possible pathogenicity of this organism in a retrospective case control study. We hypothesized that A. xylosoxidans is a coloniser of more damaged lungs rather than a destructive infectious organism, however it is obvious that more, especially prospective, studies on the clinical relevance of A. xylosoxidans infection or colonisation are needed

Effects of propidium monoazide (PMA) treatment on mycobiome and bacteriome analysis of cystic fibrosis airways during exacerbation

Introduction and Purpose : Propidium monoazide (PMA)-pretreatment has increasingly been applied to remove the bias from dead or damaged cell artefacts, which could impact the microbiota analysis by high-throughput sequencing. Our study aimed to determine whether a PMA-pretreatment coupled with high-throughput sequencing analysis provides a different picture of the airway mycobiome and bacteriome. Results and Discussion : We compared deep-sequencing data of mycobiota and microbiota of 15 sputum samples from 5 cystic fibrosis (CF) patients with and without prior PMA-treatment of the DNA-extracts. PMA-pretreatment had no significant effect on the entire and abundant bacterial community (genera expressed as operational taxonomic units (OTUs) with a relative abundance greater than or equal to 1%), but caused a significant difference in the intermediate community (less than 1%) when analyzing the alpha biodiversity Simpson index (p = 0.03). Regarding PMA impact on the airway mycobiota evaluated for the first time here; no significant differences in alpha diversity indexes between PMA-treated and untreated samples were observed. Regarding beta diversity analysis, the intermediate communities also differed more dramatically than the total and abundant ones when studying both mycobiome and bacteriome. Our results showed that only the intermediate (or low abundance) population diversity is impacted by PMA-treatment, and therefore that abundant taxa are mostly viable during acute exacerbation in CF. Given such a cumbersome protocol (PMA-pretreatment coupled with high-throughput sequencing), we discuss its potential interest within the follow-up of CF patients. Further studies using PMA-pretreatment are warranted to improve our "omic" knowledge of the CF airways

Seismo‐turbidites in Aysén Fjord (Southern Chile) reveal a complex pattern of rupture modes along the 1960 megathrust earthquake segment

Grainsize analysis and end‐member modeling of a long sediment core from Aysén Fjord (southern Chile) allows to identify over 25 seismo‐turbidites in the last 9,000 years. Considering the shaking intensities required to trigger these turbidites (V½‐VI½), the majority can be related to megathrust earthquakes. Multiple studies in south‐central Chile have aimed at finding traces of giant, tsunamigenic megathrust earthquakes leading to the current 5,500‐year‐long paleoseismological record of the Valdivia segment. However, none of these cover the southern third of the segment. Aysén Fjord allows to fill this data gap and presents the first, crucial paleoseismic data to demonstrate that the 1960 event was not unique for the Valdivia segment, yielding a recurrence rate of 321 ± 116 years in the last two millennia. Moreover, the oldest identified events in Aysén Fjord date back to 9,000 cal years BP and, thus, also extend the regional paleoseismological record in time. We infer a large temporal variability in rupture modes, with successions of full‐segment ruptures alternating with partial and cascading ruptures. The latter seems to significantly postpone the occurrence of another full rupture when consecutively occurring in different parts of the segment. Additionally, one outstanding period of seismic quiescence ¿during which no megathrust earthquake evidence has been found at any paleoseismic site¿occurred after a full rupture in AD ~745 that presents an unusual uplift/subsidence pattern. Such variability makes it highly speculative to anticipate the rupture mode of the next megathrust earthquake along the Valdivia segment

Comparison of the sensitivity of culture, PCR and quantitative real-time PCR for the detection of Pseudomonas aeruginosa in sputum of cystic fibrosis patients

Background: Pseudomonas aeruginosa is the major pathogen involved in the decline of lung function in cystic fibrosis (CF) patients. Early aggressive antibiotic therapy has been shown to be effective in preventing chronic colonization. Therefore, early detection is important and sensitive detection methods are warranted. In this study, we used a dilution series of P. aeruginosa positive sputa, diluted in a pool of P. aeruginosa negative sputa, all from CF patients-to mimick as closely as possible the sputa sent to routine laboratories-to compare the sensitivity of three culture techniques versus that of two conventional PCR formats and four real-time PCR formats, each targeting the P. aeruginosa oprL gene. In addition, we compared five DNA-extraction protocols. Results: In our hands, all three culture methods and the bioMerieux easyMAG Nuclisens protocol Generic 2.0.1, preceded by proteinase K pretreatment and followed by any of the 3 real-time PCR formats with probes were most sensitive and able to detect P. aeruginosa up to 50 cfu/ml, i.e. the theoretical minimum of one cell per PCR mixture, when taking into account the volumes used in this study of sample for DNA-extraction, of DNA-elution and of DNA-extract in the PCR mixture. Conclusion: In this study, no difference in sensitivity could be found for the detection of P. aeruginosa from sputum between microbiological culture and optimized DNA-extraction and real-time PCR. The results also indicate the importance of the optimization of the DNA-extraction protocol and the PCR format

Comparison of culture and qPCR for the detection of Pseudomonas aeruginosa in not chronically infected cystic fibrosis patients

Pseudomonas aeruginosa is the major respiratory pathogen causing severe lung infections among CF patients, leading to high morbidity and mortality. Once infection is established, early antibiotic treatment is able to postpone the transition to chronic lung infection. In order to optimize the early detection, we compared the sensitivity of microbiological culture and quantitative PCR (qPCR) for the detection of P. aeruginosa in respiratory samples of not chronically infected CF patients.Comparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Astma op kleuterleeftijd: astma?

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Psychiatrische aandoeningen bij mucoviscidose: een overzicht

De gemiddelde levensverwachting van patiënten met mucoviscidose is de laatste twintig jaar sterk toegenomen Dit leidt niet automatisch tot een even grote toename van de levenskwaliteit De intensieve therapieën en de beperkingen die de ziekte meebrengt vragen een sterke psychosociale aanpassing van de patiënt en zijn omgeving. In dit artikel wordt het voorkomen van psychiatrische aandoeningen bij patiënten met mucoviscidose beschreven Er is hierover veel inconsistentie in de literatuur Veel heeft te maken met de methodologie van de studies Als algemeen besluit kan gesteld worden dat het psychosociale functioneren van de patiënten vrij gelijklopend is met dat van de algemene bevolking tot de ziekte ernstiger wordt Toch is er evidentie dat de prevalentie van een aantal psychiatrische symptomen en stoornissen significant gestegen is Er is een duidelijke evolutie in de aard van de psychiatrische symptomatologieën volgens de leeftijdscategorie Bij kinderen komen voornamelijk gedragsstoornissen en een verstoord eetgedrag voor Bij adolescenten en volwassenen is voornamelijk het voorkomen van angstsymptomen en klinische depressies significant verhoogd in vergelijking met de algemene bevolking evenals de symptomen passend bij atypische eetstoornissen. Ook het opvolgen en behandelen van de geestelijke gezondheid zou dus deel moeten uitmaken van de totale aanpak van de ziekte

Een geconjugeerd pneumococcen vaccin voor kinderen.

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